Arctic Sea Ice Faunal Assemblage: First Approach to Description and Source of the Underice Meiofauna

Abstract

The ice meiofaunal assemblage in shallow Stefansson Sound off the northern coast of Alaska included Polychaeta, Nematoda. Rotifera and Crustacea. The crustaceans conlprised calanoid copepods, nauplii, 2 species of harpacticoids (Halectinosoma neglecturn and Pseudobradya sp.) shared with the benthos and a cyclopoid copepod (Cycloplna gracilis), probably a benthic epiphytic form. Much of the ice meiofaunal assemblage was dominated by larvae and juveniles. The ice taxa were sparse in numbers (100-1,000 tlmes less than the sediments) and depauperate in specles (e.g. 2 species of harpacticoids versus 28 in the sediments). The ice meiofauna appears to b e derived from both sediments and water column. We hypothesize that during sprlng the undersurface of nearshore sea ice acts as a substrate for benthic recruitment and for nourishment of a highly selected fauna. However, the meiofauna is too sparse to be significant in the food web or energy budget in the protected nearshore Beaufort Sea.