Sublitloral gammaridean amphipods of soft sediments in the Bay of Fundy

Abstract

Two benthic sampling designs were used to collect gammaridean amphipods of soft sediments in the Bay of Fundy for taxonomic analysis. The first was a survey consisting of two grab samples at 266 stations spread throughout the Bay to determine geographic distribution. The second involved intensive sampling at two stations to determine seasonal changes in species richness, density, and biomass. Ninety-nine amphipod species were found . Two species were new to science and 6 are additions to the Canadian Atlantic fauna. Certain amphipods were limited to 1 or 2 of the 3 major surficial sediment types in the Bay, while other species were found on all sediment types. Seasonal sampling over a 2-yr period showed that gammaridean amphipod species richness was less, individual density and biomass were greater, at a shallow estuarine location compared to a deep {80 ml location. Two of the 3 dominant gammarideans at the shallow location were only temporary occupants. The deep location had 6 dominant species which were present throughout the 2-yr sampling period, although changes in subdominant species and densities suggested the occurrence of a perturbing event of unknown nature.