Sediment resuspension is a common phenomenon whose importance may be magnified in nearshore environments surrounding Antarctica, especially during the austral winter. Analyses suggest that sediments in the vicinity of McMurdo Station contain viable algal material throughout this period of darkness. The resuspension of these sediments, shown by sediment trap collections and underwater observations, would introduce organics into the water column and may provide an alternative food source for planktonic herbivores inhabiting nearshore environments during the Antarctic winter.
The following observations and experiments were undertaken from January to November 1981 (except the sediment pigment analysis) while we were studying the ecology of benthic foraminifera in McMurdo Sound, Antarctica. During this period 190 dives were conducted in the vicinity of McMurdo Station, 55 during the austral winter from April to August. The maximum depth of these dives was 30 m. From March through July 1981 suspended material was collected in a sediment trap anchored to the bottom at 18 m depth and buoyed by a 5 gallon airfilled container. This trap consisted of an array of PVC collecting cones placed individually at 0 m, 1 m, 5 m and 10 m above the bottom. Each collecting cone had a diameter of 3.8 cm and a height of 8.7 cm (Gardner 1980a). The contents from each sediment trap collection were dry weighed according to Gardner (1980b) and then identified by light microscopy. Sediment cores 3.5 cm in diameter were taken to investigate changes in benthic activity, and each sampling consisted of three to six replicates.