Exploring protection priorities for Southern Resident killer whale foraging areas

• Main Author: Robertson, Frances
• Format: Text
• Language: English
• Published: Western CEDAR 2022
• Subjects: San Juan; Killer Whale; Killer whale
• Online Access: https://cedar.wwu.edu/ssec/2022ssec/allsessions/522

The traditional core summer critical habitat of the endangered Southern Resident killer whales (SRKW) is located in the heart of the Salish Sea. Important foraging habitat, and fishing grounds for Coast Salish Tribes, commercial and recreational fishing lie along the westside of San Juan Island. The popularity of the area with local user groups and the fact that the whales are more vulnerable to disturbance from vessel noise and presence when they are feeding has made this area a priority for implementing management policies to reduce the impacts of vessels during critical foraging activities. The goal of this study was to define defensible management options that would allow the whales greater accessibility to their already scarce prey, Chinook salmon. A combination of acoustic and whale foraging hotspot studies were conducted along with a community engagement effort to inform social values and attitudes of local user groups. During 2019-2020 200 days of acoustic data were collected at four locations off the southwest side of San Juan Island. Key SRKW feeding areas were identified using data collected between 2003-2020. Focused surveys and targeted interviews provided an assessment of community values for the area. High priority foraging areas did not overlap with high boat use to the extent expected. Boat use varied across the study area with the highest boat and echosounder use detected in the areas also popular with recreational and commercial fishing, however, areas with the highest probability of foraging occurred along the southern edge of San Juan Island with the highest proportion taking place on Salmon Bank. Mandatory go-slow zones received wide support compared to no-go zones, but a combination of approaches may be required to achieve a balance that is both protective of the whales and continues to offer traditional uses by Tribes and the community.