New legislation, passed by the state Legislature earlier this month, requires boats and vessels in Puget Sound to maintain a 1,000-yard buffer between them and endangered Southern Resident orcas.
But scientists and researchers at Western Washington University’s Salish Sea Institute don’t know if it’s enough, and say more research on the endangered animals is necessary.
The legislation — Senate Bill 5371 — was sponsored by Sen. Liz Lovelett (D-Anacortes), and increased the buffer zone between Southern Residents and vessels from 400 to 1,000 yards.
The goal, Lovelett said, is to help support the recovery of the endangered orca population, which uses echolocation to hunt for meals. Noise disturbance from vessels is contributing to their inability to catch salmon, and degrading existing habitat in the region. Currently, just 73 Southern Resident orcas — ecologically distinct killer whales that hunt chinook salmon — remain in the waters along the West Coast. Other orca subgroups that rely more heavily on marine mammals for sustenance have not experienced similar declines.
“Our constituents have been loud and clear in voicing strong support for taking the hard but necessary steps to protect our iconic resident orcas from extinction,” Lovelett said in a statement the day the legislation passed. “SB 5371 has passed with overwhelming support and shows our commitment to the survival of these beloved creatures who are emblematic of the health of the Salish Sea.”
But a recent whitepaper from the Salish Sea Institute, written by Rob Williams from the Oceans Initiative, said the “right” distance for vessels is yet to be determined.
“On the management side, boaters are being asked to make sacrifices to give the whales space to hunt, and shipping companies are taking an economic hit to slow down to make less noise,” Williams said via email. “These are all valuable efforts. But without an evidence-based target, we won’t know if the whales’ habitat is still too noisy for the whales to thrive, or if our mitigation measures are bold enough to ensure survival and recovery of killer whales.”
Cindy Elliser, a marine mammalogist and associate director of the Salish Sea Institute, voiced similar sentiments.
“The big issue is that we don’t know what that [distance] should be,” she said last week. “If we can figure it out, it makes it easier for policymakers to make the policy changes that would actually be meaningful for the animals.”
Williams said a carrying capacity study is necessary to understand what legislation would support population recovery. Such a study would allow researchers to know what the animals can handle, and what level of noise would be damaging to them.
Williams identified three main threats to population recovery, including access to chinook salmon, vessel noise and contaminants.
“Of these three main threats, reducing vessel noise and disturbance is among the most tractable,” he wrote in his article “How Much Noise is Too Much for Southern Resident Killer Whales in the Salish Sea?” Reducing the vessel noise, he said, would have “immediate benefits” for the population.
The 1,000-yard buffer is complicated, Williams said in an email, because a noisy boat at 1,000 yards can be louder than a slow boat 400 yards out.
“We’re trying to come up with simple rules to manage a very complex system,” he said.
In the coming years, Williams said, the Washington Department of Fish and Wildlife will complete a study exploring the effectiveness of vessel regulations.
“What I like best about Washington state’s approach is that it explicitly acknowledges complexity, variability, and uncertainty and adopts an adaptive management framework,” Williams said in an email. “That means they’ll choose a precautionary rule, but also conduct studies to see if it’s working, and revise the rules accordingly.”
Ginny Broadhurst, the director of the Salish Sea Institute, voiced similar thoughts.
“Underwater noise is one of those things that’s tractable,” she said. “There’s immediate benefits from reducing noise, but there’s not real clarity beyond ‘how much is too much.’”
Even so, the new buffer is better than the previous 400-foot buffer.
“There’s a balancing act between what’s feasible and what’s right for the animals,” Broadhurst said. “We’re still learning about the full impacts of underwater noise.”
Part of the problem, Williams said, is that despite best efforts, the Southern Resident population continues to fall.
Throughout the last century, live-capture hunting decimated populations in the Salish Sea, as did the collapse of local, native chinook salmon.
“Most marine mammal populations recover after the cessation of hunting,” Williams wrote in his paper, published this month. “Some evidence is emerging that highly-social toothed whales and dolphins (including killer whales) are inherently less resilient to overexploitation than seals, sea lions, and baleen whales.”
Elliser said supporting the failing population is vital for the environment of the Salish Sea.
“It’s so important to keep that population alive because it’s part of the ecosystem and it’s been that way for hundreds of thousands of years,” she said. “Losing it may cause more damage than we can understand.”
