Simulated Trading for Maryland’s Nitrogen Loadings in the Chesapeake Bay: A Policy Overlook

• Point sources of nitrogen and phosphorus are facilities that discharge wastewater containing these nutrients directly into the waterway. nonpoint sources discharge nutrients indirectly by rainwater runoff; agriculture can be a cause of nonpoint nutrient pollution from chemical fertilizers and animal manure. Nutrients, primarily nitrogen and phosphorus, are a leading cause of water quality impairment in lakes, estuaries, rivers, and streams. Though one may at first be inclined to think that an abundance of nutrients can only benefit a given environment, this is not so. In actuality, an excess of nutrients causes eutrophication. Eutrophication is characterized by an influx of biodegradable organic material, the rapid growth of algal blooms, and the depletion of dissolved oxygen. Depletion of dissolved oxygen is a severe threat in waterways because an adequate level of dissolved oxygen is a necessary to sustain life in a healthy aquatic ecosystem. Most aquatic species “breathe” oxygen dissolved in the water column, and while some aquatic life can adapt to low oxygen levels posteutrophication, most can not. This, in turn, results in a variety of problems, including clogged pipelines, fish kills, and reduced recreational opportunities.