Quirks & Quarks

Vessels as small as kayaks can impact endangered killer whale behaviour

Killer whales of the coast of Washington State are protected by regulations requiring all vessels to keep a required safe distance.
In the U.S. boaters are required to stay clear of killer whales. (Elaine Thompson/Associated Press)
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The issue

This past Summer 10 North Atlantic right whales were killed in the Gulf of St. Lawrence either by ship strikes of entanglement in fishing gear. Because the population is listed as endangered, a mandatory speed limit for ships over a certain size was put in place. On the West Coast, southern resident killer whales are also struggling to deal with ship traffic. But the issue there is not so much ship strikes as it is changes in the whales' behaviour in the presence of vessels. A study by Grace Ferrara, a biologist from the U.S. National Oceanic and Atmospheric Administration in Seattle has found that the killer whales forage less and travel more when vessels are around.  

The whales

At present, there are only 76 in this population of killer whales that inhabit the Salish Sea. This is a 30-year low, and they are also endangered. Historically, their numbers have been well over 100, with a modern era high of 83 in 2015. Unlike the North Atlantic right whales on the East Coast, these killer whales are more sensitive to the sound and presence of all vessels — from large cargo ships to kayaks. It is not clear why, but all vessels disturb their behaviour, whether it is engine sound masking echolocation, or simply the physical presence, as in the example of smaller crafts like kayaks.   

The regulations

In 2011, the United States introduced two regulations to help these whales. The regulations are that vessels must stay 182 metres (200 yards) away, and the other is that they can't 'park' in the path of a moving pod within 366 metres (400 yards.) So far compliance has been good and vessels including the commercial whale watching boats are staying away, but more research needs to be conducted to determine if noise is still having an impact. Canada's Ministry of Fisheries has plans to put similar regulations in place soon.