A new report says southern resident killer whales have a better chance to find their prey if speed is cut on passing vessels.
The findings are in a Vancouver Fraser Port Authority study that had more than 60 marine shipping industry organizations take part.
The results showed reduced speeds were effective in lowering underwater noise generated by ships and total noise in nearby habitats, which can help the behaviour and feeding success of southern resident killer whales.
Speeds were dropped to 11 knots by crews on participating vessels through a 16 nautical mile corridor of the Haro Straight between Aug. 7 and Oct. 7 last year.
The Haro Straight is an important summer feeding area for resident killer whales, that use echolocation to forage for food.
A vessel slowdown trial infographic says a three-knot speed reduction can result in a 50 per cent drop in sound intensity.
Officials say there are only 76 southern resident killer whales left.
The port authority says along with the federal government’s efforts to help increase the southern resident population, it will support an industry-led voluntary slowdown initiative in the Haro Strait this summer.
It will test the level of participation in the industry when ships slow down to optimized speed based on vessel type and when the slow down comes into effect when whales are present in the area.