The killer whale population continues to decline in Puget Sound as two new deaths were recorded this year.
Since 2012, there have been no new calves that were born to help increase the number of killer whales, according to The Guardian. It is also worrying that the whales are breaking away from their pods.
Ken Balcomb of Centre for Whale Research noted that in the past couple of years, the whales divide themselves into small groups, which isn't natural, as they usually socialize and hunt in large groups.
The number of whales in J, K and L pods has dropped to 78, its lowest level since 1985, according to a census by the Center for Whale Research (CWR).
Since 1976, Ken Balcomb of the CWR has been researching the Puget Sound orcas, or "southern residents." Balcomb creates an annual census of the population for the federal government, according to The Guardian.
Usually all three pods come together in the San Juan Islands during the summer months, to feed and socialize in large groups, Balcomb said. But recently the pods have been dividing up into small groups, sometimes staying together but often staying apart.
"What we're seeing with this weird association pattern is two or three members of one pod with two or three from another pod," Balcomb said, according to The Guardian. "It's a fragmentation of the formal social structure, and you can see that fragmentation going further. They are often staying miles and miles apart and not interacting.
"If we were trying to name the pods now, we couldn't do it. They aren't associating in those patterns anymore."
Killer whale offspring usually stay with their mothers for life, sustaining identifiable "matrilines" that typically contain youngsters, their mothers and their grandmothers, according to Balcomb. So far, the matrilines have stayed together for the most part, but many of these groups are now smaller.
Balcomb believes the main reason for the population decline is the whales are having a hard time finding food. Killer whales normally hunt chinook salmon passing through the San Juan Islands on the way back to Canada's Fraser River. The whales have a strong preference for the large and fat fish, but they will eat other species of salmon and even other fish occasionally.
"The salmon issue is huge, and it is ongoing," Balcomb said.
The two orcas that are most likely dead are L-53, a 37-year-old female named Lulu; and L-100, a 13-year-old male named Indigo. Lulu's mother died in 2010, and both were members of L pod, the Kitsap Sun reports.