On both sides of the border, the recent health woes of Southern Resident Killer Whales in the Salish Sea have rightfully shone a spotlight on their plight.
Most recently, Canada’s National Energy Board released its reconsideration report to the government, recommending that the Trans Mountain Expansion Project be approved, along with a number of noise-reduction measures for various vessels, including whale-watching boats.
Unfortunately, the NEB’s report on these topics and the ensuing coverage rely on old data and do not accurately represent the reality of what’s occurring on the water and the steps that should be taken to save the Southern Residents.
For more than 40 years, I have studied killer whales and other Salish Sea wildlife extensively and it’s crucial to note upfront that the lack of Chinook salmon is widely agreed to be the leading cause behind the whales’ recent decline. Humpbacks, Bigg’s (transient) killer whales and grey whales are thriving in the same waters, highlighting the fact that Southern Resident orcas are struggling to obtain salmon.
But a particular focus of my studies has been on how vessel disturbance affects killer whales. Given the available research, I’m confident that responsible whale-watching protects whales on the water and contributes to their recovery off the water.
Professional whale watchers have closely followed the research from myself and others on how Southern Residents’ eating and swimming patterns change around vessels and have called on their ranks to take actions that reduce negative effects on the whales. Their operators have since changed their best practices, so that those who follow them no longer have a negative impact on whales.
Research has shown that the top driver of noise is vessel speed. When viewing wildlife, whale-watch boats operate at a go-slow speed that’s at the ambient noise level of rainfall. On the other hand, commercial ships like tankers dominate the soundscape from miles away — so for the NEB to group these together is misleading.
Recent columns on the NEB report state that Southern Residents are being “chased” by whale watchers virtually all day from May through September. While recreational vessels are on the water throughout the day, the Pacific Whale Watch Association recently reported that it sees Southern Residents on approximately 15 per cent of its tours. In May 2018, there were zero reported sightings in the inland waters of the Salish Sea, the first time that’s happened since 1976, when the Center for Whale Research began tracking such data.
Creating go-slow zones that apply to all small vessels would be a science-based action that reduces noise exposure around Southern Residents, expanding the volume of water they can search for salmon. For the foreseeable future, vessels that comply with go-slow zones’ rules would expose whales to less noise than distant non-whale watching vessels.
The whale watch industry has led in educating boaters and warning recreational vessels when to slow down for years, having a net positive effect when it comes to noise reduction, and this is how go-slow zones are best implemented.
Finally, it’s important to remember that ongoing mishaps in oil transport pose a greater threat to the whales than noise from tankers, and that an increasing number of Vessels of Opportunity standing by to respond to oil spills are likely to be commercial whale-watching boats.
I urge the Canadian government to follow the carefully considered scientific recommendations of researchers who’ve studied these issues for decades and implement actions that will actually help save the whales. Treating these actions as mitigation for increased tanker traffic will trap whales in their endangered status, rather than allowing these to be the first steps toward recovery.
David Bain is chief scientist of Orca Conservancy, a Washington State non-profit organization working to protect orcas and their habitat.