Ships crossing parts of the North Atlantic will be asked to slow down to 10 knots when whales are migrating, under a voluntary scheme agreed this week by the Atlantic Maritime Safety Council. The plan covers four corridors used by humpback and fin whales moving between feeding grounds and breeding waters.
Collisions with ships are among the leading causes of death for large whales. Research has shown that the chance of a fatal strike falls sharply when vessels travel more slowly, partly because whales have more time to move away and partly because the impact is less severe. Most container ships cruise at between 16 and 22 knots.
Industry support, with conditions
Several of the largest shipping lines have said they will take part, noting that slower speeds also save fuel and cut emissions. Others warned that delays could ripple through tight schedules. The council will publish monthly figures showing how many ships complied, based on satellite tracking data that every large vessel already broadcasts.
Every time we have asked ships to slow down, the number of dead whales washing ashore has fallen, and the cost to the voyage has been a few hours.
Marine biologist Dr Sigrid Ellefsen, who helped map the corridors, said acoustic buoys would alert ships' bridges when whales were detected nearby. Captain Owen Mbeki, who represents a group of shipmasters, said crews supported the idea but needed clear charts and consistent rules from one zone to the next.
Recommended speed in zones: 10 knots or less
Number of corridors: four
Review of compliance after two seasons
The corridors were drawn using decades of sightings from research vessels, ferries and aerial surveys, together with data from satellite tags fitted to more than 200 whales. They follow the continental shelf edge, where cold, nutrient-rich water rises to the surface and draws in krill and small fish. The zones will apply only during the main migration seasons, so most routes will be unaffected for at least half the year.
Conservation groups welcomed the agreement but said the scheme should become mandatory if voluntary uptake falls below 80 per cent. Scientists at the Wrenhaven Marine Institute, which tracks humpbacks passing the western approaches, will contribute sighting data to the alert system.