The year 2019 was the International Year of Salmon and featured a 'signature event' in the North Pacific with a study of the behavior of Pacific salmon. The study was conducted a group of 18 scientists aboard a Russian charter vessel spending 25 days in the Gulf of Alaska. (A second voyage was in March 2020 truncated by Covid-19.)
Dr Dick Beamish was instrumental in putting together this close examination of the iconic Pacific fish species in its offshore habitat, a major science expedition included with the year of Pacific salmon recognition. Beamish spoke to the B.C. Salmon Farmers Association at Seafood West in fall of 2018.
"The Russians caught 650,000 metric tonnes of pink salmon last year. Why was the number so high? They don't know." The record pink salmon catch in Russia was made primarily for the purpose of harvesting highly prized caviar. Nevertheless there is no explanation for the extraordinary size of the harvest.
Beamish notes Russia doesn't catch salmon the same way Canadians and Americans do. Russians set nets close to shore near the mouth of the rivers and the fish swim in to be caught. Canadians and Americans remain largely engaged in hunting the catch.
"Not long ago Japan had a rising amount of chum salmon to harvest," he says, peaking at 250,000 metric tonnes, but more recently their total catch of chum dropped to 70,000 metric tonnes.
The numbers of Pacific salmon being caught in wide ranging amounts creates a fount of mystery. "In the 1970s the thinking was doubling the catch was possible until the quantity of the catch dropped in Canada to 30,000 metric tonnes. After the 70s we believed we were seeing a shortage of juveniles but that thinking has been proven incorrect."
Knowledge of the behaviour of wild salmon is still basically at square one. "We may have an understanding of the fish. it seems when they grow faster, quicker they survive better. What we need out of the study from the science teams is focus on the fundamental reasons of salmon abundance."
The International Year of Salmon was announced in St. Petersburg, Russia, in 2018 to take place in 2019. It is a chance for Pacific salmon harvesting countries to promote effective stewardship of ecosystems, says Beamish.
"We need the scientists to come up with hypotheses and test them. It costs $1.1 million to charter a Russian vessel, which we got reduced to $900,000. We have raised money from the Pacific Salmon Foundation, North Pacific Salmon Commission, and others, and the salmon farmers of B.C. have been major supporters."
The expedition's purpose is to take into account everything known, and work on the unknowns to find a way to accurately forecast returns, or even explain the size of returns, like record numbers of pinks in Russia, and shrinking numbers of chum in Japan.
The cooperating scientists from several nations will be storing the recovered data at University of British Columbia to be made available to all. "The aim is to discover fundamental mechanisms behind salmon migrations."
Beamish asks, "What are the probables? We will probably find Pacific salmon rear in the Gulf of Alaska in winter. Their abundance is determined by the end of the first winter. Specific populations grow in specific areas. Faster, quicker growth contributes to better survival."
Beamish says anomalous warming in the North Pacific in recent years has had a major impact on growth, but it's difficult to qualify the effect. Furthermore, hatchery production adds complications. There is a need to understand variables in the release of hatchery salmon. "You have to be more experimental about raising smolts to be released."
Whatever the outcome, next year promises to contain an exciting learning process related to the understanding of Pacific salmon dynamics in their ocean habitat.
Dr. Richard J. Beamish C.M., O.B.C., Ph.D., D.Sc.,F.R.S.C. http://www.richardbeamish.com/
INTERNATIONAL YEAR OF SALMON IN 2019