Abundance and biomass of macrobenthos in the vicinity of Carson Submarine Canyon, northwest Atlantic Ocean

Abstract

The abundance, biomass and mean weight of macrofauna in the Carson Canyon region (Lat. 45°30′N, Long. 48°40′W) of the Grand Banks were estimated from 40 quantitative infaunal samples taken at 15 stations in June 1980. In contrast to other areas, there were no significant differences in these values between samples taken in and outside of the canyon. Abundance (\(\bar x\) = 716 individuals m-2), biomass (\(\bar x\) = 10.9 gm-2), and mean weight (\(\bar x\) = 0.03 g individual-1) displayed no consistent relationship with depth, but stations grouped according to sediment type had differing dominant taxa. Biomass and abundance at the edge of the Grand Banks are unexpectedly low. Larger animals, including fishes, that forage there must depend more on pelagic than on benthic food sources.