In 2014, Fisheries and Oceans Canada proposed a 3-year program to evaluate the effect of smolt size and age on the migration timing of Fraser River Sockeye Salmon out of the Strait of Georgia by conducting a weekly sampling program in southern Johnstone Strait with a purse seine. We proposed to use DNA analyses to infer stock-specific migration timing through this area and, combined with the sampling in the Lower Fraser River (Evaluation of abundance and stock composition of downstream migrating juvenile Sockeye Salmon in the lower Fraser River), provide accurate estimates of residence time within the Strait of Georgia at the Conservation Unit (CU) level. In addition, by examining changes in the relative abundance of different CUs between the lower Fraser River and Johnstone Strait, this study was expected to determine whether mortality rates differ among CUs within the Strait of Georgia. In addition, we proposed to assess the feasibility of using hydroacoustics as a tool to monitor how the abundance of juvenile Salmon changes over time in this area.
S16-I25 Migration timing of juvenile Fraser River sockeye in Johnstone Strait Interim Report 2016
The Pacific Salmon Treaty (PST) Chum Annex requires biological benchmarks to inform the development of fishery reference points for PST related fisheries, including the lower fishery reference point for the Johnstone Strait fisheries as well as subsequent terminal fisheries. Biological benchmarks for data-limited populations have been proposed and are currently being applied to Conservation Units (CUs), or population units, of chum salmon in southern BC. The first phase of this project evaluated percentile-based benchmarks for data-limited CUs of chum salmon on the Inner South Coast of BC. Our preliminary results suggest that the 25th percentile lower benchmark is more precautionary than the stock-recruitment based lower benchmarks developed under Canada’s Wild Salmon Policy, except when CU productivity is low and historical harvest rates are high.
For 2016, we will expand our evaluation of percentile-based benchmarks to include the west coast of Vancouver Island and Fraser River, and expand our use of assessment models to include hierarchical multi-CU models. Finally, we will provide recommendations on the application of benchmarks to chum management units (through component CUs within management units) and chum salmon Genetic Units, as identified by a project funded by the PSC SEF on genetic stock identification, on the west coast of Vancouver Island and in the Fraser River within the context of the PST Chum Annex.
S16-I05 Adapting benchmarks of biological status for persistent changes in productivity and variability in exploitation history with a focus on data-limited populations of chum salmon in southern BC
S15-I13 Adapting benchmarks of biological status for persistent changes in productivity and variability in exploitation history with a focus on data-limited populations of Chum Salmon in southern BC.