Humpback and Blue Whale Photo-ID Project – US West Coast


Two humpback whale flukes show the wide variation in markings

The dorsal fin and pigmentation pattern on the side of blue whales provide a fingerprint for identification.

Cascadia Research conducts long-term research on humpback and blue whales both along the West Coast of the United States as well as off Central America. We began this photo-identification research in 1986 and have continued annual surveys each year since. This photo-ID effort serves as the basis for the abundance estimates and trends for these species off the US West Coast. Cascadia also relies on contributions from a number of opportunistic sources (including citizen science) as well as collaborators to provide sighting information along with the photo-IDs. Through 2022 the humpback catalog includes more than 7100 unique individuals with just under 102,000 encounters of those individuals. And as of 2022 Cascadia’s blue whale catalog includes over 2700 individuals with over 19,000 encounters. In 2018 Cascadia Research under a contract with the National Oceanic and Atmospheric Administration (NOAA), Southwest Fisheries Science Center (SWFSC) took park in the California Current Ecosystem Survey (CalCurCea) and was able to conduct small boat surveys all along the US West Coast from northern Washington to southern California. For this project Cascadia followed a NOAA ship conducting line transects and surveyed areas of known whale concentrations collecting photo-ids and biopsy samples. Cascadia was also the principal organization conducting and coordinating the SPLASH humpback whale research effort from 2004-2006,and Cascadia was conducting the matching but also coordinated all efforts for US West Coast and Central America. Starting in 2020 Cascadia helped organized a SPLASH-2 effort with funding from NOAA. This effort did not include a field component but was more centered around pulling together researchers studying humpbacks since the initial SPLASH effort top help update the abundance calculation of humpbacks in the North Pacific Ocean and to update migratory pathways.


The objectives of our research include:

  • Determine the abundance of humpback and blue whales off California
  • Determine trends in these populations
  • Identify critical feeding habitats that need protection
  • Monitor potential human-caused threats to large whale populations off California including ship strikes and sonar impacts

See additional information in these reports and publications by topic:

Humpback and blue whales off California, Oregon, and Washington

Please click here to be taken to a searchable page for all of Cascadia’s publications.

Underwater behavior of blue, fin, and humpback whales using a variety of tags (suction-cup tags, satellite, etc.) 

Humpback whale research in Central America

To learn more about these research efforts please see the following:

SPLASH research project