Puget Sound Orcas Presumed Dead

Scientists at the Center for Whale Research have been carefully tracking the population of orcas, or killer whales, in the Puget Sound, and seven of the orcas are missing and presumed to be dead. They say that this could be the biggest drop among the orcas in nearly a decade. "This is a disaster," says Ken Balcomb, a senior scientist at the center. "The population drop is worse than the stock market."

The group of whales that have vanished includes two young females who recently gave birth to calves, as well as one leader of the three southern resident pods, who is 98 years old. One of the young calves is also missing. Scientists say it isn’t unusual to lose older or younger whales, but losing two females in the reproductive prime of their lives is a bit concerning since they typically have a high survival rate.

One of the missing female whales, called L-67, was expected to bear two or three more calves, Hanson said. One of her previous calves, known to scientists as Luna, made headlines seven years ago when he somehow became separated from his pod and turned up off the coast of Canada’s Vancouver Island. Five years later, a killer whale was killed in that area when it was hit by a tugboat propeller, and that whale was believed to be Luna.

Hanson said that before she disappeared in September, Luna’s mother was showing signs of emaciation. It definitely showed she was not eating, but researchers did not know why. They collected samples from her a few weeks before she disappeared, and now they are conducting tests to see if they can figure out what was causing her not to eat.

Chinook salmon, which are a preferred food for these whales, were not as prolific this year as in previous years, and that may be a factor in the high number of orca deaths this year. "It was a bad salmon year and that’s not good for the whales," Balcomb said. "Everybody considers these wonderful creatures, but we really have to pay attention to the food supply." According to Howard Garrett, director of the Orca Network, the whales seem to be having a harder time finding the salmon and have been traveling over greater distances than usual, supposedly ranging farther for food.

The three pods that live in the inland marine waters off the coast of Washington are genetically and behaviorally different from other killer whales. They mate only among themselves, they eat salmon instead of other animals, they make sounds that researchers believe are a unique dialect, and they are particularly attracted to that region of the ocean. Over the last century, the combined population of the pods reached 140 or more, but their numbers have fallen in the last few decades, with only 83 remaining. They were listed as endangered in 2005.

Pollution and the low numbers of salmon may be the primary causes of concern for the whales, but other threats have been underwater sonar tests conducted by the Navy and stress from increased numbers of whale-watching tour boats in the area. In the late 1960s, the population dropped when dozens of orcas were captured for transport to marine parks. The whales seemed to be coming back in recent years, growing to a population of 90 just three years ago. But now the population appears to be in a decline again. A 6-year-old male among the missing is Luna’s brother, and a calf that was born in November is missing, believed to have not survived the winter.

Researchers are hopeful that the whales may appear somewhere else, as Luna did before he was killed accidentally. The populations may increase if more baby orcas are born this fall. But for now, the declining numbers are troubling as scientists keep a careful watch. "We’ve been monitoring," Balcomb said. "They’re just gone."