Analysis of the benthic Cumacea and Gammaridean Amphipoda from the western Beaufort Sea

• Main Author: Castillo Alarcon, Jorge Gonzalo
• Other Authors: Carey, Andrew G. Jr, School of Oceanography, Oregon State University. Graduate School
• Format: Doctoral or Postdoctoral Thesis
• Language: English; unknown
• Published: Oregon State University
• Subjects: Marine animals > Beaufort Sea; Beaufort Sea
• Online Access: https://ir.library.oregonstate.edu/concern/graduate_thesis_or_dissertations/8049g748z

A multidisciplinary western Beaufort Sea Ecological Cruise (WEBSEC) was conducted from August 15 to September 20, 1971. During the cruise, one hundred ninety-nine 0.1 m² Smith-McIntyre grabs samples were taken at forty stations located on the continental shelf and slope of the western Beaufort Sea. The Gammaridean Amphipoda and Cumacea collected were sorted and identified. Each sample was analyzed for the number of species and specimens within those groups. The data for all samples at each station were pooled to obtain station data; these were analyzed for abundance, diversity at each station, and similarity between stations. Environmental parameters including sediment data, temperature, salinity and organic carbon content measured during the same cruise were also analyzed for each station. The diversity indices chosen were the Simpson index (SDI) and the Shannon-Wiener index (H'[subscript e]). The results obtained show a e relatively high diversity and animal density in the outer continental shelf, but low diversity values on the inner continental shelf and slope. The lowest SDI value obtained is 0.43 at 2572 m depth. The SDI values on the outer continental shelf are higher than 0.9 and compare well with values obtained in more temperate regions. The similarity between stations is low, and the percentage of rare species found is high. This indicates a patchy distribution of the Amphipoda and Cumacea fauna. The variability of the processes affecting the benthic environment of the western Beaufort Sea suggest that more intensive and seasonal studies are necessary in order to understand the seasonal as well as the annual variation of the infauna of the western Beaufort Sea.