Arrow crabs are the daddy-longlegs of the sea. They move slowly and deliberately as if in slow motion. This behavior, combined with their raggedy appearance, makes them very difficult to spot under water. Their long legs are hollow tubes made up of tough chitin and filled with muscles down the center, just the opposite of humans, who have bones inside and muscles outside. These tubes of muscle are what you buy as crab legs in the supermarket. Crabs cannot exist out of water for more than a few minutes because their shells dry out very easily.
During low tide these crabs can be found under piles of moist seaweed, down in shady crevices, or in the remaining water of a tidepool. Crabs breathe by pumping water over the feathery gills on their bodies.
If you were a squid, an amberjack is one fish you wouldn't want to meet in a dark kelp bed. Amberjacks are fierce, powerful hunters that travel in giant schools and cruise the warm and temperate waters of the Atlantic in search of small fish and squid. Like the tuna and mackerel, amberjacks are well built for long-distance swimming. They have streamlined, muscular bodies and their skin is covered by tiny, almost invisible scales that allow them to cruise through the water with little resistance. Amberjacks can grow to lengths of six feet or more and weigh as much as 120 pounds.
Amberjacks are such determined hunters that they will often chase a school of small fish into a shallow lagoon just to get a meal.
Young amberjacks look quite different from adults. Their bodies are thick, rather than thin, and covered with stripes. Even as young fish, amberjacks like to travel in enormous packs. Eventually, as amberjacks get older, they become less sociable and begin swimming in small groups of just a few fish.
Sea anemones may look like beautiful flowers, but watch out! Like their relation, the jellyfish, sea anemones have stinging, and sometimes deadly, poisonous tentacles. When a fish or other prey swims too close, the sea anemone's snakelike tentacles will release a poisonous stinging cell into the skin of the animal. If the animal is small enough, the stinging cell will paralyze it. Then the anemone's tentacles push the stunned prey into its mouth where it is quickly digested.
The sting of most sea anemones isn't strong enough to hurt a human. Sea anemones like the one in this picture have up to 200 tentacles connected to their outer body. They spend most of their time with their suckerlike underbellies attached securely to rocks. Even the roughest waves cannot pull them away. The Waratah anemone is often found in tide pools along the rocky coasts of the Pacific. When the tide goes out and leaves the tide pool dry, the Waratah seals itself up, keeping enough water inside its digestive system to survive until the tide returns.
Whoever said that things get strange when the lights go off was probably thinking of the deep-sea anglerfish. Found at depths of 6,500 feet below the ocean's surface, the anglerfish lives in almost complete darkness. Most other fish would find it nearly impossible to hunt for food in such a lightless environment. But the anglerfish has developed an interesting solution to the problem.
What was once a dorsal fin on the anglerfish's back has become a long strand of flesh that stretches out from the anglerfish's face just like a small fishing lure. At the tip of this lure is a piece of skin that glows in the dark. Using this glowing lure like a fishing rod, the anglerfish attracts deep-sea fish to the light. When a fish comes close enough, the anglerfish quickly snaps it up in its large mouth. The anglerfish's mouth is so large that it can swallow fish several times larger than its own body. Of course, it takes a while to digest such a large meal.
Anglerfish have other bizarre traits. Some kinds of anglerfish can only reproduce when the male attaches itself to the female's body and lives off her blood supply. The male anglerfish, which is much smaller than the female, fuses his mouth to the female's skin, and turns himself into a kind of parasite. A female anglerfish can have as many as three or four males attached to her body.
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Southern Ocean - The Deep Freeze
Length: NA;Depth: 5,552 Feet/1,692 Meters
ANTARCTIC
The Southern Ocean, the great unbroken expanse of sea linking the Pacific, Atlantic and Indian Oceans, surrounds the unique continent of Antarctica. Its waters are ruled by powerful winds known as the Roaring Forties, the Furious Fifties and the Shrieking Sixties, and its southern boundary is the ice cliffs and rocks of the Antarctic coast. The continent itself forms a hub around the South Pole.
The shores of Antarctica are fringed by seas that are almost entirely ice-covered. In winter, 8 million square miles of sea have an ice crust. Even in summer the coastal waters bear 1.2 million square miles of ice. This fluctuating fringe of ice can be seen as one boundary of the Antarctic, but most biologists prefer using a boundary known as the Antarctic Convergence Zone, an invisible frontier in the sea where cold surface waters meet warmed surface seas.
The icy seas and frozen wastes of Antarctica present one of the most inhospitable environments on Earth, yet the Southern Ocean is home to large numbers of sea birds, seals and whales. This abundance of life depends on the biological productivity of the Southern Ocean. It is estimated the Southern Oceans produce as much as 610 million tons of plant matter a year.
Today, Antarctica contains over 90 percent of the Earth's ice. This represents about 70 percent of the planet's fresh water. The ice has accumulated to an average depth of about 6,500 feet over the continent as a whole, with more than 9,850 feet at many points above the low lying rock floor of the continent. If all this ice melted, global sea levels would be raised by 200 feet. If the enormous weight of all this ice were removed the surface of Antarctica could rise by 650-1,000 feet.
Glaciers move slowly towards the sea and feed floating ice shelves. Known to pioneer explorers as ice barriers, the shelves are 657-984 feet thick and border the ocean over hundreds of miles. They can reach a depth underwater of between 490-820 feet. In winter massive icebergs float among the sea ice. This creates a danger to shipping and mobile oil installations, which become trapped in the surface ice, unable to move out of the path of the icebergs.
Only a narrow coastal fringe lies between the Antarctic ice cap and the sea. It is on this tiny area of land that most of the wildlife of the Antarctic lives and breeds, and where more than 70 scientific research stations have been set up.
Two to three thousand tourists visit Antarctica each year, attracted by the scenery and abundant wildlife. ...FROM "THE RANDOM HOUSE ATLAS OF THE OCEANS"
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Arabian Seas: The Oil Route
Length: NA;Depth: 7,434 Feet/2,266 Meters
ARABIAN SEAS
The waters of the Arabian Peninsula and neighboring countries form a distinctive subregion of the Indian Ocean. This area includes the Red Sea and Gulf of Aden, the Arabian Sea and the Persian Gulf. The shores of this region have attracted human activity for thousands of years. The prosperous trading civilization of Dilmun flourished some 4,000-5,000 years ago, and included what is now Bahrain and eastern Saudi Arabia. Before the 10th century AD, Arab ocean explorers had established a trade network which extended from the Persian Gulf as far east as China. Long voyages were made possible by the Arabs' sophisticated knowledge of astronomy and navigation. The trade in textiles, frankincense and pepper led to contacts between distant cultures.
The Red Sea is very deep, reaching more than 6,560 feet in some places. However, the Gulf of Suez is quite shallow. The clear waters of the Red Sea have favored development of an extensive coral reef system along both its western and eastern seaboards. The reefs run for a distance of nearly 1,240 miles. Some 220 species of coral have been recorded there. As a result, the variety of species of marine life is much greater in the Red Sea than it is in either the Arabian Sea or the Persian Gulf.
The Arabian Sea is much deeper than the Red Sea and reaches a maximum depth of more than 13,000 feet. The major influence on the climate of this region is the monsoon system. From November to April, the North East Monsoon prevails, but from April to October the system reverses and the South West Monsoon is more important.
In contrast to the Arabian Sea, the Persian Gulf has an average depth of only 115 feet. Because of its shallowness, the Gulf waters have higher concentrations of salt in them and wider seasonal changes in sea temperatures than the Red Sea and most parts of the Arabian Sea. There is a great abundance of different marine animals found in the Persian Gulf including starfish, sea urchins, and sea cucumbers.
While coastal use in much of the Red Sea and Arabian Sea has so far been limited, human pressures are beginning to mount. Many of the countries surrounding these waters produce large quantities of oil. Much of that oil must be processed and shipped from oil plants and facilities located along the coast. It is estimated that the 1991 Gulf War which was fought between Iraq and the United Nations, caused the release of over five million barrels of oil into the sea. This harmed the habitats and food supplies of many birds, turtles and fish. ...FROM "THE RANDOM HOUSE ATLAS OF THE OCEANS"
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Arctic Ocean: Small and Cold
Length: NA;Depth: 18,399 Feet/5,608 Meters
BEAUFORT SEA
The Arctic Ocean is the smallest of the world's oceans. Its average depth is about 3,300 feet, though in places it does reach about six times this. There are four major basins separated by three oceanic ridges of which the largest, the Lomonosov Ridge, extends for 1,100 miles.
Water enters and leaves the Arctic Ocean through the gap between Svalbard and Greenland. A deep water current near Svalbard accounts for nearly 80 percent of the incoming water, which is balanced by a less saline outflow on the surface. Two percent of the water leaving the ocean is in the form of icebergs. The ocean itself is covered by a layer of sea ice which in later winter extends to up to six million square miles. In summer, it shrinks to about half this size.
Many marine animals in the Arctic migrate as the sea ice advances and retreats with the seasons. Most live near the edge of the ice which provides a hauling-out area for such animals as polar bears, seals and walruses. Numerous species are found all round the North Pole, but are often divided into several distinct stocks or subspecies. Many bird species are seasonal and also undergo long migrations.
Human populations have existed around the Arctic Ocean for thousands of years. A distinction is often made between the Nordic populations, whose life style is based on the herding of reindeer and the North American, Siberian and Greenland populations who subsist by hunting marine mammals.
Mammals dominate the Arctic marine ecosystem. They include seals, walrus, whales and polar bears. Although there is little wildlife at the center of the Arctic Basin, around the edge, where the sea ice advances and retreats with the seasons and winds and currents bring up nutrients from the depths, an abundance of marine animals and plants flourishes during the summer. Polynyas, which are small areas of open water in the ice, are used by birds and mammals as feeding grounds, as well as by the peoples of the Arctic. These areas only open in warm weather.
The animals of the Arctic are suited to the extreme climatic conditions by a number of physiological and behavioral adaptations. Physiological adaptations in mammals include the thick layer of insulating blubber, which acts as a food reserve in times of hardship, a high body mass and a low surface area. The blubber is built up by seals and whales during their summer feeding period. Constant foraging when conditions are favorable and the rapid development of young are adaptations that help individuals to meet their high energy requirements. The excellent insulating qualities of feathers enable birds to survive and even spend the winter in the Arctic; however a high proportion of the Arctic birds migrate southwards in the summer. ...FROM "THE RANDOM HOUSE ATLAS OF THE OCEANS"
┬Harp Seal: Dances with Seals
Length: 6 Feet/2 Meters;Depth: 0 Feet/0 Meters
NEWFOUNDLAND
Did you know that harp seals can dance? During the mating season the male harp seal will court the female harp seal by dancing up and down in the water next to her, keeping his body and head held in a vertical position.
Harp seals can be found in the White Sea, on the east coast of Greenland and on the northern coast of Newfoundland. Young harp seals are born with a white coat, which gradually changes into a dark brown pattern as they grow older. Baby harp seals feed on mysids and euphausiids while adults eat crustaceans as well as herring, squid and polar cod. Harp seals follow a migratory pattern and move south in the winter and north in the summer as the ice begins to melt.
Brooding Anemone: Reef Flower
Length: 1 Foot/.30 Meters;Depth: 20 Feet/6 Meters
NORTH VANCOUVER ISLAND
Some of the largest sea anemones in the world live in the cold waters of the Pacific Northwest. Acting like large colorful flowers, they actually are little death traps for many small marine animals. Most of their barrel-shaped bodies are taken up by a large stomach. A short throat or pharynx lies on top of the stomach, just below a small mouth opening. The mouth is the center of a round, flat, oral disc that is surrounded by rows of tentacles that are sticky to the touch. The stickiness comes from many microscopic stinging cells that shoot very small darts into your skin.
Anemones do not have or need a heart, a brain, kidneys, lungs, or a hard skeleton. They do have muscles that contract around their water-filled stomach, holding them up like water balloons. When the anemone uses its tentacles to sting and kill a small fish or other animal, its muscles help it slowly drag the prey toward its mouth. Later, muscles carry it into the stomach. When the tide goes out and exposes the anemone, or if it becomes disturbed, it contracts strongly and hides its tentacles inside its body. The sticky tubercles on the sides of its body have small rocks and shells stuck to them. This acts as a kind of camouflage and hides the anemone from sight when it is curled up.
░Barracuda: Mr. Determination
Length: 6 Feet/2 Meters;Depth: 131 Feet/40 Meters
BAHAMAS
Found throughout the tropical waters of the Atlantic and Pacific Oceans, the Great Barracuda is a fierce and frightening fish. Any experienced diver would quickly recognize a barracuda's lean silver body and its jutting jaw filled with long rows of small, sharp teeth.
The barracuda has a hard bony skeleton covered by powerful muscles which help propel its body through the water at great speeds. These strong muscles also allow the barracuda to accelerate at a moment's notice, starting and turning almost instantly.
Barracudas travel both alone and in large schools. Often, they will gather around marine estuaries and coral reefs where there is plenty of marine life to eat. When hungry, a barracuda will attack just about any shiny object that moves. Some inexperienced swimmers have been bitten by barracuda that have confused a watch or a piece of equipment with a fish.
Like sharks, barracudas are well concealed by their camouflage coloring. Barracudas are darker on top and lighter on the bottom. Seen from above, a barracuda almost completely blends in with the darker deep waters. Seen from below, the barracuda's silvery stomach blends in with lighter shallow water.
For many years, not even the most experienced marine biologists knew much about basket stars. These thin, multiarmed relatives of the starfish are extremely sensitive to light. As a result, they spend most of their daylight hours curled up tightly around other invertebrates, such as sea fans, or tucked underneath rocks and sand. Hidden like this, basket stars are either invisible or look just like a plant. Some basket stars, such as the grasping snake star and the clinging snake star, wind themselves so tightly around the branch of a sea fan that it is impossible to detect them unless you are just a few inches away.
At night, however, the basket star unwinds its many arms and goes searching for its favorite food, such as plankton or mollusks. Most basket stars use stationary organisms like sponges, sea whips, sea fans and hydroids as their platforms for feeding.
tBat Ray: Dracula of the Deep?
Length: 5 Feet/2 Meters;Depth: 66 Feet/20 Meters
HAWAII
If you've ever seen a bat ray jump out of the water and skim along the surface for several seconds, you'll understand just how this member of the eagle ray family got its name. The bat ray does indeed resemble its namesake. It has a large head with protruding eyes and two very long pectoral fins that taper off similar to those of a bat. Like other rays, the bat ray's skin is smooth and its underbelly is white. Most bat rays are dark brown or black and can measure five feet wide and weigh up to 200 pounds. Bat rays are members of the same group of ancient fish as sharks and skates. All three types of fish have skeletons made of cartilage rather than bone.
Bat rays live in coral reefs, on sandy bottoms, in the mud or in the rubble of the ocean floor. They are generally found along the western North American coast and range from Oregon to the Gulf of California. Bat rays are carnivorous and will eat mollusks, crustaceans and small fish, sometimes digging them up along the sandy bottom by flapping their powerful wings to create a disturbance. Like the manta ray, bat rays can be seen swimming alone or in schools.
xBrain Coral: Brainy but Hard Headed
Length: 8 Feet/2 Meters;Depth: 90 Feet/27 Meters
GULF OF MEXICO
Corals are large colonies of tiny animals that grow slowly upward and outward as a thin layer of living tissue. Each year these colonies leave behind a layer of limy skeleton which is so tough it almost feels like rock. Scientists measured one coral head that grew from 30 to 76 inches in diameter in 23 years. If you were to carefully saw through a limestone coral head, you would see yearly growth rings much like those found in a tree's trunk. Some coral heads have been found to be hundreds of years old. This means some were around when Christopher Columbus discovered America, or even earlier. Like most coral, brain coral thrives primarily in the tropics where the water is warm all year around. Because of their hard structure, brain corals can live in ocean currents and strong waves. More delicate branching or plate-like corals can survive only in protected lagoons or deeper water. The large, solid coral heads often serve as a "cleaning station" for certain kinds of animals known as "cleaners." A cleaner can be a type of shrimp or fish that will clean parasites and diseased tissue off fish or other animals.
Brain Coral: Big Brain, Low IQ
Length: 8 Feet/2 Meters;Depth: 90 Feet/27 Meters
GULF OF MEXICO
For years, many people wondered how colonies of brain coral produce furrows that are shaped just like the furrows on the human brain. As it turns out, most coral animals grow like plant buds out of tiny round or star-shaped skeletons. In brain corals, however, this budding process is incomplete and the rows of coral polyps are only partially connected. This results in rows that bend and curve like furrows.
A brain coral's massive skeleton may seem indestructible, but corals only thrive in warm, clear, unpolluted tropical waters. Since the water cannot be murky or filled with plankton that might block out sunlight, most corals do not live near large river mouths. They also cannot tolerate sea water diluted with fresh water, or water that is too salty. In isolated lagoons, evaporation can take away water, leaving water that is saltier than seawater. This can kill corals.
Corals have been recorded living at water temperatures from 61 to 97 degrees Fahrenheit. However, they only thrive at 73 to 77 degrees. Ultraviolet light which burns humans can also damage corals in shallow water where there is no protection. If the thinning of the earth's protective ozone layer allows more ultraviolet light to reach the earth, corals may disappear from shallower waters.
╕Beluga Whale: Singing for its Supper
Length: 18 Feet/5 Meters;Depth: 50 Feet/15 Meters
ARCTIC OCEAN
Whales are capable of making many different types of sounds. These sounds can travel for miles underwater and although humans cannot understand them, other whales can. The beluga whale has a very distinctive way of "singing." Its large, bulging forehead (or "melon") changes its shape and size according to the type of sound it emits, not unlike a bagpipe when it is being played.
The beluga whale swims mainly in Arctic waters in and around coastal areas. It is very adept at swimming through large ice floes, and is a spectacular diver. The beluga feeds mostly on fish such as the Arctic cod. However, it is a very slow and cumbersome swimmer, and often falls prey to polar bears and killer whales. The beluga is also a dinnertime treat for the Eskimos.
Like all whales, the beluga has very smooth, hairless skin. And since whales are warm-blooded, they are covered with very thick layers of fat, or blubber, to keep them warm.
Blennies are small, energetic fish that can be found in coastal waters all over the world. There are numerous varieties of blennies. Some, like the butterflyfish blenny, are colorful and have large, ornate fins. Others, like the leopard blenny, are spotted. Most blennies are quite tiny, never measuring more than three to four inches long.
Despite their size, blennies are real survivors. Most blennies take up refuge in small holes in the ocean floor or in empty shells and bottles. They can tolerate wide ranges of water temperature and salinity. Some blennies can even survive in highly polluted water without suffering any ill effects. Large amounts of mucus cover the blenny's skin and protect it from dangerous chemicals in the water. Some blennies that live in shallow rocky coastal areas are so rugged that they can live outside of the water for short periods of time. When the tide goes out, blennies can move from one pool of water to another by jumping along the dry land.
Blennies have large eyes that dart around rapidly, taking in everything that is going on above them. The quick, jerky movement of their eyes, combined with their oversized heads give blennies a very expressive, almost comical set of facial features.
When blennies are ready to reproduce, the male must attract a female to its refuge. The female then lays its eggs in the male's home. It is then up to the male to protect the eggs. Male blennies are very aggressive and will attempt to fend off almost any animal that swims too close to the eggs. Male blennies also brush the eggs lightly with their stomachs so that the antiseptic chemical in their mucus will kill any bacteria that might damage the eggs.
These blue sea stars are not having a wrestling match. This pair of blue sea stars, also known as starfish, is probably sharing the same piece of food. Quite often, when one starfish finds something to eat, it doesn't take long before another starfish tries to join it.
Blue sea stars like these are among the only starfish in the large family of echinoderms that are colored such a brilliant blue. Generally found in coral reefs and shallow coastal pools in the Indian and Pacific Oceans, blue sea stars are herbivores, which means they like to eat only certain kinds of algae such as seaweed.
Like other echinoderms, there are male and female blue sea stars. When it is time to reproduce, the male releases his sperm into the water and the female releases her eggs into the water. If they are lucky, the eggs will be fertilized and eventually turn into small starfish larvae which float along in the ocean currents until they land at a new destination.
It is believed that no animal -- living or dead -- has ever been larger than the blue whale. This giant marine mammal can grow up to 120 feet in length and weigh more than 100 tons. Like other large undersea animals, the blue whale reaches its massive size by feeding on microscopic animals known as krill. To maintain its immense weight, a blue whale must spend its day filtering krill out of tens of thousands of gallons of water it sucks into its mouth. The blue whale is a filter feeder which means it uses a filtering system in its mouth known as baleen. Baleen resembles the bristles in your hairbrush. When ocean water is pulled through a blue whale's mouth the baleen separates the krill from the water, allowing it to be pulled into the whale's digestive track. The water is then squeezed out of the whale's mouth and back into the ocean.
Blue whales are gentle and slow-moving. They migrate from the Equator to the South Pole in small packs. In the early part of this century, blue whales were nearly hunted into extinction by whalers who were eager to use the huge animals for their blubber. In the 1960s, all the nations around the world banned the hunting of blue whales. Since then, the number of these gentle giants has grown slowly but steadily.
Is it an underwater spider? That's what many people think when they first notice a bristle star hiding beneath a rock or clinging to a piece of coral. Thin and fragile, bristle stars like the Schayer's bristle star in this picture, are the misunderstood relatives of the sea star or star fish. The bristle star has five extremely thin arms that radiate out from a small central body that is shaped almost like a disc.
During the day, most bristle stars take shelter beneath rocks and stones to stay away from the light and to avoid predators like fish. At night, the bristle star uses its long thin arms to move along the ocean floor in search of food. Bristle stars are omnivorous, which means they eat both animals and plants.
The Schayer's bristle star is usually found around rocky reefs or rubble flats. It is not often seen by humans, since it is always hiding from its enemy the tropical fish. Like the sea star, the bristle star reproduces by fertilizing its eggs in the water.
It may seem unlikely, but sponges are giant feeding machines. Sponges are constantly filtering water through their bodies to trap the microscopic animals and small pieces of organic matter that float in the water. Sponges with large openings at the top of their bodies are the best at filtering lots of sea water for food. If you gently put your hand over the top of a sponge the flow of water feels like a spring welling up out of the ground. On some shallow reefs you can even see the ocean's surface continually bubbling up because large sponges are pushing water up through their mouths.
Sponges use the same filtering system to reproduce. The sponge's male cells release tiny swimming cells into the water. These cells are tadpole-shaped and have a long hair that waves on their back end. The cells get swept up in the water currents of another sponge and then fertilize the eggs that are embedded in its wall. At this stage, the egg cell divides into more cells and the resulting larva, covered with hairlike cilia, swims out to find a new home.
Once the larva settles somewhere, it grows rapidly, sometimes living only a year or so. It's also possible for a sponge to produce small buds that turn into new sponge animals without sexual reproduction. In fact, people who fish for sponges to sell have known for some time that if you separate a living sponge into little pieces and attach these pieces to good spots on the sea bottom, each would develop into a new sponge in several months to a year.
When there is blood in the open ocean, blue sharks are often the first ones on the scene. And usually they are ready to eat. Of all the world's sharks, few are as elegant and as beautiful as the brilliantly-colored blue shark. Few sharks are as deadly. Gathered in large groups, blue sharks can wreak havoc on a fisherman's catch and put fear in a sailor's heart. During World War II, blue sharks were thought to be responsible for eating the bodies of injured servicemen who were shipwrecked in the Atlantic and Pacific ocean.
With their sleek, streamlined bodies, blue sharks are fast, aggressive hunters. They can chase prey at high speeds and when they attack they are masters of surprise. True to its name, a blue shark's skin is bright blue on top and white on the bottom. This makes the blue shark nearly invisible when seen from above or below.
Blue sharks are found in warm and cool waters all over the ocean. Most prefer the deep water of the open ocean, but some will stray close to the coastline of places like California if they are hungry. Blue sharks are not as large as well-known hunters such as the great white or tiger shark. The average blue shark grows to a length of ten feet, though some measuring as much as 15 feet have been caught. Despite being smaller, blue sharks are often more aggressive and ready to feed whenever food is in the vicinity.
Blue sharks hunt alone. Sometimes, a large injured marine animal such as a sick whale will attract a large group of blue sharks which feed on the animal's body together. Blue sharks' favorite meals include mackerel, herring, squid and sometimes other sharks. Blue sharks will also snap up an occasional ocean bird when it is sitting on the water too long. In the old days, blue sharks were well known for following whaling ships and feeding off the whale carcasses that were thrown overboard.
Giant Red Sponge: Big Eater
Length: 4 Feet/1 Meters;Depth: 97 Feet/30 Meters
CARIBBEAN
From the looks of it, this giant red sponge is doing little more than waving gently back and forth in the warm Caribbean current. Actually, it's busy feeding on thousands of microscopic pieces of plants and animals. Sponges are among the simplest organisms on the planet. Even so, they still use a fairly complex system for getting proper nourishment from the sea. The outside of a red sponge's body is made up of thousands of miniature pores that allow water to pass inside the sponge. Each of these pores leads to a set of small channels within the sponge that are lined by tiny cells called collar cells. The collar cells contain microscopic whips that beat the water in the channels of the sponge, pushing a stream of water into the sponge's body. As the water flows through the sponge, tiny parts of the collar cells catch pieces of animal and plant, drawing them into the sponge cells to be digested. The constant flow of water through a sponge helps to flush oxygen into the sponge and clean out waste products.
Butterflyfish are among the most colorful and beautifully-patterned fish in the ocean. Their bright colors make them a favorite subject of underwater photographers' cameras.
Butterflyfish come in many different varieties, each with its own distinctive colorings and patterns. Most butterflyfish share the same flat, disk-shaped body with a short, protruding snout. These physical traits make it easy for butterflyfish to weave in and out of the coral reefs where they live to look for food.
Butterflyfish never grow more than 12 inches in length and live primarily in warm water regions such as the Indo-Pacific ocean. Their diet varies among the different species but for the most part they are carnivorous, feeding on coral polyps.
Wider Caribbean: Honeymoon Heaven
Length: NA;Depth: 23,293 Feet/7,099 Meters
CARIBBEAN
The Wider Caribbean region occupies the southwestern corner of the North Atlantic Ocean. It includes both tropical and subtropical waters with Cape Hatteras as the northern limit for most tropical marine animal life. The eastern boundary of the Caribbean is defined by the Bahamas and the Greater and Lesser Antilles. The Gulf of Mexico is a single basin separated by the Straits of Florida and Cuba. The region is linked by the warm Guiana Current which sweeps northwards from Recife, joins the North Equatorial Current then flows between the southern Caribbean islands and into the Gulf of Mexico, where loop currents form. It eventually joins the Gulf Stream off the Florida coast.
The Caribbean is filled with coral reefs, sea grass beds and mangroves. These areas provide habitats and rich feeding grounds for fish. About 14 percent of the world's coral reefs are found in the region. Coral reefs known as fringing and patch reefs are the most common kinds of reefs found around islands. Usually these reefs are located on the side of the island facing the prevailing wind. Closely associated with coral reefs are the highly productive sea grass beds. Sea grass colonizes the bottom layers of the ocean floor produced by the erosion of coral reefs. These sea grasses provide grazing for sea turtles, manatees, fish and invertebrates.
Coastal mangroves fulfill a similar role. Mangroves trap the top layers of the ocean floor, and also help to support a complex food chain. Coastal lagoons are an important mainland feature in the Wider Caribbean region. Common to the main islands are shallow tidal ponds or other areas known as salinas. Both systems protect coral reefs since they trap the top layers of the ocean floor known as sediment. Coastal lagoons and salinas were probably important feeding grounds for the Caribbean monk seal, which is now believed to be extinct. The threatened Amazonian manatee, which is hunted for its meat, is now limited to the lower reaches of the Amazon River. ...FROM "THE RANDOM HOUSE ATLAS OF THE OCEANS"
Oceans, Climate and Weather
Length: NA;Depth: NA
NORTH ATLANTIC OCEAN
The oceans have been referred to as "the flywheel of the climate system," since like a flywheel they store energy in the form of heat when it is in plentiful supply, during the day or summer, and release it to the atmosphere when sunshine is absent or in short supply at night or during the winter. But this analogy is inadequate because the oceans do not just act as a passive energy store, but also play an active role, with ocean currents moving thermal energy from the warmer, tropical and subtropical regions to higher latitudes.
As warm ocean currents move toward the poles they lose heat to the atmosphere, and the warm air, when carried by winds over neighboring land masses, warms the land at night or during the winter. Oceans, therefore, play a part in determining the climate of a specific region by reducing the extremes of temperature which would otherwise occur. Western Europe, for instance, has a much more mild climate than Eastern and Central Europe because of the heat from the Gulf Stream which moves into the atmosphere.
The temperature differences between land and sea reflect the different rates at which they absorb and lose heat. The land surface heats up faster than the sea during the day, but loses heat faster during the night or in winter. This is because the upper layers of the ocean mix with those below, passing some of the heat gained during the day downwards, and so reducing the rate at which it is lost to the atmosphere. The temperature range of the entire ocean is therefore small - from about 28 F, the freezing point of salt water, to 86 F, although temperatures as high as 95 F are found in some semi-enclosed seas. During the course of a day ocean temperatures rarely vary by more than one degree, and usually no more than 18 degrees over a year. For comparison, the range of temperature experienced in the middle of a continent during a year can be as great as 144 F, and deserts may be scorching during the day but freezing at night. ...FROM "THE RANDOM HOUSE ATLAS OF THE OCEANS"
Despite its name, the brightly-colored clown fish or anemone fish as some call it, is not to be taken lightly. To protect itself, the clown fish spends most of its time swimming among the tentacles of stinging anemones. Few predators are willing to risk a poisonous encounter with a sea anemone to catch a clown fish. In return for its sanctuary, the clown fish helps keep small animals away from the anemone that might damage its tentacles. Sometimes, as many as four and five clownfish will inhabit a single anemone. When a clown fish is in great danger, it will often swim all the way inside an anemone's mouth. It's not clearly understood why the clown fish is not stung by the anemone's tentacles. Most scientists believe it is due to a special mucus layer that covers the clown fish's body.
ZCoastal Process: A Battered Shore
Length: NA;Depth: NA
CALIFORNIA
The shorelines of the world form a transition between the land and the sea and consist of two zones, the intertidal and subtidal. The daily cycle of the tides exposes the intertidal zone alternately to the action of both the air and the water. Below the extreme low-water level, the environment of the subtidal zone grades into the ocean proper, passing through the continental shelf, which generally terminates at a depth of about 660 feet in submarine cliffs which drop to the ocean deeps. The waves, currents and chemistry of these shallow coastal waters differ markedly from the more uniform conditions in the open ocean.
Because of the proximity of land, coastal and near-shore waters receive huge inputs of sediment, nutrients and freshwater. These alter the chemistry of the water and contribute to the high biological productivity of these regions. With the exception of the zones of upwelling, coastal and near-shore waters are the most productive parts of the ocean environment. Their animals and plants display remarkable adaptations to the enormous range of physical factors which characterize these regions.
There are two types of shores. On eroding shores, the action of the waves and tides removes material from the land. On depositing shores, eroded material from the land is deposited, and forms both sandy and muddy beaches, dunes, spits and beach ridges. In general, rocky shores are found in areas of past or present erosion which are exposed to strong wave action, while depositing shores are usually found in more sheltered areas.
In areas of comparatively high wave action, shingle beaches form where large pieces of rock are continuously rolled and moved by the waves. These areas are generally inhospitable environments for animals and plants owing the continuous grinding actions of the shingle. Pebble, sand or muddy beaches form in areas where the actions of waves and currents are less strong. Depending on the size and composition of the deposited particles, these areas are home to a wide variety of organisms. Some burrow in the sand or mud, while others are so small that they slide through the microscopic water film surrounding each particle. Farther from the shore, the sediments become much finer, so continental shelves are covered by very fine mud and clay.
Waves are a feature of both the open oceans and coastal waters, but it is on coasts that they "break," dissipating their energy. As a wave moves through the sea it represents a large store of energy, with individual particles moving in a circular path beneath the wave peak. The water close to the surface moves faster and in a larger circle than the water deeper down. As a wave approaches shallow water, the friction of the submarine surface slows the deeper water, while the particles at the wave's crest move ahead. Eventually the water at the crest is so far in front that the wave breaks against the shore.
Contrary to popular belief, water itself does not cause erosion. It is the particles of sand, pebbles, rocks and other debris caught up in the wave which crash against the beach and erode the shore.
If every coast underwent continuous erosion, then the sea would eventually cover all the land. In coastal areas where wave action is small, deposition of sediments occurs. In this way, dunes, spits and beach ridges are formed. In addition, rivers bring a considerable quantity of sand, silt and clay into coastal areas. Material eroded inland is often deposited in river estuaries and deltas. In areas where currents run parallel to the shore, sediments may be carried along the coast before being redeposited - a process known as longshore drift.
Along with their load of sediments, rivers carry nutrients and freshwater. The nutrients increase the amount of food production in coastal waters.
Where there are flat coastal plains, rivers may form wide deltas when they reach the coast. In temperate zones, deltas are characterized by distinctive fresh and saltwater communities of marsh plants. In the tropics, mangrove communities dominate such areas. The growth of coastal vegetation slows down water movements, and the roots of the mangroves trap the mud carried downstream by the river water. This causes silt to be deposited, and helps to build up the land.
Coastal wetlands are important habitats for many migratory birds. As areas of distinctive vegetation they are important conservation areas, and are also vital to many marine animals as nursery areas. The growth of human populations in deltas which are used as centers of mariculture, agriculture, trade and commerce threatens such habitats. In other areas, coastal developments including the construction of harbors, sea walls, groins and piers interfere with the natural process of sediment transport in the coastal zone, and can lead to the "export" of environmental problems to neighboring areas. ...FROM "THE RANDOM HOUSE ATLAS OF THE OCEANS"
îCoral Reefs: Home to Millions
Length: NA;Depth: 230 Feet/70 Meters
CARIBBEAN
The beautiful shapes of this coral reef provide a home to countless varieties of undersea animals. If you looked closer at this picture, you might find a starfish crawling along the reef floor picking out food particles from the coral debris. A small butterflyfish might be hiding among the branches of a sea fan as a hungry reef shark circled nearby while waiting for a school of fish to swim within reach.
Coral reefs are found only in the warm waters of the tropics where there is enough sunlight for coral organisms to grow. Coral reefs are formed from the limestone skeletons of dead coral animals that are cemented together over thousands of years. At any one time, only the surface layer of a coral reef is made up of living coral organisms. Coral reefs do not grow in areas such as the western continental coastline where the water is too cold. They also cannot grow in places where the water is filled with too many suspended particles or at depths below 230 feet.
Each individual polyp of a coral colony is a cup-shaped creature sitting in its own coral shelter. Coral colonies can produce massive coral blocks, plates or tree-like structures. Growth of coral colonies can be quite rapid. Individual colonies grow at a rate of 0.3 to 1 inch a year. Over a few thousand years that rapid rate of growth can result in enormous coral reefs such as those found around Australia and the Caribbean.
Anyone who has collected sea shells would instantly recognize the elegant pattern of a reticulated cowry's shell. A relative of your everyday garden snail, cowries are members of a large group of mollusks known as gastropods. Cowries and other gastropods are univalved, which means that their bodies are covered by a single hard shell. They get around by using a so-called "foot" which is a muscular tissue that extends out of their shell and runs the length of their body. The cowry's "foot" secretes a slippery mucus which lets it slide over most surfaces. Many gastropods also move along surfaces another way. By contracting the muscles of their "foot" they produce tiny waves that propel their body forward.
Like a garden snail, the cowry has a tiny head at one end of its body with eyes located at the tips of two touch-sensitive tentacles. The cowry breathes through gills located just below their eyes.
During the day, cowries usually hide underneath a rock or coral reef. At night, they come out to forage for food. Cowries are vegetarians that love to feed on sponges and algae. However, other members of the same group of marine gastropods are meat-eating hunters. The cone shell, for example, tracks down other gastropods and then sends a poisonous dart from its foot into the body of its prey. Once the prey is stunned, the cone shell slowly devours it.
Anyone who has ever walked along the beach or gone exploring in tidepools has probably seen a crab scurrying among the rocks. Crabs are one of the most common animals to be found along the seashore.
Crabs have a hard outer shell, or exoskeleton, that protects them from crashing waves as well as from biting fish. This outer shell is also a popular place for sea plants and animals to settle and live. Often crab shells are covered with brown or green seaweed and many barnacles. These hitchhikers help camouflage the crab so he does not become a meal for someone else. Large, active crabs like this one can chase down other crabs, snails, and sometimes even small fish for food. Their large claws are like pincers, and can pry open clam shells and other hard-shelled sea creatures.
Like lobsters and shrimps, a female crab carries her eggs under her abdomen for protection until they hatch into small larvae. These very small baby crabs are on their own, living and growing while drifting around for days and sometimes weeks in the water. A dramatic change, or metamorphosis, takes place when they transform into juvenile crabs and settle on a coral reef. Then they must learn to find a new kind of food and learn how to avoid a host of new dangers including people who like to turn crabs into a meal.
Sea cucumbers are the vacuum cleaners of the deep. Crawling along the ocean floor at a pace of three inches an hour, a sea cucumber can suck in 200 pounds of sand a year. The sea cucumber sends this sand through its simple stomach, digesting anything that is organic such as pieces of dead animals or plants and then passing the leftover sand out of its body.
Like its close relatives the sea urchin and the starfish, the sea cucumber's body is covered by a spiny skin. It moves around on thousands of tiny tube feet located along the underside of its body. The sea cucumber's body can be divided into five symmetrical parts, with a mouth at one end and a body at the other. Generally, sea cucumbers are found on the bottoms of coral reefs, rocky shorelines and sandy coasts.
Most sea cucumbers search for food at night. To grab hold of pieces of organic matter, sea cucumbers produce a sticky mucus which makes sand stick to their bodies or tube feet. The sea cucumber can then bring its tube feet to its mouth and suck the food off.
Sea cucumbers may look relatively defenseless but they have a unique way of protecting themselves. When attacked, sea cucumbers can literally push part of their intestines out of their body and onto their attacker. These body tissues are quite sticky and will deter many of the hungriest predators. Within just six weeks, a sea cucumber can regenerate its lost intestines.
Decorator crabs love to hang ornaments on themselves. It may look like fun, but to the crab it is a matter of life or death. The decorator crab's body is covered with small bristly hooks, which the crab uses to hang pieces of algae and sponge. Every time the crab sheds its skin, or molts, it has to redecorate its shell since the hooks are lost with the old skin. This kind of decoration makes the crab very hard to see in its native environment. People working with these crabs in the laboratory have also noticed that the crab uses this decoration for food when it can't find anything else to eat.
Like many slow moving crabs with small claws, the decorator crab picks small particles and pieces of food from the rocks and plants it crawls over.
∙Drifting Continents: World's Jigsaw Puzzle
Length: NA;Depth: NA
NILE RIVER
Have you ever noticed that the present-day continents can be fit together into a single land mass like a jigsaw puzzle? The German meteorologist Alfred Wegener did, and it led him to propose the theory of continental drift in 1912. He suggested that more than 200 million years ago the earth's surface was made up of one gigantic land mass, the supercontinent called Pangaea. Eventually, this giant land mass broke up into separate pieces. Slowly these pieces drifted apart to form the continents as we know them today. There is now a wealth of geological evidence to support this theory, but it was not until the early 1960s that a theory explaining continental drift was finally proposed.
About 200 million years ago the land mass known as Pangaea broke up into two major continents, Gondwana in the southern hemisphere and Laurasia in the northern hemisphere. Panthallasia, the single ocean which surrounded Pangaea, began to shrink and a new, shallow ocean, the Tethys Sea, was formed between the new continents. Another split divided Gondwana into what we now know as Australia and Antarctica, and Africa. By about 65 million years ago the Atlantic and Indian Oceans had appeared, but the North American and European continents were still joined. The Pacific became separated from the Atlantic and Indian Oceans when the North and South American continents became joined and Australia drifted northwards away from Antarctica toward its current position; while the separation of Greenland from North America, and the widening of the North Atlantic, completed the encirclement of the Arctic Ocean. The Caribbean took shape when South America moved into its current position and the Central American land bridge was formed.
The way in which the continents broke up also influenced the distribution and evolution of marine fauna and flora. New land barriers prevented certain species from mixing together and forming separate species. But removing these land barriers helps a species spread out into new areas, coexisting with or out-competing species that already reside in these areas. When the Suez and Panama Canals were formed, links between oceans long separated were reopened, enabling species to spread into new habitats. ...FROM "THE RANDOM HOUSE ATLAS OF THE OCEANS"
With its eerie shape and flapping dorsal fins, the eagle ray is among the most elegant and mysterious-looking fish in the ocean. Its back is covered with a symmetrical dot pattern ranging in color from white and yellow to green. Its underbelly is white and its long tail, sometimes measuring twice as long as its body, is black. When an eagle ray is resting on the sandy ocean floor, its highly-patterned back acts as a camouflage, hiding it from both prey and attackers.
The eagle ray, like all rays and sharks, has a skeleton of cartilage. Its large "wings" are tapered like a bird's and can measure up to seven and a half feet across. The eagle ray's shovel-shaped snout and its duckbilled mouth are extremely sensitive to smells and electrical currents in the water. This makes the eagle ray an effective hunter. Feeding on mollusks, crustaceans and small fish, this beautiful ray can reach weights of up to 500 pounds.
The eagle ray can be found in both the eastern and western Atlantic as well as the Caribbean Sea. It lives mostly among rocky and muddy coral reefs and feeds along the sandy ocean bottom.
jElephant Seal: Hundreds of Harems
Length: 20 Feet/6 Meters;Depth: 93 Feet/28 Meters
CALIFORNIA
The southern elephant seal is one of the largest members of the Pinniped family of marine mammals. This family includes seals, sea lions and walruses. Pinnipeds are, in fact, related to modern cats, dogs and bears.
In addition to being well known for their size, elephant seals are also famous for their unique mating ritual. Near the end of August of each year, giant male sea elephants begin to gather at the chosen breeding ground. Once there, the male sea elephants climb onto the beach and stake out their territory, the bigger and stronger of the seals grabbing the better places along the shore. At the end of September, the females (also called cows) begin to arrive at the grounds. The stronger male elephant seals then establish groups of 10 to 20 females called breeding harems. To determine who is the strongest, male elephant seals will sometimes go through what look like very violent battles with one another. These battles take the form of a head-butting match in which both males slam their fleshy snouts against each other until the weaker male finally retreats. Usually, neither male is badly hurt, but the weaker male may have to wait another year before it gets a chance to mate.
After the elephant seal pups are born, they are nursed for about four weeks. During the last days of nursing, the males and females breed again.
Male and female elephant seals are physically very different from one another. The males are generally three or four times heavier than the females and have much longer and more pronounced snouts. The skin around their necks is also more wrinkled and hangs in loose folds.
No tropical reef fish is better recognized for its dazzling colors than the angelfish. Found in warm coral reefs all over the world, the angelfish comes in many different sizes and patterns. Some angelfish, like the Herald's angelfish are a bright solid yellow. Others, such as the Regal angelfish, are covered by wildly colorful stripes. Some angelfish have circular eyespots near their tail. Others have thin horizontal stripes that run the entire length of their body. As hard as it is to believe, these bright colors and patterns help protect angelfish from predators. Bright colors blend in well with the colors of the coral reef. They also help to hide parts of the angelfish's body, such as the eye, in dark patterns that resemble shadows. The dark circle found at the tail of many angelfish can confuse predators into thinking that the angelfish's head is actually located somewhere behind the tail.
Angelfish are closely related to the butterflyfish, another colorful reef fish. The major difference between the two is that angelfish have a shorter snout and a longer, thicker body. Angelfish spend most of their day scraping bits of algae and sponge off the sides of coral reefs. Typically, they remain in deeper reef waters. Angelfish prefer swimming alone rather than in large schools. When confronted by another angelfish they become very territorial and even attack one another.
USchools of Fish: Free Time
Length: NA; Depth NA
BIMINI
There are many reasons why fish swim together in large schools. For small fish, swimming in groups help protect them from predators. The changing shape of a school often confuses and even scares large predators from attacking. Large schools of fish also make it quite difficult for predators to separate out a single prey from the group. Most fish swim in schools to help track down and catch food to eat. Tuna and amberjacks cover great distances of the ocean in search of small fish and squid. Other kinds of fish only gather together in schools at certain times of the year to breed.
ΦOcean Floor: Mountains under the Ocean
Length: NA;Depth: 36,161 Feet/11,022 Meters
MARIANA TRENCH
If it were possible to remove the water from the oceans to expose the floor beneath, a truly remarkable landscape would be revealed: long mountain ranges, vast plains covered in a thick layer of sediment, volcanos and deep trenches. It was not until the late 1960s that the theory of plate tectonics provided an explanation of the way in which the formation and destruction of the Earth's crust accounts for the topography of the ocean floor and for continental drift.
According to this theory, the Earth's surface is made up of about 12 rigid crustal plates, which overlie and move about on the semi-molten rock beneath. Where these plates meet, different types of borders appear resulting in different types of ridges, valleys and mountains beneath the ocean's surface. The three different types of borders are constructive borders, where magma rises to the surface forcing the plates on either side apart, and forming new oceanic crust in between, destructive borders, where two plates collide and one is overridden by the other, and conservative borders, where plates move past one another, the friction between the two causing faults and fractures.
Sometimes lava emerges from an oceanic ridge, forming submarine volcanos which may break the surface and become volcanic islands or remain hidden under water as seamounts.
Evidence for the sea floor spreading is to be found in the magnetism of basaltic minerals in the floor itself, the direction of which is fixed according to the prevailing direction of the Earth's magnetic field when the rock solidified. The patterns created by the magnetic bands give scientists the ability to calculate the rate at which the sea floor is spreading: spread rates are estimated to range from less than 0.4 inches per year from the Mid-Atlantic Ridge, to as much as 6.3 inches a year for the East Pacific Rise. The divergence of plates and formation of new crust may also occur beneath continents. This leads to the formation of a rift valley, such as the Great Rift Valley in East Africa, and in some cases to the subsequent formation of a new ocean.
The addition of new crustal material at constructive boundaries is compensated for by the destruction of oceanic crust at destructive boundaries; otherwise the surface of the Earth would be continually expanding. This accounts for the young age of the oceanic crust. Where two continental plates collide, dramatic folding of the land and the upthrust of mountain chains such as the Himalayas occurs. Where continental and oceanic plates collide, the continental plate overrides the more dense oceanic plate in a process known as subduction. Subduction zones are characterized by oceanic trenches which can be a staggering 6.2 miles deep, and mark the line along which the oceanic plate is forced downwards. At a depth of 435 miles, the leading edge of the subducted plate melts and dissolves back into the mantle. The magma may then rise back up through the continental plate above, forming a chain of volcanos along the continental margin, as had happened with the Andes. These mountain chains are then built up further by more sediment from the ocean floor.
Sediments on the sea floor come from three main sources: the land, from which material is eroded by water, ice and wind; the surface water of the ocean, from which organic matter, both living and dead, falls to the floor beneath; and deep-ocean waters, from which there is a very gradual production of material by crystallization. ...FROM "THE RANDOM HOUSE ATLAS OF THE OCEANS"
The flounder is a member of the flatfish family of which there are about 500 different species. This family has one thing in common: all of its members are flat as a pancake.
Like most flatfishes, the flounder has both its eyes on one side of its head and keeps its other side very flat against the sea bottom. Oddly enough, the flounder is not born flat. After it hatches from its egg, the baby flounder swims upright like most other fish. A few weeks later, however, the flounder's body goes through a dramatic change. Slowly, its skull starts to twist to one side and one eye begins to move toward the center of its head. One side of the flounder now becomes the top side, as its body grows and flattens out. It takes close to seven weeks for the baby flounder to completely change into a "flat" fish.
Flounder, like other flatfishes, also have the amazing ability to change their skin color and pattern to blend in with the sea floor. It is very difficult to spot a lounging flounder.
Flounder live for the most part in the cold waters throughout the ocean. The flounder buries itself in the sand or mud of the sea floor with only its head exposed as its powerful telescopic eyes watch for food (mainly a variety of crustaceans).
A frogfish's appearance may look quite strange, but it is very effective at attracting a good meal. This bulky, slow-moving fish lives on the floors of coral reefs and temperate oceans. Its body is often brightly colored and covered with small pieces of loose flesh that resemble floating algae. This helps the frogfish blend in with its surroundings.
The frogfish spends its days lying motionless among rocks or coral. When the frogfish gets hungry, usually at night, it uses an interesting method for catching small fish. Like its cousin the anglerfish, the frogfish has a thin strand of flesh attached to its head which can be wiggled like a tiny fishing lure. When small fish come to investigate the moving object, the frogfish lowers the lure closer toward its mouth. Once the fish is close enough, the frogfish leaps forward, using its strong pectoral fins, and snatches the fish with its large mouth.
Frogfish are greedy eaters. They will often try to swallow fish that are larger than themselves. When they do this, they must enter a state of half sleep for several hours to digest the big meal.
Frogfish are not great swimmers. They get around by using their pectoral fins and ventral fins to drag themselves along the ocean bottom. Some frogfish even use their fins to climb up rocks.
The Galapagos shark is a fast-moving meat-eater that frequents the warm waters around islands in the Western Pacific and Indian Oceans. Like its close relatives the white tip reef shark and the grey reef shark, the Galapagos shark has a sleek body that can reach a length of ten feet. It is capable of swimming at high speeds and turning on a dime, both of which make the Galapagos shark an excellent hunter.
Galapagos sharks like to swim in schools when they hunt for fish, squid or marine reptiles. Normally, warm water sharks like the Galapagos shark are fairly predictable in their actions. They attack prey when hungry and snap at humans only when provoked. The only real exception to this is when sharks like this are in the midst of a feeding frenzy. Feeding frenzies among sharks usually occur when there is a great deal of blood and food in the water and a large group of sharks are all trying to get their fair share. In such a frenzy, sharks will often lose all control and begin biting and attacking anything in the vicinity including each other.
While there are no reported attacks of humans by Galapagos sharks, many divers have been scared out of the water by this fast shark's sudden movements.
Giant sea anemones live in the warm, shallow water of the Caribbean coral reefs near places like Cuba, Puerto Rico, and the Virgin Islands. Their long pointed tentacles are coated with stinging cells that can paralyze small fish and other animals that venture too close. The tentacles also hold onto the paralyzed prey while they push it into the anemone's mouth.
Some giant sea anemones have a small, almost transparent shrimp living among their tentacles. These shrimp appear to be immune to the anemone's stings. It's also possible that the anemone is accustomed to the shrimp and no longer injects it with the stinging cells from its tentacles. Shrimp like these are also known as "cleaner" shrimp because they spend their days cleaning bigger fish. This relationship which is called symbiotic helps both animals. First, the shrimp will do a little dance to attract any large fish wishing to be cleaned. If a fish is interested in getting cleaned it will move closer then gently spread its fin and open its mouth. At this point, the shrimp starts its housecleaning. The shrimp cleans the fish by gliding over the fish's body, even going inside its mouth and gills and picking off small parasites and diseased tissue. When the shrimp is finished with one fish, another fish may be already waiting in line.
Imagine swimming halfway around the world just to go on a winter vacation. The gray whale makes this trip once a year! Each winter, this 49-foot-long marine mammal embarks on a 12,500-mile migratory trek from the Arctic Circle to subtropical Baja California and back. Now, that's a journey.
The gray whale is a member of the Cetacean family, the only mammals in the world to spend their entire lives in the water. Gray whales are found in the open ocean along the coast of North America. They are called a baleen whale, which means that they have whalebones (or baleen) instead of teeth. Baleen looks like the bristles of a brush, and acts like a giant sieve which filters the organic matter out of seawater. Most baleen whales feed by scooping up large quantities of water in their mouth and then filtering out the microscopic organisms which are in turn swallowed by the whale. But the gray whale does things a little differently. It takes large bites out of muddy or sandy bottoms of the ocean floor and then squeezes out the sediment until all that is left are tasty plants and animals. Gray whales eat mostly small crustaceans that never measure much bigger than a matchstick.
Whales like the gray whale breathe through a vent, often called a blowhole, located at the top of their head. Every time a whale wants to take a breath, it must first come to the surface, blow water out of its blowhole, and then almost instantly breathe air back in. The amount of time a whale can spend underwater without surfacing to take another breath varies depending on the species but some can stay below the surface for 25 minutes at a time.
Undersea hunters aren't always sleek swimmers with large mouths and loads of razor-sharp teeth. Just take one look at the grouper. This bulky, solitary fish is a relative of the giant sea bass and it is anything but sleek and streamlined. Reaching weights of 135 pounds, giant groupers look a lot like floating military tanks.
Groupers live on rocky sea beds in warm and cool coastal waters. They prefer to hide out in shelters, and will spend much of their time searching for the perfect cranny protected by rocks or coral.
Groupers are determined hunters. They will often wait perfectly still for hours to catch a favorite meal such as a squid or octopus. The large mouth of a grouper is filled with many small teeth that grow in narrow rows. The outer teeth are set slightly backwards while the inner teeth are mobile and can be pushed in quite easily from the front. This helps the grouper hold onto an animal, keeping it from slipping out of its mouth.
Groupers can grow to very large sizes. Because they are hard to find and put up such a good fight, they are also a favorite fish for sports fishermen to catch. While some very large groupers may reach lengths of four feet and weights of 140 pounds, most of the 300 different species of grouper weigh between 15 and 30 pounds.
Sponges spend most of their time filtering and cleaning seawater. They are constantly sucking in water through small pores on their sides and shooting it back out through the ostium, or opening, located at the top of their bodies. In a large coral reef, hundreds of gallons of water get strained by sponges each day. While they are filtering, sponges hold onto the small, edible particles of organic matter. These are passed through the sponges cells as food. The unusable material in the water is shot out of the sponge again. Most sponges are colored a drab gray, brown, or green. When scientists first began studying ocean life, they disagreed over whether the sponge was a plant or an animal. Several factors definitely make a sponge an animal.
First, sponges lack all signs of chlorophyll, the green material that plants need to make food from sunlight. Many species have blue-green bacteria living in their tissues but these are called symbionts, which means they live in concert with the sponge. Secondly, sponges release sperm that travel through the sea water to fertilize the eggs found in the body walls of nearby sponges. Finally, some individual sponge cells can act like muscles, contracting the ostium at the top of the sponge. Other individual cells can extend flowing arms around particles and ingest them. These muscle-like cells are called phagocytes, and the ability to use them is characteristic of animals.
No fish is more feared or famous than the great white shark. One look at a 16-foot great white cruising the ocean depths in search of a meal, and it's easy to understand why. Found in cool ocean waters off coasts like California and Australia, great whites are among the most deadly and fearsome hunters in the sea. Stretching an average of 18 feet in length, and boasting a terrifying mouth full of razor sharp teeth, great whites can frighten even the most seasoned underwater divers.
When a great white is born, it measures only between three and four feet long and lives on a diet of rays, skates and small fish. Within several years, however, great whites reach their full length of 16 to 18 feet and weigh close to 3,500 pounds. As adults, their favorite meal consists of marine mammals including seals and sometimes dolphins. The largest recorded great white shark measured 21 feet long and weighed 7,000 pounds, or nearly three tons. Many fishermen and divers have claimed to have seen great whites as large as 25-30 feet long, though none have been officially recorded. Great whites are built like a torpedo with a pointy head and large muscles in their neck and body. Great whites are not well known for speed. Their main method of attacking prey is surprise. With their gray and white skin, great whites are nearly invisible when seen from either above or below in murky water. When a great white tracks down an inviting meal, it often circles below the animal, then darts up from the depths, striking the animal with its massive mouth. The great white jaws are only loosely attached to its skull. This makes it possible for the great white to extend its rows of serrated teeth and take an enormous bite from an animal.
Most people still believe that great whites are bloodthirsty animals willing to attack at a moment's notice. To the contrary, most great whites do not attack other animals unless they are hungry. It is true that great whites have attacked and killed humans, but many scientists believe they are not true man-eaters. In most cases, it is thought that great whites confuse humans, who are diving or surfing, with their favorite meal, seals. Once they bite into a human, great whites usually spit them out. Unfortunately, one bite from a great white can often be fatal.
Sleek and dangerous, the gray shark is a smaller version of the dreaded great white shark, although not quite as famous. The gray shark is a member of the Carcharhinidae or "maneater" family of sharks. It is most commonly found in the waters of the Mediterranean and Atlantic and feeds on fishes, crustaceans, reptiles and the occasional human.
Gray sharks are cartilaginous fish, which means that their skeleton is made out of cartilage instead of bone. Like other sharks, the gray shark has finely-tuned sensory organs that help it locate prey. Both its vision and sense of smell are well developed for tracking animals at night and in murky waters. Gray sharks, like all sharks, also have a special sensory system known as the ampullae of Lorenzini. These are tiny jelly-filled cups that cover the gray shark's snout and are capable of detecting weak electric current that are generated by animals in the water. Because of its diet, the gray shark's jaw is extremely powerful and lined on both top and bottom with several rows of razor-sharp teeth.
Though the gray shark does not have the same mean reputation as the great white shark and tiger shark, it has been known to attack humans. There have even been several reported cases of a gray shark killing people.
^Gulf of Mexico: Easy Going
Length: NA;Depth: 17,070 Feet/5,203 Meters
GULF OF MEXICO
The Gulf of Mexico forms the northeastern component of the Wider Caribbean. Surrounded by the Yucatan Peninsula, the island of Cuba and the coast of Florida, the Gulf contains rich marine habitats and major petroleum reserves. The continental shelf is wide, and the Campeche Bank off the Yucatan Peninsula provides a rich fishing ground, particularly for certain kinds of shrimp. The northern shoreline of the Gulf of Mexico consists mostly of sedimentary material that comes from the Mississippi Basin. Over the last 7,000 years, the flat plain along the coast has increased in width by as much as 93 miles as a result of shifts and expansion in the Mississippi's delta. During the 19th century, engineers attempted to control the rate of flow of the river, to prevent new shifts in its course. But over time, the rate of the river's flow has increased as the Mississippi's course has become streamlined and straightened.
The western and southern coasts of the Gulf of Mexico are characterized by large lagoons separated from the sea by barrier beaches. The concentrations of salt in these areas vary with the movement of the tides, evaporation, and the inflow of fresh water from rivers and rain. The lagoons are an important habitat for numerous animals, including crocodiles and manatees, as well as for birds such as flamingos, ibises and pelicans. The endangered Kemp's Ridley turtle nests only on the barrier beach of Rancho Nuevo, on the west coast of the Gulf. The Gulf coast of the United States is densely populated and heavily industrialized. Pollution problems affect coastal waters and estuaries around busy industrial and shipping centers such as Houston and New Orleans. A very important pollution problem in the Gulf comes from the oil industry. Oil reserves in the Gulf are estimated to total over five billion tons. The coastal areas off Louisiana and the Mexican states of Veracruz and Campeche are the centers of Gulf oil production. In recent years, shipping accidents and oil well explosions have made oil-related pollution problems very noticeable. ...FROM "THE RANDOM HOUSE ATLAS OF THE OCEANS"
Like other sharks, great whites find their prey by using a variety of different senses. A great white's vision is good enough to let it make out shapes as far away as 30 to 40 feet, even in dark water. Great whites can also smell minute quantities of blood in the water from wounded fish or mammals. The unique way great whites have of tracking down a meal is by detecting small changes in the electric field of the ocean. Almost all sharks have tiny sensors in their skin that can detect very low levels of electrical current in the water. Once a great white is within a certain distance, it can use the animal's electric field as homing device.
If you ever build a wooden bookshelf, don't ever try using a hammerhead shark to pound in your nails. He certainly wouldn't like it too much.
The hammerhead shark is one of the more oddly-shaped fish in the sea. Instead of a pointed head, which most sharks have, the hammerhead's head is shaped like a broad, flat T with its eyes and nostrils located at the far ends of the T, rather than along the sides of its body. In order for a hammerhead to see what's in front of it, it must make wide swinging movements with its head as it swims.
Scientists have never quite agreed on why the hammerhead's body is shaped in such a way. Some believe that the long distance between the hammerhead's two sets of eyes and nostrils, helps the shark more accurately detect its prey. Others believe that the T-shaped head acts like an airplane wing giving the shark more lift when it is swimming. The most obvious explanation is that the hammerhead has a much better view of what is going on to either side of it.
One thing is true, a hammerhead's shape doesn't impair its ability to hunt. Hammerheads are very effective at tracking down and killing small bottom-dwelling animals and occasionally large rays, tunas and tarpons. Most hammerheads can be found in warm waters throughout the world's oceans. Hammerheads usually travel alone or in small groups. However, when they mate, some species of hammerhead will migrate in large groups to the same place each year. Sometimes these groups can number as many as a thousand, making an awesome sight for any underwater diver lucky enough to be present.
Harbor Seal: Popular Pup
Length: 6 Feet/2 Meters;Depth: 0 Feet/0 Meters
NORTH PACIFIC OCEAN
The harbor seal is by far the most commonly known and widely distributed member of the seal family and can be found in both the North Atlantic and North Pacific Oceans. Both males and females weigh between 220 to 330 lbs. and measure four to six feet long. Their coloring is varied and can range from a very light silver to a dark black. However, the most common harbor seal is light gray with dark spots.
Harbor seals eat cod and other regional fishes, and can dive to depths of up to 330 feet. During the winter months they spend most of their time below the ice floes where the water is warmer. Harbor seals can hold their breath for almost 10 minutes before having to come up for air. They are also quite playful and like to spend hours sunning themselves among the rocks and on pieces of floating ice. Often, they can be found sleeping belly up on top of the water.
Harbor seals have always been hunted commercially for their beautiful coats, and polar bears, whales and sharks are their most feared natural enemies.
When most crabs get too big for their shell, they grow another one. Not the hermit crab. Beginning as tiny larvae, hermit crabs must use the empty shell of another animal as their home. Each time a hermit crab goes through a growth spurt it moves out of its borrowed home and finds a larger shell in which to live. At these times, a hermit crab's body has no protection and is very vulnerable to attack by hungry predators.
Hermit crabs are usually found in coral reefs where they like to roam over a familiar area. Most hermit crabs will eat just about anything, including mollusks, fish and organic matter that is left on the ocean floor. Hermit crabs are not very fast. That's mainly because they have to move around with some other animal's clunky shell on their back.
Does this nudibranch look slightly confused? One might think so. As a member of the mollusk family, the nudibranch is a hermaphrodite, which means it is both male and female. Most animals under the sea and on land are either male or female, but not both. The nudibranch, like the hooded nudibranch in this picture, is capable of producing both eggs and sperm. When it is time to reproduce, one nudibranch can fertilize its own eggs or two nudibranches can join together and exchange both eggs and sperm with one other. After their eggs are fertilized, the nudibranches either lay them on the ocean floor or carry them until they become baby nudibranches.
Not all sharks are terrifying monsters of the deep. The horn shark is a fairly docile shark that lives along the bottoms of kelp beds feeding on mollusks, sea urchins and crustaceans. Horn sharks are members of a small family of sharks known as bullhead sharks. The family received this name because of the thick, compressed head and short, pig-like snout shared by its members.
Horn sharks do not grow much larger than five feet in length, though most measure only a few feet long. They are oviparous, which means they reproduce by laying eggs. The horn shark egg is enclosed in a conical case which is deposited in a nest site among rocks in late winter or spring. It takes between seven and twelve months for a young horn shark to be born and another ten years before it reaches adulthood.
╛Hawksbill Turtle: Vegetarian Hawk
Length: 3 Feet/1 Meters;Depth: 50 Feet/15 Meters
INDIAN OCEAN
Turtles have been around in one form or another for millions of years. The largest turtle alive today is an oceangoing turtle called the leatherback. It can reach a weight of 1,500 pounds and grow up to eight feet in length. All sea turtles have very smooth and streamlined shells. Their feet are shaped like long paddles for swimming, which makes it very difficult for them to move around on land. Sea turtles do not have the ability of other turtles to retreat inside the protection of their shell. However, once they grow to a large enough size, almost nothing, except human desire, is a serious danger to them.
For centuries people have hunted sea turtles for their meat as well as for the outer layer of their shell, often called tortoise shell. Many sea turtles also become entangled and die in large nets meant to capture fish and shrimp.
Before the invention of plastic, tortoise shell was in great demand for jewelry, combs, and other items. The hawksbill turtle has always been famous for having the thickest and most colorful kind of tortoise shell. This shell is made from a protein-rich, fingernail-like substance. It was once thought among turtle hunters that if the tortoise shell was peeled from the turtle it would grow back. They often rolled the turtles in campfires, heating up the outer shell so that it could be peeled from the animal. Afterwards, the turtle would be released into the ocean with the belief that it would later return with newly grown shell. However, we now know that few if any of these turtles survived this brutal treatment.
Sea turtles are considered to be an endangered species. Some are now being raised in seaside farms in hopes of preserving the species.
All marine mammals love to play. And the humpback whale is no exception. Perhaps its favorite pastime is leaping clear out of the water and landing with a tremendous splash.
The humpback whale's other well-known pastime is singing. Humpback whales are famous for the haunting songs they create underwater. They can be heard for hundreds, and some think, even thousands of miles through the ocean. These eerie and beautiful songs have distinct melodies and are sung over and over by the same humpback. The true purpose of these songs is not completely understood, but most scientists think they are for calling distant mates.
The humpback whale is a baleen whale easily recognized by its giant pectoral fins. In fact, its Latin name megaptera novaengliae means "great wing." These fins are serrated along their front edge and can be as long as a third of the creature's total body length.
When not leaping out of the water, humpbacks are slow-moving because they lack the aerodynamic body shape that most whales have. They feed on krill, mackerel, sardines, anchovies and plankton and will only hunt for food in cold waters. Most humpbacks can be found in cold oceans and spend the winter months in warmer, tropical waters where they mate and give birth. A mother humpback will only give birth to one calf every two to three years. Baby humpbacks are 15 feet long when they are born.
Since 1966 it has been illegal to hunt these beautiful creatures, but because humpbacks were fished for so many hundreds of years they are still, despite the ban, an endangered species.
iHydrocoral: Deep Sea Jewelry
Length: 4 Feet/1 Meters;Depth: 300 Feet/91 Meters
VANUATU
Hydrocorals are similar to sea whips and sea fans. They have a single row of eight tentacles that wrap around their mouths with stinging cells arranged in rows along the tentacles. The hydrocoral's flower-like polyps are scattered all over its hard glassy skeleton. These skeletons come in many different bright colors and some are even shiny black. Hydrocorals differ from most other corals because they do not need small single-celled plants living with them to produce their skeleton. Because of this, hydrocorals can live in deeper waters, out of range of light. Usually hydrocorals are attached to rocks in areas where currents carry lots of small animals right into their hungry little tentacles.
For centuries hard corals have been valued for making jewelry. The hard skeleton can be highly polished and comes in bright yellow, red, blue, and purple.
╒Indian Ocean Basin: Old Trade Routes
Length: NA;Depth: 24,442 Feet/7,450 Meters
INDIAN OCEAN
The Indian Ocean lies across the Equator, extending from the Tropic of Cancer in the north to the Tropic of Capricorn in the south. Its western boundary is the African coast, while the Malay Peninsula and a group of islands known as the Indonesian Archipelago define its eastern boundary. The semi-enclosed Persian Gulf and Red Sea are extensions of the Indian Ocean in the north, and together with the Arabian Sea, the Gulf of Aden and the Gulf of Oman, they define the boundaries of the Arabian Peninsula.
There are two surface current systems that dominate the waters of the Indian Ocean. One is in the north, the other is in the south. Over most of the Indian Ocean's surface, temperatures vary between 77 and 86 degrees Fahrenheit. Because of the direction the water in the Indian Ocean circulates, the temperatures tend to be higher in the west than in the east.
The climate of the region varies depending on which season it is and on location. Generally, the climate is normally dominated by the cycle of monsoons, which are rainy storms. This pattern results in a dry season during the first quarter of the year, then gradually develops more frequent rain systems in the second quarter. During the third quarter of the year, wind speeds and rainfall reach their maximum. The monsoon gradually shifts back to its original starting place in the final quarter of the year.
A great many different kinds of marine animals live in the Indian Ocean. Over 4,000 different fish species have been recorded there. A large number of whales breed in the Indian Ocean. The ocean is also crossed by other large migratory animals such as marine turtles and a number of species of tuna. ...FROM "THE RANDOM HOUSE ATLAS OF THE OCEANS"
╓
Jacques Cousteau
INTRODUCTION FROM "THE RANDOM HOUSE ATLAS OF THE OCEANS" by Jacques Cousteau
The health of the global water system rooted in the ocean is vital to the future welfare of our planet, and is of particular concern to me as an ocean explorer. The future needs of society will be well served, however, only if we change our short-term mentality and often arrogant indifference to the results of our actions and focus on long-term considerations and a sound attitude in the use of all our resources.
It is an unavoidable fact of international life that the decision-makers in governments everywhere are most influenced by vested interests with extravagant lobbying budgets and by organizations with enormous memberships. Those of us who love the sea, who recognize the blood relationship of all earth's beings, who see on this Water Planet a growing threat to our most fundamental biological machinery, do not command the money and the power of even a single major multinational corporation. But we can wield the formidable power of our numbers, the strength of a great unified crowd of citizens of the planet.
The rate of environmental devastation is alarming. We ourselves are increasingly threatened by toxic debris and lethal miscalculations. This is unbelievable and unacceptable. We must stop this stupidity and the most effective weapon we have as citizens -- as parents -- is the sheer force of our numbers. That is the strategy of the dolphin when threatened by an animal armed with greater strength and size. Pursued by a large shark, a pack of dolphins will suddenly turn en masse, dive below the shark and drive their blunt noses into its belly, one after another. It is the perfect strategy. With no ribs or diaphragm to protect its vital organs, the shark is vulnerable. For all its power, the shark is defeated by intelligence and the force of numbers. It is the weaponry of the peacemakers and the common people throughout history.
For all the darkness that presently confronts us and our descendants, there is no reason to give up. There is every reason to take up the fight, because we have within our grasp the power of the people to force the right decisions. The more people, the more power, the more hope. On behalf of future generations whose legacy we are squandering, let us begin to make waves -- forcing decision-makers to protect and to nurture the environment. How can we accomplish this? We can rise as a human family and compel the powerful and the profit-only-minded to consider life the greatest priority. We can take our inspiration from the dolphins, who defend themselves and their offspring through an instinct to mass together in the face of danger ... and to attack power with wisdom. ...FROM "THE RANDOM HOUSE ATLAS OF THE OCEANS"
The jewel anemone really does look like a magnificent underwater gem. Its spectacular red, pink or mauve-colored tentacles have white tips, and contrast brilliantly with the green and brown ocean floor. Like most sea anemones, the jewel anemone is carnivorous and ensnares its prey with its sticky, stinging tentacles. Because it is immobile, the jewel anemone must wait for an unsuspecting guest to wander into its clutches before injecting it with its poisonous stinging cells. Then it's dinnertime!
The jewel anemone can usually be found growing in large colonies beneath ledges and stones, in shallower waters. This type of anemone does not like direct sunlight.
When swimmers in tropical areas such as the Caribbean or the Great Barrier Reef feel a sharp, burning streak across their arms or bodies, they have probably come into contact with a jellyfish's tentacles. Large jellyfish like the one in this picture are famous for their long stinging tentacles. The moment these tentacles come into contact with a person or an animal they fire off scores of tiny stinging cells called nematocysts.
Upon leaving the water, the streaks on a swimmer's body will quickly turn into painful red welts that may take days to go away. Amazingly, common meat tenderizer often will relieve the symptoms if applied quickly after the attack. This is because the tenderizer has enzymes that break down protein in meat and have the same effect on the venom from the stinging cells, which is also a protein. If a person accidentally comes into contact with many jellyfishes, they might need to be hospitalized and could even die from the stings.
Normally, the jellyfish uses its stinging ability to catch food. Jellyfishes feed mainly on small fish, and sometimes will sting larger animals that try to prey on it such as sea turtles, ocean sunfish and other smaller fishes.
This small jellyfish represents no danger to most animals. Indeed, many animals would like to eat this little delicacy. Its only defense against hungry enemies is its transparency. Clear as glass, the globe jelly is almost invisible as it floats in the water with only its red gut exposed. It is thought that this brightly-colored jelly belly probably scares many predators away.
The globe jelly's small tentacles have the same stinging cells of other jellyfish. However, because of its small size, this animal restricts its feeding to tiny crustaceans. During the day, the ocean bottom may be covered with hundreds of these tiny jellyfish. At night, though, they swim upward into the water to fish for the small animals that only come out into the safety of darkness. The following morning the jellyfish return to their resting places in the sand or among the blades of sea grass.
True to their name, jellyfish are about 95 percent water and have no hard skeleton. Their large jelly-like bell is ringed by stinging tentacles that surround a mouth and stomach. Although it is difficult to make out, the jellyfish's bell is filled with nerves and muscles. These produce wavelike contractions which flow down the jellyfish's body and slowly propel the animal through the water. Jellyfish have no real control over the direction in which they travel so they must be carried passively by the ocean's currents. Jellyfish do rise and fall in the water in reaction to light, temperature, and changes in the water's salt content.
Some fish feed on jellyfish, but the fish shown here are living with the jellyfish for protection. Sometimes these fish learn to avoid the jellyfish's stinging tentacles. In other cases, the jellyfish gets used to certain individual fish and does not sting them. The fish that are most commonly found living with jellyfish are usually young jacks and butterfishes. As these fish get larger, they leave the protection of the jellyfish and live in large schools along the coast. One kind of fish, the man-of-war fish, lives its whole life among jellyfishes.
To many divers, nothing is more beautiful than the sight of a giant kelp forest swaying gently in the ocean waves. Found in temperate waters, such as those off the coast of Northern California, these underwater forests are made up of long strands of kelp that stretch as tall as 100 feet from the ocean floor. Giant kelp, as these plants are called, is a type of brown algae. It has the distinction of being one of the fastest growing plants in the world. In some kelp forests, the kelp strands grow 100 feet a year and sometimes as much as two feet in a single day. Because they are algae, kelp has no roots. To remain in one place, kelp anchor themselves to the bottom of the sea floor with thin, sturdy tentacles.
Kelp forests are home to hundreds of different kinds of marine life. Seals and otters dart among the kelp strands as they look for fish and other animals to eat. Starfish move slowly along the sea floor in search of shellfish. Brightly-colored Garibaldi fish wriggle among the bottoms of kelp plants trying to attract their colorful mates. Some animals like the kelp fish have changed over many years so that they look almost exactly like a kelp leaf. Kelp forests are very delicate environments. When the sea otter was nearly hunted into extinction, sea urchins -- which sea otters eat -- began to spread rapidly. As their populations grew, the sea urchins ate the bottoms of the kelp plants, destroying many kelp forests in the process. Now that the sea otter is beginning to increase in numbers again, sea urchins are disappearing in some places, and the kelp forest is making its return.
«Killer Whale: Friendly Killer
Length: 33 Feet/10 Meters;Depth: 30 Feet/9 Meters
ALASKA
Killer whales (also called orca) have had a bad reputation ever since the great whaling days of the 1700s. Orcas were then thought of as ferocious killers, swallowing adult sea lions whole, capsizing fishing boats and viciously attacking larger baleen whales, often trying to tear out their tongues. Today, however, we know that the killer whale is in fact a "gentle" predator, a fierce hunter who likes human company and can often be taught to do special tricks in zoos or aquariums.
Killer whales are easily recognized by their black and white markings and their large, teeth-lined jaw. Killer whales have 40 - 56 very powerful teeth that can measure up to four inches long and have a diameter of one to two inches. These whales can swim at speeds of close to 30 mph and can dive to over 3,300 feet, sometimes remaining underwater for 20 minutes or longer.
Killer whales live all over the world but are mostly found in the oceans of the Arctic and Antarctica. They will usually travel in groups of up to 15, and their diet includes sea lions and seals, penguins and turtles, octopus, squid, various species of fish and even other whales. The killer whale has only one enemy: man.
The patient yet aggressive hawkfish takes its name from its "wait and watch" style of hunting. Hawkfish generally live among the lower branches of coral reefs where they will rest and wait for potential prey. When something appetizing approaches, the hawkfish will pounce without warning to devour its dinner.
This particular hawkfish has a very elongated snout and a beautifully patterned body. Hawkfish are easily approached by humans, although they are sometimes hard to spot among the coral "trees." The long-nosed hawkfish lives in the Southwest Pacific and because of its unique markings has become a very popular aquarium fish. Hawkfish are carnivorous and feed mostly on crustaceans.
éSun and Ocean: The Importance of Light
Length: NA;Depth: NA
INDIAN OCEAN
Although living organisms are found throughout the oceans, their diversity and abundance vary considerably from area to area. The basis of all life is light energy, which is converted into chemical energy by photosynthetic organisms. Because most of the light falling on the oceans is absorbed within the surface layers, the zone of highest productivity in the tropics occurs within 100 feet of the surface. Their surface waters are also where the oxygen needed for respiration and the carbon dioxide needed for photosynthesis are absorbed into the seas from the atmosphere above.
In deeper waters, life is less abundant, limited by the absence of light and lower oxygen concentrations. In some specialized deep sea environments, underwater volcanic vents release sulphur-bearing chemicals which are used by chemotropic bacteria as a source of energy. Another source of energy and food in deeper waters is "fecal rain," falling from the upper layers of the ocean. This rain is made up of the remains of dead animals and plants and the waste products of organisms living near the surface. ...FROM "THE RANDOM HOUSE ATLAS OF THE OCEANS"
Slow and elegant, the lionfish is one coral reef inhabitant you don't want to cuddle. While their colorful stripes and long arching fins make them favorites of aquarium collections, the lionfish's spines are loaded with venom. An injection of venom from a lionfish can be deadly and will always make you very sick.
Lionfish live in the warm waters of coral reefs around the world. The most colorful and interesting-looking lionfish come from the Indian Ocean and the western Pacific. Like its cousin the scorpionfish, lionfish are hunters that like to remain motionless until a favorite meal passes by. During the day, lionfish remain near rocky outcroppings, but at sundown they leave their hiding place to hunt for their favorite meals such as small fish, shrimp and even crabs.
A lionfish's mouth is large enough to swallow animals nearly as large as its own body. Unlike many of its relatives, the lionfish doesn't rely on camouflage to hide from predators. Instead, it uses its bright colors and distinctive patterns to remind hungry predators that it is poisonous. Even if fish are not very smart, they usually have enough brain power to recognize a poisonous animal like the lionfish.
If patience is a virtue, then the lizard fish must be a very virtuous fish. When a lizard fish gets hungry it will often sit without moving for hours on the ocean floor while waiting for its favorite prey, a small flatfish or a shrimp. To make itself nearly invisible, lizard fish usually bury every part of their body under the sand, except their head and eyes. At the moment a small fish swims by, the lizard fish uses its pectoral fins to leap out of the sand and grab the fish with its strong mouth. This happens so quickly that it is almost impossible to see with the naked eye.
There are several different kinds of lizard fish which live in warm and cold ocean waters around the world. Most of them live at depths of 60 to 100 feet and have skin colors that blend in perfectly with the sand and plants of their habitat.
Slipper lobsters are sometimes called shovel lobsters because they have a trowel-shaped front end that is used for digging into the soft sand or gravel of the sea bottom. The front of the slipper lobster's body differs greatly from the front end of spiny or Maine lobsters which are developed for life in rocky environments. Many of the lobster tails people buy in stores now come from the slipper lobster. That's because other popular lobsters such as the Maine lobster have been greatly reduced in numbers by heavy fishing. Slipper lobsters are caught by dragging wide-bottom fishing nets called trawls over the sand or gravel. The spiny and Maine lobsters are caught in large wire and wooden traps that are baited with dead fish. These traps float in the water for a day or two, before they are pulled up and the live lobsters are removed. The traps have backward, funnel-shaped baffles that allow the lobster to enter. Once inside, however, the animal can't figure out how to get back out.
Lobsters are members of a group called arthropods that includes shrimp, crabs, spiders, and insects. "Arthro" means jointed, and "pods" mean feet or legs. Lobsters have hard outer skeletons that they must shed to grow. This hard shell, or exoskeleton, contains lots of calcium salts, making it very rigid. When the lobster sheds its skin, or molts, most of these salts leave its body. This makes the animal very soft for a day or two while it sheds the skin. While a lobster is soft, it is very easy for other animals like octopuses to eat it, so lobsters usually hide away when molting. Lobsters generally eat other animals smaller than themselves, using their strong claws to pry open their prey or tear it apart.
The mother lobster carries thousands of small eggs under her abdomen until they develop into larvae that hatch into the water. The larvae drift around for weeks in the plankton and are protected because they are invisible. When the larvae transform into small lobsters they settle into areas where they can seek a safe hideaway in the reef. Lobsters are thought of as secretive by day and easier to find when diving at night. In the good old days in Hawaii, Florida, and the Great Barrier Reef in Australia, people used to talk about walking to the reef edge and seeing hundreds of pairs of lobster antennae sticking up out of the water in the shallows. They could just walk out in knee deep water and pick out their dinner! Obviously, those days are long gone. Today many rules and regulations govern fishing of lobster. In a few areas, considerable work is being done to raise lobsters in captivity and increase the numbers where they have been fished to near extinction.
The longnose filefish takes its name from its protruding snout and its scaly, rough skin that feels just like sandpaper. The filefish has a compact body with two dorsal fins, one of which is peculiarly situated almost right above the eyes. Its strange skin is covered with spiny plates and has the unique ability to change its color with ease, depending on its environment or particular emotional state. For this reason the filefish is a popular aquarium fish.
There are several different species of filefish, but all live along coasts, mostly in tropical regions. They are smallish, 7 to 11 inches long, and have a habit of hovering, like a hummingbird, in one place. They feed on algae and small crustaceans and, by rubbing their lower teeth against the inner sides of their upper teeth, are actually able to make sounds that are recognizable to other ocean dwellers.
The mackerel, along with the tuna, is one of the commercial fishing industry's most valuable fish. Each year, hundreds of thousands of tons of mackerel are caught by fishermen and turned into food for people all over the world.
The mackerel is a fast open ocean fish, swimming in giant schools over long distances of a thousand miles or more. Found in warm and temperate waters throughout the ocean, mackerels are perfectly adapted for high-speed, efficient swimming. Their bodies are streamlined and tapered into a shape known as fusi-form. This particular type of body shape allows the mackerel to swim at great speeds while expending little physical energy.
Mackerels live on a diet of shrimp, small fish and squid. To keep fed, giant schools of mackerel, must constantly follow large schools of small fish and shrimp wherever they may appear. The benefit for the mackerel of swimming in such large schools is that predators like sharks have a difficult time attacking individual mackerels.
Mermaids with moustaches? It seems surprising that the manatee, or sea cow, could belong to the order Sirenia which takes its name from the sirens or mermaids of ancient folklore. Anyone who has ever seen a fat, whiskered manatee would hardly liken it to a beautiful mermaid of legend. But then again, beauty is in the eye of the beholder.
Manatees are aquatic mammals that live in tropical and subtropical coastal waters throughout the western Atlantic. Their two frontal flippers are equipped with claws, and instead of hind legs they have a single horizontal tail flipper. Manatees have big, rubbery lips and a very flexible muzzle, good for grazing on the water plants that make up their diets. The hair on their muzzle is thick and coarse, almost like walrus whiskers.
A female manatee is pregnant for 13 months before she gives birth. A baby manatee weighs 33-44 pounds and measures over three feet. The mother manatee is a very affectionate parent and will spend hours playing with her baby. Sometimes she will even give it a ride on her back.
[Manta Ray: The Good Devil
Length: 19 Feet/5 Meters;Depth: 66 Feet/20 Meters
CAYMAN ISLANDS
For centuries it was thought that the manta ray or "devilfish" was an evil ocean beast capable of destroying fishing boats and devouring people. In fact, the manta ray is one of the gentlest creatures in the sea whose only wish, it seems, is to float peacefully in the water sucking in mouthfuls of water in search of its favorite food -- plankton.
It's understandable why people have been frightened by this tremendous fish. The manta ray is the largest member of the ray family and can measure up to 19 feet long and weigh as much as 2,300 pounds. Some manta rays have been caught that measure an unbelievable 23 feet across. This giant sea creature takes its name from the Spanish word "manta" meaning blanket. With its enormous black fins extended, the manta ray really does look like a huge floating blanket.
Manta rays live mainly in tropical waters and feed on zooplankton and small fish and crustaceans. Like other rays, the Manta has a skeleton made out of cartilage instead of bone, and its nostrils, mouth and gill slits are ventral, or located on its underside. Manta rays can be found browsing through sandflats in search of food or, sometimes, leaping clear out of the water. Manta rays give birth to live young. When their babies are born they are wrapped up in their little wing flaps like pigs in a blanket. Baby manta rays are called "pups."
Manta rays usually swim in pairs, and although they may seem frightening, manta rays are so gentle that many will even let humans pet them. Some experienced divers have actually taken rides on the backs of these beautiful, harmless fish.
╛Blue Marlin: Making a Point
Length: 12 Feet/3 Meters;Depth: 50 Feet/15 Meters
CALIFORNIA
Few fish in the ocean can keep up with a blue marlin and its close relative the sailfish. Swimming near the surface of the water, these powerful fish can reach top speeds of up to 30 miles an hour and some people claim to have seen marlins swim as fast as 40 miles an hour. That's nearly as fast as the fastest speed boat. Blue marlins and sailfish are also well known for the dramatic way in which they leap great distances out of the water and then come crashing down with a giant splash.
Blue marlins are found in warm and temperate ocean waters around the world. Generally, marlins spend their time swimming near the coastline rather than the open ocean, but are known to migrate great distances to feed and spawn. Blue marlins are quite similar to their relative the sailfish, except that the dorsal fin on a blue marlin's back is much shorter than the giant sail-like dorsal fin of the sailfish. Of the two species, blue marlins are the largest. Female blue marlins, which can reach weights of 2,000 pounds, are much larger than male blue marlins, which rarely get bigger than 300 pounds.
When the blue marlin's close cousin the sailfish is not racing through the water at top speeds, it will raise its sails out of the water and let the wind carry its body along in the ocean currents.
Marlins are sociable animals and sometimes gather together in groups of forty or more to hunt or mate. Marlins are also extremely aggressive hunters that feed on squid and large schooling fish such as tuna. Marlins make good use of their swordlike snout by rounding up schools of fish and then slashing them with their sword when the fish are close to the water's surface. Marlins then move in and eat any of the injured fish.
Because of their tremendous strength and speed, sports fishermen have long loved trying to catch blue marlins with a hook and reel. Some fisherman have spent eight hours at a time battling to bring a single marlin in on a fishing line.
╥Mediterranean Sea: Europe's Bath Tub
Length: NA;Depth: 16,801 Feet/5,121 Meters
MEDITERRANEAN SEA
The Mediterranean Sea is an almost completely enclosed sea covering an area of 0.98 million square miles, and with a mean depth of 0.93 miles. It is linked to the Atlantic through the Strait of Gibraltar, to the Black Sea by the Dardanelles and to the Red Sea by the Suez Canal which was opened in 1869. Water entering the Mediterranean remains there for 150 years or more before being flushed out.
Atlantic water, which enters the Mediterranean through the Strait of Gibraltar, has a greater volume than the outflow of more saline, cooler Mediterranean water. According to legend, this deep-water current was harnessed by the ancient race of people known as the Phoenicians, who lowered the sails of their ships several fathoms into the sea to enter the Atlantic against surface currents. Today, this strong underwater current is used by submarines, which can turn their engines off to pass silently through the strait.
The impact of the warm Mediterranean climate leads to a transformation, over decades, of the Atlantic water which enters the basin. The most marked change is in salinity, which increases as you travel east. In summer, the warming of surface waters leads to a marked temperature change which separates the warm, water with high levels of salt and the cooler less salty water.
The warm, dry Mediterranean climate means that the amount of water lost through evaporation exceeds the amount entering the sea from precipitation and runoff. The Black Sea which is at the east end of the Mediterranean has a low level of salt compared with the Mediterranean.
The Mediterranean is one of the world's busiest seas. Over 70 percent of the world's tourists are drawn by its sandy beaches, historical sites, food, wine and warm dry climate. It is also a major shipping route, particularly for oil from the Middle East. The current population of the countries around the Mediterranean coast numbers some 360 million. ...FROM "THE RANDOM HOUSE ATLAS OF THE OCEANS"
If anyone worships the beautiful Moorish idol, it is the marine photographers who always take its picture. Found in the shallow waters around tropical coral reefs, the Moorish idol is a member of the same large family of tropical fish as the surgeonfish. Moorish idols have a tall, thin body with a slightly protruding snout. This type of body shape helps the Moorish idol maneuver easily among coral reefs when searching for food or hiding from predators. Moorish idols can be easily recognized by their distinctive yellow, black and white stripes and their elongated dorsal fin which stretches backward like a graceful feather.
Moorish idols spend most of their time swimming alone or in pairs as they pick algae and tiny invertebrates off pieces of coral. When it is time to mate, Moorish idols gather in large schools, perhaps because it is easier to fertilize their eggs.
The mushroom coral can be easily confused with a sea anemone. It has long, waving tentacles and varies in color from brown to green. Each of its many tentacles has white colored tips. But unlike its neighbor the anemone, the mushroom coral's tentacles are extended both day and night. The mushroom coral is also able to move around by using its tentacles in a spider-like motion. Mushroom corals are carnivorous but they will also feed on plankton. Mushroom corals can be found at depths of three to 66 feet, and inhabit areas in the Indian and North Pacific oceans.
The nautilus is a member of an ancient group of animals known as nautiloids, whose ancestors swam in the ocean hundreds of millions of years ago. Related to the octopus and squid, the nautilus is the only species in the class of animals known as cephalopods to have an external shell.
The nautilus is an active swimmer. It moves by drawing water into its shell through a hole in its mantle and pushing the water out through a hole near its mouth. The force of the water being expelled propels the nautilus quickly through the ocean. Each of the different chambers within the nautilus's shell is filled with gas. By adjusting the amount of gas in each chamber, the nautilus can rise or sink at will. The nautilus spends most of its day bumping along the ocean floor at depths of 600 feet or more. At night, however, the nautilus rises vertically to hunt for crab and other invertebrates found in the shallow waters of a coral reef.
ÑNorth Atlantic Basin: Hot and Cold
Length: NA;Depth: 20,751 Feet/6,325 Meters
NORTH ATLANTIC OCEAN
The North Atlantic is divided into two basins by the Mid-Atlantic Ridge, an undersea mountain range. The ridge was formed by the upwelling of volcanic material from beneath the Earth's crust, and in some places -- such as Iceland and the Azores -- it rises above the ocean surface.
The waters around Greenland and Svalbard are major sources of bottom water -- the cold, dense water which flows along the ocean floor. North Atlantic bottom water comes from the meeting of cold water from the Arctic Ocean with warm water from the Gulf Stream. Cold winds chill the mixed water, which then sinks to the bottom. These are extremely rich in nutrients and are important feeding grounds for fish, marine mammals and sea birds.
The surface currents of the North Atlantic are dominated by the North Atlantic Gyre, a roughly circular system driven in the south by North-east Trade Winds and in the north by the winds known as the Westerlies. The most important part of the North Atlantic Gyre is the Gulf Stream. This fast-flowing current of warm water is formed by the junction of the Antilles and the Florida Currents at the Florida Straits. From here it flows northeastward along the coast of the United States at about five knots. Around Long Island it turns eastward across the Atlantic Ocean, and becomes known as the North Atlantic Current.
In the southwest of the North Atlantic region lies the Sargasso Sea, an area of warm, clear water bounded by a clockwise current system. The most famous feature of the Sargasso Sea is its drifting, wind-blown seaweed, which floats in the water, supported by numerous small air bladders. Sailing vessels often have to negotiate areas of the weed, which could stretch for considerable distances. The Sargasso Sea is also the spawning ground for the European eel and the American eel. Both species inhabit coastal waters and rivers, but migrate to the Sargasso Sea to reproduce. During the autumn the European eel crosses the Atlantic in as little as 80 days, reaching the Sargasso Sea in February. Spawning occurs as deep as 3,940 feet below the surface of the ocean. After they are born, the young eels, known as elvers, take about two and a half years to reach the European coast. The American eel takes only one year to complete its migrations from the Sargasso Sea to the North American continent. The North Atlantic is also home to some of the most threatened species of marine mammals, including the bowhead whale, the humpback whale and the northern right whale.
The North-East Atlantic includes the busy coastal waters around western Europe, a wide continental shelf surrounding the British Isles, and the North Sea. Linked to the North Sea is the shallow basin of the Baltic Sea. The warm Gulf Stream, or North Atlantic Drift, ensures that the waters of the region remain ice-free year round.
The temperate waters support a rich coastal fishery. Annual catches averaged nearly three million tons from 1985 to 1987. The total amount of fish that can be caught each year without the total population of fish declining could be as high as 4.3 million tons. The most important species for the region's fisheries is the herring. This valuable species was initially caught using drift nets, but the fishing became more intensive with the use of trawls.
From the 1960s onward, the use of large wide, fishing nets known as purse seine nets, led to over-fishing, and the eventual decline of many fish populations. In 1976, a complete ban was imposed on herring fishing, a measure that has stimulated some recovery. Stocks of many other commercial fish such as mackerel, haddock, whiting, saithe and Norway pour are still in decline.
Fish species support large populations of sea birds and seals. Important breeding populations in the region include the fulma, gannet, shag, great skua, lesser and great black-backed gulls and razorbill. Northern populations of birds from Arctic Canada and Siberia may spend the winter in the North Sea, while other populations migrate southward.
The habitats of birds which live by the water, better known as waterfowl, include numerous river deltas and the Waddenzee, a shallow portion of the North Sea surrounded by the West Frisian Islands, and the coasts of the Netherlands, Germany and Denmark. River deltas in the United Kingdom alone support around 1.5 million wading birds, or about 40 percent of the European total.
Three species of seal are found in the Northeast Atlantic region. The most numerous is the grey seal, whose numbers have increased since the 1940s. An estimated 92,000 live around the British Isles; however, numbers in the Baltic are declining. In 1988, the harbor seal was severely affected by the sudden appearance of disease which caused nearly 18,000 deaths. The ringed seal is found in the northern and eastern parts of the Baltic. Its population has declined from more than 100,000 at the start of the 20th century to around 7,000 today. ...FROM "THE RANDOM HOUSE ATLAS OF THE OCEANS"
VNortheast Pacific: Let's Go Surfing Now
Length: NA;Depth: 22,115 Feet/6,741 Meters
NORTH-EAST PACIFIC OCEAN
The Northeast Pacific coast extends from Alaska through the densely populated state of California to the tropical waters off southern Mexico. Major urban-industrial centers include Vancouver, Seattle, San Francisco, Los Angeles and San Diego.
The fisheries of the Northeast Pacific are not nearly as productive as those of the west. In terms of quantity, the Alaska pollock is the most important single species. However, the number of fish caught each year amounts to only about 20 percent of that in the Northwest Pacific. Other commercially important species include the Pacific salmon, the yellowfin sole, and the Pacific cod. As in the Northwest Pacific, bivalves dominate shellfish catches.
The rich kelp forests along the California coast support a variety of animals, which include animals such as abalone, spiny lobster, sea bass and red urchin. The giant kelp itself produces algin, a sticky substance which is used as a thickening ingredient in the food industry.
The islands of the Northeast Pacific support a number of endangered and vulnerable populations of marine birds and mammals. The only known population of the Guadelupe fur seal lies on Mexico's Guadelupe Island west of Baja California.
There has been a steady reduction of the California Sea Otter population. Initially, this was due to fur trapping, but later through the loss of habitat and food.
The region's coastal waters have become polluted especially around major cities such as Los Angeles and San Francisco, leading to problems of contaminated seafood. ...FROM "THE RANDOM HOUSE ATLAS OF THE OCEANS"
F Northwest Atlantic: American Waters
Length: NA;Depth: 21,430 Feet/6,532 Meters
NORTHWEST ATLANTIC OCEAN
The North Atlantic Ocean extends from tropical to chilly, icebound Arctic waters. Most of the world's major industrial countries lie on its shores. As a result, it is one of the world's busiest shipping areas. The North-West region of the Atlantic takes in the coastal waters of the eastern United States and Canada.
From its origins in the Caribbean Sea, the Gulf Stream carries warm water north from the tropics and then eastward to Europe. The broad continental shelf of the Northwest-Atlantic supports one of the richest fisheries in the world. It is narrower near Delaware and Chesapeake Bays which, with the Gulf of Maine, are exceptionally productive because of their extensive salt marsh systems. Great glaciers shaped the coastal landscape of the Northwest Atlantic region. The coasts of Maine and the Canadian provinces of Nova Scotia and Newfoundland are rugged, with numerous small rocky islands. Narrow estuaries lined by salt marshes are characteristic as far south as the New York Bight, and mark the furthest limit of glaciation during the last Ice Age, which ended around 10,000 years ago. Cape Hatteras is the southern limit of cold temperate fauna and the northern limit of tropical fauna. Some scientists regard the transition zone between Cape Cod and Cape Hatteras as a separate region, but there are few endemic species.
In the coastal plain area, extensive salty marshes have developed behind the barrier beaches of Long Island, New Jersey and North Carolina. These areas provide an important wildlife habitat. Salt marshes act as feeding and wintering grounds for many species of wildfowls and shore birds. However, marshes are increasingly threatened by industrial pollution, dredging, land reclamation, drainage and river control.
The cord grass is the dominant plant in salt marshes from Florida to the Bay of Fundy. Other primary producers include single-celled algae known as plankton, which bloom in the nutrient-rich waters of estuaries and support consumers. The eelgrass grows below the tide limit. Its roots help to stabilize bottom sediments and it is important as a fish nursery. The dominant alga over much of the coastline is the knotted wrack which occurs as far as 40 degrees south and as far north as the Arctic Circle. The Gulf of Maine is an important feeding area for many marine mammals, including the northern right whale, which is believed to be the most endangered of the large whales.
The current annual total weight of fish caught for the purposes of commercial fishing is around three million tons - close to 75 percent of the amount of fish that can be caught each year without decreasing the size of the fish population over time. Fishing is central to coastal communities in Nova Scotia, Newfoundland and the Gulf of Maine. The most productive fishing grounds are the Grand Banks. Cod, flounder, haddock, pollock and scallops are harvested on Georges Bank. Four thousand lobster boats operate in the Gulf of Maine. Farther south, striped bass, bluefish, mackerel, menhaden, clams and crabs are caught. ...FROM "THE RANDOM HOUSE ATLAS OF THE OCEANS"
¡ Northwest Pacific: Sushi Central
Length: NA;Depth: 34,586 Feet/10,542 Meters
NORTHWEST PACIFIC OCEAN
The North Pacific Ocean extends from the Equator to the Bering Strait, the narrow passage which links the North Pacific to the Arctic Ocean. On its western edge lie the heavily populated countries of China, Korea and the island groups of the Philippines and Japan. In the northwest lies the Kamchatka Peninsula.
A massive clockwise circulation drives the waters of the North Pacific, and carries warm southern waters northward along the coast of mainland Asia. In the east, cooled water flows southward along the west coast of the United States and Mexico. The range of temperature is much more marked on the western coasts. Over 50 species of marine mammals are found in the North Pacific, including the polar bear, fur seals, the walrus, dolphins and the sea otter. Threatened whales include the bowhead whale and the northern right whale, believed to be near extinction in the Northeast Pacific.
The North Pacific albacore tuna undertakes one of the longest fish migrations. In less than a year, it travels the 5,300 miles from California to Japan. The United States and Japan operate the two largest tuna fisheries and harvest the albacore at both ends of its migration journey. Most tuna meat is canned but the raw flesh of old fat tuna is particularly prized in places like Japan.
As a result of climate conditions and ocean currents, the fisheries of the Northwest Pacific are among the world's most productive. The joining of the warm, north-flowing Kuoshio Current and the south-flowing Oyashio Current helps support an enormous number of different fish species.
The most important marine animal for fisherman in this region is the Alaska pollock. The two species which dominate open ocean fishing are the chub mackerel and the Japanese sardine. The Japanese sardine fishery underwent explosive growth during the 1970s. The sardine is caught primarily in the warm waters of the Kuroshio Current and Tsumima Warm Current region. Over the years, populations of sardines have fluctuated greatly for sometimes mysterious reasons.
Industrial pollution, domestic sewage and agricultural runoff have a large impact on inshore fishing. As a result of the runoff of fertilizers and sewage, algae has grown rapidly in some areas of the Northwest Pacific. Red tides, which are sudden increase in the populations of single-celled algae, are now an annual occurrence in the Inland Sea of Japan. ...FROM "THE RANDOM HOUSE ATLAS OF THE OCEANS"
This regal member of the wrasse family is easily recognized by the splendid markings around its head. Like most wrasses, the Napoleon wrasse is quite territorial. It is also very bold and can be easily approached by divers. The Napoleon wrasse's gorgeous color pattern makes it a popular subject for underwater photographers. This particular wrasse certainly seems to crave the limelight.
The wrasse family of fishes is made up of many different kinds of species which are among the most colorful of all fish. Some of the smaller wrasses are known as "cleaner fish" because they spend their days in the jaws of much bigger fishes, picking out pieces of old food and parasites from between teeth, fins and gills. The host fish gets a cleaning and flossing, and the tiny wrasse gets a free meal.
EOctopus: Quick Change Artist
Length: 6 Feet/2 Meters;Depth: 82 Feet/25 Meters
MEDITERRANEAN
How many times have you wished you could change the color and pattern of your skin? The octopus, and its cousins the squid and cuttlefish, can do just that. Using a special pigment cell in its skin, an octopus can change colors almost instantly. To do this, an octopus must rely on its highly-developed eyesight and complex brain to determine the appearance of its surroundings and then to select the right color for its skin.
With its flexible body, an octopus can hide itself among the rocks and sand of a coral reef until it is nearly invisible. When an unsuspecting fish or crab wanders by, the octopus strikes, jetting out from its hiding place and grabbing its prey with long, powerful tentacles.
Normally, octopuses use their long arms to crawl stealthily across the ocean floor. In emergencies, however, an octopus can propel itself through the water by taking in water through an opening in its head and expelling the water rapidly out of a separate opening. Another defense the octopuses has is to squirt an inky substance into the water which clouds an attacker's vision. Octopuses have among the most complex brains of any undersea animal. Not only can an octopus see well in fairly dark water, but it has a very well-developed sense of touch which allows it to pick up even tiny objects with its long tentacles.
Few animals in the ocean have a nervous system as elaborate and complex as that of the octopus. Without a shell for protection, the octopus must rely almost entirely on its wits and its powerful tentacles to defend itself and to hunt for prey.
The brain of an octopus consists of a large concentration of nerves in its head called a ganglion. This primitive brain is connected to a network of nerves that runs throughout the octopus's body and arms. Much of what the octopus's brain does is process huge amounts of visual information that come through its highly sensitive eyes. The octopus can see extremely well in either light or dark. The ability to see well not only helps the octopus in locating crabs and other crustaceans which the octopus lives on, but also helps the octopus figure out quickly the color of its environment so that it can change the color of its skin to match its surroundings.
The octopus also has an incredible sense of touch which allows it to sense very tiny objects and then manipulate them with its tentacles. The most amazing feature of the octopus brain, though, is the ability to remember things and even experiences.
?Ocean Origins: Evolution of the Oceans
Length: NA;Depth: NA
HAWAII
The oldest known rocks on the planet are thought to have solidified almost 4,200 million years ago, but the oldest rocks on the ocean floor are only 200 million years old. How can that be? The first water probably appeared as vapour, one of the many gases expelled from the Earth as it began to cool. This gas later condensed to form the great oceans.
The first life forms appeared in the oceans between two and three million years ago. This occurrence had an important effect on the chemistry of the oceans, of the atmosphere and on the evolution of all organisms. The early atmosphere lacked oxygen, but the development of new life produced oxygen as well as an ozone shield in the earth's upper atmosphere. This set the scene for the evolution of present life forms. ...FROM "THE RANDOM HOUSE ATLAS OF THE OCEANS"
Few animals in the sea are as colorful or as interesting as the unassuming nudibranch. This flat-bodied creature is a member of the mollusk phylum, making it a close relative to the squid and octopus. The nudibranch has a soft body that grows no longer than three or four inches. Similar to a snail, it has a head at one end of its body and an anus at the other. The nudibranch's gills consist of two small vertical stalks with what looks like a small flower at the end of each. The nudibranch can be found crawling or swimming along the bottoms of both warm and cool water oceans as it searches for sponges or stray pieces of organic matter to eat.
Nudibranches come in a stunning array of brilliant colors and patterns. Some, like this orange nudibranch, are covered by a bright solid color while others are covered by wild patterns of yellow, blue, and even purple stripes, circles and dots.
Without a shell, nudibranches look as if they would be any animal's quick meal. Their soft bodies offer little in the way of protection and they have no means of grabbing an attacker like an octopus does. But nudibranches are far tougher than they first appear. Many nudibranches, for instance, excrete a mucus that smells unpleasant to man and is distasteful to many fish. The mucus of some nudibranches is even mixed with sulfuric acid, which does not digest well.
When in danger, nudibranches can also make a hasty retreat by undulating their body in a way that creates a rippling effect in the water and propels them forward. If part of a nudibranch is bitten off, it can regenerate the part in a matter of weeks.
Most interesting of all, some nudibranches are immune to the sting of anemones and can absorb the stinging cells from the sea anemone and then incorporate them into their own skin to be used against an attacker.
With all of these defenses, a nudibranch's vivid colors help advertise its presence to potential predators.
For centuries, dolphins have enchanted men with their playful nature and stunning displays of intelligence. Dolphins, like whales and porpoises, are members of the family of oceangoing mammals known as cetaceans. They are warm-blooded, breathe air through a blowhole located at the top of their head and bear live young. Dolphins inhabit both warm and cool waters around the world's oceans. With their muscular, streamlined bodies, dolphins are fast, agile undersea swimmers. They can easily out-race most fish and are often seen keeping pace with high-speed motorboats. Dolphins travel together in closely-knit family groups as well as in large packs. Dolphins like to swim beneath giant schools of tuna, feeding on the same small fish that tuna eat. Unfortunately, many dolphins are killed each year in fishing nets meant for schools of tuna.
Some scientists believe that dolphins may be among the smartest animals on the planet. A dolphin's brain is nearly as large as a human's brain. Not only can dolphins learn complex tricks, but some dolphins have been taught to communicate in simple languages. Much of a dolphin's brain is used for navigation. Dolphins find their way through the ocean by using a form of sonar known as echolocation. Dolphins do this by making a noise that sounds like a click. By listening to the returning echoes from these clicks, dolphins can determine what objects look like and how far away they are.
Among the most beautiful inhabitants of a coral reef is the brightly-colored parrot fish. Like the bird with whom it shares a name, the parrot fish lives almost exclusively in the tropics. It has a curved hard "nose" which it uses to scrape algae and coral organisms off rocks and a set of large, tough teeth near its throat which it uses to chew its food. The parrot fish's throat teeth, as they are called, are fused tightly together to form two solid, bony plates that are perfect for grinding coral into tiny grains of sand. Parrotfish are responsible for creating much of the sand that surrounds a coral reef.
When they sleep, parrotfish secrete a transparent mucus around their body. This "sleeping bag," as some people like to call it, keeps the parrotfish's smell from reaching the noses of predators in the coral reef. Perhaps its most serious predators, though, are snorkeling tourists who seek the fish out for its beautiful colors and want to take its picture.
Most fish think twice before making a meal of a porcupine fish. By swallowing large amounts of water or air very quickly, a frightened porcupine fish can puff its body up to several times its normal size. This instinctive response to danger makes the porcupine fish too big for most predators to consider swallowing. And with its pointy spines sticking straight out, a porcupine fish would cause any predator a good case of indigestion. If that's not enough of a defense, the porcupine fish's flesh is poisonous to most animals, including humans.
When a porcupine fish is not frightened, its body is long and oblong-shaped and its pointy spines rest along its back. Most commonly found in coral reefs, the porcupine fish spends its days swimming along the sandy bottom looking for small crabs and shrimp to eat. Because its body is covered with thick skin and spines, the porcupine fish can only swim very slowly using its tiny feather-like pectoral fins.
Who says fish are the silent types? If you were out in a boat in the middle of an excited school of porkfish you might just complain about the noise pollution they were making. Porkfish are members of a family of tropical fish known as grunts that make a distinct grunting sound, almost like a pig, when they rub their teeth together. This sound is amplified further by the porkfish's swim bladder and can be heard underwater by nearby divers. Sometimes the noise from a large group of grunts is so loud that people in boats above water can actually hear the sound of grunts.
Porkfish swim in large schools around tropical and subtropical coral reefs. They are wider and more colorful than most other grunt species, with several bright orange and dark stripes that cross over their head and eyes.
Young porkfish look quite different from adult porkfish. A young porkfish has large horizontal stripes and other dark markings which disappear as they become adults. Porkfish generally like to feed on invertebrates such as shrimp and small squid. One unexplained behavior that most grunts, including porkfish, engage in -- is kissing. When two grunts find themselves face to face, they will open their mouths wide and push them together until they are nearly touching. This gives the odd impression that they are kissing. Some people think it is the first part of a mating ritual, while others believe it is an act of aggression between two territorial males or females.
Sponges are one of the simplest of animals on the planet. They consist of collections of similar cells held together by prickly, needle-like spicules. These minuscule spicules can be made of glass or limestone-like material. Sponges collected for home use do not have these hard spicules, so their skeletons are spongy and bounce back after they are used. With the development of plastic sponges for household use, however, the need to harvest living sponges has dropped considerably.
If sponges with spicules are handled carelessly, they can cause rashes and the spicules can become imbedded in your flesh. Aside from providing support for the sponge animal, the spiny spicules help keep predators away. Many sponges have noxious chemicals in their tissue that also deter predators. Some of these "chemicals from the sea" are being investigated for possible use as medicines or as pesticides.
The female redfish (or ocean perch) is sometimes called a "living incubator" because it uses internal fertilization to hatch babies inside its body. There are many different kinds of redfish which can be found in both warm and cold waters. For those redfish which live in the cold Atlantic and Arctic Oceans it is better to fertilize their eggs internally than laying them directly on the cold seabed where they would take a long time to develop. After a redfish's babies have hatched, they must fend for themselves, catching food among floating plankton and waving clumps of seaweed.
Redfish are a medium-sized fish with very long spines. The dorsal fin alone has 15 very distinguishable spines. Redfish can be easily identified by their bright coloring. They also have the peculiar habit of hovering motionless among the floating seaweed in a vertical position, head pointing upward.
There are more than 100 different species of rockfish and fishermen love almost every one of them. Members of a large family of fish known as scorpionfish, rockfish are widely distributed in cool ocean waters throughout the world.
All rockfish have a spiny dorsal fin which runs along half the distance of their back. They also have large eyes and a mouth which sometimes give the appearance of frowning. Rockfish live at all different depths of the ocean, from 200 feet to 2,000 feet. Rockfish are carnivorous. To capture their prey, some rockfish will remain motionless near the bottom of the ocean while other varieties of rockfish such as the ocean perch are fairly active swimmers and will chase their prey at high speeds for short distances.
Red lined shrimp live in caves and on rocks in coral reefs. They have ten walking legs and use their front two legs as pincers for picking up small objects and defending themselves. Shrimp, like the red lined shrimp, eat almost any animal matter they can get their pincers on, including fish, other shrimp, snails, sea anemones, or any of the microscopic animals living on a reef.
Red lined shrimp are known as "cleaning shrimp" because they spend much of their time cleaning tiny crustaceans and diseased tissue off fishes' bodies. This relationship between cleaning shrimp and the fish they clean is quite beneficial to both parties. The shrimp gets a good meal and the fish gets potentially harmful materials removed from its skin. The ritual for a cleaning can be quite complex. First, the shrimp uses its antennae to wave down any nearby fishes that are interested in getting cleaned. The fish communicates to the shrimp that it is ready to be cleaned by assuming an unthreatening posture. The shrimp then clambers aboard the fish, removing or eating any stray parasites from the fish's skin. The shrimp may even enter the fish's gills and dance around near the throat without being harmed. When the shrimp is finished, the fish will move away and another fish will usually be waiting in line to take its place. During the night, the shrimp retires to crevices and caves and remains quiet until the next day, when the cleaning begins again.
■Southeast Pacific: Darwin's Spot
Length: NA;Depth: 20,895 Feet/6,369 Meters
SOUTHEAST PACIFIC OCEAN
The coast of the Southeast Pacific region stretches for about 6,500 miles and its ecosystems vary from the tropical mangrove and coral coasts of the Gulf of Panama to the cold, rocky shores of Chile's fjord region. Numerous fast-flowing rivers cross the narrow coastal plain carrying large amounts of sediment down from South America's highlands to the waters of the Southeast Pacific. The continental shelf is also narrow, measuring no more than four miles wide in the south and extending to a maximum width of 17 miles off the coast of Ecuador.
Offshore, the cold, nutrient-rich waters of the Antarctic Circumpolar Current dominate the region. This current approaches the southern tip of the continent from the west and splits into two major branches, the Humboldt Current and the southward flowing Cape Horn Current.
The Peruvian Current is one of the most productive marine systems in the world. The fish in this system account for nearly 10 percent of the world's catch. More than 16 percent of the total catch of the Pacific Ocean is caught off the coasts of Chile, Peru, Ecuador and Colombia. In 1980, the total weight of the fish and crustaceans caught in these waters amounted to more than six million tons. By 1985, this total had increased to more than nine million tons for Chile and Peru alone.
The development of coral reefs in this region is limited by the cool ocean currents and the high river discharges into the sea. Coral are very sensitive to temperature, fresh water and suspended sediment. Most well-developed coral reef communities are found in the vicinity of islands such as the Secas Islands off Panama, Gorgona Island in Colombia and the Galapagos Islands off Ecuador.
A high proportion of the population of the countries in this region live on the coast, and marine resources provide these countries with much of their food and livelihood. As human populations increase, the environmental problems will grow and become more intense. ...FROM "THE RANDOM HOUSE ATLAS OF THE OCEANS"
West African Seas: Population Explosion
Length: NA;Depth: 20,875 Feet/6,363 Meters
WEST AFRICAN SEAS
The West African seas stretch over 5,600 miles of ocean. The climate varies greatly, from humid and tropical around the Equator to arid in the north and south. Coastal features are also very different, ranging from drowned river valleys to sand dunes, lagoons, mud flats and -- in the far south -- algae beds. The width of the continental shelf beneath the water varies from 45 miles in the Gulf of Guinea to only 2.5 miles off Angola.
Dolphin and porpoise species are present throughout the region, as well as the West African manatee, which is found in rivers, estuaries and coastal areas. The manatee lives in shallow swampy areas where it feeds on submerged plant life. Despite international protection, the manatee is threatened by hunting and accidental deaths in fishing nets.
The coastal areas and lagoons of the West African Seas are important wildlife habitats and are visited each year by millions of migratory birds. Beaches along the coast provide nesting for the green and olive Ridley turtles, and for three other turtle species. More remarkably, over 9,650 square miles of mangroves, extend from the West African coast to Angola.
Because of a rich supply of food, An abundance of fish live in this area of the ocean. The most important fishes are the sardine and the Horse Mackerel. Lobsters are fished for in the north and south of the region. Deep-water shrimp are found off Senegal and Angola.
Fishing is central to the economies of the countries along the West African Sea.
The environmental problems of the region include rapid population expansion, oil pollution, coastal erosion, and the discharge of raw sewage.
The Southwest portion of the Atlantic Ocean ranges from tropical to temperate waters. The Brazil ocean current flows southward along the coast of South America until it joins with the north-flowing Falkland Current at the Rio de La Plata River in Brazil and turns eastward.
The Rio de la Plata River forms an important boundary between warm temperate and cold temperate waters of the Southwest Atlantic Ocean. Tropical marine animals of the north include corals and sea turtles, while the south is home to various species of seals and penguins.
Mangroves, lagoons and estuaries in the north of the region provide nurseries for fish and shellfish. Magellan's penguin, which can be found in parts of southern Brazil, lives farther north than any other penguin. The southern fur seal is found on the Falkland Islands, and on the mainland. The kelp beds of the Patagonian Shelf and Tierra del Fuego, along with those of southern Chile, constitute one of the largest seaweed ecosystems of the world. It is believed that 1,200 of the estimated 1,500 surviving southern Right whales may spend their winters near the Valdes Peninsula. The southern Right whale is well known for its antics, including leaping out of the water and raising its flukes.
Coastal fish benefit from the large quantities of plankton which are created by the mangrove system. Fish that are used for eating include the Patagonian hake, the Argentine anchovy, the common squid, and the shortfin squid. In the warmer northern waters, crustaceans such as penaeid shrimps and mollusks such as the white seabob are more important to fishermen. ...FROM "THE RANDOM HOUSE ATLAS OF THE OCEANS"
An unsuspecting fish swims too close to what appears to be a large sand-covered rock. A moment later, the rock comes to life and swallows the fish. Unfortunately, the rock was not a rock, it was a scorpionfish.
Scorpionfish are one of the great masters of ocean camouflage. Covered by rough spines and loose pieces of skin called "wattles," scorpionfish can blend in almost perfectly with the rocks and seaweed that surround them.
Scorpionfish usually don't grow much longer than a foot, though some have been seen to reach lengths of three feet or more. Scorpionfish have a very large head and a giant mouth which is perfect for snapping up sizable fish in its jaws. The scorpionfish's body then tapers off sharply to a small, narrow tail.
There are several different kinds of scorpionfish. Most of them can be found in the shallow waters around the Atlantic Ocean.
Scorpionfish are solitary fish. Their preferred hunting technique is to sit absolutely motionless on the ocean bottom until a fish or shrimp comes close to its mouth. Then, using its pectoral fins as a lever, the scorpionfish lunges forward and tries to swallow the animal in a single gulp. Scorpionfish will often attempt to swallow animals as large or larger than they are.
To keep predators from trying to swallow them, scorpionfish have highly poisonous spines on their back which can kill or hurt most undersea animals. There is always one unfortunate diver who gets stung as he or she is reaching into rocks or seaweed where a scorpionfish is hiding. The poison is not lethal to humans, but it certainly hurts a great deal.
The spinner dolphin is named after the dramatic way in which it jumps, twisting and twirling, out of the water like a madly spinning airplane. These acrobatics are not performed all the time. During the daylight hours, spinner dolphins are, in fact, very quiet, lazily swimming around inshore bays. But just when the sun goes down, the spinner awakens and the spectacular spinning show begins!
Dolphins are among the most friendly of all the marine mammals and usually travel in groups (or pods) of a dozen to more than several hundred. Spinner dolphins weigh close to 250 pounds and measure up to seven feet long. They inhabit the tropical and temperate waters of the Atlantic, Pacific and Indian oceans. Spinner dolphins feed on fish and cephalopod mollusks which they catch with their tiny, sharp teeth. Because they often hunt for food alongside yellowfin and skipjack tuna, every year thousands of these beautiful creatures are accidentally trapped in tuna nets and killed.
[Sea Lion: Bark is Worse than His Bite
Length: 10 Feet/3 Meters;Depth: 0 Feet/0 Meters
CALIFORNIA
The male sea lion is famous for his loud bark. During the mating season when sea lions are establishing their territories, the male will bark constantly, barely stopping long enough to breathe. A sea lion pupping ground during the mating season sounds more like a dog kennel than anything else.
There are several different species of sea lion, but the California sea lion pictured here is the best known sea lion and is popular in zoos and at the circus. A medium sized creature, it is found mainly along the western coast of North America from Baja California in Mexico, to San Francisco. The males tend to be dark brown in color and the females are slightly yellowish with darker flippers. When sea lions are born, they are almost black. Sea lions feed mostly on squid, octopus, anchovies and herring.
The main difference between sea lions and seals is that the flippers on sea lions look and operate more like real "legs." Sea lions are capable of walking and even running by twisting their hind legs into a slightly forward position, whereas seals must drag their hind flippers behind them.
1Variegated Sea Fan: Reef Bouquets
Length: 6 Feet/2 Meters;Depth: 150 Feet/46 Meters
SOLOMON ISLANDS
Sea fans are cousins to the corals and sea anemones. They have small, anemone-like polyps that are attached to branches made of a skeleton-like material. These tiny polyps are very difficult to see in the daytime when they are folded up and not fishing for plankton. Each polyp has eight arms, or tentacles, instead of six like the corals. The tentacles are covered with a row of branches down each side, like a palm frond. At dusk, the polyps open up like little flowers to catch the small crustaceans that come out of hiding at night. The best place for the sea fan and corals to live is in ocean channels and near the outer face of a coral reef where passing currents carry lots of food in the water.
The sea fan is anchored to the ocean floor or to a hard coral head like a tree or a bush.
Soft Coral: Reef Trees
Length: 7 Feet/2 Meters;Depth: 100 Feet/30 Meters
SOUTH PACIFIC
Soft coral looks true to its name. Its polyps retracted, this coral has a velvety soft appearance. However, it is firm and leathery to the touch. Soft coral lives in shallow waters along the coastal areas of the Indian and North Pacific oceans. It feeds on plankton.
»Blacktip Reef Shark: Short and Feisty
Length: 6 Feet/2 Meters;Depth: 100 Feet/30 Meters
PACIFIC OCEAN
The blacktip shark may not be large, but it is fast and aggressive. Found in the warm waters of the Atlantic and Pacific oceans, the blacktip shark grows to a length of six feet and can be easily recognized by the clear black markings on its dorsal and ventral fins. The blacktip shark is a powerful swimmer capable of moving quite rapidly when it attacks a favorite prey such as a stingray, school of sardines or butterfish. Blacktips are often seen leaping completely out of the water, though no one is quite sure why they do this.
Blacktip sharks are most common in the Gulf of Mexico and the Caribbean where sports fishermen like to try to catch them with a hook and reel. Like all other sharks, blacktips have a skeleton made of cartilage and not bone. Cartilage is lighter than bone and allows sharks to swim farther while expending less energy. Sharks, such as the blacktip shark, are not built for long periods of fast swimming. Most sharks' bodies are best suited to long distance cruising during which very little of their energy is used up. The moment food or danger is nearby, though, a shark like the blacktip is capable of high speeds of close to 20 miles an hour.
Bright red rock crabs or shore crabs are very easy to spot as they scurry along the rugged coastline of oceanic islands. They are very agile and can scamper rapidly over the sharp, jagged lava rocks on their nimble feet. The tips of their eight walking legs have short stiff spines that grab on to the rock and prevent wearing away of the legs on the rough surface. Although the nearby water may be cold, the warm rocks warm the crabs enough so that they can remain very active. They move so quickly that they are very hard to catch by hand. Although they seem to spend all their time out of the water, they must return once in a while to moisten their gills.
Female crabs carry their eggs under their bellies, and will frequently return to the water to keep the eggs wet. When the eggs are ready to be hatched, the female must again return to the water. Baby crabs must spend several weeks in the ocean before they are big enough to take up seashore life. Once they are adults, crabs will only retreat to water as a last resort when chased. To a crab, there is more danger in the waves than on land.
It's hard to believe that this strange looking creature is really a fish. But it is. Seahorses have one of the most peculiar shapes in the fish world. Their bodies are long and covered by a hard armor-like skin that is perfect protection against hungry fish. A seahorse's long snout takes up most of its head and is perfect for sucking up tiny fish and microscopic animals that float along in the water.
One of the seahorses' most interesting physical traits is its prehensile tail, which can wrap around objects like weeds, keeping the seahorse in one place for long periods of time. Seahorses move around by fluttering the tiny dorsal fins on their back and the small fin by their head. They can also change the color of their skin to match their surroundings.
Seahorses also do something that few animals in the world do -- the males carry the babies! When seahorses mate, the female deposits up to 200 eggs in a small pouch in the front of the male seahorse's stomach. After two to six weeks the eggs develop into baby seahorses. At this time, the male seahorse grabs onto a thin weed with its tail and then squeezes out the babies four and five at a time. Measuring only a half inch long, the tiny seahorses float to the surface of the water, take a gulp of air to fill their swim bladders and then begin looking for microscopic animals to eat.
Sea Snake: Poisonous Serpent
Length: 6 Feet/2 Meters;Depth: 60 Feet/18 Meters
SOUTH PACIFIC OCEAN
Sea snakes are very poisonous cousins of the cobras and are well adapted for swimming and living in the water. Many of the 70 or so kinds of sea snakes are very brightly colored. This is believed to be a warning color pattern, like the stripes on a skunk, so other animals can know to avoid them. Sea snakes tend to be flattened from side to side for swimming. In fact, their muscles are so specialized for swimming that it is difficult for these snakes to move on land. Many seafaring people have learned that these flabby snakes cannot curl upward to bite if held by the tail. Sea snakes are usually quite tame and will rarely strike out at humans. Since they must drink salty sea water to live, they also have a salt gland next to their tongue. The gland helps them get rid of the extra salt taken in when they drink.
Sea snakes mainly eat fish. Divers frequently see sea snakes looking into crevices, cracks, and holes in the reef, searching for fishes. Some sea snakes have bodies with thin heads so that they better fit into the burrows of eels and other slender fishes. One kind of sea snake eats only fish eggs.
Most sea snakes give birth to living young. The pregnant females often come into rocky areas or mangrove forests to give birth. These areas provide protection for the young until they can fend for themselves. A few sea snakes go into rocky areas to lay eggs.
South Pacific: Islands Galore
Length: NA;Depth: 36,161 Feet/11,022 Meters
SOUTH PACIFIC OCEAN
The Pacific islands are home to just over five million people. Their combined land area is no greater than 193,000 square miles. The Pacific Basin, where these islands are located, contains some of the world's smallest nations.
Pacific islands range from low-lying atolls, up to 13 feet above sea level, to high volcanic islands with steep profiles. Atolls are living coral reefs growing on submerged volcanic cones. The atoll islands are made of piles of sand derived from weathered coral skeletons and other reef organisms such as algae. These islands are formed in long, narrow strips, either entirely enclosing a central lagoon or forming a series of small islets around the edges of it. They are unstable and very vulnerable to destruction by hurricanes. They also have only a limited underground supply of freshwater.
Raise coral islands are composed of reef limestone. They tend to have poor soils and little or no surface fresh water. In contrast, volcanic islands are densely covered with vegetation and have rich soils. The shapes and sizes of islands will greatly affect the pattern of rainfall and water runoff. Volcanic islands are among the highest in the Pacific and generally have very steep hills which drop off rapidly to the ocean depths. These islands are usually surrounded by barrier and fringing reefs.
The Pacific Ocean is renowned for its coral reefs. Some of the most diverse and dramatic reef structures in the world are found in the South Pacific. Three basic types of reefs can be found there. The first is called a fringing reef, which grows directly adjacent to island and continental land masses. The second is called an extended barrier reef, such as the Great Barrier Reef, which surrounds much of Australia. These reefs occur some distance offshore and are separated from the mainland by a deep-water channel. The last kind of reef is called an atoll, which is an island made up of a large concentration of coral formed around the top of an old volcano.
Human population densities are generally high in the South Pacific. On average 386 people live on every square mile of land. These heavy concentrations of human population lead to environmental problems such as sewage pollution of enclosed lagoons and coastal waters. ...FROM "THE RANDOM HOUSE ATLAS OF THE OCEANS"
The Spanish Dancer nudibranch may be one of the most vividly colored animals under the sea, but it won't get many requests for a dance. In fact, the Spanish Dancer's brightly colored skin does just the reverse, it reminds other animals to stay away.
Like other nudibranchs, the Spanish Dancer is a horrible thing for predators to eat. While it may have no protective shell, it gives off a bad tasting mucous that most fish dislike. Spanish Dancers are also able to absorb the stinging cells of anemones and then use them in their own skin to sting the mouths of any animal that bites them. The Spanish Dancers' bright colors are a reminder to hungry animals that this is one meal they won't relish.
Spanish Dancers live along the shallow bottoms of cool-water oceans. They feed on a mix of sponge and decayed organic matter. Like most members of the mollusk family, the Spanish Dancer has a head at one end of its small body and an anus at the other. It uses a pair of tiny tentacles near its head to help navigate and moves through the water either by crawling or undulating its body to swim. It also has a small set of external gills which help it breathe. The Spanish Dancer is very sensitive to light and will usually hide during the daytime, then come out to search for food at night.
░Spotted Dolphin: See Spot Swim!
Length: 6 Feet/2 Meters;Depth: 0 Feet/0 Meters
BAHAMAS
The spotted dolphin is, like its close relative the spinner dolphin, a spectacular acrobat. It is a very fast swimmer that loves to play in large groups called pods and, frequently, it will jump high out of the water, spinning and twisting its body around in the air. This dolphin is easily recognized by the tiny white spots covering its backside.
Dolphins are among the most intelligent creatures on the planet. Their brains are as large as, and sometimes larger than, the average human brain. For many centuries dolphins have been known to perform brave acts for people. There have been numerous reported cases of dolphins helping people who are shipwrecked back to shore. Dolphins are also well known for their intelligence. Dolphins in captivity can learn tricks at incredible rates of speed, and when they are feeling creative they can change and modify tricks to their own liking.
Because they are mammals, dolphins give birth to live young. Most dolphins are very attached to their young babies and will travel closely with them for long periods of time before they let them fend for themselves. Dolphins like the spinner dolphin hunt and navigate by use of echolocation and their eyesight.
Echolocation is like sonar. A dolphin constantly makes noises that sound like tiny clicks. When these sound waves strike an object, an echo returns to the dolphin. The head of a dolphin is filled with very sensitive nerve endings that can detect minute changes in the water pressure created by these echoes. Collecting all of this information, the dolphin can produce a very accurate picture of its environment.
Spotted dolphins are characterized by the large schools in which they swim. These dolphins have been known to travel in packs of up to several thousand as they criss-cross large parts of the ocean. What a spectacular sight that must be!
Because spinner and spotted dolphins will school together with yellowfin tuna they often become entangled and die in tuna fishermen's nets. In 1972, more than 380,000 dolphins were killed by tuna netting, and most of them were spotted dolphins. Fortunately, due to new restrictions on fishing nets, the spotted dolphin has staged a successful comeback.
No trip to a coral reef is complete without an accidental run-in with a moray eel. But don't worry. Unless a moray eel is provoked, this mean-looking animal will stay in its cave until you have moved on.
The slimy and slippery spotted moray is a member of the eel family and looks more like a giant slithering snake than a fish. It is easily recognizable by its dark brown body covered with tiny white spots. Like most morays, the spotted moray is more active at night and tends to be territorial. During the day it hides in crevices and coral reefs with only its head poking out.
Morays have a fearsome reputation. They are savage predators that feed mostly on invertebrates like octopus, squid and shrimp. Sometimes it is thought that the bite of a moray is poisonous, but this is untrue. Although morays have a vicious looking set of fangs, they will not strike out unless provoked. If touched, they will almost certainly retreat. Many people are frightened by the way in which moray eels rythmically open and close their large mouths. But this is not done to be threatening. Rather, the moray eel must move its mouth to help push water over its gills.
Normally, squid are solitary creatures that prefer living alone rather than congregating in large groups. However, when squid mate, they will often gather in giant schools in places like Hawaii or off the coast of California. At such times, the male squid will engage in a mock battle over a female by rushing toward each other and then stopping just before making contact.
After this ritual, the male and female squid will engage in a long dance, in which both circle each other and grapple with one another using their tentacles. Eventually the male and female will join as the male fertilizes the eggs of the female. At that moment, both the male and female squid will turn white.
Once fertilized, the female squids will deposit their eggs in large groups of tubular sacks along the ocean bottom. In some areas where large groups of squid mate, the ocean floor looks like it is covered by tiny white balloons. A single female squid may lay up to 200,000 eggs. After she is done, the female squid sometimes will die. Most of the eggs, or the baby squid, will be eaten before they can leave the area. Of the 200,000 eggs a female squid will produce, perhaps only two or three will reach adulthood.
Dynamic, sensitive, and intelligent. Those aren't the words that normally come to mind when describing a squid. In fact, squid are among the most highly developed creatures in the ocean. Members of a group of animals known as mollusks, squid are close cousins to clams and snails. Unlike these animals, though, squid do not have a hard external shell to protect their bodies. Also different, squid have a well-developed nervous system. Squid, like their cousin the octopus, can change the color of their skin almost instantaneously in response to changes in their surroundings. They have remarkable vision which lets them see things almost perfectly in light or dark. They also have a great sense of touch, making it possible for them to handle delicately the most fragile objects, such as their miniature eggs. Recently, scientists have shown that some types of squid use their ability to change color as a way of communicating simple emotions such as anger or fear. Another amazing observation is that squid and octopus actually have a limited ability to remember things.
Squid are predators that like to hunt at night. Most often, squid catch their prey by grabbing it with their long tentacles. The squid pulls its victim into a small mouth at the bottom of its head. A squid's mouth is a sharp parrot-like beak which can inject a deadly poison into the skin of its prey. Most squid measure between two and four feet long. But there are giant squid which live in the ocean depths that may grow to a length of 50 feet. No one has actually caught a squid this long, but some sperm whales have been seen with tentacle markings on their skin so large that they could only have been made by a giant squid.
First-time divers will frequently ask, "What's all that clicking and snapping?" What they're hearing is the snapping of the giant claw of the snapping shrimp!
Hundreds of these shrimp live in holes, burrows, and in sponges and corals on most reefs in warm and even cooler ocean waters. Sometimes large tropical sponges are found full of snapping shrimp. Snapping shrimp are very territorial and the snapping noises warn other sea creatures not to trespass. It is also thought that the loud snaps actually stun or repel potential invaders. The snapping can be heard day and night.
The noise of the snapping shrimp comes from the gigantic claw on one of its front legs. This claw can be cocked open like the hammer of a gun, and when the shrimp releases it, a large noise is produced. Sometimes a small jet of water squirts out too.
Found in the warm waters of the South Pacific, the orange sea star is a real standout. Its bright orange coloring makes it highly visible in either day or night. The orange sea star most frequently inhabits the rocky and coral reefs surrounding volcanic islands in the Pacific. Unlike many starfish, which are carnivorous, the orange sea star feeds on algae and tiny organisms known as sessile invertebrates.
When it is time to mate, the male orange sea star releases sperm into the water and the female releases eggs into the water. If they are close enough together, the eggs will be fertilized and eventually turn into tiny starfish larvae that will float along with the currents. These larvae feed on microscopic plankton in the water, until they transform themselves into small orange sea stars and then drift back to the bottom.
A dreaded killer? A high speed eating machine? It's hard to believe that any starfish could be described in such a way. But the twenty-rayed starfish is one of the largest, fastest, and most aggressive of its kind. And boy does it like to eat!
The twenty-rayed starfish is a great hunter, capable of capturing many kinds of foods, including mollusks, crustaceans and even small fish. Like other carnivorous starfish, the twenty-rayed starfish attacks its prey by smothering it with its long suction-covered arms. Once the prey is in the starfish's grip, the starfish uses acids from its stomach to weaken the animal's resistance. When the animal is weak enough, the starfish literally pushes its stomach outside of its body and digests the animal on the spot. As an adult, a twenty-rayed star can reach a size of 40 and sometimes 50 inches in diameter. When they are very young, twenty-rayed stars only have five arms. As they mature, they grow more and more arms until they have 24 arms.
The twenty-rayed starfish is found in the western coastal waters off North America. They are extremely territorial and will engage in combat whenever they encounter another starfish or another member of its species.
VStar Coral: Stony Star of the Sea
Length: 8 Feet/2 Meters;Depth: 70 Feet/21 Meters
SOUTH PACIFIC OCEAN
The stars of the star coral are actually blades of a living coral's limestone skeleton. Each star is the bottom of a coral polyp. Polyps resemble small sea anemones with six tentacles, or arms, extending upward. These arms are normally folded down inside the polyp during the day for protection from coral eating animals. At night they expand into the surrounding water where they catch small animals. These arms have the same stinging cells as sea anemones.
Thousands of corals will grow together to form a colony. Large colonies may extend over eight feet in diameter. As they grow they produce lime rock and over a few hundred years this lime rock may weigh hundreds of pounds. However, the thin layer of actual living coral weighs only a few pounds.
This coral is green because a small, one-celled green plant called algae is imbedded in it. Like all plants, the algae need sunlight, as does the coral. This means that reef-building corals are not found in caves or in the deep sea where the light is scarce. Corals also require clear water without sediment, because the sediment will often fall on them and block the light. Sometimes sediment will settle only on the tops of large rounded corals. In this case, the center of the coral will die, but the sides will continue to grow. This often results in a donut-shaped coral head.
vStingray: Deadly Stingers
Length: 13 Feet/4 Meters;Depth: 66 Feet/20 Meters
INDIAN OCEAN
Stingrays are famous for their powerful "sting." Unlike the giant, harmless manta ray, this type of ray is quite dangerous due to the poisonous sting in its tail. With its flat, diamond-shaped body, large flapping "wings" and protruding eyes, the stingray looks very similar to its nonpoisonous relatives. But watch out! Sticking out of its long tail are one or more skin covered stings, each having razor sharp backward facing teeth. These sharp spines inject a powerful poison which can be deadly!
Stingrays vary in size and weight, and some of the largest can measure up to 13 feet in diameter and weigh several hundred pounds. Stingrays live mostly among muddy and rocky coral reefs in the Indian and Pacific Oceans, but some species are exclusively river fish and can be found in South America just east of the Andes. Stingrays feed on fish and invertebrates.
Without a doubt, the stonefish is one of the ugliest fish in the ocean. It is also one of the most poisonous. Stonefish are found living on the sandy or rocky bottoms of coastal waters in the Atlantic, Indian and parts of the Pacific Ocean. Growing up to a foot in length, this bulky fish is not much of a swimmer. But it still manages to be a very effective hunter.
To catch its meal, the stonefish relies on camouflage and surprise. Like the scorpionfish, the stonefish usually rests motionlessly on the ocean bottom until an unsuspecting fish or shrimp swims too close. The stonefish's coarse body blends in well with rocky ocean floors and its skin can change colors to match its surroundings. Some stonefish have large pieces of loose skin on their body that resemble small shreds of seaweed.
Once a fish or octopus swims within reach, the stonefish leaps forward and literally sucks the fish into its large mouth.
Since stonefish are not good swimmers they need other ways to protect themselves from predators like sharks and moray eels. Their most effective defense is the set of 12 poison spines running along their back. When a stonefish is resting, the spines lay in a safe horizontal position. But when a stonefish is in danger, the spines are raised so that they stick straight up. Each spine carries a lethal dose of poison which is instantly injected into anything that touches it. The poison is so deadly that it can kill a human in just three hours. If that's not enough to keep potential predators away, the stonefish's flesh is also toxic to most marine animals.
When one ochre sea star finds something good to eat, it's not long before most of the sea stars in the vicinity find out. Quite often, sea stars, also known as starfish, will pile up on top of each other to get a piece of some food that is lying on the ocean floor. It might take several hours for a group of starfish this large to come together in one place. But starfish are determined eaters and will travel large distances to get a good meal. Once the food disappears, though, starfish will wander away in different directions in search of another meal.
Most people don't think of starfish as the kinds of sea animals that get around a lot. In fact, most of the times we see starfish they look about as mobile as a cactus. But like other echinoderms, such as the sea urchin and sea cucumber, starfish have rows and rows of tiny tube feet that enable them to move much quicker than you would think. These tube feet are located on the underside of the starfish's arms and are powered by a current of water which is channeled through the starfish's body cavity and down along its arms.
Ochre sea stars like the ones in this picture are voracious carnivores which love to eat mollusks lying along the ocean bottom. When an ochre sea star catches up with a mollusk it will wrap the mollusk in its arms and then push its intestines out of its body and into the mollusk's shell, digesting the mollusk's insides right there on the spot. Ochre sea stars are so adept at tracking down their prey that some mollusks have developed a way of detecting the scent of an approaching ochre sea star.
Ochre sea stars are generally found off the rocky coastline of the western United States.
The common sun star has a voracious appetite unmatched by almost any other starfish. A sun star will and can eat just about any mollusk or starfish that gets in its path. Like other starfish, sun stars consume their prey by first covering them with their arms and then pushing their stomach out of their body and onto their victim. The sun star's stomach acids literally digest the prey outside of the sun star's body. Sun stars are known to swallow certain kinds of shelled mollusks whole. After 24 hours, the mollusk's soft tissue will be completely digested and the shells will be emptied from the sun star's stomach. Eating at this rate, a sun star can double its size in its first year of life.
Most sun stars have 8-13 short arms which they use to maneuver along the ocean floor. Like other echinoderms, the sun star uses tiny tube feet -- located on the underside of its arms -- to get around. Inside its body cavity, the sun star has a small stomach and a reproductive organ that produces sperm or eggs depending on whether it is a male or female. There is also a water-canal system which brings water from outside of the sun star into its body. The water then flows to the tiny tube feet to make them move.
Some dangerous people carry knives, but the beautiful surgeonfish carries a scalpel. On either side of the back of its tail, the surgeonfish has two hard, sharp spines that are imbedded in its skin. When the surgeonfish is in danger, these spines pop out like tiny switchblades and can slash any predator with a painful wound. Many inexperienced divers have made the mistake of trying to pet this seemingly harmless fish only to get a nasty cut from one of its spines.
Surgeonfish come in many bright colors and patterns. They are found almost exclusively in the shallow waters of coral reefs in the Indian Ocean and the Pacific Ocean. The colors of surgeonfish vary greatly between species. Some surgeonfish, like the Thompson's surgeonfish, are a dark, solid blue with a white tail, while the blue-lined surgeonfish is covered by stunning blue, yellow and black stripes. Some surgeonfish have large dorsal fins and others have almost no dorsal fin at all. Most surgeonfish are herbivores, which means they eat only plants such as the algae growing on coral and rocks.
The swellshark is a member of a large family of bottom-dwelling sharks known as catsharks. This group of sharks is the largest in the ocean with approximately 92 different species known throughout the world. Swellsharks are commonly found in the cool waters off of the coast of California. They have long snouts and a long mouth that stretches behind their eyes. Swellsharks' skin is covered with colorful patterns of spots and blotches that serve as a perfect camouflage in kelp forests and on dark sandy ocean bottoms. Swellsharks feed on crustaceans, squid and other bottom-dwelling animals. Unlike many sharks which give birth to live babies, swellsharks lay their eggs in flattened, elongated sacs that look like a large leaf of seaweed.
Look in any aquarium and you will probably find one or more fish belonging to the colorful wrasse family.
There are more than 600 species of wrasses living in warm tropical waters around the world. All wrasses are quite active during the day, spending most of their time looking for food. During the night wrasses do something that is highly unusual for a fish. They go to sleep. Normally, a wrasse will find some protected place like a rocky overhang or outcropping of coral and then it will enter a state that is close to what we know as sleep.
Some wrasses perform a very valuable function for other undersea animals in the coral reef -- they clean them. When the wrasse receives the right signals from another fish or animal, it will swim up to the fish and begin to remove dead skin, parasites and other organic matter from the fish's body. In this manner, the wrasse gets a tasty meal and the other animal gets a much-needed cleaning.
Some fishes have flesh that is poisonous to humans when eaten. The toadfish (along with the pufferfish or glovefish) is very tasty when prepared the right way. But watch out! These fishes have poisonous body parts that need to be carefully removed before the flesh of the fish is consumed. The toadfishes dorsal and opercular spines are deadly, and eating them could result in sickness and even death!
The toadfish really does look like a toad with fins. It has a big gaping mouth with fleshy lips and a bulky, compressed body covered with loose, wrinkled, scaleless skin. Toadfishes live all over the world in mostly tropical and temperate waters.
hGreen Sea Turtle: Long Distance Swimmer
Length: 5 Feet/2 Meters;Depth: 80 Feet/24 Meters
MALAYSIA
Green turtles occur worldwide and love to feed on sea grasses and algae. They are the grazing cattle of the warm seas. Young sea turtles feed mostly on sponges, snails, small crabs and jellyfish. They don't have teeth, but their jaws have a sharp edge for slicing off blades of the green sea grass that grows in shallow sandy lagoons.
Green turtles are usually widely scattered during their feeding ground, but often get together in large numbers during egg laying season. Sometimes they migrate for hundreds of miles over the open ocean to lay their eggs. Even though a turtle may never have revisited the island on which it was hatched, it knows to return to it when it is ready to lay its own eggs. Biologists have attached tags to turtles to learn more about their migration habits. Because turtles make such long migrations over the open sea without any landmarks, scientists believe that they must use the sun, moon or stars to navigate. It is possible that when a turtle nears the island it is searching for but can't yet see it, a distinctive smell of "home" might provide enough clues to guide them in.
╚Green Sea Turtle: Doting Mother
Length: 5 Feet/2 Meters;Depth: 80 Feet/24 Meters
MALAYSIA
For a long time, scientists believed that sea turtles came ashore only to lay eggs. However, early naturalists recorded that sea turtles occasionally hauled out on sandy beaches and other areas to bask, just as other turtles do.
Mother sea turtles come up on low sandy beaches to lay their eggs after sundown. On dark, moonless nights they lumber over the first rows of sand dunes and dig a shallow trough to lay in while they complete the task of digging a hole for their eggs. As she is doing this, a mother sea turtle will use her front flippers to cover herself with sand, helping to hide her from potential enemies.
By alternately dipping down with one back flipper and then the other, she excavates a hole two or three feet deep. By curling up her hind foot like a small sand shovel she can efficiently remove the sand from her "nest." She will then lay 75 to 200 eggs in the bottom of the hole, carefully placing sand on top of them when she is done. Then, with a great flailing of flippers, she messes up the sand covering to try and confuse any animals that may later try to find the nest to eat the eggs. It takes most of the night for her to finish. Females are known to lay up to five or six clutches in a season and this probably takes several nights to accomplish.
Today, after hundreds of years of being hunted, a wild sea turtle is indeed a truly remarkable and rare sight. All types of sea turtles are on the world's endangered species list.
ïThe Underwater World: The Water Planet
Length: NA;Depth: NA
SARGASSO SEA
Popular perceptions of our planet as illustrated by its name, Earth, have only recently begun to change as satellite pictures have brought back home the extent to which the Earth is in fact a "blue" planet, covered by water. The oceans contain some 330 million cubic miles of water which act as a giant store of minerals, nutrients and dissolved gases such as oxygen and carbon dioxide, that provide the essential basis for life in the oceans.
These essential elements vary in their concentration, from area to area and with depth. The movement of the water in the oceans mixes water masses of different composition, and living organisms themselves alter these concentrations by taking up some elements and producing others.
The influence of the oceans goes far beyond their own boundaries, shaping the physical conditions and biological processes of the planet on local, regional and global scales. Gas exchange with the atmosphere, climate and weather, the carbon and hydrological cycles, and other atmospheric and physical processes are all critically influenced or determined by the oceans. ...FROM "THE RANDOM HOUSE ATLAS OF THE OCEANS"
Ouch! Nothing can spoil a pleasant swim in the ocean more than stepping on a hidden sea urchin. A relative of the starfish, the sea urchin has a great built-in defense system -- its hard, sharp spines. Most hungry marine animals will look elsewhere when they encounter the prickly sea urchin.
Sea urchins are members of the large family of marine organisms known as echinoderms, which includes starfish and sea cucumbers. Though difficult to see, sea urchins' bodies can be divided into five parts, just like a starfish. Internally, sea urchins have a tiny mouth at the bottom of their body and a hole at the top of their body where digested food is evacuated.
Sea urchins thrive in shallow rocky waters where it is usually too cool for coral to grow. Contrary to appearance, sea urchins are highly mobile little animals. Using tiny tube feet similar to the tube feet of a starfish, sea urchins move around their habitat constantly in search of food. Sea urchins are voracious eaters which love algae. Giant groups of sea urchins can turn a lush field of seaweed into an underwater desert in no time.
Even with their spines, sea urchins do have enemies. The sea otter of northern California is famous for its love of sea urchins. When the sea otter was nearly hunted into extinction in northern California coastal waters, sea urchin populations there grew out of control. Without their enemy, hungry bands of sea urchins ate through many of the giant forests of sea kelp in the area. Today, however, the California sea otter is making a comeback and it is having a feast on all the sea urchins. In the same span of time, the sea urchin has developed another unlikely enemy -- man. The Japanese love the organs of sea urchins so much that they will pay large sums of money for fresh sea urchins.
|The Moving Waters: High Tide
Length: NA;Depth: NA
OCEANS
The sea is never still: it moves in different directions, at different speeds and is influenced by many forces. Understanding the ways in which oceans move is a complex task for oceanographers. Even though the basic processes causing these movements are each quite simple, their combined interaction results in regional differences in current patterns which are strikingly varied in each of the world's oceans.
Convection currents drive surface waters from the warmer regions near the Equator to the poles, where the water becomes colder and more dense and sinks to great depths before moving back to the Equator. Vertical movement of water in the oceans is influenced by water density, which is a function of salt content and temperature. When heated, surface water in the tropics expands and becomes less dense. This is countered by evaporation which increases salt content and also density. The balance between these forces determines whether the water sinks or remains at the surface.
In the tropical Atlantic the water lost through evaporation is greater than water gained through rivers and rainfall. The upper layer of the sea becomes warm and full of salt, flows north as the Gulf Stream, and gives off heat to the atmosphere as it moves north. When it reaches the Greenland Sea this highly saline water is near freezing and has become more dense than the deeper water below it. Convection sets in and the water sinks to the bottom, where it spreads and flows southward. Deep, cold water masses are also formed in the seas near the Antarctic continent, and some of this water moves northwards along the western coasts of the continents before being forced to the surface in certain areas, which form productive upwelling zones. Deep-water currents are influenced by the shape of the ocean floor, with submarine ridges deflecting currents and trenches channeling water flow.
The atmosphere above the oceans is not still and winds that blow strongly in one direction for extended periods of time, such as the trade winds, which occur around the latitudes 15 N and 15 S, move the surface waters of the oceans. As surface waters move, so does the underlying water as far down as 1,500-2,500 feet. Wind-driven surface currents move water across the oceans where it piles up against the continents and then moves down along the coasts. Where the winds are less strong, the water starts to flow back in the opposite direction.
Because the Earth spins on its axis, the direction of these major currents and the winds above them is deflected to the right in the northern hemisphere and to the left in the southern hemisphere.
When the atmosphere changes, so does the sea surface; in high pressure areas the surface is depressed, in low pressure areas it is raised. Atmospheric pressure varies greatly, setting up waves and short-term surface currents of varying strengths, and influencing local weather patterns.
To all these different influences must be added the effect of the gravitational pull of the Moon, the Sun and the Earth. Where the Earth's gravity is higher than average, the surface of the sea is lower than where it is less strong. The gravitational pull of the Moon, and to a lesser extent the Sun, is stronger on the surface of the sea which is directly facing these celestial bodies, causing the daily cycle of tides, with intervals of approximately 12 and 24 hours. ...FROM "THE RANDOM HOUSE ATLAS OF THE OCEANS"
RWeather: The Oceans and Weather
Length: NA;Depth: NA
FLORIDA
The interplay between the oceans and the atmosphere is complex, with each affecting the other in different ways. For example, wind direction is determined in part by temperature differences between land and ocean, which result in onshore breezes at night when the land is cooler and offshore breezes during the day when the sea is cooler than the land. Ocean surface currents are in turn affected by wind speed and direction. Another important role of the oceans in weather and climate is as a store of water, which evaporates from the surface under high temperatures, forming clouds and ultimately falling again as rain when the atmospheric conditions change.
Tropical ocean areas, which lie outside 5 N and 5 S of the Equator, are also the breeding grounds for violent storms, including hurricanes, which cause much damage when they pass over the surface of neighboring land. On a larger scale, changes in ocean circulation have marked effects on regional climates and weather, as happens during the El Nino Southern Oscillation, when rainfall is reduced in Australia and Southeast Asia. If climates change under the influence of the "greenhouse effect" or from other causes, then changes in ocean circulation may be expected, with possible major consequences for marine and terrestrial ecosystems. ...FROM "THE RANDOM HOUSE ATLAS OF THE OCEANS"
Of all the fish in the ocean, none is larger than the slow-moving whale shark. Adult whale sharks can reach lengths of up to 60 feet and weigh as much as 10 tons. Some whale sharks have measured an unbelievable 75 feet long when caught. Whale sharks should not be confused with whales, which are marine mammals and can be much, much bigger than any fish. A blue whale, for instance, can grow to twice the length of a whale shark.
Whale sharks, as their name attests, are members of the shark family. Yet, whale sharks are not killers. In fact, the whale shark is one of the most docile creatures in the sea. Whale sharks get their nourishment by filter feeding much like the blue whale or the manta ray. They live entirely on microscopic animals known as plankton which they scoop up in their giant mouths and then filter through a giant set of gill slits.
To satisfy their tremendous hunger, whale sharks spend most of their time moving very slowly through the warm waters of the tropics and subtropics where there is a rich abundance of plankton. Like other filter feeders, whale sharks must scoop up many thousands of gallons of water a day just to get enough plankton to maintain their body weight.
Whale sharks usually swim alone. They are so slow that many fish will follow behind them for food and protection. Not many fish in the sea are willing to tackle a whale shark, however peaceful it might be. Underwater divers who are lucky enough to encounter a whale shark have been able to hitch rides on their giant dorsal fin.
For more than 300 years this whale was indeed the "right" whale to hunt because of its beautifully silky baleen and high oil yield. It was also slow and quite easy to spot and kill. Sadly, it was so heavily fished that today the right whale is very rare.
The right whale has a very compact, stocky body and adults are black with a mottled black and white underbelly. When baby right whales are born, they are pale white in color. Right whales are easily recognized by a heavy outcropping of skin callouses around their upper and lower jaws. These strange looking growths are home to whale lice and barnacles.
The right whale can be found throughout the Antarctic, South Africa, southern South America, Australia and New Zealand. It feeds mostly on copepods and krill. Since a worldwide ban on right whale hunting went into effect two decades ago, the numbers of this gentle giant have risen slowly, but they are still one of the most endangered whale species alive.
The wolf eel (or wolffish as it is sometimes called), really does look like a big, bad wolf! Its five-foot-long eel-shaped body doesn't have scales and is covered with a disgusting mucus. This brownish gray fish has a huge gaping mouth full of highly developed teeth that are powerful enough to grind up sea urchins, mollusks and shells.
The wolf eel lives mainly in the cold and temperate seas off the coasts of Iceland, Norway and North America. It is mostly found in shallow waters, and lives near rocky coastlines.
The wolf eel, despite its hideous appearance, makes a very tasty meal. It is especially popular dinnertime fare in Scandinavia and Spain.
This white tip reef shark can be a heart-stopping sight to any inexperienced diver swimming in a coral reef. The truth, however, is that white tip reef sharks are one of the less dangerous warm-water sharks. Well known for their curiosity, white tip reef sharks will swim very close to anyone or any thing that happens to be in their territory. But they almost never attack, unless of course, they are provoked. With their slender bodies and large teeth, white tip reef sharks are very effective hunters. They will eat most of the animals found in a coral reef, including fish, crustaceans and marine reptiles. Unlike many sharks, white tip reef sharks can stop swimming for short periods of time without depriving themselves of oxygen that comes from the water passing over their gills. The only time to beware of a white tip reef shark is during a feeding frenzy with other sharks. This usually happens when there is too much blood and flesh in the water. White tip reef sharks are also known to grab a fish off a fishing line or a spear.
The live cells of the sponge are organized around microscopic limy or glassy needle-like structures called spicules. Spicules take on a variety of shapes but mostly look like dumb bells, arrows, darts, angles, and donuts. If you take a live sponge and push it through a fine screen, the cells will be separated into a disorganized lump. However, if this lump is kept in clean sea water, the cells will get together again to form a new living sponge.
Most sponges are rounded or columnar, hollow in the center, and have a wide opening at the top. Numerous very small pores and holes connect the outside walls with the inner hollow tube, also called the atrium. The cells that line these small pores have hairlike flagella that constantly wave to move currents of water inside to the atrium. From the atrium the water escapes through the opening in the top of the sponge, called the ostium. Once it was thought that the water flow was due only to the lashing of the flagella. Scientists now know that the sponge grows with its ostium positioned in the currents, which also helps pull the water into the atrium. It remains a mystery as to how an animal without a brain can be so smart!
vYellowfin Tuna: Gang Violence
Length: 4 Feet/1 Meter;Depth: 93 Feet/28 Meters
PACIFIC OCEAN
Tuna are one of the largest predators in the open oceans. They can be found in almost every ocean in the world. There are many different kinds of tuna. Some tuna, like the blackfin tuna, weigh only ten pounds. Others, like the bluefin tuna, can grow to a weight of one ton or more.
The yellowfin tuna in this picture swims in giant schools and covers vast distances in search of food. With its streamlined, muscular body, yellowfin tuna are fast, efficient swimmers. Some schools of tuna can cross thousands of miles of ocean in just several months.
Because they are always moving, tuna have enormous appetites. Their favorite meals consist of schools of small fish like herring or shrimp and squid. Tuna's special hunting technique is to encircle a large school of smaller fish and then drive them up to the water's surface. Once the small fish are near the surface, the tuna close in and eat them.
Tuna are hunted by sharks, killer whales and humans. Each year, fishermen around the world catch hundreds of thousands of tons of tuna. Eventually these tuna make their way into cans of tuna or foods like sushi.
