Between January 1, 2019 and February 8 of this year, 613 stranded gray whales have been found along the west coast of North America between Puerto Vallarta, Mexico and the Chukchi Sea in northern Alaska. Eight were found along the coast between South Humboldt Bay and the Oregon border. This has been declared an Unusual Mortality Event (UME)...Photo credit: NOAA Fisheries. ...by NOAA Fisheries, which studies marine mammal population trends and mortality. The cause has yet to be determined, but several of the dead whales have shown evidence of emaciation, suggesting that changes in ocean conditions may be a contributing factor. A similar UME event happened in 1999-2000, when 650 gray whales stranded along the West Coast. The population eventually recovered, peaking at around 27,000 in 2016. However, after this recent UME, the NOAA Fisheries reported a 38 percent decline to 16,650 Eastern Pacific gray whales in October 2022. The cause for these population fluctuations remains unknown, but gray whale populations have shown long-term resilience in rebounding from near extinction during whaling to these recent UME events.There are currently four other active UMEs in North America, all in the Atlantic Ocean, where humpback whales have died in unusual numbers since 2016 due in large part to vessel strikes. Although some news reports have attributed these deaths to offshore wind energy research vessels, most of these whale deaths were reported before offshore wind activities began, pointing to shipping traffic as the main culprit. Because slower vessel speeds can prevent marine mammal injuries, Humboldt Baykeeper and other environmental groups successfully advocated for a speed limit. In April 2022, the Coastal Commission adopted a 10-knot speed limit for offshore wind activities.If you see a stranded whaleCal Poly Humboldt Professor Dawn Goley has been studying marine mammal biology in northern California and southern Oregon since 1996. As the Director of Humboldt's Marine Mammal Stranding Program, she said that "it is most helpful when people reporting stranded marine mammals include their names and contact info along with an exact location of the stranding, a detailed description - including general size, type (seal/sea lion or a whale/dolphin), and information about any unusual markings, tags, or entanglements. Photos or videos of the body and head are incredibly helpful and always help us plan an effective response."To report a stranded whale, dead or alive, contact the Cal Poly Humboldt Marine Mammal Stranding Program at 707-826-3650 or send an email to
