Meiofaunal assemblages associated with scallop beds (Adamussium colbecki) in the coastal sediments of Terra Nova Bay (Ross Sea, Antarctica)

Meiofaunal community structure in coastal sediments of Terra Nova Bay (Ross Sea) was related to quantity and biochemical composition of sedimentary or ganic matter. The sediments were generally characterized by large amounts o f chloropigments and labile compounds (dominated by proteins), indicating h igh inputs of primary organic matter. Meiofaunal densities were very high a nd comparable to those from the most productive areas worldwide. Sediments with high densities of the scallop had low meiofaunal densities especially in the top 2 cm, suggesting that scallop clapping contributed to meiofauna resuspension. However, it is not possible to exclude the probability that m eiofauna are part of the scallop diet. Scallop beds apparently have an impo rtant role in structuring meiofaunal communities with nematodes dominant wh ere Adamussium colbecki is absent, and gastrotrichs dominant (44-51%) in A. colbecki beds, reaching the highest density reported so far.