The discovery of elevated levels of mercury in the spiders and songbirds of Dome Island has led the Nature Conservancy of Eastern New York and the Dome Island Committee, the organizations responsible for the island’s preservation, to test for mercury contamination on Crown Island and protected shorelines.
That will help the groups determine how pervasive mercury and its toxic form, methylmercury, is in Lake George, said Henry Caldwell, the chairman of the Dome Island Committee.
Researchers from the BioDiversity Institute of Gorham, Maine, which conducted the original studies of Dome Island’s birds and spiders, returned to Bolton Landing earlier this week to begin the broadened study.
“No one expected to find mercury pollution at these levels on Lake George,” said Caldwell. “Working with the Nature Conservancy of Eastern New York, which is the island’s owner, we decided to take the next step and look beyond Dome Island.”’
In July, the Dome Island Committee received a draft of a study by the BioDiversity Institute of Gorham, Maine, that found that “mercury concentrations in spiders from Dome Island represent some of the highest recorded in the Northeast.”
That study followed one conducted in 2006, which concluded that “mercury levels in songbirds sampled on Dome Island rank among the highest in New York and across the region.”
The island’s spiders, which the birds feed upon, may be the source of the elevated mercury levels found in birds, the scientists surmised.
From Crown Island and a site on the mainland, researchers will collect spiders of the type sampled on Dome Island and subject them to mercury tests, said David Buck, an aquatic biologist with the BioDiversity Institute.
The researchers will also test crayfish, Buck said.
“Crayfish reflect mercury in their immediate surroundings and provide a useful yardstick for comparing mercury levels throughout a specific watershed,” said Buck.
Results of the studies should be available by next spring, Buck said.
“I’d be surprised if we found that mercury contamination was limited to Dome Island,” said Buck.
Additional studies will permit scientists to assess the environmental impacts of mercury pollution on Lake George, said Buck.
The Dome Island and Lake George studies will become part of more comprehensive studies of air pollution and its impacts on ecosystems and biodiversity in the northeast, said Mark King of the Eastern New York Nature Conservancy.
“Our focus should be making people aware of how widespread mercury contamination is,” said King. “We have an opportunity here to show how mercury moves through the ecosystem; Dome Island and Lake George are pieces in the big picture.”
For more news from Lake George, read the Lake George Mirror