In the middle of an East Hampton salt marsh swarming with bugs and brimming with knee-high grass, a group of about 20 biologists, conservationists and a few friends circled around a 40-foot net. Clapping their hands, yelling out directions and darting right and left, the group could have been playing a friendly game of soccer. However, the boot-wearing bunch had another mission in mind: catching sparrows and testing them for mercury.
Members of the Nature Conservancy Long Island, in conjunction with the Biodiversity Research Institute, based in Maine, gathered at the Merrill Lake Sanctuary on Accabonac Harbor last Wednesday morning at 6:30 to test the songbirds.
To catch them, the group slowly closed in on the sparrows living in the grassy marsh. As they closed the gap, birds flew away from them and into the net. Carefully, the team gathered the birds as soon as they were caught and took them to their field lab, where they measured, examined, tagged them, and drew blood for testing. The birds were released as soon as their checkups were completed.
“We want to identify the key threats so that we can better protect the marshes that serve both people and nature,” explained Marian Lindberg, the senior staff writer at the conservancy. According to Oksana Lane, the wetland-bird program director for BRI, sparrows and other songbirds are chosen because they eat spiders and other invertebrates that are higher on the food chain, where higher concentrations of mercury are found. Mercury, a neurotoxin, can harm the birds’ central nervous system and impair reproduction.
Ms. Lane said that Long Island songbirds, including those in Accabonac Harbor, do have somewhat high concentrations in their blood. “Salt marsh sparrows have levels higher than what we consider a threshold—the level is elevated, especially along the south shore of Long Island,” she said. “There can be many factors as to why, and we’re in the process of investigating the reason.”
Ms. Lane said the mercury might have come from a source that is no longer there, like an old incinerator. North Cinder Island in Hempstead Town has a high concentration of mercury, according to Ms. Lane, because there used to be an incinerator nearby, and discarded thermostats containing mercury are burned in most waste incinerators. The mercury ends up in the environment, and traces can be found years later, she said.
Assemblyman Fred W. Thiele Jr. came along for the field work Wednesday morning and casually but enthusiastically announced that a bill requiring thermostat manufacturers to establish collection programs for out-of-service thermostats, free for consumers, was passed in the Senate last week and is headed to the governor’s office. On the marsh, the news was met with cheering.
“Any kind of recycling is a good thing, as long as people recycle [thermostats] properly and don’t throw them in the garbage,” Ms. Lane said, although she added, “It has to be done at the international level to reduce emissions.”
In the meantime, BRI and the Nature Conservancy are trying to identify and track areas of concern across the Northeast.
In 2006, the Nature Conservancy held a workshop on the effects of air pollution, and BRI was invited. Since that meeting, the two organizations have worked alongside one another to look more closely at mercury in songbirds.
Since 2008, the conservancy has been studying marsh habitat in a variety of ways to determine why many Long Island salt marshes have visibly deteriorated, according to Ms. Lindberg.
“Marshes are vital for certain birds, fish and other animals that depend on marshes for breeding, protection and feeding, and marshes are hugely important for people, because marshes filter pollutants from the water and air and offer some protection against storm waves,” she said. “It was long felt that salt marshes could absorb pollutants to an almost unlimited extent, but recent deterioration and studies have shown that is not the case.”
Depending on the concentration, mercury can pose a health threat to humans. Minamata disease, a neurological syndrome, can show up in unborn babies or infants if the mother ingests enough mercury. According to the Centers for Disease Control and Prevention, between 300,000 and 630,000 infants are born in the United States each year with mercury levels high enough to be associated with IQ loss; additionally, adults are more likely to have a heart attack if they come into contact with high levels.
The disease is named for Minamata, Japan, where, in the late 1950s, a Japanese factory released mercury-polluted wastewater, which accumulated in shellfish and fish in Minamata Bay and the Shiranui Sea. More than 2,000 people were poisoned, and more than half of them died. Mercury levels found here are far from those associated with the Minamata disaster.
The conservancy measures sediment depths, as well as taking water and root samples to evaluate below-ground processes, especially the effects of excessive nitrogen on marsh root health, which also includes the BRI mercury research. The conservancy has also partnered with the U.S. Geological Service to install equipment that monitors acid rain, which includes airborne sources of mercury.
Two years ago, the New York State Energy Research and Development Authority awarded both groups a $400,000, five-year grant to test sites across New York State, using Nature Conservancy land for research. The conservancy owns or manages 175 acres around Accabonac Harbor alone.
Back at the harbor on Wednesday, the sparrows seemed to wait anxiously to be released as the BRI and Nature Conservancy biologists sat in the middle of the Merrill Lake Sanctuary examining them closely. As if on an assembly line, they were passed from biologist to biologist until they were gently released back to the grass.