Eutrophication, fisheries, and consumer-resource dynamics in marine pelagic ecosystems

Anthropogenic nutrient enrichment and fishing influence marine ecosystems worldwide by altering resource availability and food-web structure. Metaanalyses of 47 marine mesocosm experiments manipulating nutrients and consumers, and of time series data of nutrients, plankton, and fishes from 20 natural marine systems, revealed that nutrients generally enhance phytoplankton biomass and carnivores depress herbivore biomass. However, resource and consumer effects attenuate through marine pelagic food webs, resulting in a weak coupling between phytoplankton and herbivores. Despite substantial physical and biological variability in marine pelagic ecosystems, alterations of resource availability and consumers result in general patterns of community change.