The combination of human population growth, urbanization, and agricultural and industrial expansion is causing unprecedented and alarming rates of nutrient over-enrichment and accelerated plant growth in receiving waters worldwide. The increasing levels of nitrogen and phosphorus are of particular concern because an excess of these two nutrients promotes accelerated production of plant-based organic matter (or eutrophication) to the extent that excessive production, including harmful algal blooms, contributes to the expansion of marine ‘dead zones’ and leads to the destruction of fisheries habitat.