Depth related changes in the composition of infaunal invertebrate communities were investigated at two sites in the Windmill Islands around Casey station, East Antarctica, during the 2006/07 summer. Sediment cores (10cm deep x 10cm diameter) were collected from 4 depths (7m, 11m, 17, and 22m) from each of three transects at two sites (McGrady Cove and O'Brien Bay 1). Cores were sieved through a 500 micron mesh and extracted fauna were preserved in 8% formalin and were later counted and identified to species or to morphospecies established through previous infaunal research at Casey. This work was conducted as part of ASAC 2201 (ASAC_2201).

Sediment Recruitment Experiment 4 (SRE4) was a large, long term (5 year) field experiment run at Casey Station (from 2001 to 2006) testing the effects of 4 different hydrocarbons on marine sediment ecosystems. Four different types of hydrocarbons were individually mixed with defaunated marine sediments and deployed in trays on the seabed at O'Brien Bay-1. Trays were collected after deployment periods of 5 weeks, 56 weeks, 62 weeks, 2 years and 5 years. In addition there was a bioturbation treatment using the burrowing urchin Abatus (at 56 weeks only). Samples were collected from 4 replicate trays of each treatment at each sampling time. Analyses were done of sediment hydrocarbon chemistry, microbial communities, meiofaunal communities, macrofaunal communities and diatom communities. The hydrocarbon treatments were: a synthetic Mobil lubricating oil; the same Mobil lubricating oil after 125 hours use in a vehicle engine; a Fuchs synthetic lubricating oil marketed as highly biodegradable; and Special Antarctic Blend diesel fuel (SAB). A control uncontaminated sediment treatment was used for comparison.