A variety of epifaunal invertebrates were collected from hard substrates and soft sediment habitats at various sites in the Windmill Islands near Casey station in East Antarctica. Collected fauna were frozen (-18oC) and returned to Australia for analysis. Stable isotope analysis (carbon and nitrogen) was conducted on 376 samples. This work was completed as part of ASAC project 2948 (ASAC_2948), "TRENZ: The TRophic Ecology of the antarctic Nearshore Zone: local and global constraints on patterns and processes".

Project Objectives 1) To describe trophic relationships in near shore marine benthic ecosystems of East Antarctica and determine the importance of environmental forces (such as sea ice and primary production) to the structure of food webs and biological interactions in benthic assemblages. 2) To determine how marine benthic food webs in East Antarctica respond to local scale disturbances (such as sewage outfalls and abandoned waste disposal sites) and develop predictive models of the influence of local human activities on trophic relationships. 3) To develop predictive models for the potential effects of global climate change on the trophic structure and function of near shore marine benthic assemblages and determine the sensitivity of Antarctic near shore ecosystems as sentinels of climate change. 4) To measure toxicity of organic contaminants to Antarctic marine benthic invertebrates, determine concentrations in upper trophic level fauna and to model the risk of bioaccumulation of organic contaminants (from local and global sources) in near shore marine benthic food webs in East Antarctica. Collections of organisms from coastal ecosystems around Casey and Davis stations were made between 2006/07 and 2010/11. These samples have been used in a variety of ways to examine trophic interactions in Antarctic coastal ecosystems. Methods include stable isotope analysis, diet and gut contents DNA analysis, analysis of POPs (persistent organic pollutants) and the impacts of local disturbances on food webs.

Project Objectives 1) To describe trophic relationships in near shore marine benthic ecosystems of East Antarctica and determine the importance of environmental forces (such as sea ice and primary production) to the structure of food webs and biological interactions in benthic assemblages. 2) To determine how marine benthic food webs in East Antarctica respond to local scale disturbances (such as sewage outfalls and abandoned waste disposal sites) and develop predictive models of the influence of local human activities on trophic relationships. Collections of organisms from coastal ecosystems around Casey and Davis stations were made between 2006/07 and 2010/11.

Untreated, macerated wastewater effluent has been discharged to the sea at Davis Station since 2005, when the old wastewater treatment infrastructure was removed. This environmental assessment was instigated to guide the choice of the most suitable wastewater treatment facility at Davis. The assessment will support decisions that enable Australia to meet the standards set for the discharge of wastewaters in Antarctica in national legislation (Waste Management Regulations of the Antarctic Treaty Environmental Protection Act - ATEP) and to meet international commitments (the Madrid Protocol) and to meet Australia's aspirations to be a leader in Antarctic environmental protection. The overall objective was to provide environmental information in support of an operational infrastructure project to upgrade wastewater treatment at Davis. This information is required to ensure that the upgrade satisfies national legislation (ATEP/Waste Management Regulations), international commitments (the Madrid Protocol) and maintain the AAD's status as an international leader in environmental management. The specific objectives were to: 1. Wastewater properties: Determine the properties of discharged wastewater (contaminant levels, toxicity, microbiological hazards) as the basis for recommendations on the required level of treatment and provide further consideration of what might constitute adequate dilution and dispersal for discharge to the nearshore marine environment 2. Dispersal and dilution characteristics of marine environment: Assess the dispersing characteristics of the immediate nearshore marine environment in the vicinity of Davis Station to determine whether conditions at the existing site of effluent discharge are adequate to meet the ATEP requirement of initial dilution and rapid dispersal. 3. Environmental impacts: Describe the nature and extent of impacts to the marine environment associated with present wastewater discharge practices at Davis and determine whether wastewater discharge practices have adversely affected the local environment. 4. Evaluate treatment options: Evaluate the different levels of treatment required to mitigate and/or prevent various environmental impacts and reduce environmental risks.