Of the many cargo ships in California, only a tiny fraction pass through the large swathes of marine habitat along the coast, such as the Monterey Bay National Marine Sanctuary. It’s unknown how many of these ships collide with whales, but research indicates the number is much higher than what endangered populations of blue, fin and humpback whales can withstand.
Robert Mazurek, director of conservation for the California Ocean Alliance, says the number of human-caused deaths these whales can suffer before major population decline is “shockingly small.” For blue whales, that number is 2.3 whales per year. Mazurek says conservative estimates show 18 blue whales are being killed by ship strikes each year off the West Coast.
The alliance’s new ship strike initiative is trying to reduce that number. Because of the small number of ships and the industry’s willingness to work with scientists, Mazurek says the Monterey Bay could become “an incubator of ideas and solutions for this problem worldwide.”
Cargo ships travel at average speeds of 18 to 23 knots (21 to 26 mph). Like deer on a highway, Mazurek says the speed and size of the ships overtake whales by surprise. And people on board have difficulty seeing whales, even after the ship has hit one.
Research shows that moving shipping traffic further offshore will help, but Mazurek says more data is needed to specify exactly where shipping lanes should be. Scientists have been accompanying ships, gathering data on whale sightings.
For now, they’re working with the shipping industry on a voluntary basis. “They care about these whales too,” Mazurek says. “And we don’t have time to wait around for legislation to be enacted.”