January 20, 2021 — The following was released by NOAA Fisheries:
The population of gray whales that migrate along the West Coast has declined about 24 percent since 2016. It now stands at an estimated 20,580 whales, a new population assessment (PDF, 7 pages) has found. That is similar to previous fluctuations in the Eastern North Pacific population that has long since recovered from the days of whaling.
The decline coincides with an ongoing Unusual Mortality Event that NOAA Fisheries declared in 2019 for gray whales when strandings increased on the West Coast. It resembles a similar 23 percent decline documented after an unusual mortality event 20 years earlier, in 1999 and 2000. The gray whale population rebounded following that previous UME to greater numbers than before.
The continuing change in gray whale numbers “suggests that large-scale fluctuations of this nature are not rare,” scientists wrote in a NOAA Fisheries Technical Memorandum that reports the new estimate. “The observed declines in abundance appear to represent short-term events that have not resulted in any detectable longer-term impacts on the population.”