Endangered Puget Sound Orca Died While Pregnant, Scientists Learn

Ashley Ahearn, KUOW

Scientists determined this weekend that the dead orca that washed up on Vancouver Island last Thursday was pregnant when she died.

The young female was a member of the endangered southern resident killer whale families of Puget Sound.

Experts who conducted the necropsy on the whale said her fetus was between 5 and 6 feet long – about a half the length of the mother. The fetus was already decomposing, suggesting to scientists that the mother was attempting to expel her stillborn calf when she died.

Ken Balcomb is the head of the Center for Whale Research and helped conduct the necropsy.

He said the loss of a female of reproductive age is a blow – especially since the babies aren’t surviving.

“Over the last two and a half years we have not had any calves survive and of course 100 percent mortality in offspring is not good for future,” Balcomb said.

Balcomb and others believe that lack of food and high levels of pollution in the orcas bodies are to blame for the low survival rates of the young.

He said whales are now swimming one thousand miles or more in search of salmon to eat — a species that is also endangered.

“So when they don’t have a lot of food they have to metabolize their body fat, their blubber, and that’s when it starts affecting their reproductive and immune systems,” Balcomb said.

He said the dead orca, known as J32 or Rhapsody, was “not in great condition. The fat content seemed to be quite low and her blubber layer was not that thick.”

There are just 77 southern resident killer whales left.

The bodies of the orca and her fetus have been taken to Vancouver for further testing.