Underwatertimes.com News Service
Washington, D.C. (Jan 5, 2007 16:25 EST) A NOAA research project shows nutrient pollution in estuaries, bays and harbors from the mid-Atlantic to New England is on the rise, showing excess nutrients like nitrogen and phosphorus are a threat to coastal water quality nationwide. The study's findings are compiled in a report, "Improving Methods and Indicators for Evaluating Coastal Water Eutrophication: A Pilot Study in the Gulf of Maine."
"Nutrient pollution is a pervasive problem that impacts and human activities, particularly in highly developed areas," says co-author Suzanne Bricker, physical scientist at the NOAA Center for Coastal Monitoring and Assessment. "Our study found that the problem is greater in the mid-Atlantic region, which has a higher population density and more intensive watershed development than coastal New England."
New England, however, has similar problems that are likely to get worse. The study's results indicated that nutrient pollution in the Gulf of Maine is higher than it was early 1990s, and conditions are expected to worsen as the coastal population in that region is expected to increase in the future.
"By including the socioeconomic impacts of pollution in coastal watersheds, we not only prove the value of applying integrated coastal and ocean observing technology in coastal management issues, but also in promoting a coastal stewardship that more fully evaluates the environmental impacts of development and other human activity," said John H. Dunnigan, director of the NOAA Ocean Service.
In many coastal ecosystems, future nutrient load increases of 10 percent to 25 percent are expected. These increases, in addition to the natural processing of nutrients once the loads reach estuarine waters, are important factors related to "eutrophication," the process by which excess nutrients—whether from storm water runoff, sewage treatment plants, septic systems, airborne dust or agriculture—fuel excessive algal blooms that lead to low oxygen conditions. Severe eutrophication causes a number of impacts to ecosystems, ultimately leading to the death of marine organisms, including important commercial fish species.
"Evaluating the extent of eutrophication, and how it affects different parts of the ecosystem, is the first, critical step toward developing strategies to address it," said Dwight Trueblood, NOAA co-director for the Cooperative Institute for Coastal and Estuarine Environmental Technology, which co-sponsored the study. CICEET is a partnership between NOAA and the University of New Hampshire.
NOAA scientists developed a "human use indicator" that examined the impact of nutrient pollution on recreational fish catches, making the study distinctive by including human activity as part of the ecosystem, improving traditional methods to assess eutrophication.
"Coastal managers and the public need a way to understand how low oxygen conditions impact the fisheries that are major economic drivers for their regions," said Bricker. "We've developed an indicator that, once tested and expanded, can be used to predict the loss of fish that will potentially occur when dissolved oxygen concentrations drop to a specific, low level."
The assessment methods were originally developed in the 1990s and were modified through this study. They will serve as the basis for an update of the NOAA National Estuarine Eutrophication Assessment that will be released in 2007.