Human impacts threaten not only species, but also entire ecosystems. Ecosystems under stress can collapse or transition into different states, potentially reducing biodiversity at a variety of scales. Here we examine the vulnerability of shallow invertebrate-dominated ecosystems on polar seabeds, which may be threatened for several reasons. These unique communities consist of dark-adapted animals that rely on almost year-round sea-ice cover to create low-light shallow marine environments. Climate change is likely to cause early sea-ice break-out in some parts of Antarctica, which will dramatically increase the amount of light reaching the seabed. This will potentially result in ecological regime shifts, where invertebrate-dominated communities are replaced by macroalgal beds. Habitat for these endemic invertebrate ecosystems is globally rare, and the fragmented nature of their distribution along Antarctic coast increases their sensitivity to change. At the same time, human activities in Antarctica are concentrated in areas where these habitats occur, compounding potential impacts. While there are clear mechanisms for these threats, lack of knowledge about the current spatial distribution of these ecosystems makes it difficult to predict the extent of ecosystem loss, and the potential for recovery. In this paper we describe shallow ice-covered ecosystems, their association with the environment, and the reasons for their vulnerability. We estimate their spatial distribution around Antarctica using sea-ice and bathymetric data, and apply the IUCN Red List of Ecosystems criteria to formally assess their vulnerability. We conclude that shallow ice-covered ecosystems should be considered near threatened to vulnerable in places, although the magnitude of risk is spatially variable. This dataset comprises two files. Both are provided in netCDF format in polar stereographic project (see nc file for projection details). light_budget_6km.nc : this gives the estimated annual light budget (in mol photons/m^2/year) at the surface of the water column, having been adjusted for sea ice cover (see paper for details). This is calculated on the 6.25km grid associated with the sea ice concentration data. benthic_light_500m.nc : this gives the estimated annual light budget (in mol photons/m^2/year) at the sea floor, having been further adjusted for water depth. It is provided on a 500m grid (as per the IBCSO bathymetry used). Areas deeper than 200m are given no-data values, and areas outside of the coverage of the sea ice grid are assigned a value of -999. See paper for details.

This project aims to assess the vulnerability of and risks to habitats in Australian fisheries in the Australian Exclusive Economic Zone (EEZ)/Australian Fishing Zone (AFZ) of the Southern Ocean to impacts by different demersal gears - trawl, longline and traps. The project which is a collaborative initiative between the Australian Antarctic Division (AAD), the Australian Fisheries Management Authority (AFMA), industry and research partners, and substantially funded by the Fisheries Research and Development Corporation, was developed in order to resolve outstanding questions relating to the potential impacts and sustainability of demersal fishing practices in the AFZ at Heard Island and the McDonald Islands (HIMI). It will also help resolve similar outstanding questions for other fisheries in the Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR) in which Australian industry participates and provide technology for use in other fisheries to address similar questions. The proposed project will assess the degree to which demersal gears interact with and possibly damage benthic habitats. It will also assess the degree to which these habitats might be damaged within the AFZ in the HIMI region. The project is not intended to estimate rates of recovery of benthic habitats following damage by demersal gears. However, information from the literature on rates of recovery of different benthic species and habitats will be used to assess the risks of long-term sustainability of these habitats. Objectives To develop deep sea camera technologies that can be easily deployed during fishing operations, to facilitate widespread observations of demersal fishing activities (trawl, longline and trap) and their interactions with benthic environments. To assess the vulnerability of benthic communities in Sub-Antarctic (Australian AFZ) and high latitude areas of the Southern Ocean (Australian EEZ) to demersal fishing using trawls, long-lines or traps, using video and still camera technologies. To assess the risk of demersal fishing to long-term sustainability of benthic communities in these areas, based on the assessment of vulnerability and information from the literature on potential recovery of benthic species and habitats. To recommend mitigation strategies by avoidance or gear modification, where identified to be needed, and practical guidelines to minimise fishing impacts on benthic communities. Field work: Field work for this project is well advanced. Sampling of benthic habitats was conducted off East Antarctica from the AA in the summer season of 2009/10. Sampling yielded biological samples and camera footage over a number of sites spread across a large section of the East Antarctic coast and across a range of benthic habitats, however sampling was limited by the extent of ice and number of ship days (10) allocated (the project was originally planned for 16 ship days and later in the summer, when ice was predicted to be less extensive). The camera units are currently deployed on commercial vessels fishing the sub-Antarctic. The close of the 2010 commercial fishing season in September 2010 will mark the conclusion of field activities for this project.

Taken from the biology report for Davis Station, 1982, prepared by Mark Tucker. A hardcopy of the report and field books are available in the Australian Antarctic Division library, and pdf copies of the report and field books are available for download at the provided URLs. Introduction The year biology programme for the 1982 season was divided amongst three persons into Phytoplankton, Chlorophyll, Invertebrates and Fish. As the zoologist, I will therefore concentrate on the animal, aspect. The aims of this programme as outlined in the ARPAC approved "A survey of the inshore marine area of Davis" are: 1) A systematic investigation to determine the flora and fauna of the marine inshore environment. 2) To explain their distribution and abundance in response to environmental variables. The first aim can be divided into two categories: 1) Wide range collection of the benthic, planktonic, pelagic and epontic faunas from the inshore waters of the Vestfold Hills. 2) Quantitative examination of the seasonal and distributional changes of the more common species. Most of the wide range collecting of the benthos and to a certain extent the plankton was carried out over the 81/81 summer. Collections were made from as far north as the Wyatt Earp islands and in the south near the Sorsdal Glacier. As wide a coverage as possible of the Vestfolds was made plus a visit to the Rauer group on one occasion. The planktonic fauna was collected throughout the year on a monthly basis from three sites from January 82 to December 82 while the pelagic and epontic faunas were collected monthly from the same sites after fast ice formation - April to December. Additions were made to the benthic collections throughout the year if any previously uncollected or interesting specimens were observed. These collections have culminated in over 150 species. I would expect the total number of different species to be around 200 once all are identified. Representatives of all the species collected will be returned to Biology, Kingston, for reference for future workers in the marine invertebrate field. The second aim, the quantitative examination, was carried out over a 12 month period from January 82 to December 82 at three sites - A, B and C (figure 1). These sites were selected on the criteria of depth, proximity to Davis and most importantly sediment types. Site A is 9m deep with a sandy bottom and a few odd rocks. It has a relatively low (5% or less) macrophytic cover. Site B is 20m deep with a mud bottom and zero macrophytes while site C is 15m deep with a rocky bottom and scattered pockets of sand and shell fragments etc. and 5-10% macrophyte cover. Sites A and B are relatively flat while C is situated on quite a steep slope. Sediment samples have been retained from each site to enable particle size analysis for more accurate descriptions of the sediment types. Several zooplankton, sediment inhabiting and macroscopic benthic species were monitored on a monthly basis for the year. Fish were sampled at sites A and C while the epontic community was sampled after ice formation at all three sites. The environmental variables measured were ice and snow thickness, tide, hours of daylight, salinity, nutrients, water temperature plus chlorophyll data and phytoplankton numbers. These variables are to be used in statistical analysis as a means of explaining the abundance and distribution of the species studied.