Particle flux beneath fast ice in the shallow southwestern Beaufort Sea, Arctic Ocean

Flux of organic particulate materials under sea ice to the benthic environment was measured in the nearshore Arctic Ocean during spring 1980. Downward flux of organic carbon started early in the spring and continued at fairly uniform but low levels (approximately 1 % of daily carbon production of ice algae) from April until early June. Particulate organic nitrogen flux tended to be low and erratic. Fecal pellets from 2 crustacean species were among the few recognizable large particles. The amphipod Pseudalibrotus (= Onisimus) litoralis, normally a benthic species, lives in spring on the undersurface of sea ice in the shallow polar environment. Collected pellets from adults decreased through spring, while those from juveniles increased until 5 Jun when their flux declined markedly. Late in spring these pellets contained primarily pennate diatom frustules from the ice algal bloom. Crustacean molts and Mysis relicta fecal pellets were also present, particularly in April and early May. The sinking particles were derived from both the pelagic and ice environments, although most of the material appeared to be from the ice biota. Data suggest that particles falling from the productive ice community during spring are a carbon source for the benthos; one that is small but available earlier than that from phytoplanktonic or benthic microalgal production.