Algal availability of phosphorus discharged from different catchment sources

Citation

Land & Water Australia. 2009. Algal availability of phosphorus discharged from different catchment sources. [Online] (Updated July 30th, 2009)
Available at: http://lwa.gov.au/node/3659 [Accessed Tuesday 12th of March 2013 12:21:25 PM ].

Algal Management Strategies, Nutrient Management Strategies and Catchment Management Plans frequently have as a major focus the reduction of phosphorus loads to surface waters. The expressed intention of the nutrient control is to reduce the frequency and intensity of algal blooms, particularly blooms of toxic cyanobacteria. In many instances a direct link between the magnitude of algal blooms and phosphorus loads has not been demonstrated. However, there is appreciable information in the scientific literature reporting on eutrophication that indicates phosphorus supply is likely to exert a major control on the intensity of algal blooms (Hecky and Kilham 1988). Certainly continued reduction in supply, if possible, will eventually restrict algal growth (Sas 1989).

Project Objectives

Describe the chemical forms and availability to algae of phosphorus contained within the discharge from a sewage treatment plant (STP), an irrigation return drain and an agricultural catchment within the Goulburn-Broken catchment.
Describe changes in the quantity of algal available phosphorus, including that associated with suspended sediments, from the different sources under different conditions of supply, including different flow rates and different seasons.
Measure longitudinal changes in the particulate and dissolved phosphorus concentrations immediately downstream of the three input sources.
Determine the algal availability of phosphorus in bottom sediments of the Goulburn River downstream of the three discharges.
Develop and test a non-specific sediment transport model incorporating particle settling and re-suspension, and couple this to a P-speciation model describing transformations between dissolved, particulate, and bottom sediment forms of P, to predict the downstream effects of nutrient discharges to streams.