Two-thirds of the surface area of US estuaries and bays at risk
A report by a new independent commission says that that runoff from farms and cities has mostly been unabated or has actually increased over the past 30 years, threatening to turn much of America’s coastlines into new ‘dead zones’.
The Pew Oceans Commission, an independent body composed of leaders from business, science, government, and the conservation and fishing communities, issued the warnings in its first report on the state of the US’s oceans. It said that despite 30 years of progress in reducing pollution from ocean dumping, waste treatment facilities, and toxics, two-thirds of the surface area of US estuaries and bays at risk. Polluted runoff from farms and cities, often far inland, has been largely unabated or actually increased over the past 30 years, in many cases negating gains made in controlling direct sources of pollution.
Scientists from the University of Maryland and University of Rhode Island in Marine Pollution in the United States: Significant Accomplishments, Future Challenges cite increases in plant nutrients as the most pervasive pollution risk for estuaries, coral reefs, seagrass beds, and other coastal ecosystems. Leon Panetta, the commission’s chair and a chief-of-staff under President Clinton, warned that ‘dead zones’ like the Gulf of Mexico’s are likely to proliferate as heavy coastal development continues. In the case of the Gulf of Mexico fertilisers and manure from farms together with vehicle emissions travelling in the Mississippi River have starved a 5,500 square mile (14,000 sq km) area of oxygen for much of each year (see related
story). Panetta said that smaller ‘dead zones’ already exist in areas of heavy coastal development like Southern California, Florida and New England.
Besides lack of oxygen, algal blooms (some of which may be toxic) and the loss of seagrasses and coral reefs are adding to threats to biodiversity, making ecosystems less resilient to natural and human influences and declining fish numbers. The report notes that, besides nutrients travelling downstream, the coastlines are already home to half the US population and is forecast to increase to 75% by 2025, adding further coastal stress.
“We’ve done a good job tackling many of the obvious causes of ocean pollution, now we need to get serious about the less obvious sources of pollution that flow from our cities, farms, and ships if we want to protect our coastal waters and the communities they support,” Panetta commented.
The report notes that the main barriers to improving the situation are largely administrative and not scientific. “We have only recently removed nutrients from treated waste, and new emission standards, if fully implemented, could reduce atmospheric deposits of nitrogen by 40%,” said Dr. Donald Boesch from the University of Maryland Center for Environmental Science, who led the research. “Reduction in agricultural sources of nutrients is also feasible through improved agricultural practices and watershed restoration.” The main obstacle to progress has been legal and institutional approaches to controlling coastal pollution, which have thus far been only modestly successful, the report finds.
However, the authors conclude that watershed approaches to managing pollution are beginning to have an effect, citing a multi-state effort between agencies and fishermen to control pollution in the Chesapeake Bay as one example (see related
story).. Panetta said that water quality and fish stocks in the bay, which had been “dying”, were now improving, thanks to economic pressure on fishermen and officials
Another example of success is in Florida’s Tampa Bay where seagrass beds are slowly recovering after improved sewage treatment greatly reduced nitrogen inputs.
The report calls for solutions that combine voluntary and regulatory approaches to pollution abatement and Pew Oceans Commission will submit its proposals to Congress in 2002.
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