Comox Valley Naturalists Society

Sunday, April 18, 2004
Dr. Jane Watson
Sea Otters

The meeting of the Comox Valley Naturalists Society on Sunday, April 18 at 7:00 p.m., in the Rotary Room of the Filberg Centre, 411 Anderton Avenue in Courtenay, featured guest speaker Dr. Jane Watson, who described recent changes in the abundance of sea otters off the west coast of Vancouver Island, their feeding behaviour and how nearshore ecosystems change in response to sea otter foraging, including long-term changes in kelp forests.

Dr. Watson has been studying the interactions between sea otters and nearshore ecosystems along the British Columbia coast for the last 17 years. She presently teaches at Malaspina University-College in Nanaimo and is an adjunct professor with the Marine Mammal Unit at the University of British Columbia.

Sea otters, which were once highly valued for their fur, were hunted to extinction in British Columbia by the early 1920Ís. During the period from 1969 to 1972, sea otters from Alaska were introduced to Checleset Bay on the northwest coast of Vancouver Island. This translocated population was successful and has grown and expanded its geographic range. There are now approximately 3,000 sea otters spread from just north of Tofino to Cape Scott and off the central coast of British Columbia.

Sea otters prey on a variety of invertebrates. By eating grazers such as sea urchins, sea otters reduce grazing pressure and indirectly promote the growth of seaweeds such as kelp. Urchin grazing can limit the abundance and distribution of seaweeds. Thus, in most areas with sea otters, there is an abundance of kelp, whereas in areas without sea otters there is little seaweed and lots of urchins. Kelp forests are an important component of coastal ecosystems, increasing productivity, providing habitat for fish and changing patterns of water flow.

Click on a link below to view descriptions of previous guest speakers.