Researchers sound alarm over health of 13 endangered southern resident orcas

Researchers in Washington state are sounding the alarm over the health of the southern resident killer whale population, saying at least 13 of the orcas appear to be in poor condition.

The Washington Department of Fish and Wildlife also detected several pregnancies among the endangered population in research conducted between September 2021 and April 2022.

Studying aerial drone images of the mammals, researchers say 12 members of the J- and L-pods were found to be in poor health, based on measurements of fat behind the skull. The lack of girth puts the orcas at two to three times higher risk of mortality, according to SR3 Sealife Response Rehabilitation and Research.

The researchers say the images also showed three K-pod orcas were in the last nine months of pregnancy in September 2021, and possibly in the last six months. The researchers say a typical full pregnancy term lasts from 17 to 18 months.

"Based on recent online videos showing a calf with K-pod, it is likely that at least one of these pregnancies was successful," according to a statement from the state wildlife department.

The researchers believe two L-pod orcas are also pregnant, including one of those believed to be in poor health.

The group also identified two young orcas, J53 and L123, that were showing slower-than-expected growth, with J53 exhibiting poorer-than-average body condition.

Aerial photographs show fat deposits behind the skulls of southern resident orcas have apparently shrunk among several southern resident orcas. (SR3 Sealife Response Rehabilitation and Research)

"While we have reason to remain hopeful with the reports of recent pregnancies, the reality is that there are several southern residents that aren’t doing well and we’re very concerned about the population at large," said WDFW director Kelly Susewind.

"We’re taking action today to address these immediate concerns, and we continue working with our partner organizations to implement the governor’s task force recommendations for the long-term health of these orcas," Susewind added.

The task force recommendations include efforts to restrict pollutants and limit vessel noise in local waters, while also promoting growth in salmon populations, a dietary staple for the southern resident orcas.

Washington state is also implementing an emergency order requiring whale-watching vessels to keep at least half a nautical mile – or 926 metres – from southern resident orcas over the summer, saying all other boaters are urged to follow suit.

On the Canadian side of the border, federal regulations require vessels to keep at least 200 metres from all orcas off British Columbia, except in southern coastal waters of the Salish Sea stretching from Campbell River to Victoria to Tofino, where vessels must keep a distance of 400 metres.