Ships Slow to Help Orcas
1 August 2017 - 6:20pm
Large ships are being asked to slow down this summer and fall while traversing an area of critical habitat for the endangered Southern Resident orca community. The Port of Vancouver’s initiative known as “Enhancing Cetacean Habitat and Observation,” or the ECHO Program, is dedicated to mitigating threats to endangered whales from shipping activities.
They are starting with a unique vessel slowdown trial to see if reduced speeds can decrease the underwater noise received by the Southern Resident orcas. Large ships regularly pass through Haro Strait on the west side of San Juan Island, an area considered to be a historical foraging hotspot for the orcas. Ships will be asked to slow their speed to 11 knots, and hydrophones will be used to record underwater noise for comparison to current levels.
This trial ship slowdown follows last year’s approval of the Kinder Morgan Trans-Mountain pipeline project, which would send hundreds of oil tankers from Vancouver, Canada through Southern Resident orca critical habitat per year; Canada’s National Energy Board estimates that resultant oil tanker traffic would increase from 5 vessels to 34 per month – a 700% escalation.
Vessel impacts such as ocean noise and disturbance are considered to be one of the top threats to the critically endangered Southern Resident orca population, now down to just 78 individuals. Increasing noise in their habitat makes it more difficult for the orcas to find their preferred food, salmon - also an endangered species that is becoming more scarce and difficult to find. A lack of food and a noisy environment increases stress to individuals in the population, and further exacerbates the effect of biotoxins present in the bodies of the orcas. The synergistic impact of threats has reduced the survival and reproductive capacity of the Southern Resident orca community, and requires an ecosystem-based approach to recovery strategies.
“The trial slowdown will be an interesting project to explore mitigating the impact of noise on the Southern Resident orcas, and may help to reduce current stress from this particular threat,” says WDC’s Rekos Orca Fellow, Colleen Weiler, “but it will not be enough to negate the expected increase in large vessel traffic from the Kinder Morgan expansion. These orcas are already living on the brink of extinction; we need to focus on reducing the impacts of current threats, not worry about adding more stress to their lives.”