5-year study: West Coast orca population falls to lowest level in almost 50 years

||| FROM NEWSWEEK |||

A population of orca that resides off the West Coast is at its lowest level in almost 50 years, with just 73 individuals now remaining.

The Southern Resident killer whale population has not fallen below this number since 1974, when the first complete count was undertaken.

The Southern Resident killer whale population consists of three pods made up of family groups. They spend the summer in Washington State’s Puget Sound and travel along the West Coast, having been spotted as far south as California, up to Canada.

Population numbers fell in the 1960s as many were captured to be sent to marine parks. This was stopped by the Marine Mammal Protection Act enacted in 1972 and the population started to recover, peaking in 1996 when 97 orca were counted.

But soon after numbers started to decline, falling into the 70s in the 2000s. The population was listed as an endangered species in 2005 and efforts are being made to recover it. The latest report, however, suggests impacts of these efforts are yet to be seen.

The report says a catastrophic event, such as an oil spill, could impact the entire population. It also lists threats such as prey availability, contaminants in the water and interactions with vessels as being highly likely and having a severe impact on the pods.

Dr. Meg Wallen, marine mammal specialist in NOAA Fisheries’ West Coast Region, led the five-year review. She told Newsweek the last five years have seen incredible work and progress in understanding these whales and the threats facing them.

“The Southern Resident population is closely studied and monitored year-round by researchers, government agencies, non-profit organizations, industry, and even the general public,” she said. “So while we knew the number of whales in the population, the results underscore the need for continued focus on the primary threats to the whales’ survival. We hope to see slow, incremental growth with surviving calves each year.”

A study published in 2020 looked at the cause of deaths of orca stranded in the Pacific Ocean between 2004 and 2013. Researchers found calves tended to be killed by infectious diseases, nutritional deficiencies and malformations. Adult deaths were caused by trauma, blunt force trauma, malnutrition, infectious diseases, emaciation, and bacterial infections. The authors concluded that “death related to human interaction was found in every age class.”

READ FULL ARTICLE: www.newsweek.com/orca-killer-whale-population-lowest-level-west-coast-noaa-report-1666254