Research team scores lucky sighting of rare North Pacific right whales near Bristol Bay

Aug 24, 2017

During POWER survey that began in late July, two right whales were heard, then spotted, allowing researchers to photograph and take biopsy sample of critically endangered species.

North Pacific right whale spotted Aug. 6, 2017, about 50 miles east of Bristol Bay.
Credit NOAA Alaska Fisheries Science Center

“Even after so many years of doing field work, sometimes you are still left amazed. Because every now and then the stars all align, and everything works out exactly as you hoped it would. Today was one of those times, because we found that needle in the haystack,” wrote Jessica Crance on August 6.

Crance is a research biologist at the Alaska Fisheries Science Center’s Marine Mammal Laboratory and is spending 60 days this summer in the Bering Sea on board the Yushin Maru #2, part of Pacific Ocean Whale and Ecosystem Research (POWER) survey for the International Whaling Commission.

The needle in the haystack was sighting a pair of North Pacific right whales in the eastern Bering Sea, about 55 miles “east of their critical habitat inside Bristol Bay.” Crance, whose work focuses on listening for whales, first heard the two whales early that afternoon. Her network of deployed sonobuoys detected their calls.

“Around 3:45 this afternoon, while listening to a group of very chatty killer whales and some walrus, I heard a faint upsweep, and then one more. Not wanting to get my hopes up, since it could easily have been a humpback whale, I waited, until finally I heard it. The faintest gunshot call - so quiet I almost missed it,” Crance wrote.

Jessica Crance deploying a sonobuoy to listen for marine mammals, including the North Pacific right whales which she heard (and spotted) on Aug. 6.
Credit B. Rone / NOAA AFSC

It was tough to triangulate the exact location, but the whales were estimated to be at a distance of 10 to 32 miles from the vessel. After a “frustrating” few hours trying to close in for a visual sighting, Crance worried that the day’s survey would end and the chance would pass. The whales had “stopped vocalizing.”

With just 15 minutes left, the research team’s luck changed and the North Pacific right whales announced themselves again. The vessel closed in to take stunning photos and gather a biopsy sample from one.

“We are all elated,” she wrote. “The information obtained from this survey will help us better understand the population dynamics of this critically endangered species, and help guide conservation and management efforts in the future.”

This survey is the eighth of its kind, and the first to make use of an acoustic component, according to an Alaska Fisheries Science Center press release. There is a reason the scientists, including Crance, are particularly interested in the North Pacific right whale: they are not just rare, but considered “critically endangered.”

“At one point, some of the scientists at our center estimated that the North Pacific Right Whale population was once around 15-20,000 animals. Now it’s estimated to be around 30-50 animals in the Eastern North Pacific,” said Maggie Mooney-Seus, the AFSC communications manager.

Little is known about North Pacific right whales compared to similar species, and the researchers hope to be able to use the data collected from the whales to accelerate their understanding of the whales’ health, genetics, migration patterns, habitats, and breeding.

“We really don’t know anything about this species, where it spends most of the year, where it’s mating, raising its young and so this gives us a lot of good information. We’re excited because we haven’t had many of these opportunities over the last decade or so,” said Mooney-Sues.

The North Pacific right whales can grow to 59 feet long and adults weigh an average of 132,000 pounds. They can also live as long as 70 years. According to NOAA’s Alaska Fisheries Science Center, their population “pre-exploitation” likely exceed 11,000, but that the species was “heavily impacted by whaling, especially by large, illegal catches that were made by the former Soviet Union in the 1960s.” While their exact migration patterns are unclear beyond spending summers feeding at high-latitudes and winters in more temperate waters, right whales have often been seen in one area of western Bristol Bay between May and early November.

The survey is expected to continue during the summers of 2019 and 2020, moving the focus to the Central and then the Western Bering Sea in the coming years.

Reach the author at liam@kdlg.org or 907-842-5281.