Distribution of Arctic Marine Isopods of the <i>Mesidotea</i> (= <i>Saduria</i>) Complex in Relation to Depth, Temperature, and Salinity in the Southern Beaufort Sea

Abstract

Three benthic isopods of the Mesidotea (= Saduria) complex are common in the coastal waters of the southern Beaufort Sea. Their relative distribution in relation to water depth, temperature, and salinity was studied by means of 146 trawl, grab, and trap samples. Mesidotea entomon is restricted to the warm, brackish nearshore estuarine zone, in water depths of less than 10 m. M. sibirica is most commonly encountered at intermediate depths of 5-25 m. M. sabini is the most common marine form, occurring at depths from 10 to 441 m. This distribution pattern is similar to that reported for these species in the European Arctic. Salinity fluctuations caused by wind-induced shifts in the location of the river plume, and the occurrence of deep, high-salinity water close to shore, results in overlaps in distributions of the isopods in some areas adjacent to the delta.

Key words: isopods, Beaufort Sea, Mesidotea entomon, Mesidotea sibrica, Mesidoteau sabini, Sduria, distribution