Saturday January 06, 2018
Vessels as small as kayaks can impact endangered killer whale behaviour
more stories from this episode
- How an oddly large beetle penis could inspire new medical technology
- This food additive is hard to avoid and could make hospital superbugs more deadly
- Doctors say blueberries can help radiation kill cervical cancer
- Low level air pollution costs the economy billions of dollars in lost productivity
- Vessels as small as kayaks can impact endangered killer whale behaviour
- You won't believe just how sensitive our sense of touch is
- Water is able to conduct electricity, but is the same true of snow?
- Full Episode
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.
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.
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.