(Beyond Pesticides, July 31, 2009) A group of advocates and experts is warning that pesticide pollution from farm fields and households is contributing to the Chesapeake Bay’s decline, and may well be linked to declines in frogs across the region and intersex fish seen in the Potomac River.
In a report released yesterday, the group calls on federal, state and local government to accelerate research into what threats pesticide contamination may pose to the bay, and to step up efforts to reduce such toxic pollution.
“The thing that alarms us the most are the endocrine disruptors and the findings that have come out about intersex fish and frogs with reproductive problems,” said Robert SanGeorge, director of the Pesticides and the Chesapeake Bay Watershed Project. Endocrine disruptors are chemicals that mimic the natural hormones in humans or animals and can disrupt their growth and reproduction.
The project is a partnership between the Maryland Pesticides Network and the Johns Hopkins Center for a Livable Future. The group’s warning and recommendations are the product of a two-year study, in consultation with scientists, public health experts, government officials, watermen, environmentalists, farmers and pest management industries.
The report comes as federal and state governments attempt to jump-start the 26-year-old effort to restore the bay. The multi-state bay campaign has focused mainly on reducing nutrient pollution from sewage, farm and lawn fertilizer, power plants and vehicles. But the report argues that not enough attention is being paid to the potential harm being done by pesticides, primarily herbicides that wash off farm fields but also the many household products with a plethora of chemical ingredients that are washed down sewers.
“There’s no smoking gun,” Mr. SanGeorge says, acknowledging the lack of conclusive research showing toxic chemicals in the bay and its tributaries are harming fish and wildlife and bay grasses. But he points to studies suggesting problems and “enormous data gaps” that need to be filled.
Researchers suspect pesticides in the Potomac, for instance, may be causing the development of “intersex” fish, with both male and female reproductive organs. They have yet to find clear evidence of such a link however. Likewise, researchers have raised concerns about the impact on frogs and fish of low levels of the weed-killer atrazine found in water samples across the bay region. That connection also is still being studied and debated.
“We know there are some gaps in the data and our understanding of the effects,” said Greg Allen, a scientist in the U.S. Environmental Protection Agency’s Chesapeake Bay office. One area deserving further study, he suggested, is the impact on spawning fish and frogs in springtime, when herbicides freshly applied to farm fields at planting time tend to show up in greater concentrations in nearby streams.
While officials have gone to great lengths to figure the amounts of nutrient pollution entering the bay from all sources, there are no similar catalogs of pesticide use in the region. The report urges required reporting of some uses, but largely calls for voluntary measures and incentives to encourage less use of pesticides and potentially toxic chemicals.
Jeff Lape, director of EPA’s bay program office, acknowledged the report and said in an email that government agencies would continue to work “to promote sensible alternatives and other options that will reduce the input of pesticides to the bay.”