What’s Killing These Critically Endangered Whales?
It has been another calamitous year for the critically endangered Southern Resident killer whales of the Pacific Northwest.
On Thursday, the carcass of an 18-year-old female orca was discovered near Courtenay, British Columbia, in Georgia Strait. The whale, which was believed to be pregnant, was identified as J32, also known as Rhapsody.
It was the fourth death of a Southern Resident orca in 2014, leaving only 77 of the marine mammals in the wild. Making matters worse, there have been no successful births among the population for more than two years.
Rhapsody—whose mother, J20, died in 1998, when Rhapsody was only two—was raised by her aunt, J22, known as Oreo.
“It’s very bad news,” Naomi Rose, an orca expert and a marine mammal scientist at the Animal Welfare Institute, said in an email.
“A young reproductive female, even if she wasn’t pregnant as they think she might have been, is a huge loss for this population,” Rose said. “No births in two years and four deaths in one year? Do the math—this population is heading nowhere but down, and it has to stop or we’re going to lose them.”
The four deaths this year come on top of the loss of four other Southern Residents between 2012 and 2013, and another five dead whales between 2011 and 2012. The total population fell from 89 to just 77 members—a decline of more than 13 percent.
“This loss brings the overall number of Southern Resident orcas below their number in 2005, when they were listed as endangered under the Endangered Species Act,” the Washington state–based Orca Network said in a statement.
The last surviving Southern Resident calf was born in August 2012, according to the nonprofit conservation group.
The fish-eating Southern Resident population is divided into three distinct groups, known as J, K, and L pods.
Last October, a seven-week-old calf, L120, was reported missing when its mother and other members of L pod were spotted in the Strait of Juan de Fuca without the newborn. Two other Southern Residents—L53, or Lulu, a 37-year-old female, and a 13-year-old male, L100, or Indigo—were reported missing earlier this year and are presumed dead.
It was not immediately known why Rhapsody died.
“A necropsy Saturday led by Dr. Stephen Raverty will reveal if she was indeed pregnant and hopefully will find the cause of death,” the Orca Network said. “She was believed to have died in the past 24 to 48 hours.”
There are several contributing factors to the decline of the Southern Resident population, which has suffered far more losses than its Northern Resident counterparts in British Columbia. Those animals, whose numbers are rebounding, are listed as threatened, but not endangered, by the Canadian government.
In the 1960s and 1970s, more than 50 Southern Residents were killed or captured by whale hunters working for theme parks such as SeaWorld. Only one, Lolita, at Miami Seaquarium, is still alive today.
PCBs and other toxins polluting Puget Sound build up in the bodies of the whales, leading to increased illness and reproductive problems.
“Southern Resident habitat is far more polluted than it is for the Northern Residents…they live in a very urban environment,” Rose said. The southern pods have far higher concentrations of pollutants in their tissues than the northern population.
“They are toxic waste,” Rose added.
But the biggest threat to the whales is likely a steep decline in the region of the number of Chinook salmon— the orcas’ preferred prey because of its high-fat, high-calorie content. Pollution, overfishing, and dam construction have severely limited Chinook salmon runs over the past decades.
Some dams in the area are being demolished, including two on the Elwha River on Washington’s Olympic Peninsula.
But it could take years for the Chinook population to rebound. The Southern Residents may not have that long to wait. As the old Pacific Northwest Native American saying goes: “No fish, no blackfish.”