Atlantic salmon dying at sea
Mystery persists as to why many of the fish fail to return to spawning rivers
Raymond Elliott rounded the point off Goose Cove, N.L., and steamed his skiff into a bay of memory.
It was a warm June morning in 1990 and the St. Anthony, N.L., fisherman was heading to haul the lumpfish nets he still set off Locke’s Cove – the community he’d been resettled out of in 1967.
“My entire life (up till then) you’d have had to pick your way carefully to avoid getting your prop fouled up in someone’s salmon gear,” said Elliott, now 82.
“Not a buoy on the water, it made me want to head back to the wharf and hang my oil clothes up for good.”
In 1989, the commercial fishery for salmon, one of Canada’s last, had been closed.
To Elliott, it was the end of a world — his own.
“Nothing makes sense,” said Elliott.
“Catches for us had been steady right till the end. They used to run logs down Main Brook and that didn’t seem to slow them down. Then they close the fishery and they tell us they’ve dropped off.”
Nothing does make sense, at least not yet, about what has been happening to Atlantic salmon since 1990.
Until 1989, an estimated eight to 12 per cent of Atlantic salmon survived their journeys from home rivers to northern waters off Labrador and Greenland, to then come back and spawn.
In 1990, that plummeted to between one and four per cent.
The total population crashed too — from an estimated eight million salmon alive on either side of the Atlantic to between one- and two-million fish. It hasn’t gotten better since. “The timing of that is concurrent with the major cod collapse and a major shift in oceanographic and climate patterns,” said Edmund Halfyard, a research scientist for the Nova Scotia Salmon Association.
“We’ve seen evidence of this shift in everything from phytoplankton and capelin up to large commercial fish species and even predators like gannets and seals. Everything shifted at about the same time period. It’s a new ocean.”
This story isn’t about gannets or cod, although they’re important too.
It’s about salmon because their lives rely on both the health of land and sea. Though threats were initially in rivers, the danger appears to have shifted oceanward.
Earlier this month, Jonathan Carr of the Atlantic Salmon Federation was in Qaqortoq, Greenland, trying to find out why.
Greenland banned the export of salmon in 1998 but maintains a small market/personal use commercial fishery with a 20-tonne quota.
“Not by any means is that fishery the reason for the decline in the oceans,” said Carr, vice-president of research for the federation.
“That fishery hasn’t changed a whole lot over last several decades.”
It was only in the 1950s that the rest of the world discovered the Atlantic salmon feeding off the coast of Greenland.
The commercial fishery reached its height in 1971 when 2,689 tonnes of salmon were caught there.
It was scientists who pieced together where the fish were coming from.
The answer — they come from everywhere.
Genetic testing has shown that the salmon arriving at southern Greenland to feed on capelin and herring come from both European and North American rivers. They are predominantly older, larger fish — many of which have already spawned once — that make the long trip.
Younger fish, typically less than 63 centimetres long, usually make the arduous journey to the Labrador coast, while salmon from the Bay of Fundy’s rivers will sometimes spend their first year at sea feeding in the Gulf of Maine.
“Greenland is one of the last stages of the life cycle for many Atlantic salmon,” said Carr.
“We’re trying to create a map of where they go, what they do and where they die with the goal of ultimately finding out what’s happening. Whether there’s anything we’ll be able to do about it when we find out remains to be seen.”
He and colleagues from the American National Oceanic and Atmospheric Administration, guided by members of Greenland’s Association of Fishers and Hunters, are catching and fitting large salmon with pop-up transmitters.
Though this is the first of a four-year project tagging salmon off Greenland, the Atlantic Salmon Federation began tagging smolts in rivers around Atlantic Canada in 2003.
Receiver stations placed around estuaries, across the Cabot Strait (between Cape Breton and Newfoundland) and the Strait of Belle Isle (between Newfoundland and Labrador) by Halifax-based Ocean Tracking Network, showed how far the salmon got.
They found fish, from as far away as Maine, congregated in the Gulf of St. Lawrence, schooled with salmon from the rivers of Nova Scotia, Prince Edward Island and New Brunswick that passed each year through the Strait of Belle Isle over a 10-day period in each July.
Not everyone is sold on the argument that salmon’s great threat is at sea.
“The marine environment is important but too many people make the mistake of separating the environments,” said Edmund Halfyard, the research scientist for the Nova Scotia Salmon Association.
“We need to give the fish that do come back the best possible chance to reproduce and have healthy offspring.”
Hence the three-and-a-halfstorey lime storage silo on the West River. Halfyard’s association built the facility in 2005 to mix pelletized lime into the river and lower its acidity — much like some do on their lawn.
The results were remarkable — within 10 years they were counting 12,000 smolts leaving the West River compared with 3,500 when they began.
When they finally get home, Atlantic salmon are prodigious spawners. A 12-pound adult female can lay about 8,000 eggs. But despite the large runs of smolts, they’ve only counted about 70 fish returning to the West River annually.
The irony of it all is that Atlantic Canada is more forested now than it was a century ago (due to rural decline rather than good intentions). Those water-powered saw and grist mills are all gone from the rivers.
Large fleets of trawlers no longer ply the North Atlantic for cod. Canada’s commercial Atlantic salmon fisheries are closed and Greenland’s is a mere shadow of its former self. After all we’ve done to this species, they stop coming back when we finally begin to ease our torment of their homes. It won’t be next spring until the transmitters start popping off the salmon Carr has been tagging off Greenland and, hopefully, start pointing to directions to look for answers.
“We’ve learned a lot about the issues that happen in freshwater but in trying to fix it we’re up against 150 years of altering and damning these rivers,” said Halfyard.