The impact of plant nutrients on primary productivity in running waters: evaluating the risk to stream health
Excessive plant growth is the main factor associated with the degraded health of eutrophic streams and rivers. Our capacity to effectively manage the nutrient economy of running waters is hindered by a poor understanding of the relationship between nutrient inputs, mainly phosphorus and nitrogen - and ecological responses. In some rivers, for example, high nutrient levels may be associated with high algal and/or macrophyte growth, whereas in other systems primary productivity may be curtailed by confounding physical, chemical and biological factors. In this project, we will quantitatively assess the impact of these confounding factors on the relationship between plant nutrients and primary and secondary producers in flowing waters, across a range of nutrient-rich streams in Munster. We will also determine the quantitative responses of benthic algae to variable nutrient concentrations, light levels (shading) and grazing pressure in both natural streams and experimental stream channels at UCC. The deliverables of this project will include methods for identifying streams most at risk of ecological degradation through excessive nutrient inputs, management guidelines aimed at mitigating the impact of eutrophication in flowing waters and fundamental insights in nutrient economies of Irish streams.
If you want to read more about this project, you can do so at erc.epa.ie.
Environmental Protection Agency 2005-W-MS-39-M1
Keywords: Plant growth; Water quality; Eutrophication; Nutrient loading