Bold experiment hopes to boost salmon population in B.C. waters
- Bold experiment hopes to boost salmon population in B.C. waters
VANCOUVER- From Thursday's Globe and Mail
Published Wednesday, Apr. 06, 2011 9:06PM EDT
Last updated Wednesday, Apr. 06, 2011 9:24PM EDT
Carol Schmitt got up early for the move because she had a lot to pack - 48,500 live salmon to be exact.
Luckily she had rented a semi-trailer tanker truck the night before, sterilizing it so the fish could safely be transported from the Omega Pacific Hatchery, near Port Alberni, to the Sarita River, on the west coast of Vancouver Island.
The fish - precious not only because Chinook are endangered in many places in British Columbia, but also because they are part of a bold experiment - had to be handled with care.
Unlike millions of salmon that are being released from Department of Fisheries and Oceans hatcheries in B.C. this spring, Ms. Schmitt's fish have been held almost one year longer and grown more slowly, to mimic conditions in nature.
DFO releases Chinook from hatcheries at eight months of age. The fish are known as S-0s, because they are smolts, with less than one year in freshwater. Ms. Schmitt's approach, perfected over decades growing salmon for B.C. salmon farms, is to keep the fish for 17 months, raising them in water as cold as the native stream from which their brood stock originated. And she restricts feed, so the fish mature more slowly. Those fish are known as S-1s and she believes such "stream type Chinook" are the key to the restoration of wild salmon populations in B.C.
"If you raise them in warmer water and feed them lots, as DFO does, they grow bigger and faster, but you trigger 'smoltification' too soon," Ms. Schmitt said.
Smoltification is when young salmon undergo dramatic physiological changes, turning from fry into smolts, as they adapt for the move from freshwater to salt water.
DFO's Chinook look ready when they are released, but their immune systems aren't fully evolved, she said - and most will die from vibriosis, a bacterial disease that attacks fish in salt or brackish water.
"I feel 85 to 90 per cent of federal S-0s are dead within four to six months," Ms. Schmitt said.
The statistics appear to bear that out, as DFO typically gets only about 1 per cent of its hatchery salmon back as adults. On the Sarita River, only 500 Chinook spawners returned last year - 0.1 per cent of the fish DFO had released as S-0s four years earlier.
Ms. Schmitt, with whom DFO is working on an experimental trial of S-1s on three Vancouver Island rivers, said she is expecting returns of up to 10 per cent.
"If you ship those fish out as S-0s you are accelerating the decline of the river," she said. "If you release them as proper S-1s, you will get three to ten times as many fish back."
Ms. Schmitt said in Alaska, releases of S-1 Chinook have resulted in returns as high as 22 per cent.
"Can you imagine what returns like that would mean in B.C.?" she asked. "That would be incredible. It's pretty exciting stuff."
With funding support from DFO and four fish farm companies (Mainstream Canada, Marine Harvest Canada, Creative Salmon and Grieg Seafood), Ms. Schmitt is doing trial releases this week of about 100,000 salmon in the Sarita, Phillips and Nahmint Rivers. The first release was Wednesday.
She said it has been tough to get to this point, because DFO has been resistant to change. "Getting DFO to allow us to participate in enhancement has and continues to be a challenge."
DFO was unable to provide a spokesman to talk about the Omega project.
But Stewart Hawthorn, general manager of Grieg Seafood, said fish farms, which have been under attack for their environmental impact, are supporting the Chinook project for a simple reason: They want to see wild salmon flourish.
"British Columbians are passionate about our native salmon and our employees ... are no different," he said.
More related to this story
a.. Why turn off the tap on B.C. salmon hatchery success?
b.. Researcher suggests 'salmon leukemia' is to blame for decline of Fraser sockeye
c.. Health of salmon run affects ecosystem of forest
d.. Natives urge closing of sport fishery to save chinook salmon
e.. Unguarded note conveys Fisheries' manager's frustrations
f.. Fisheries habitat being steadily eroded, panel told
[Non-text portions of this message have been removed]