Food web structure, function and contaminant accumulation in coastal ecosystems
Environmental change may influence trophic efficiency. In this project we seek to understand how contaminant accumulation in coastal ecosystem will affect the food web structure.
About the project
Climate-driven changes in temperature, catchment land-cover, and terrestrial runoff of DOM, nutrients and contaminants are likely to have strong effects on coastal biogeochemistry and ecology. In particular, changes in terrestrial inputs can be expected to lead to shifts in aquatic food web structure and function in coastal ecosystems, and thus the flux of energy and contaminants into and through aquatic food webs. A key aspect of this is how environmental change may influence trophic efficiency (i.e. the proportion of production by one trophic level that is converted to production by trophic levels above). This will depend on responses in both exploitation efficiency (percentage of one trophic level ingested by the trophic level above) and net growth efficiency (percentage of assimilated energy that is converted into biomass). The latter will also influence accumulation of contaminants in the food web, as lower trophic efficiency is predicted to increase such accumulation. Although trophic efficiencies are crucial for how climate change may affect aquatic productivity and cascading effects throughout the food web, they are rarely considered in this context.
The main aim of the thesis will be to quantify and describe how climate-mediated changes in temperature and terrestrial DOM loading to aquatic ecosystems will affect energy flux, food web structure and contaminant distribution. Key themes of interest will include:
- Effects of terrestrial inputs on coastal biogeochemistry and ecology (productivity, food web structure, dietary reliance on terrestrial energy)
- Contaminant uptake and food web transfer across a gradient in relative influence of terrestrial loading of dissolved organic matter (DOM).
- Climatic impacts (changes in DOM, temperature, nutrients) on trophodynamics (energy and contaminants), growth efficiency and life-history variation in aquatic systems (including potential future contaminant concentrations in coastal fish)
Department of Chemistry, UiO