The discovery of high mercury levels in a type of sparrow that lives in New England saltmarshes has led to renewed calls for a nationwide mercury pollution monitoring effort.

The BioDiversity Research Institute of Gorham and the U.S. Fish and Wildlife Service released the findings this morning during a press conference at the Wells National Estuarine Research Reserve. Sen. Susan Collins also attended and called for Congressional action on a bill she co-sponsored called the National Mercury Monitoring Establishment Act.

Tests of over 220 individual birds from 11 coastal sites in Maine, Massachusetts, Connecticut and Rhode Island found unexpectedly high levels of mercury in saltmarsh sharp-tailed sparrows. Along with elevated mercury in the sparrows, scientists found evidence that fewer chicks survive where mercury levels are highest. Although the birds eat insects, some had mercury levels as high as those found in loons that eat fish from contaminated lakes.