NOAA report finds most coastal areas suffer from excess nutrientsBy Karl Blankenship
Chesapeake Bay Journal, October 2007
The vast majority of the nation’s estuarine waters suffer from excess nutrients, and most are predicted to worsen by 2020 as populations in coastal areas continue to swell, according to a recent report.
The report from the National Oceanic and Atmospheric Administration also showed that the mid-Atlantic region-including the
It was an update of a 1999 assessment, and while it found relatively little change in conditions over the last decade, it predicted coastal conditions will worsen in the future.
"What these results show is that we are just holding the line against nutrient-related degradation," said Suzanne Bricker, of NOAA’s Center for Coastal Monitoring and Assessment, and the report’s lead author. "Holding the line in the future is a daunting task in light of continued increases in coastal population that are expected."
For the systems with enough information to make future projections, the report acknowledged a "bleak outlook," predicting eutrophic conditions would worsen in 48 systems, stay the same in 11, and improve in only 14 systems by 2020.
The report illustrates that the problems that plague the Bay-excess nitrogen and phosphorus-are becoming more widespread among the nation’s estuaries. Estuaries are highly productive ecosystems where fresh and salt waters meet. Their condition is considered a key indicator of overall coastal water quality.
(A recently completed analysis for the World Resources Institutes by Robert Diaz, of the Virginia Institute of Marine Science found worsening low-oxygen conditions near coasts globally.)
The NOAA report said that two thirds of the 141 systems assessed, representing 78 percent of the total area covered by the assessment, had moderate to high levels of eutrophication.
Overall, the top sources of pollution were agriculture, wastewater treatment plants, urban runoff and atmospheric deposition.
Symptoms of eutrophication included high concentrations of chlorophyll a, (a measure of algae growth); loss of underwater grasses; frequent nuisance or toxic algal blooms; macroalgae; and low levels of dissolved oxygen.
Eutrophication takes a toll in many ways. It leads to fish kills, nuisance algae blooms and reduced fishery landings. Declines in tourism may result when floating algal mats ruin the aesthetics of an area, or when toxins from algal blooms accumulate in fish and shellfish.
The mid-Atlantic region, which stretches from the Chesapeake Bay through
The prognosis of the Bay was mixed.
Of nine areas of the Bay that were assessed, four were considered worse than they were in 1999: the
Looking to the future, the report predicted small improvements in the
Nationwide, few systems have significantly improved, the report said. All of the improvements came in places where discharges were aggressively controlled, such as
Areas where pollution sources were dominated by runoff from agriculture or development have generally remained unchanged or worsened.
Mark Rey, undersecretary for natural resources and environment at the U.S. Department of Agriculture, said progress is being made to reduce nutrient pollution on farms throughout the nation, but that it takes years for actions on the land to be felt far downstream.
"The good news is that nitrogen loss from farmers’ fields is falling so we are making progress," he said. "The bad news is that this nitrogen reduction from the field has not yet translated into an immediate reduction in nitrogen loads reaching many estuaries. We know that Farm Bill programs are making a difference, but that difference will take more time to manifest."
Donald Boesch, president of the University of Maryland Center for Environmental Science, which cooperated on the report, said stepped-up monitoring is needed in watersheds to verify that actions taken on the ground are having intended results.
"We need to verify," he said. "We need to know whether the fact that we don’t yet see results in the river and down in the coasts is due to the lag time, or that the