Anderson, James J. “Decadal Scale Climate Pattern and Salmon Survival: Indicators, Interactions and Implications.” ms. Proceedings of the NMFS Workshop on Estuaries and Ocean Survival of Salmon. Newport, Oregon. March 1996. 8 pages. (reviewed by Laura Johnson)
Summary:
The author supports an “ecosystem perspective” for the management of fisheries, with more analytical factors than are currently in use. The author argues the climate and ocean condition variation are important factors in Columbia River salmon survival, even though they have been ignored in adaptive management regimes since the 1860's. His rationale is that previous stock recruitment attempts may not have failed if this major factor had not been left out. For example, the catch decline in 1920 (before major damming projects) corresponds with a switch in the Pacific Northwest Index (PNI) rainfall, snow pack and air temperature to a warm/dry regime from a cool/wet regime, and harvest regulations were not able to make up for the decrease in salmon survival. Conversely, the cool/wet regime in the 1940's may be what buffered a sharper decline in salmon during major hydro-development enterprises. Unfortunately, these speculations about the susceptibility of salmon to climate change cannot be fully supported because we have no solid data on stock numbers and survival prior to the start of European American influence on the runs of the fish.
This manuscript from a 1996 conference proceeding contains 9 figures showing the predicted and actual harvests from the Columbia River during three major periods of management perspectives, the steps in an adaptive management experiment, and how major changes in the PNI coincided with changes in harvest, and the beginning of hydro-system development and fish transportation programs. The figures are at times difficult to read. The bibliography is short and varied, with works pertaining to salmon survival, climate change and salmon populations.
Critique:
As a work to be presented during a conference I feel that perhaps the argument of this paper may have been bolstered by the arguments of others submitted and present at the same conference. The author's suggestion that climate change and ocean conditions may be major factors in decadal fish survival is intriguing and plausible; however his reasoning is not compelling. This is of course a major flaw of all non-experimental scientific papers.
This is another area where for practical purposes, natural history overlaps with European American action on the Columbia River. Due to the ever-changing nature of water, for all intents and purposes written or possibly oral histories are the way we can apply to the analysis of the correlation of fish survival with climate. I appreciated that the author did not suggest that ocean and climate variations are the only factors missing from current salmon stock recruitment models. An “ecosystem perspective” of fish survival is by necessity the evolving study of fish characteristics (physiology, behavior, and genetics) in addition to their response to changes in the environment. This is an insightful paper, and potentially a good place to begin to harvest sources for research on the topic of salmon survival.
Robert D. Clark Honors College, University of Oregon
HC 441: Science Colloquium, Columbia River Ecology
Fall term, 2005
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