A team of California researchers may rewrite environmental textbooks after uncovering evidence that a saltwater marsh is a source of potentially hazardous fecal bacteria that is contaminating the swimming and surfing waters of one of the Golden State's most popular beaches.
The team's conclusions, which contradict accepted environmental science theory that wetlands should purify contaminants flowing into the ocean, are reported in the June 15 issue of Environmental Science & Technology, a peer-reviewed journal of the American Chemical Society, the world's largest scientific society.
The research shows that bacteria generated in Talbert Marsh, a man-made saltwater marsh near Huntington Beach, Calif., may be partially responsible for fecal bacteria levels thousands of times over the legal limit, according to Stanley Grant, Ph.D., who led the research team from the University of California-Irvine. Grant identified droppings from resident sea gulls as the source of the contamination, which spreads from the marsh to the shallow ocean water near the beach.
Depending on a wetland's size and water flow rates, some 4.6 million saltwater marshes in the continental United States could be affected similarly, Grant said. Research to that effect could throw those favoring the expansion of wildlife habitats for a loop -- to say nothing of the environmental scientists -- he suggested.
"One scenario is that anywhere along the coast in the United States, you might run into this problem," he said. "We thought there were multiple sources for the bacteria at Huntington Beach. What we've found is that the marsh is one of those sources. This beach is ground zero of what could be a national problem."
Elevated fecal bacteria levels were discovered in California after a 1999 state law set uniform bacteria standards for the state's beaches and required additional water testing, Grant said. The tests in Huntington Beach forced the beach closures. Federal legislation
Contact: Beverly Hassell
American Chemical Society