January 17, 2025 — NOAA Fisheries scientists have completed a 4-month, roughly 4,500-nautical-mile, survey of marine mammals and seabirds off the U.S. West Coast. They collected a trove of some of the most thorough data and biological samples ever on West Coast whales, dolphins, and other marine mammals.
Researchers also saw immense schools of dolphins, an unusual number of sei whales, and rare seabirds. Scientists said several marine mammal species appear to have shifted north along the coast compared to earlier surveys. That change may reflect their response to marine heatwaves and other ecosystem changes that have become common off the West Coast in the last decade.
“We’re definitely seeing things farther north,” said Jeff Moore, chief scientist of the marine mammal survey led by NOAA Fisheries’ Southwest Fisheries Science Center. He said the survey spotted striped dolphins off the Oregon and Washington coasts, beyond their more typical range in California’s warmer waters. The species may be following their preferred water temperatures and prey.
Details from the survey help inform marine mammal stock assessments required by the Marine Mammal Protection Act and decisions on fishing seasons and areas. We also use the data collected by surveys to help assess the risk fisheries and other activities may pose to the protected species. Expanding the number and types of platforms these observations are taken from will ultimately lead to greater efficiencies in how we conduct these surveys.