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.

Nutrient limitation of the bottom‐ice microalgal biomass (southeastern Hudson Bay, Canadian Arctic)1

“…Although no systematic estimates of herbivore concentrations in our samples were made, amphipods or copepods were never seen in the water collected by our sampler: its slow operation (see methods) made it easy for zooplankters to escape. Only a few nematodes were seen, but it is unlikely that they biased the results of the algal growth experiments since the ice meiofauna is very sparse (Carey and Montagna 1982;Cross 1982;Kern and Carey 1983).…”

The Faunal Assemblage Inhabiting Seasonal Sea Ice in the Nearshore Arctic Ocean with Emphasis on Copepods

“…The ice fauna in Stefansson Sound, south of Narwhal Island and close to our study site, was examined in March and May 1979 (Carey and Montagna, 1982). Their density estimates were much smaller (x=6200 individuals m-') even though they included calanoid copepods, crustacean nauplii, and rotifers in their count.…”

“…Despite the temporary nature of the seasonal Invertebrates inhabit sea ice, but in contrast to the ice flora (reviewed by Horner, 1977), little is known about these organisms. Heliozoans, ciliates, nematodes, copepods, polychaetes, turbellarians, and amphipods have been collected from sea ice (Andriashev, 1968;Horner, 1976;Cross, 1982;Carey and Montagna, 1982), but quantitative estimates are rare. The type of information required to assess the importance of these organisms to polar marine ecosystems is not available.…”

Grazing of Arctic under-ice amphipods on sea-ice algae

“…The ice interior provides a unique habitat for a diverse and specialized flora and fauna, ranging from bacteria to metazoans (e.g. Horner 1976, Carey & Montagna 1982, Cross 1982, Gradinger & Zhang 1997. Many sea-ice organisms have their abundance and biomass maxima in the lowermost centi-to decimetres of the ice (Booth 1984, Grainger & Mohammed 1986, Gradinger et al 1991.…”