An Analysis of the Zooplankton Community Structure of the Western Beaufort Sea. WEBSEC 1971

The Beaufort Sea, north of the North Slope Oil Field in Alaska, is an area in which the likelihood of future oil pollution is great. As an attempt to assess the effects of this pollution upon the marine environment, the United States Coast Guard Oceanographic Unit sampled an area from 143 30 to 154 30 west longitude between 70 and 72 north Latitude, in the Western Beaufort Sea, from August to mid September 1971. A community analysis of the resulting samples is undertaken in this data set by the investigation of relationships within the plankton community and between the plankton community and various oceanographic variables. Initial enumeration and identification of the samples indicated that the species and their abundances were characteristic of the area. Examination of the distributions of the species disclosed that they could be split into five distributional categories apparently defined by individual species tolerances to salinity, temperature, ice cover, and other hydrographic factors. Temperature was suggested as a major factor controlling species abundance. Cluster analysis of species absence and presence data revealed vertical migration as the major factor influencing the community structure in the summer and fall. During the day, surface and deepwater communities were separable. At night, vertical migration patterns disrupted this division, and horizontal distribution patterns appeared to define community structure. The ecosystem theory hypothesized by others for the area was substantiated by the data from the WEBSEC-71 Cruise. This data is extrapolated from a thesis dissertation. University of Rhode Island, 1977 and comprises 1240 records covering 34 taxonomic categories.