Fishing for Answers: analysis of ecosystem dynamics, tropic shifts and salmonid population changes in Puget Sound, 1970-1999
2001 | PDF
Edited by Preikshot, D., and Beattie, A.
The impetus for this study arose from the shocking declines in early marine survival rates of South Puget Sound (SPS) coho salmon (Oncorhynchus kisutch) after 1990. This phenomenon coincided with declines in other species and prompted an inter-agency working group1 to seek ways of investigating the ecological relationships between salmon and other marine organisms in SPS. Ecosystem modelling, and the Ecopath with Ecosim (EwE) software in particular were determined as the most efficient method to summarize marine organism relationships in response to changing anthropogenic and environmental stressors. In general, it was hoped that EwE could address the following areas of concern:
More specifically, it was hoped that the EwE approach could elucidate the factors influencing coho early marine survival rates and determine crucial trophic relationships among the organisms of SPS. The EwE modelling of SPS is envisioned as the first phase of a three-phase process to evaluate ecosystem-level processes in Puget Sound. It is hoped that additional funding might be obtained to complete phases two and three. The second phase consists of building ecosystem models for two other sub-regions of Puget Sound: Hood Canal and the 'Central Basin'. The third phase of this process involves the synthesis, evaluation, and potential application of the information derived in phases one and two for use in an ecosystem level assessment of Puget Sound.
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