Response of deep-water sponge fauna to mine tailings

Mine tailings are finely ground waste products from the mining industry, left after the valuable fraction (metals/minerals) has been extracted. In Norway industries can get permission to dump mine tailings in the deep basins of fjords or along the shoreli ne. Mining produces large quantities of wastes containing significant amounts of particulate matter of fine fractions (<40?m) and coarse fraction (40-250?m) (i.e. 4 million tonnes of waste can be dumped annually in Bøkfjorden by a single company). Fine p articles stay in suspension for long periods and can affect vast areas of the fjord at low concentrations. Indications are that bottom-dwelling organisms are the marine component most susceptible to this impact. This impact is at present complelely un-inv estigated, which is surprising as sponges are important components of benthic communities in terms of both diversity and biomass, and their high sensitivity to changes in their ambient environment is known, making them good model organisms. This project p roposes to investigate the ecosystem role of sponges in the vicinity of waste disposal sites, and their threshold tolerance to the environmental impact of mining waste products. We aim to test the effects of particulate waste at different concentrations o n physiological parameters (respiration, pumping, particle-deposition and food-uptake) of sponges in a laboratory setting. Dependent upon the duration of the aquarium experiments, survival, growth and development (histology, deformity) may also be assesse d. Sponges collected from field sites (with ROV) will be transported to the lab where they will be exposed to different doses of mining particles. Strengthening scientific knowledge of sponge physiology in response to environmental stressors will improve the quality of management advice given to governmental and international working groups regarding anthropogenic stressors to all Vulnerable Marine Ecosystems.