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The Pacific Northwest supports rich fishery resources,
of which salmon is of primary importance. Historically abundant in many
Pacific coastal and interior waters, salmon runs and species diversity
have been shrinking since the late 19th century, due to dam construction
(particularly in the United States), rockslides, poor management and overfishing
(DFO 1999a). By the late 1980s, both countries had imposed severe restrictions
on harvests of some salmon species but, despite these and other measures,
by the early 1990s salmon catch and value showed significant declines;
by 1999, 24 subspecies of west coast salmon had been listed under the
US Endangered Species Act and Canada had closed or curtailed salmon harvests
for some species in a number of its major rivers (Carlisle 1999, TU and
TUC 1999).
Complicating the issue have been the two international borders that separate
British Columbia's waters from Alaska's and those of the northwest United
States (DFO 1999a, TU and TUC 1999). During their life cycle, salmon of
US origin travel through Canada's waters and vice versa, resulting in
a history of intercepting fishery practices that has encouraged unsustainable
harvests (DFO 1999a). The1985 Pacific Salmon Treaty attempted to resolve
this issue but broke down in 1992 because of disagreements. A 1999 amendment
to the treaty based on sustaining wild stocks, sharing costs and benefits,
and a common basis to assess stocks, monitor fish and evaluate performance
is more promising (DFO 1999b, NOAA 1999).
The combined effects of fishing, climate change (see box) and habitat
conditions have prompted a number of status reviews, renewed fishing agreements
and new management approaches. For example, in 1998 Canada initiated the
Pacific Fisheries Adjustment and Rebuilding Program to conserve and rebuild
Pacific salmon stocks and to revitalize Pacific salmon fisheries. It has
also implemented a precautionary approach to salmon management, resulting
in significant harvest reductions to protect stocks at risk (DFO 1999c).
In December 2000, the United States released a comprehensive, long-term
federal strategy to help restore the 14 salmon subspecies in the Columbia
River Basin listed on the Endangered Species Act.
As those dependent on salmon for income struggle to survive (see graph
above), both countries are taking additional measures to help restore
these and other wild fish stocks to the region's coastal and marine waters
and to enhance and maintain global biological diversity. Recent restrictions
have indeed improved the ocean survival of some important stocks but it
remains to be seen if all Pacific salmon species rebound (DFO 2000a, 2001).
| Impacts of climate change on Pacific salmon
and other wild fish stock |
| Both Canada and the United States are concerned about the potential
effects of climate change on salmon populations and other wild fish
stocks in North America's coastal and oceanic waters. Studies by Canadian
government scientists that simulated expected changes from a doubling
of CO2 in the atmosphere indicate that the resulting change
in climate could virtually eliminate salmon habitat from the Pacific
Ocean (NRC 1998). A 1994 Environment Canada study of the impact of
climate change on Fraser River salmon reported that altered flow regimes,
aquatic temperatures, river hydrology and seasonal run-off will intensify
competition among water users in the watershed (Glavin 1996). A recent
US report on climate change impacts notes that a projected narrowing
in the annual water temperature range in many estuaries may cause
species' ranges to shift and increase the vulnerability of some estuaries
to introduced species (US GCRP 2000). |
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