Extent of Mercury Pollution More Widespread Than Previously Thought, According To Report

Mercury pollution is making its way into nearly every habitat in the nation, exposing countless species of wildlife to potentially harmful levels of mercury, according to a report released on Sept. 19 by the National Wildlife Federation.

"From songbirds to alligators, turtles to bats, eagles to otters, mercury is accumulating in nearly every corner of the food chain," said Catherine Bowes, northeast program manager for the National Wildlife Federation and principal author of the report. "This report paints a compelling picture of mercury contamination in the United States, and many more species are at risk than we previously thought. Fish, long thought to be the key species affected by mercury, are just the tip of the iceberg."

The National Wildlife Federation report, Poisoning Wildlife: The Reality of Mercury Pollution, is a compilation of more than 65 published studies finding elevated levels of mercury in a wide range of wildlife species. The report highlights mercury levels in fish, mammals, birds, reptiles and amphibians living in freshwater, marine and forest habitats from across the country.

The accumulation of mercury in fish has been well-understood for years. However, scientists have recently discovered that mercury accumulates in forest soils, indicating that wildlife that live and feed outside aquatic habitats also are at risk of exposure to mercury.

"Scientific understanding of the extent of mercury contamination in wildlife has expanded significantly in recent years," said Dr. David Evers of the Biodiversity Research Institute, wildlife toxicologist and leading researcher in this field. "We are finding mercury accumulation in far more species, and at much higher levels, than we previously thought was occurring. This poses a very real threat to the health of many wildlife populations, some of which are highly endangered."

Mercury accumulation in fish is not only a concern for the health of people who eat them, it also poses a threat to the fish themselves. Poisoning Wildlife pulls together the major findings from more than 20 of the 65 published studies that attribute adverse health impacts on fish, birds and mammals with elevated mercury levels in those species, according to the National Wildlife Federation. Fish with high mercury levels have difficulty schooling and spawning, birds lay fewer eggs and have trouble caring for their chicks, and mammals have impaired motor skills that affect their ability to hunt and find food.

"Now that we have hard evidence that mercury is affecting more species than originally thought, anything short of phasing out this toxic metal is inadequate," Bowes said. "The discovery of mercury in so many different species is a wake-up call. We need to ensure that all is being done to help wildlife cope with the stresses of a changing climate. Eliminating known threats like mercury is a critical place to start."

Poisoning Wildlife: The Reality of Mercury Pollution is available at http://www.nwf.org.

This article originally appeared in the 09/01/2006 issue of Environmental Protection.