Marine environmental quality assessment using polychaete taxocene characteristics in Vancouver Harbour

摘要

Polychaete taxocene characteristics from seven stations in Vancouver Harbour obtained during the PICES Practical Workshop are presented. Thirty families and 79 polychaete species were identified. Polychaete density ranged from 194.0 individuals m~(-2) in Port Moody Arm to 846.0 individuals m~(-2) in the Central Harbour, with a mean abundance over the seven stations of 428.9 individuals m~(-2). Biomass varied from 3.0 g wet wt. m~(-2) to 28.5 g wet wt. m~(-2), with a mean biomass for the seven stations of 12.9 g wet wt. m~(-2). High species diversity and richness of polychaete taxocene were observed at two stations, the West Vancouver Laboratory in the Outer Harbour and at a far field reference station in Thornborough Cannel. Sediment quality assessment indicated severe adverse effects at two sites in Port Moody Arm, where high concentrations of chlorinated hydrocarbons and some trace metals were found. A limited number of species, dominance of pollution-tolerant Tharyx multifilis, and the lowest values of polychaete biomass and indices of richness and diversity were detected in Port Moody Arm. Rich species composition and domination of pollution-sensitive species provided evidence of unstressed communities at the far field reference station. Sites in the Outer Harbour, Central Harbour and Indian Arm were characterised by intermediate pollutant exposure.