2019-2023 Gray Whale Unusual Mortality Event along the West Coast and Alaska

Since January 1, 2019, elevated gray whale strandings have occurred along the west coast of North America from Mexico through Alaska. This event has been declared an Unusual Mortality Event (UME).

Learn more about Marine Mammal Unusual Mortality Events

Donate to the Unusual Mortality Event Contingency Fund

Gray Whale Strandings (as of November 30, 2023)

A previous UME for gray whales occurred in 1999–2000. Below is a graph comparing 2019–2023 gray whale strandings to 1999 and 2000 strandings by month.

Why are Gray Whales Stranding?

Full or partial necropsy examinations were conducted on a subset of the whales. Preliminary findings in several of the whales have shown evidence of emaciation.  These findings are not consistent across all of the whales examined, so more research is needed.

As part of the UME investigation process, NOAA has assembled an independent team of scientists to coordinate with the Working Group on Marine Mammal Unusual Mortality Events to review the data collected, sample stranded whales, consider possible causal linkages between the mortality event and recent ocean and ecosystem perturbations¹ and determine the next steps for the investigation.

¹Northeast Pacific and U.S. West Coast:  NOAA/SWFSC Environmental Research Division

¹Alaska: NOAA/RISA Team-Alaska Center for Climate Assessment and Policy

AOOS 2019 Summary Bering Sea Report

Gray Whales

• Gray Whales Species Profile

• Gray Whales in the Eastern North Pacific

• Laguna San Ignacio Ecosystem Science Program

• Safe Whale Viewing

Interactive Map

2019-2022 Gray Whale Unusual Mortality Event Dead Animal Locations Mapping Application

Report a Stranded or Floating Whale

The most important action someone can take is to immediately report a dead, injured, or stranded marine mammal. Make the report by calling in California, Oregon, or Washington the West Coast Marine Mammal Stranding Network: 1-866-767-6114, in Alaska the Alaska Marine Mammal Stranding Network: 1-877-925-7773, and in Canada, the British Columbia Marine Mammal Response Network 1-800-465-4336.

You can also contact the U.S. Coast Guard on VHF Channel 16. Do not approach or touch injured or dead marine mammals.

All marine mammals are federally protected by the Marine Mammal Protection Act. Only local and state officials and people authorized by NOAA Fisheries may legally handle live and dead marine mammals.

Stranding Networks

• National Marine Mammal Stranding Network

• Alaska Marine Mammal Stranding Network

• West Coast Marine Mammal Stranding Network