Schiel, S. B.. Alfred-Wegener-Institut fuer Polar- und Meeresforschung, sschiel @
Metz, C. B.. University of Wales,Bangor, cmetz

Studies on the feeding of copepods have focused in the past mainly on large species. Hence, there is little information on feeding behaviour and trophic roles of small species. Grazing experiments were undertaken in the Bellingshausen Sea (Antarctica) during austral summer. The study focused on the feeding responses of small copepod species to changes in food composition and abundance. Experiments were carried out at various stations with naturally occurring microplankton. The stations spanned inproductive waters under pack ice to open water blooms. The food items ranged in size from nanoflagellates to large diatoms. Some experiments were also conducted with cultered phytoplankton and ice algae as food. All species were actively feeding at all stations but at reduced rates under pack ice. Clearance rates increased sharply from inproductive waters to bloom waters. Daily ingestion of the small copepod community was 1 to 24% of microplankton biomass. The calanoid species (Microcalanus pygmaeus, Ctenocalanus citer, Stephos longipes) had highest clearance rates on small food items such as nanoflagellates. In contrast, the poecilostomatoid species, Oncaea curvata, preferred large, non-motile food particles such as aggregates.
Day: Tuesday, Feb. 2
Time: 04:45 - 05:00pm
Location: Hilton of Santa Fe
Code: SS23TU0445H