Status of Eastern North Pacific Gray Whales

Gray whales (Eschrichtius robustus) in the North Pacific have complex stock structure, with multiple breeding stocks comprised of various feeding aggregations.  This status assessment focuses on Eastern North Pacific Gray whales (i.e., the Eastern Breeding Stock, EBS), which likely include at least two feeding groups: the large Northern Feeding Group (NFG), and the small Pacific Coast Feeding Group (PCFG).  Aboriginal subsistence hunting by Russia and the US has a combined annual limit of 140 strikes, currently all taken from the northern feeding ground.

The table below shows current IWC assessment model estimates and 90% uncertainty intervals for the 2023 abundance, depletion level, and cumulative 20-year change. 

The most recent direct abundance estimate based on surveys is 14,526 (13,194 – 16,040) for 2022/23 for the entire EBS and 212 (SE=18) in 2020 for the PCFG component. More information about this species is given here and here.

The plot below shows how modelled total EBS abundance has changed over time. This population is believed to experience periodic unusual mortality events (perhaps 20%-45% dying), as seem to have occurred in 1999-2000 and 2019-23.

The PCFG is a small population component which grew in the 1990s and early 2000s and has been relatively stable since then. The EBS population as a whole has increased from historically depleted levels and now fluctuates due to changes in Arctic prey availability and access to feeding areas as mediated by sea ice conditions.  Threats include entanglement in fishing gear, vessel strikes, disturbance from whale watching, ocean noise, habitat degradation, and climate change.

Data quality for this population is good.  This assessment date for eastern North Pacific gray whales is 2023.  Further details about the IWC Scientific Committee (SC) assessment of gray whales are available here. General information about how the IWC SC assesses stock status is here.