Abstracts
A Comparison of the Initial Impacts of Global Warming on the Marine Fish Communities off the Pacific and Arctic Coasts of Canada
Richard Beamish1,J.R. King and G.A. McFarlane
1Fisheries and Oceans Canada
Beamishr@pac.dfo-mpo.gc.ca
Most commercially important marine fish off the Pacific coast of Canada are long lived. This is an adaptation to survive prolonged periods of ocean conditions that are not favourable for reproduction. In contrast, marine fish in the Arctic are short lived. Arctic cod live for only a few years, which we propose is an evolutionary response to ocean conditions that are consistently favourable for reproduction. The early impact of global warming on these marine fishes appears to be to increase the variability associated with reproduction. Long- lived species can survive periods of increased variability in the next decades, providing the management of associated fisheries protects the evolved ability to adapt to climate variability. Short live species in the Arctic, such as Arctic cod, may not be able to adapt to increased variability. The initial impacts of global warming may require a change in fisheries management off Canada's Pacific coast. Unfortunately it may not be possible to protect marine fish in the Arctic. If the scenario we propose for the Arctic marine fishes is correct, the impacts could be immediate and alarming.
2005-04-05 |
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