In October, the Canadian Government approved a plan to cull 70,000 gray seals in the Gulf of St. Lawrence in hopes of reviving depleted cod stocks.
The Senate’s standing committee on fisheries and oceans supported “the logic of the proposed experimental reduction of grey seals in this area” and acknowledged (but ignored) “the ecological risks raised by some witnesses.”
The cull was suggested in the first place because the Department of Fisheries and Oceans (DFO) claims that the seals are preventing the Gulf cod stocks from recovering. Canada’s Atlantic cod stocks collapsed in the 1990s as a result of overfishing. Since then, there has been almost a complete ban on cod fishing, but stocks have not recovered.
Grey seals are being blamed for this because their population is increasing. In the 1970s there were only a few thousand grey seals left, due to hunting. Since the seal fur market collapsed, their population as rebounded and there are now 300,000 to 400,000 individuals.
A group of scientists from Dalhousie University in Halifax, Nova Scotia, are arguing that a cull will not revive the cod stocks. They wrote an open letter saying that the cull would be “a waste of valuable resources and animal lives.”
“One cannot credibly predict from a science perspective whether a cull of grey seals would have a positive impact on cod or negative impact on cod…or no impact whatsoever,” said Jeff Hutchings, a biologist at Dalhousie.
“It’s not a two-species ecosystem. It’s a multi-species ecosystem.”
Reports from the DFO note that cod represents and estimated one to seven percent of seal diets, but the Senate committee still believes predation by seals is major reason for the lack of cod recovery.
Scientists, however, believe that the reason cod stocks haven’t recovered is because other species have taken over their role.
Hal Whitehead, a marine biologist at Dalhousie, explained that “northern shrimp have taken over and are now the big fishery in the region.”
To learn more:
- Check out this article from The Guardian: Seal cull will not revive Canada’s cod stocks, say scientists
- Read this article about the proposed seal cull: Plan to cull 70,000 grey seals gets Senate panel’s approval
- Read the full open letter: Independent Marine Scientists Respond to Senate Fisheries Committee Report ‘The Sustainable Management of Grey Seal Populations: A Path Toward the Recovery of Cod and Other Groundfish Stocks’
Copyright © 2012 by Marine Science Today, a publication of Marine Science Today LLC.