This is critical as we are only beginning to understand the importance of links between human-induced pollution of coastal oceans and harmful algal bloom expansion. When algae blooms decompose on an ocean or river bottom, they use up oxygen in the water. Certain toxic or inedible bloom species can alter food webs on which all commercial and sportfishing species rely. In North Carolina, researchers found that increased atmospheric nitrogen in coastal waters reflects changing land use and human activities. This has been accompanied by production of animal wastes and an increase in atmospheric nitrogen from storage and land application.
Nitrogen volatilizes as ammonia from hog waste, lagoons and crop sprays.
These ammonia emissions travel downwind and are ultimately deposited in nitrogen-sensitive waters. We are closely examining the linkage between enhanced ammonia deposition and the potential for harmful algae bloom expansion. In Western European coastal regions that are downwind of agricultural, industrial and urban emissions, the increase in atmospheric nitrogen also was found to contribute to algae blooms in the Baltic Sea and North Sea. Sea Grant researchers also found that a significant amount of the new nitrogen is being directly deposited on ocean surfaces, bypassing estuarine processes that filter runoff. Sea Grant is a network of 29 university-based programs involving more than 300 institutions nationwide in research, education and the transfer of technology regarding coastal, marine and Great Lake issues.