The Chum Technical Committee (TCChum), in consideration of the requirements of the latest version of Annex IV, Chapter 6 (Chum Annex) of the Pacific Salmon Treaty, has determined that a significant amount of stock assessment work should be undertaken by the parties, in order to provide the level of information necessary for the successful implementation of the Annex. Part of implementing the strategic plan (Figure 1), the TCChum submitted various proposals over the last few years to target key components of the plan. In 2014 the first phase of the Chum Genetic and Environmental Management model (ChumGEM) was initiated to develop a run reconstruction model for Southern BC and Washington Chum salmon.
Through the initial work on ChumGEM, it was very apparent that the diversion of chum salmon stocks through the southern route (Strait of Juan de Fuca) was a significant gap in our information needed to populate the model. Currently the model structure is available to incorporate this information, but we are making assumptions on the migration pathways that require investigation and validation through this project.
The Southern Panel has identified the establishment of a chum sampling program for the Strait of Juan de Fuca as a top research priority for the next call for proposals through the Southern Endowment Fund for 2016.
Strait of Juan de Fuca Sampling Program:
With the goal of stock reconstruction for Southern BC and Washington Chum salmon, one significant data gap is the diversion of chum populations through the Southern Route via Juan de Fuca Strait. This project will work towards addressing that data gap by sampling this migration route in both US and Canadian waters to determine:
- The spatial and temporal stock composition of chum salmon migrating through the Southern Diversion route,
- Provide sampling platform for stock identification, migration rate studies etc.
- Develop time series of Catch per Unit effort data to pair with the Johnstone Strait Test Fishery to determine diversion rate of various chum populations.
This multi-year program will be broken into 2 phases. Phase 1 will involve assessing the feasibility of a structured sampling program (2016) in Juan de Fuca Strait (Canadian Area 20 and US Area 5). This will involve chartering a Purse Seine vessel to fish 4 days/week starting the 1st week of October for 5 weeks. Catch per Unit Effort information will be collected as well as biological samples for stock identification purposes. All fish will be released except for the 400 samples/week (a total of 2,000 chum) that will be collected during the program. Phase 2, dependent upon the 1st year of the program, will expand the sampling program to include a tagging component to evaluate the migration rates of chum salmon via migration route which is a key parameter in the reconstruction model (2017-2019).