Drift-sampling from ice camps: abundance, length and stage frequency of larval krill under pack ice drifting northward along the continental shelf break

R. Ross and L. Quetin

Three separate ice camps were occupied between August and September 2002 for periods of 6-8 days during a cruise aboard the R/V Laurence M. Gould as part of the United States effort for the Southern Ocean GLOBEC program. The ice camps drifted to the northeast with the total drift track covering nearly 250 nm in the vicinity of the shelf break along the western Antarctic Peninsula. The first two ice camps were at the shelf break, and the third camp located at mid shelf. Krill larvae were collected continuously using divers and drift nets along the drift track. Nets deployed from ice floes captured more larvae at night than during day and more larvae within 1 m of the ice than deeper in the water column. Distinct differences in behavior, total length and developmental stage were found between larvae captured at the different ice camps. Generally at we traveled northeast more larvae were feeding directly on the underside of the ice and larvae and were shorter with a great proportion of Furcilia 5 stages. These changes in day/night larval distributions have implications for rates of larval transport throughout the region.

STATUS UPDATE:

Title, abstract, and author list received on 06/15/05.