Decline of Pelagic Cormorants in Barkley Sound, British Columbia
FEATURE ARTICLES DECLINE OF PELAGIC CORMORANTS IN BARKLEY SOUND, BRITISH COLUMBIA Harry R. Carter1, Percy N. Hébert2,4, and Peter V. Clarkson3 1Carter Biological Consulting, 1015 Hampshire Road, Victoria, BC V8S 4S8 Figure 1. Barkley Sound, an area of 800 km2, is 2Department of Biological Sciences, Thompson situated on the central west coast of Vancouver Rivers University, Kamloops, BC V2B 5N3 Island between Ucluelet and Bamfield. Hundreds of islands and partly sheltered waters provide a popular 3Pacific Rim National Park and Reserve of Canada, recreational area for saltwater fishing, sea kayaking, 2040 Pacific Rim Highway, P.O. Box 280, and boating. 11 August 1969 (R. Wayne Campbell). Ucluelet, BC V0R 3AO 4Current Address: Hébert Biological Consulting and including Queen Charlotte Strait, north mainland Communications, #304 – 160 Tamarack Avenue, coast, Queen Charlotte Islands, Strait of Georgia, and Kamloops, BC V2B 1G6 west coast Vancouver Island (Vermeer and Rankin 1984, Campbell et al. 1990, Rodway 1991, Vermeer Abstract et al. 1992, Fraser et al. 1999, Chatwin et al. 2002). In 1989, a decline in numbers of nesting Pelagic In contrast, populations in Washington, Oregon, and Cormorants (Phalacrocorax pelagicus) was first California appeared roughly stable between 1975- reported in Barkley Sound, British Columbia. 1982 and 1988-1991 (Carter et al. 1995). Reasons for Reasons for this decline were unclear and no decline and colony shifting of Pelagic Cormorants follow-up studies occurred. In 2006 and 2007, we in the Strait of Georgia included prey changes, resurveyed all 32 known or suspected breeding disturbance of colonies, and high levels of predation colonies and confirmed this decline which appears to (Vermeer and Rankin 1984, Rodway 1991, Chatwin have resulted in a long-term reduction in population et al.
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