Spatial and Temporal Distribution of Sub-Ice Macrofauna in the Barrow Strait Area, Northwest Territories

• Published in: Canadian Journal of Fisheries and Aquatic Sciences
• Main Authors: Pike, Daniel G., Welch, Harold E.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Canadian Science Publishing 1990
• Subjects: Aquatic Science; Ecology, Evolution, Behavior and Systematics; Northwest Territories; Barrow Strait; ice algae
• Online Access: http://dx.doi.org/10.1139/f90-008; http://www.nrcresearchpress.com/doi/pdf/10.1139/f90-008

The distribution of sub-ice macrofauna was investigated in the Barrow Strait area near Resolute, N.W.T. from April–June, 1985, 1986, and 1987, and in January 1986. Invertebrates were sampled using remotely deployed net and video camera systems. Ten species of amphipods and two species of mysids were found, but over 90% of the biomass was made up of only four species of amphipods: Weyprechtia pinguis, Onisimus litoralis, Gammarus setosus, and Onisimus spp. juveniles. Species composition varied annually, with W. pinguis dominating in spring 1985, O. litoralis in 1986, and G. setosus in 1987. There were also areal differences in species composition over distances of 50–200 km. Underlying water depth was the major environmental correlate of both total biomass and species composition; total biomass decreased with increasing underlying water depth, being near zero over >100 m depth. We hypothesize that spring sub-ice distribution is a reflection of summertime benthic distribution. Total biomass decreased with increasing snow depth early in the spring, probably because the attenuation of incident light by snow reduces the concentration of sub-ice algae. Total biomass was lower within 1 km of the ice edge than in areas further from the ice edge.