UNIT 21 NEARSHORE FISHERIES INTRODUCTION Many U.S. coastal and estuarine species provide important recreational and commercial fisheries that are not Federally managed. This diverse Unit includes highly prized gamefishes like tarpon, bonefish, permit, and snook, as well as tautog, surf-perches, and Florida pompano. It also includes small fishes used for bait, food, or processing into oil and meal, such as mullet, smelts, eulachon, ballyhoo, sardines, and herrings. Valuable invertebrates like the Dungeness, blue, rock, and Jonah crabs; Pacific shrimps, abalones, hard and softshell clams, bay scallops, and oysters are also in this group. For 1990-92, the average annual dockside revenue from the commercial components of the fisheries in Table 21-1 was about $389 million. No separate values are available for the recreational fisheries, but they are certainly significant, especially to many coastal economies. SPECIES AND STATUS Most species in this group (Table 21-1) live near shore during much or all of their lives. Some, like the shads, herrings, smelts, and the striped bass, are anadromous, ascending fresh water to spawn but spending their adult lives in estuaries or at sea. In contrast, the American eel lives much of its life in fresh or brackish water but migrates far offshore to spawn in the Sargasso Sea (deep Atlantic, beyond the Gulf Stream, off the U.S. southeast). These species are widely distributed. Bay scallops, hard and softshell clams, and rock and Jonah crabs are among the important fishery resources of the northeastern United States. Shads, herrings, sardines, mullets, Florida pompano, and calico scallops are fished primarily along the middle and southern U.S. Atlantic coast and in the Gulf of Mexico. Many of the gamefishes are particularly valuable to the Florida economy, while invertebrates, like the blue crab and Atlantic oyster, support major fisheries from the Gulf to Chesapeake Bay. Corvina and striped bass are important sport fishes in California waters, while surf-perches are fished along much of the U.S. west coast. Other species like abalones, clams (hard, Pismo, razor), eulachon, and surf smelt support both recreational and commercial west coast fisheries. In the Pacific Northwest and southern Alaska, Dungeness crabs, oysters, and shrimps support valuable commercial fisheries. Bonefish, tarpon, snook, and permit are sought primarily by sport fishermen who often employ professional guides. Other popular recreational fishes, such as the surfperches and tautog, are caught primarily from the beach or small boats. The small baitfishes and food fishes are harvested by both recreational and commercial fishermen using cast nets, gill nets, seines, dip nets, and pound nets; the southern Florida ballyhoo fishery supplies bait to the charterboat industry. Many methods are also used to harvest the invertebrate species. Commercial and sport divers gather abalones, particularly off southern and central California; fishermen in small boats dive, dredge, and tong for oysters and rake hard clams; recreational clammers dig Pismo clams on sandy beaches in central California and razor clams in the Pacific Northwest; trawlers and divers take sea urchins off the New England and northern Pacific coasts; and commercial and recreational crabbers fish with pots, traps, trotlines, dredges, and dip nets for blue, rock, and Jonah crabs on the Atlantic coast and for Dungeness crabs on the Pacific coast. Pacific shrimps are harvested with pots and trawls. Other species, such as blue mussels, are both cultured and harvested from the wild. The number of participants in these nearshore fisheries is difficult to assess because of their diversity. There is no doubt, however, that millions of recreational and commercial fishermen seek these resources; there are, for example, an estimated 600,000+ recreational razor clam diggers in Washington alone. In general, landings for many of these species have declined in recent years (Fig. 21-1, 21-2, 21-3, 21-4). Atlantic hard clam, softshell clam, bay scallop, and abalone landings were substantially lower in the 1980's than in the previous three decades. Atlantic oyster landings fell sharply in the late 1980's, and Chesapeake Bay stocks are considered severely depleted. After peaking in the 1970's, Pacific shrimp landings fell off in the 1980's, primarily because of reduced Alaska landings. Dungeness and blue crab landings, though cyclical, appear to have withstood harvesting pressures well through the 40-year period examined. Because these species frequent nearshore waters, they are not included in Federal fishery management plans; some are managed under regional, state, and/or local authority. Typically, size limits are used to protect molluscan and crustacean resources from overutilization, whereas gear restrictions are the most common management measures used for the finfishes in this group. Area closures, bag limits, and catch quotas are also employed, particularly for shellfish. Interstate Fishery Management Commission plans have been developed for such Chesapeake Bay species as the oyster and blue crab to try to achieve consistent management between states. Some states, notably Florida and California, have prohibited all commercial harvest of certain species by designating them as gamefishes. It is difficult to assess the status of these stocks throughout their ranges because they are under varied management and data collection systems; though individual states may collect data and assess stocks of several of these species, comprehensive assessments are scarce. Many of the species in Table 21-1 are probably overexploited, at least in part of their ranges, as with the Chesapeake Bay oyster. Others, like many of the herrings, are difficult to assess because the data on abundance and stock structure are sparse, dispersed, or nonexistent. Stock levels of many of these species are below their historical averages. Whereas relatively good biological data exist for species such as oysters and blue crabs, they are incomplete for many other species in this unit. The recent annual yield of the species in this unit is conservatively estimated at more than 221,000 t. Table 21-1 presents the best data available, though the yields are probably low for many species because separate landings data are not always reported (many of the baitfishes are lumped into other categories, for example). Furthermore, data on sport catches are not available for many of these species, particularly the invertebrates. Recreational aspects of some of these fisheries are very large; Chesapeake Bay sport crabbers alone caught an estimated 19,000 t of blue crabs in 1983 and 9,800 t in 1988, or 44% and 32.1% of the total harvests, respectively. Some species, such as tarpon and bonefish, are sought primarily for sport and are usually released alive; consequently, few or no landings data for them are reported even though they provide significant local and regional economic benefits. ISSUES Habitat Concerns Because of their reliance on nearshore habitats (i.e. estuaries, reefs, mangroves, etc.) species in this group are particularly susceptible to habitat loss, pollution, changes in freshwater flows, siltation, and other environmental problems. Striped bass have been hurt by habitat degradation and salinity changes in the San Francisco Bay estuary; Chesapeake Bay species, such as river herrings and hickory shad, have declined drastically in recent years due to pollution, waterflow changes and habitat degradation; and Atlantic coast and Gulf of Mexico oyster and hard clam harvests have been severely reduced by pollution, disease, salinity changes, and habitat losses. More than half of the Nation's original acreage of coastal wetland marshes have disappeared, and dramatic declines in seagrass beds have occurred. Louisiana alone loses an estimated 35,200 acres of coastal wetlands habitat each year. Because many shellfish fisheries are close to large population areas, the likelihood of pollution problems is high; fishing closures due to shellfish bed contamination cause large economic losses each year. In addition to direct pollution impacts, excessive nutrient loads may increase toxic plankton blooms that cause red tides and paralytic shellfish poisoning. Mosquito control spraying near populated areas, such as in southern Florida, may result in death of juvenile fishes in important nursery areas. Environmental stresses also make fish more susceptible to diseases and parasites, either killing them outright or making them difficult or impossible to market. The diseases MSX and dermo have destroyed millions of bushels of oysters in Delaware and Chesapeake Bays since 1958, and they spread in the late 1980's to coastal North Carolina where similar devastation has occurred. Management Concerns Overharvesting has been at least partially responsible for depleting such species as Pacific razor clams, Pismo clams, abalones, oysters, and snook. Marine mammals also feed on some of these species and may compete with fishermen; for example, sea otters on the Pacific coast have depleted abalone and sea urchin stocks in parts of California.