Abstract
The aims are to assess the effects of multiple stressors on shallow-water sediments and to study the nature of their interaction (synergistic/antagonistic). Combined effects of three stressors will be studied: nutrient load, toxicant and increased temperature (climate change). The project builds on 4 basic facts (1) Shallow coastal areas provide critical ecological services, but are subjected to an array of anthropogenic stressors, including climate change; (2) Combined effects of stressors cannot be extrapolated by studying one stressor at a time; (3) For ecologically meaningful understanding, stressor effects must be considered on multiple trophic levels; (4) Understanding causal relationships and the mechanisms linking environmental stressors, and their effects, is fundamental for effective management of marine ecosystems. The importance of indirect food-web-mediated effects and the role of autotrophy as an intrinsic buffer for the ecosystem response will be studied. Approach: Flow-through mesocosm experiments with intact natural sediment are exposed to 3 stressors in combination. Together with altered nutrient load and raised temperature, an antifouling agent (e.g. an pyrithione) or a PAH (e.g. pyrene) will be used as the model toxicant. Focus will be on the microscopic food webs and key ecosystem processes driven by them. Complementing small-scale laboratory experiments, using natural sediments, will be run to clarify the mechanisms behind stressor interactions.
Sweden