ABSTRACT
Carbon, nitrogen, and phosphorus are the most significant macronutrients studied in aquatic ecosystems. These elements move throughout the environment in their respective cycles and are distributed in the atmosphere, hydrosphere, biosphere, and geosphere in different organic and inorganic species, with concentrations that vary as a function of temporal and spacial conditions (Svensson and Soderlund, 1976; Bolin and Cook, 1983). In the aquatic environment, they are distributed between the water and sediment interface in both dissolved and particulate forms. Bioavailable nutrients are taken up and metabolized by aquatic organisms in the life cycle. In a specific aquatic ecosystem, nutrient dynamics partition these elements among water, sediment, and biota to attain a natural balance. This balance may change as nutrients are introduced from agricultural, industrial, and urban sources. The nutrients in soil are studied for their value to agricultural products. On the other hand, studies of nutrients in aquatic sediments are mainly related to the assessment of the effects of their increasing concentrations originating from different sources. Accumulation of nutrients in water and sediments can result in eutrophication of lakes, ponds, and rivers. The eutrophication is often accompanied by depletion of oxygen in the water and decrease of biodiversity in the affected water body (Vollenweider, 1968; Foehrenbach, 1973; Sutcliffe and Jones, 1992).
