Abstract
Shallow coastal areas provide crucial ecosystem services, but are exposed to both local and global changes. Lately, Government and local authorities have emphasized the management of these productive systems. The aim is to study the function of these systems as filters in the nutrient transport between land and sea, and how it may change when local pressures and management actions (e.g. oligotrophication) interact with global warming. Understanding these relationships is crucial for management decisions. The filter function depends on benthic primary producers and microbial processes in shallow-water sediments (SWS). The quantitative role of SWS for nutrient retention will be assessed under current conditions and at global warming and changed nutrient loading. Focus will be on biological removal and import of nitrogen under ambient and manipulated nutrient status and ratios, considering microbial mat composition (e.g. functional genes). A central question is whether oligotrophication and warming will favour benthic N2-fixing cyanobacterial mats, found to be common in a base-line study. Ecologically meaningful predictions require studies on multitrophic systems. We will study intact natural sediment, in the field and in experiments, measuring key ecosystem properties and processes (trophic state, nutrient fluxes, N2-fixation, denitrification, functionl genes). Data will be used in a nutrient transport model (under construction) to be used as management tool.
Sweden