The biological effects of eutrophication

Abstract

Increases in the supply and availability of nutrients in water bodies affect the rate of primary production of plants, the magnitude of standing crop biomass achieved and the relative proportion of different species. Nutrient supply is only one environmental factor affecting primary production however, with light availability and temperature being the other important factors. Plant production is then available for animal production (consumers) either directly, as living plant biomass or indirectly after death, as detritus. Thus nutrient effects on any consumer component of an aquatic community are indirect through an alteration in the amount, or relative abundance, and nature (e.g. size or nutritional content) of their food supply, which may alter the balance between competitors for the overall food resources. These effects may occur at every consumer level — herbivores, detritivores and predators.