Phosphorus and the Biochemical Cycle of Lake Neerabup A wetland can function as a sink or transform nutrients, organic and inorganic matter. Wetlands are nature's filtration and purification facility for sediment and organic matter (Group, 2014). Phosphorus can arrive in wetlands as a suspended solid or as dissolved phosphorus. A significant concentration of phosphorus is associated with sediments in wetlands (Walbridge and Struthers 1993). Wetland phosphorus is removed by plants and microbial organisms (Group, 2014). Total phosphorus (TP) is in inorganic form, derived mainly from artificial sources, while it is in organic form; phosphate (PO4-P) comes from plants and animals and their remains (Group, 2014). In wetland soil, microorganisms, plants and geochemical processes are powerless factors for the transformation of dissolved phosphorus. (Walbridge and Struthers 1993). Algae use excess phosphorus and nitrogen to quickly grow and multiply in large numbers, thriving when the weather is warm and sunny and water flow is slow. Higher levels of phosphorus and nitrogen found in the Swan and Canning River systems and wetlands have caused excessive growth of blue-green and other algae, while low levels of phosphorus can support life (SERCUL, 2014). As a result, nutrients accumulate in the environment of human activity. We use too many nutrients in our daily lives. Nutrients entering the Swan, Canning and wetlands come primarily from fertilizers, garden fertilizers that use intensive agricultural resources, and industrial or urban losses. (SERCUL, 2010). It should be noted that total phosphorus is highly variable with rainfall events and the above results should be treated with caution (Group, 2014). Phosphorus...... middle of paper ......nd and Lake Neerabup); the limit value for phosphorus should be considered the same and adjusted as indicated in the table, Parameters Selected Guidelines Applications and Limitations Nutrient Contaminants in Surface Water Total Phosphorus Concentrations ANZECC Guidelines for South Western Australia for Lowland Rivers (ANZECC and ARMCANZ 2000) SCCP targets for total nitrogen and total phosphorus concentrations (SRT 2004 SCCP targets refer to the number of total nitrogen and total phosphorus samples exceeding the target value in relation to the maximum number of exceedances permitted. Target values ​​are apply only to the winter period and three years of data is used to assess compliance according to Swan River Trust 2004. These objectives can be applied in the present study at the request of the SRT as a guideline only. Table 2 Source: Nice et al, 2009