On average two million young Chinook salmon are released each spring from the federally funded hatchery on the Cowichan River. Within six months, nearly all of them are dead.
Year after year, the mortality rate is staggering, with less than 1 per cent of the fish living to return as adults. The dismal results are thought to be similar at other B.C. hatcheries, which pump out about 20 million Chinook annually, hoping for a miracle.
In a paper published last year in Environmental Biology of Fishes, Richard Beamish, a leading salmon scientist with the Department of Fisheries and Oceans, argued it is time to try something different.
Dr. Beamish and his research team netted juvenile fish at sea so that they could compare the survival rates of hatchery and wild fish.
What they found was stunning. The hatchery fish, which are much larger than their wild counterparts, just can’t hack it in the ocean. By October, almost all of them are dead, with only .08 per cent surviving.
By contrast, the much smaller wild fish proved to be hardier, with a 3.6-per-cent survival rate.
Dr. Beamish had to estimate the abundance of the wild stock and he ran different sets of numbers. But no matter how he looked at it, the wild fish always did better.
“The wild survival is between six, nine and 24 times larger than the hatchery survival, depending on the [estimated]number of wild smolts,” he wrote.
“This conclusion is not a criticism of hatcheries; rather it is meant to identify the need to be more experimental,” he wrote. “Continuing to do what we are doing and hoping that the next year will be better makes little sense.”
But what could hatcheries do differently?
Carol Schmitt asked herself that question about 20 years ago while producing Chinook at a private hatchery for the fish-farming industry.
At the Omega Pacific Hatchery, near Port Alberni, Ms. Schmitt held her fish in net pens when she moved them to salt water. Because of that, she got to observe how they fared over the first few months in salt water. She saw the mortality rate on a daily basis, and realized that if she didn’t figure out why so many were dying, her hatchery would go out of business.
Over the years, she began to grow her Chinook more slowly, using colder water and less food, mimicking the conditions in nature. Her fish were smaller, and tougher. And she saw the survival rates shoot up to 5, 10, even 20 per cent or more.
In most DFO hatcheries, including on the Cowichan, Chinook are raised for eight months before being released as smolts. They are known as S-0’s (for smolts less than one year) and they are the standard of currency for DFO. Ms. Schmitt raises her Chinook for 17 months, producing S-1’s, or smolts a year or more old. Over the years, she’s grown about 10 million S-1’s, and Omega Pacific has earned a reputation in the fish-farming industry for providing healthy, robust Chinook.
This spring, she was allowed by DFO to release a small number of S-1 Chinook in the Phillips and Nahmint Rivers, following a similar release last year on the Sarita River, in order to demonstrate that her approach works.
But that is a very modest effort. Given the shockingly bad results that DFO has been getting with its methods, and the remarkable survival rates Ms. Schmitt has demonstrated in her own operation, it is time for the government to embrace her work and the change called for by Dr. Beamish.
For starters, DFO should put her in charge of the Cowichan, to see if she can turn around more than 30 years of failure.
“Absolutely, I would grow them,” Ms. Schmitt said when asked if she would take on such a big challenge.
She said she would start by releasing 500,000 S-1’s, and predicted that between 9,000 and 30,000 adults would return to spawn within five years.
Federal Fisheries Minister Keith Ashfield should call her now – before millions more hatchery fish are released to no end.Report Typo/Error