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A series of in situ and aquarium experiments were conducted in the vicinity of the Bailey Peninsula area (Casey Station, East Antarctica) to investigate the bioturbation behaviour of the Antarctic spatangoid urchin Abatus ingens (Koehler 1928). Rates of sediment transport by A. ingens were estimated from measurements of locomotion rates, sediment reworking depth and feeding rates. A. ingens bioturbates and feeds on the surface sediment (top 1 to 2 cm) by pushing diatom communities and sediment ahead and to the side of its track, thus increasing vertical and horizontal sediment transport. Over a 24 h period in situ, A. ingens spends prolonged periods of time stationary (16.7 h) and only short periods of time in locomotion (7.3 h). In the aquarium, however, A. ingens was observed to spend half of the time moving and the other half stationary. Locomotion rate measured in the aquarium was faster (

A large-scale, in situ experiment was set up near the Bailey Peninsula area (Casey Station, East Antarctica) to monitor the natural attenuation of synthetic lubricants in marine sediments over five years. Here, we report the short-term changes after 5 and 56 weeks. The lubricants tested were an unused and used Mobil lubricant (0W/40; Exxon Mobil, Irving, TX, USA) and a biodegradable alternative (0W/20; Fuchs Lubricants, Harvey, IL, USA). Clean sediment was collected, contaminated with the lubricants, and deployed by divers onto the seabed in a randomized block design. The sampled sediments were analyzed by gas chromatography-flame-ionization detector and gas chromatography-mass spectrometry with selective ion monitoring. The base fluid of all lubricant treatments did not decrease significantly after 56 weeks in situ. Alkanoate esters of 1,1,1-tris(hydroxymethyl)propane in the biodegradable and unused lubricants were degraded extensively in situ; however, these esters constituted only a minor proportion of the lubricant volume. The additives, alkylated naphthalenes and substituted diphenylamines, were fairly resistant to degradation, which is of environmental concern because of their toxicity. The biodegradable lubricant did not break down to recognized biodegradable thresholds and, as such, should not be classified as biodegradable under Antarctic marine conditions. A separate experiment was conducted to determine the influence of sediment preparation and deployment on compound ratios within the lubricants, and we found that preparation and deployment of the contaminated sediments had only a minor effect on compound recovery. Further monitoring of this in situ experiment will provide much needed information about the long-term natural attenuation of lubricants.