Benchmark Analysis for Pacific Salmon Conservation Units in the Skeena Watershed

Note: The computer code and input data referenced in this report are available here.

Summary

Canada’s Wild Salmon Policy (WSP) calls for the monitoring and assessment of all geographically, ecologically and genetically distinct populations of wild Pacific salmon, known as ‘Conservation Units’ or ‘CUs’. The Wild Salmon Policy states that CUs will be assessed against specific reference points, or ‘benchmarks’, for indicators such as abundance or fishing harvest rate. For each CU, a higher and a lower benchmark is to be defined so as to delimit ‘green’, ‘amber’, and ‘red’ status zones. As numbers of spawning salmon decrease, a CU moves towards the lower status zones and the extent of management actions directed at conservation should increase. The status of a CU does not dictate that any specific action must be taken, but instead serves to guide management decisions in conjunction with other information on habitat, ecology and socioeconomic factors.

Over the past few years, significant headway has been made towards defining benchmarks for Fraser Watershed CUs, however, there has been much less progress towards setting benchmarks for other areas of coastal British Columbia and the Yukon. It is in this context that the Pacific Salmon Foundation (PSF) commissioned the independent analysis that is presented here. This analysis provides a foundation towards developing abundance-based status benchmarks for CUs that spawn in the Skeena River Basin, the second-largest watershed in BC and home to approximately 50 CUs of sockeye, Chinook, chum, coho, and pink salmon. The main objectives of this analysis are:

• derive and explore some possible options for status benchmarks,
• conduct a preliminary independent assessment of the status of Skeena CUs, and
• make available a foundation of computer code for performing stock-recruitment analyses that can be expanded and updated in the future.