Washington Killer Whales Affected By Engine Noise Interfering With Their Sonar

Washington state coastal waters are home to a pod of the most endangered killer whales on the planet. The group, which has shrunk to fewer than 77 individuals, spends its time between the Washington coast and the Alaskan panhandle. This particular family has been under constant watch by conservation groups, who think the rate of population decline is caused by human interference from boats and pollution.

Washington killer whales, unlike other orcas around the world, live primarily on salmon. They are among the ocean’s most formidable predators. They hunt in packs, and a group of them working together can clobber whales much larger than themselves. In fact, they have been called “The Wolves of the Sea.”

But killer whales have been the subject of great media attention with the emergence of the documentary film, Blackfish which exposed an insider’s view of practices at Sea World. A captive killer whale is not a happy creature. In October, the Coastal Commission placed a ban on captive orca breeding at Sea World in San Diego.

However, life in captivity isn’t the only thing that poses a problem for killer whales. The Washington Post published a study by PeerJ, an environmental sciences magazine, entitled, “Ship noise extends to frequencies used for echolocation by endangered killer whales.”

This may not come as a surprise to anyone who has ever snorkeled around boats. The sound travels far and the throb of an engine can feel like it’s going right through you. But just imagine if you were also equipped with sonar, and the way you communicate is through hearing and vibration in a world where sound can travel uninterrupted for miles. In fact, this is one of the factors that makes captivity so hard on whales and dolphins. As Jane Goodall said, they are living “in an acoustical hell.”

Scott Veirs of the Beam Reach Marine Science and Sustainability School indicated that low-frequency sound in the ocean had increased tenfold since the 1960s. But he wanted to see if higher frequencies had gotten noisier too. The low rumblings that ships make are on a frequency that would disturb humpback whales and sperm whales. But the study showed that the higher frequency noise of ships are also at a pitch that would disturb killer whales and dolphins. Viers indicated to the Guardian that it wouldn’t be difficult to change the noise level, because the technology already exists.

“It should be easy to reduce noise pollution. Military ships are quite a bit quieter and there could be straightforward ways of transferring that technology to the commercial fleet.”

But even without implementing these changes, Viers said there are other ways to decrease the noise level in the ocean. One way is to simply slow the craft down.

“Decreasing speed by six knots could decrease noise intensity by half,”

Viers’ studies were done in the Pacific Northwest, but it does lead one to wonder if noise pollution was the driving force behind all the beaching of the sperm whales in the North Sea, earlier this year.

Noise is just one of the many modern problems killer whales face. The warming of ocean currents are causing toxic algae bloom and toxins in their blubber. Prey is decreasing in numbers. As the climate changes, adaptation is demanded. This is nature’s way. One hopes for the best for the killer whales. As life gets tougher, the surviving prey seem to be getting more inventive. One could think that in some cases, boats and whales and prey have lived together for so long, they may be striking a sort of balance.

A seal escaped a pod of killer whales by jumping aboard a fisherman’s net and hitching a ride to safety in this video posted in the Bangor Daily News.

Seals are often considered a nuisance by fishermen along the Maine coast, as they are notorious for raiding the fish traps. The fishermen don’t discourage killer whales from hunting them. But who could resist the ingenuity of this little guy? Apparently they decided he deserved to live, so they let him come along for the ride.

It calls to mind this video of a penguin who did a similar thing. It’s a bit of a nail-biter, but be sure to hang in there until the end.

[Photo via Shutterstock]