Proceedings 2016/028

Proceedings of the Pacific regional peer review on An Evaluation of West Coast Vancouver Island Chinook Salmon Visual Spawning Escapement Estimation Methods; July 8, 2014

Chair and Editor: Lesley MacDougall

Summary

Canada assesses the escapement of West Coast Vancouver Island (WCVI) Pacific Salmon Treaty (PST) extensive indicator stocks relative to escapement goals annually and estimate the abundance for the entire WCVI Chinook salmon management unit as part of the implementation of the Chinook Salmon Annex of the PST and meet other domestic management needs under the Wild Salmon Policy.

Mark recapture studies and/or fence counts are conducted for other Chinook Salmon systems under the terms of the Chinook Salmon Annex of the Pacific Salmon Treaty (PST) but are considered infeasible for WCVI Chinook Salmon systems. Instead, escapement estimates for WCVI Chinook Salmon systems are determined using periodic visual surveys and an Area Under the Curve (AUC) estimation procedure. To address concerns regarding the potential bias of the AUC procedure and the difficulties associated with identifying uncertainty in AUC estimates, Fisheries and Aquaculture Management requested the evaluation of alternate visual survey escapement estimation methodologies relative to information gained from independent studies and simulation modelling. A Maximum Likelihood (ML) method has been developed and explored. 

These Proceedings summarize the relevant discussions and key conclusions that resulted from the Fisheries and Oceans Canada (DFO), Canadian Science Advisory Secretariat (CSAS) Regional Peer Review meeting of July 8, 2014 at the Pacific Biological Station in Nanaimo, B.C.  One working paper focused on Chinook Salmon Escapement Estimation and Stock Aggregation Procedures was presented for peer review, to provide advice respecting the applicability of the new approach for escapement estimation of WCVI Chinook Salmon index stocks. Additional publications from this meeting will be posted on the Fisheries and Oceans Canada (DFO) Science Advisory Schedule as they become available.

In-person and web-based participation included Fisheries and Oceans Canada (DFO) Science Branch, DFO Fisheries and Aquaculture Management, members of the Chinook Technical Committee (Pacific Salmon Treaty [PST]) and Sentinel Stock Committee (PST), representatives from the Alaska Department of Fish and Game, Oregon Department of Fish and Wildlife, the Washington Department of Fish and Wildlife, and the National Oceanic and Atmospheric Administration, First Nations, Academia and Non-Government Experts.

The discussions during this review, and the subsequent editorial review of revisions, resulted in the rejection of this Working Paper.

Complete document (PDF, 258 KB)

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