William Ricker 
fisheries biologist

World renowned inventor of the Ricker Curve for describing fish population dynamics.

"Try and arrange that you're doing something that you're interested in. There's quite a bit of routine in research work but I've never worked on a project that I wasn't very interested in."

The Person

Birthdate  August 11, 1908
Birthplace Waterdown, Ontario
Residence  Nanaimo, BC
Office  Nanaimo Biological Station

Family Members
  ¥ Mother Rebecca Rouse, Piano teacher
  ¥ Father Harry Edwin Ricker, Science Master at North    
                  Bay Normal School, Ontario
  ¥ Spouse Marion (Caldwell) Deceased,
  ¥ 3 sisters
  ¥ 4 sons
  ¥ 3 Grandchildren

Title Retired Chief Scientist, Fisheries Board of Canada

Status Retired. Continues to study fish population dynamics and is working on a history book about early travel in the Fraser river canyon.

Degrees     
  ¥ BA 1930 U of Toronto
  ¥ MA 1931 U of Toronto
  ¥ PhD 1936 U of Toronto
             
Awards      
  ¥ 1990 Eminent Ecologist, Ecological Society of  
               America
  ¥ 1986 Order of Canada
  ¥ 1970 Royal Society of Canada
  ¥ numerous others.

Mentors Professors Dymond, Walker, Coventry and Harkness (U of T) W. A. Clemens and R. E. Foerster (Pacific Biological Station F.I. Baranov's 1918 Monograph R. A. Fisher's "Genetical Theory of Natural Selection"

Character Generous, modest, self-effacing, quiet

Favorite music Bach, Handel, Mozart

Other interests 
  ¥ Plants
  ¥ Birds
  ¥ Geology
  ¥ Insect classification
  ¥ Bass viol
  ¥ Canadian history
  ¥ Languages
  ¥ Archaeology

The Story

Standing on a thin ledge of rock, just below Hell's Gate falls on the Fraser River, William Ricker dips his net into the eddy at his feet. He brings up a six pound sockeye salmon for tagging. This one is fresh and strong, not like the tired ones who are having trouble with the rapids. Again and again the weak ones find their way into his net. From a pocket, Ricker pulls out two little red and white metal disks and a 5 cm pin. He wipes his brow and waves to his partner who is also tagging fish a few meters away. The sun is hot. A steady hot wind blows up the narrow canyon.

"Of course there was no road down to 'The Gate' in those days," says Ricker. "Only a steep trail actually, but nothing you couldn't handle if you were young and skookum."

Ricker was 30. It was the summer of 1938, the first time he had worked on the big river and he was enjoying himself. It was also the first year of the Canadian Salmon Commission's study of Fraser sockeye.

While his partner held a fish down, Ricker used a pair of pliers to attach the bright tag through the fish's body just below the dorsal fin. Then he threw the wild sockeye back into the water to fight its way upriver. The roar of the rapids, the cool water swirling around his feet and the hot wind made a perfect combination for Ricker. The team of four men managed to catch and tag up to 20 fish per hour, several thousand in all. Enough to accomplish the goals of the study "We wanted to find what fraction of the fish went to each of a dozen or so spawning regions to mate and lay eggs at different seasons. Observers in those regions were on the lookout for the salmon and were making estimates of the numbers on each spawning ground," says Ricker.

Knowing the number of spawners is crucial if you want to predict how many fish will be available for future harvest. Ricker knows salmon runs like some people know World Series baseball statistics. He has kept track of the Commission's estimates of the Fraser River sockeye ever since that day in 1938. Each year different numbers of salmon return to spawn depending on the species. Also, they go through cycles. For example, the big salmon run of 1993 is the same "line" or "cycle" as the record run of 1913 which was around 100 million fish. For sockeye, such huge numbers occur only every 4 years. So the next big run should be 1997. Off years are one tenth as numerous or less.

Ricker was the first to suggest several possible reasons for the cyclic variation in returning salmon stocks. Biologists are still collecting evidence to determine the correct explanation. The Fraser sockeye are on a 4-year cycle possibly because most of the fish mature at 4 years of age. Farther north age 5 is also common. Pink salmon have a 2-year life cycle. For cohos it's usually 3 years, while chinook or "spring" salmon return at any age from 2 to 7 years. The most powerful and largest of all salmon, a chinook holds the world record, weighing in at over 57kg.

History

When he was eleven years old William Ricker began studying his dad's star charts. Eventually he could name all the constellations and the brightest stars. All through high school Springtime found Ricker up most mornings at 500 am. For three hours before breakfast he would ride his bike into the woods or along the shoreline near North Bay, Ontario looking for birds. Then he...
¥ Got a BA & PhD in Biology.
¥ Had summer jobs working for the Ontario Fisheries Research Laboratory mainly on trout.
¥ Studied salmon life history and enhancement at Cultus Lake, BC.
¥ Became a professor of Zoology at Indiana State University.
¥ Became Editor of Publications for the Fisheries Research Board of Canada, and then Chief Scientist.
¥ Wrote the "Green Book" on the computation of fish population statistics.
¥ Wrote a Russian/English dictionary of fisheries terms.
¥ Kept fit with hiking, and played violin and bass viol.

The Science

1. The Ricker Curve, developed in the 50s, is still used all over the world to determine average maximum catches for regional fisheries. Each coloured curve represents a different type of fish population.

2. Line of natural replacement. Along this line, spawners are replaced by an equal number of adult progeny

3. Salmon are interesting because their Ricker curve looks more like this. At this point you have reduced the population to 40%, but some fish, like salmon, produce many more mature progeny when spawning grounds are less crowded.

4. Natural Equilibrium. At this point, spawners equal progeny. You can't catch any fish, if you want to maintain the population at this level. Fish don't naturally go much beyond this level because they get too crowded. Spawning beds get messed up and many eggs die.

5. When you catch fish, say 20%, you move back here on the green Ricker curve. You have less progeny, but enough to sustain a catch of 20%--a surplus.

6. The point of maximum sustainable catch is actually a bit to the left of the maximum point on the curve. This is because the distance between the curve and the replacement line is the greatest at this point. Anywhere to the left of this line you are overfishing and will reduce the next generation's harvest.

Activity

Biologists must be able to tell the difference between many different species. You can try it too

¥ You'll Need
    -A library book with good pictures and descriptions of 
      fish local to your area. Try cod or salmon.
    -A trip to a big fish market or your favourite fishing spot.

¥ What to do
    -Take your book to the fish market and try to find the  
      distinguishing feature of each type of salmon, or cod 
      that is available.
    -Write down their proper Latin names
    -See if you can find any fish that are mislabeled in the 
      market. If you go fishing
    -Try to identify everything you catch. Note the depth, 
      water temperature and time of day.
    -Keeping records like this is not only scientific, it will 
      help you catch more fish!

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