Download or read book Status of the European Green Crab, Carcinus Maenas, in British Columbia, 2006 written by Graham E. Gillespie and published by . This book was released on 2007 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: European green crab, Carcinus maenas, is a recently-arrived non-indigenous species on the Pacific Coast of North America. After appearing in San Francisco Bay in the late 1980s, they subsequently spread north, arriving in British Columbia through larval transport in 1998. Fisheries and Oceans Canada noted 24 public reports of European green crab on the west coast of Vancouver Island since 1999. In 2006, trap surveys were carried out on the west coast of Vancouver Island, Desolation Sound, Discovery Passage and Johnstone Strait. Crabs or moults were also collected from beach surveys during the same period. A total of 375 crabs were trapped from beaches in Barkley, Clayoquot and Nootka Sounds and Esperanza Inlet. Notably high catch rates were reported in Pipestem Inlet (Barkley Sound, 2.28 crabs/trap-day), Pretty Girl Cove (Clayoquot Sound, 1.42 crabs/ trap-day) and Queen Cove (Esperanza Inlet, two beaches, 1.33 and 1.18 crabs/trap-day, respectively). No green crabs were found in Desolation Sound, Discovery Passage or Johnstone Strait. Sex ratios ranged from 61-80% male with an overall ratio of 66.4% male for the west coast of Vancouver Island collections; one ovigerous female was collected in Barkley Sound in May. Analyses of size frequency and shell condition data indicate that there were at least three year classes present in the population; most crabs were assigned to the 2005 year class. High incidence of damage (injuries or missing limbs) was correlated with high catch rates, suggesting that damage was a result of intra-specific agonistic behaviour rather than unsuccessful predation. The establishment of green crab populations on the west coast of Vancouver Island increases the potential for further dispersal of the species into northern British Columbia and possibly Alaska