Garton 9813318 Antarctic coastal environments have been the site of recent studies on the effects of human activities on marine ecosystems. This international, collaborative study will focus on developing methodologies to generate biological baselines for the benthic nearshore habitat in the Ross Sea region of Antarctica. These baselines will be useful to for studies to distinguish between natural environmental variability from anthropogenic impacts and to assess the recovery capacity of coastal marine populations which have been exposed to natural and anthropogenic stresses. The study will take place in Terra Nova Bay and will be conducted in cooperation with the Italian Antarctic Program. The research will focus on populations of the scallop Adamussium colbecki from a natural-impact site (meltwater stream), anthropogenic-impact site (in the vicinity of the Terra Nova Bay Station in Tethys Bay) and control site (no meltwater stream in a pristine area of Tethys Bay). Diver- assisted collection and remotely operated vehicle photo- surveys will provide data to determine bivalve size frequencies and densities along with benthic community patterns across depth and distance gradients from the shoreline at each site. Environmental gradients will also be measured. Bivalve physiology profiles will be generated by micro-respirometry measurements of oxygen consumption rates as well as nitrogen excretion rates under ambient and temperature-stressed environmental conditions. Biochemical assays will be used to assess metabolic activity. The physiological and biochemical assays will be complemented by cellular biomarker analysis performed by the Italian collaborators. Integration of these biochemical, physiological and population assays will provide examples of biological baselines for assessing indicator species' responses to natural and anthropogenic impacts in the Antarctic coastal zone.
