West Coast Marine Mammal Survey Spots Unusual Whales, Dolphins, Turtles and Seabirds

By Michael Milstein, NOAA Public Affairs Officer

An on-going NOAA Fisheries marine mammal and ecosystem survey off the West Coast has sighted several surprising species of tropical cetaceans and birds, including pygmy killer whales and Band-rumped Storm-Petrels, never before documented so far north, and loggerhead turtles, likely attracted by unusually warm Pacific Ocean waters. 

Feresa attenuata and R/V Ocean Starr.PAOlson
Pygmy killer whale in foreground with Research Vessel Ocean Starr in background (photo: Paula Olson).

The survey has encountered strikingly warm sea surface temperatures as high as 23˚ Celsius (74˚ Fahrenheit), which NOAA Fisheries researchers have been watching for months. The warm conditions have been linked to other recent sightings of unusual species of seabirds, fish and marine mammals rarely seen in the northern Pacific.

The recent sightings are part of the four-month CommonAndStripedDolphins_CBoydCalifornia Current Cetacean and Ecosystem Assessment Survey (CalCurCEAS), conducted every three to six years by the Southwest Fisheries Science Center (SWFSC). The CalCurCEAS assesses marine mammals off the U.S. West Coast and tracks conditions that affect the ecosystems in which they live. The findings inform NOAA decisions on West Coast fisheries, ensuring safeguards to protect marine mammals and other protected and endangered species, such as marine turtles and seabirds.

“There’s no substitute for actually getting out on the ocean and systematically surveying the number and location of these animals,” said Jay Barlow, a SWFSC marine mammal biologist who is chief scientist for the survey. “The ocean is always changing, and we need current data to understand how these top predators are doing and how they are responding to ocean conditions.”

The survey began in San Diego in early August and has continued in legs of about 24 days each, crisscrossing waters up to 300 miles off the West Coast north to Washington. The survey coincides with fall whale and seabird migrations and will continue into December. Research scientists describe their findings from each leg in reports available on the SWFSC website.

Among the highlights so far:

The surveys take frequent environmental measurements and sample plankton and marine life such as squid as indicators of ocean conditions and the state of the marine ecosystem. Researchers also deploy acoustic equipment to listen for whale and dolphin vocalizations. The equipment includes a towed hydrophone array, buoys that listen to high-priority species and free-floating recording devices that monitor ocean sounds 100 meters below the surface without noise interference from the research ship.

In one mid-September report researchers recounted recording humpback whale songs once described as a “barnyard chorus.” They identified one humpback whale 0.2 nautical miles from the starboard side of the research vessel. After retrieving the hydrophone array so the vessel could better maneuver, researchers found they could hear the whale vocalizations in the open air.

“Out on the back deck we could actually hear, with our bare ears, the singing humpback whale just behind the boat on the starboard side,” they described. “Out in the open air, it is easy to understand how whale song has inspired decades of research and centuries of curiosity on cetacean vocalizations.”

Reports from future legs of the survey will be posted as they become available.Please contact the Chief Scientist, Jay Barlow, for additional information. 

Pilot whales on left (photo: Paula Olson) and juvenile loggerhead turtle basking in warm waters on right (photo: Mridula Srivivasan)

Red-billed Tropicbird resting on left (photo: Michael Force) and blue whale at surface on right (photo: Paula Olson)