Abundance and migratory phenology of eastern North Pacific gray whales 2021/2022

The Southwest Fisheries Science Center (SWFSC) regularly conducts shore-based surveys of eastern North Pacific (ENP) gray whales (Eschrichtius robustus) to estimate abundance. These estimates are obtained from visual survey data collected off central California between December and February during the gray whale southward migration and provide regular updates to a time series of abundance estimates that began in 1967 (Laake et al. 2012; Durban et al. 2015, 2017; Stewart and Weller 2021a). In 2016, abundance was estimated at 26,960 (95% Credible Interval = 24,420-29,830) whales, indicating that the population had roughly doubled since 1967 when it was estimated at 13,426 whales (95% Confidence Interval = 10,952-15,900; Table 1). Since 2016, however, the population declined to 20,580 whales (95% Credible Interval = 18,700-22,870) in 2020 (Stewart and Weller 2021a). This report presents a new estimate of abundance for ENP gray whales migrating southward off the central California coast between December and February 2021/2022. 2022 NMFS (National Marine Fisheries Service) SWFSC (Southwest Fisheries Science Center) Submitted https://doi.org/10.25923/x88y-8p07 Public Domain 2256