Better phosphorus, nitrogen control urged

A U.S. scientist urges that equal attention be given to phosphorus and nitrogen produced by human activity that are degrading water quality and aquatic life.

University of North Carolina at Chapel Hill Professor Hans Paerl notes the priority has historically been given to controlling phosphorus. But Paerl argues nitrogen imbalance is equally damaging and a dual nutrient strategy is necessary to manage the problem effectively.

The combination of human population growth, urbanization and agricultural-industrial expansion is causing unprecedented and alarming rates of nutrient over-enrichment and accelerated plant growth in receiving waters worldwide, the researchers said. That level of nitrogen and phosphorus is of concern because an excess of the two nutrients promotes eutrophication — accelerated production of plant-based organic matter — that contributes to the expansion of marine ‘dead zones’ and leads to the destruction of fisheries habitat.

The dual nutrient approach represents an evolutionary step in arresting eutrophication, with consideration of the larger scale freshwater-marine continuum being the driving force, Paerl said.

The research appears in the online edition of the journal Estuaries and Coasts.