Salmon decline all along Pacific coast

Sockeye salmon stocks are in decline from Alaska to Washington, and have been since the 1980s.

This is likely evidence of a large trend affecting all fish in the ocean — something related to climate change seems most likely.

One of the technical reports prepared for the Cohen Commission, a report which has been generally overlooked by the media and environmental groups,  includes this very interesting conclusion which has implications for all salmon stocks, and also for farmed salmon, which share the same ocean.

most Fraser and many non-Fraser sockeye stocks, both in Canada and the U.S.A., show a decrease in productivity, especially over the last decade, and often also a period of decline starting in the late 1980s or early 1990s.

Thus, declines since the late 1980s have occurred over a much larger area than just the Fraser River system and are not unique to it.

This observation that productivity has followed shared trends over a much larger area than just the Fraser River system is a very important new finding. It is particularly noteworthy that the shared downward trend in productivity starting in the late 1990s for most B.C. sockeye stocks is similar to trends shown by Lake Washington sockeye (to the south of the Fraser River), as well as Alaskan sockeye stocks from Southeast Alaska and the adjacent Yakutat peninsula in Alaska.

In contrast, western Alaskan sockeye populations have generally increased in productivity.

The large spatial extent of similarities in productivity patterns that we found suggests that mechanisms that operate on larger, regional spatial scales, and/or in places where a large number of correlated sockeye stocks overlap, should be seriously examined in other studies, such as the ones being done by the other contractors to the Cohen Commission.

For example, large-scale phenomena such as climate-driven oceanographic changes, or widespread predation or pathogen-induced mortality, might be major drivers of the observed decreases in productivity throughout the region through effects on freshwater and/or marine conditions.

Something is going on out in the ocean where fish stocks overlap. Where is that? Their feeding grounds in the North Pacific.

But we know virtually nothing about what happens to salmon after they leave B.C. and Alaska coastlines, heading to the North Pacific to feed and grow.

This is an area of research that desperately needs to be explored.

We need to look at the whole picture, to see the forest for the trees, or the ocean for the salmon, so to speak.


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