Conclusions from the country where salmon farming began underscore the grave threat posed to Pacific wild salmon by farms sited near spawning rivers on Canada’s western coast
by Craig Weatherby
The salmon farming industry started in Norway, and billion-dollar Norwegian firms run most of the world’s salmon farms.
Today, their holdings include hundreds of crowded pens anchored off the coasts of Chile, the eastern U.S., and western Canada.
So it stunned Norway’s powerful salmon-farming firms when, earlier this month, the Norwegian government’s Directorate for Nature Management called for radical, rapid reductions in salmon farming.
The warning was directed to the new Minister for Fisheries, Lisbeth Berg-Hansen, who, predictably, is the former head of the Norwegian salmon farming association and the owner of a salmon farm.
The Norwegian Directorate for Nature Management and the Norwegian Institute for Nature Research (NINA) jointly estimate that the current level of fish farming in Norway is six to seven times the sustainable limit.
Alarm is raised over sea lice
The chronic problem that led to the new call for reductions in fish farming relates to sea lice.
These pests originate as sparse, non-lethal annoyances that latch onto wild salmon… but they thrive on the captive “buffet” provided by crowded salmon-farm pens.
There are at least 250 million farmed salmon in pens along the Norwegian coast, versus only about two million wild salmon.
This means that Norwegian salmon farms generate over 100 times more sea lice than regional wild Atlantic salmon would normally have to contend with.
Sea lice swarms generated by salmon farms are a major threat to juvenile wild salmon that migrate past the pens—and to the survival of all wild salmon that originate near these industrial sites
Giant swarms of lice easily overwhelm young wild salmon and suck the life out of them.
The huge numbers of lice generated in the pens have cost the salmon farm industry millions in losses as well.
Accordingly, even the Norwegian Salmon Association has called for a halt to further growth in the industry, because they’ve found no solution to the costly pest’s growing resistance to the main pesticide used.
Sea lice problem afflicts wild salmon worldwide
The damage done to migrating juvenile salmon by farm-generated sea lice has also been researched by Irish, Scottish, and Canadian scientists, with conclusions similar to those reached in Norway.
The only solution is to site industrial fish farms far from the migration routes of young salmon, and remove the farms already sited near salmon rivers.
This is exactly what biologists and locals in British Columbia—which provides some of our canned sockeye—have proposed.
So far, they’ve met with resistance from Canadian politicians… despite recent, devastating drops in the numbers of pink and sockeye salmon from “runs” that pass by salmon farms.
The fight to control harmful salmon farms in B.C. has been led most persistently by B.C-based researcher Alexandra Morton.
She joined with University of B.C. scientists to co-author papers that documented the threat convincingly, and were published in the rigorous, prestigious journal Science.
To learn more about this topic, search our newsletter archive for “morton”.
- Evans D. Norway alert on lice. The Irish Times. December 28, 2009. Accessed at http://www.irishtimes.com/newspaper/ireland/2009/1228/1224261298224.html
- Norwegian Institute for Nature Research (NINA). Lice monograph. Accessed at http://www4.nina.no/akvatisk/