The southern resident orcas are struggling for survival.
“This population of animals is so small and is just really hanging by a thread at this point,” said Dr. Deborah Giles, a research scientist at the University of Washington’s Center for Conservation Biology.
The southern resident killer whales diet is the increasingly scarce chinook salmon. The 74 remaining orcas travel up and down the west coast from Alaska to California to hunt for the salmon.
But now there is another threat: increased naval testing and training in Washington state waters.
“It just seems not the right time to be increasing potential impacts to an already hugely, highly endangered population,” said Giles.
The U.S. Navy has tested torpedoes, detonated underwater bombs, and conducted sonar testing off the west coast for decades, with a cap on how many times naval exercises can affect marine animals.
But this year, the number of “level b” harassments, anything that may alter behavioural patterns of feeding, migration, or breeding behaviour (like disturbing loud noises, sonar, or even just getting too close to a pod of orcas) has increased from a maximum of two instances per year to now 51 legal instances of harassment per year, for the next seven years.
“It just another knife, another flesh wound if you will, that’s potentially causing these animals to teeter on the brink of extinction,” said Giles.
The U.S. Navy says they make up less than one per cent of vessel traffic in Puget Sound, but nonetheless, “are committed to balancing national defense and environmental stewardship responsibilities’,” by keeping on the lookout for whales and using passive acoustic detection to avoid harassing marine life.
“The most likely impacts on marine mammals from sonar based on modelling results are short-term, temporary, and non-cumulative behavioural responses,” said the U.S. Navy in a statement to CHEK News.
But because of how stressed the southern resident killer whale population is, researchers say any short-term disturbance, could have huge ramifications.
“These animals are more impacted by marine realm noise and vessel preserve when they’re not getting enough to eat,” said Giles.
Some mitigating measures were written into the new agreement, requiring the Navy to institute shutdowns and delay its activities if marine mammals are sighted within certain distances, and limiting sonar in areas that are important for feeding.
But killer whale researchers say the changes weren’t meaningful enough.