Meiofauna 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 organic matter. The sediments were generally characterized by large amounts of chloropigments and labile compounds (dominated by proteins), indicating high inputs of primary organic matter. Meiofaunal densities were very high and 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 meiofauna are part of the scallop diet. Scallop beds apparently have an important role in structuring meiofaunal communities with nematodes dominant where Adamussium colbecki is absent, and gastrotrichs dominant (44-51%) in A. colbecki beds, reaching the highest density reported so far.