Chum salmon catch per unit effort, CPUE, collected from small vessel Nita Maria in Strait of Juan de Fuca from 2018-10-04 to 2018-11-09 (NCEI Accession 0284471)

This dataset contains only cruise report on chum salmon survey in Strait of Juan de Fuca in autumn 2018. Through the initial work on the ChumGEM reconstruction model, 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 the assumptions on the migration pathways being used require investigation and validation. The purpose of this project was to 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.
2018 was the third year of this multi-year program which was initiated in 2016. The program began as planned on October 4th and ran until November 9th. A total of 145 sets were completed (71 in Canadian waters and 74 in US waters). A total of 8,680 Chum were encountered and 1,656 were sampled for stock id and other biologicals. There was a significantly higher Catch per Unit Effort (CPUE) in the Canadian side of the Strait compared to what was encountered in the US. This was the complete opposite as to what was encountered in 2016 but very similar to what was observed in 2017. The catch information demonstrated an bit later timing on the Canadian side of the Strait with a peak CPUE during week 43 and an earlier peak CPUE in the US waters during week 42 (although CPUE in week 42 and 43 were very similar in US waters). Over the period of the program, Chum CPUE was higher in Canadian waters than in US waters except in week 44.
Stock composition information demonstrated that Canadian Chum stocks dominated the samples throughout the program in Canadian waters similar to previous years. US Chum stocks in Canadian waters varied in composition but increased later in the program. In US waters, US Chum stocks dominated the mixtures throughout the program. Stock timing and distribution differences were observed and this new information has improved our understanding of Chum stock composition and timing through the migratory pathways of Juan de Fuca Strait.
This cruise is U.S. State Department MSR U2018-020 as part of the World Data Service for Oceanography. Report is in PDF.