Indicator protocols: Total phosphorus + flow leaving a sub-catchment or whole catchment 2008-08-12T01:21:17Z 2008-09-03T13:04:43Z Indicator protocols: Total phosphorus + flow leaving a sub-catchment or whole catchment Nutrients in aquatic environments: phosphorus. National Land and Water Resources Audit National Land and Water Resources Audit <p>Phosphorus is an essential element required by animals and plants and high levels of phosphorus can be an important contributor to eutrophication &ndash; especially in freshwater and estuarine systems. Symptoms of eutrophication may include algal blooms and seagrass decline.</p> <p>Phosphorus in aquatic systems is generally partitioned into particulate (organic and sediment-bound) and dissolved fractions. Dissolved phosphorus (measured as FRP) is found in the form of phosphate ions (H2PO, HPO2-) and may be readily taken up by aquatic plants and microorganisms.</p> <p>Particulate phosphorus enters stream channels primarily through riparian litter fall, soil erosion and sediment transport. The concentration and load of particulate and dissolved forms of phosphorus in waterways reflect the stresses imposed by land uses and land practices in the catchment.</p> PN21559 PN21559