Report reveals contaminants in dive eggs

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A new report released Tuesday indicates that toxic contaminants could move up the food chain in several lakes in New Hampshire.

The Loon Preservation Committee has found significant levels of a range of difficult-to-detect toxic chemicals in stranded loon eggs, including at Squam Lake, Lake Sunapee, Pleasant Lake and Grafton Pond, according to its report.

“It’s not surprising that we found contaminants, but the levels were surprising,” Harry Vogel, senior biologist at the association, said on Tuesday.

The LPC has tested 81 stranded loon eggs collected from 24 New Hampshire lakes over the past 10 years. Sixty percent had levels of contaminants “documented to cause adverse health or reproductive effects in other bird species,” according to the report.

These contaminants “amplify” as they move up the food chain. When a loon, for example, eats a fish that has consumed hundreds of insects that have fed on contaminated sediment at the bottom of a lake, the loon will have high levels of the contaminant that can endanger its health. A contaminant can be present in a fish high in the food chain at a concentration “a million times” greater than its concentration in water, said Vogel.

“In water, they are present in trace amounts,” he said. The concern for human health is eating fish, not swimming or wading, he said.

The LPC tested a range of common contaminants, including PFAS, an “emerging” contaminant widely used as a stain and fire suppressant; PCBs, which were once widely used in electrical equipment; and pesticides, including DDT.

“One of the problems is that once they’re in our environments, especially in sediment, lake bottoms, they stay,” Vogel said. “The best way to keep them out of our lakes is to never let them in. Nature struggles to break down “forever chemicals” like PFAS and PCBs, so that they remain in the environment for decades after the first contamination.

The results are a source of concern for loons and lake ecosystems in general. Loons are difficult to keep in captivity, so it is difficult to study the effects of contaminants on their health in the lab, Vogel said. Still, LPC has found levels high enough to be of concern to other bird species.

“Dives face multiple concurrent stressors,” said Vogel. “In many cases, many contaminants affect them at the same time – then lead fishing tackle, climate change. … The sum of all of these stressors is that they reduce the breeding success and health of loons in New Hampshire.

But loons are also an indicator species that offers insight into the health of a lake. They return to the same lakes year after year and can live up to 25 years. If they contain high levels of contaminants, other wildlife species are also likely to be threatened.

The majority of the eggs sampled came from Squam Lake, near Holderness, in Grafton County.

LPC found high concentrations of PCBs and polybrominated diphenyl ethers, a class of flame retardants better known as BDEs. Their source remains a mystery.

“These numbers are high enough to be of concern, but also low enough that you have to be careful that the cure is not worse than the problem,” said EB James, director of the Squam Lakes Association. Replacing the lake bottom, for example, would be too drastic and likely do more harm than good, he said.

The lake association is already studying what it can do to limit contamination throughout the watershed to limit nutrient levels in the lake.

The New Hampshire Department of Environmental Services tested fish in Squam Lake after the LPC data was discovered. His results corroborated the committee’s findings, and he advised fishermen not to consume yellow perch or smallmouth bass. These two fish are at the top of the food chain and had concentrations of cancerous contaminants high enough to endanger human health.

“Now that they have the advice on eating fish we are protected,” James said. “Water is not the problem. It’s the sediment and then the food chain.

The LPC opened its report calling for more state-led testing, and New Hampshire plans to test more fish for contaminants, said Ted Diers of the state’s Department of Environmental Services. However, the cost is a barrier. The LPC spent $ 3,000 to test each egg individually, and the state paid a contractor “a few hundred thousand dollars” to test fish in 14 lakes in southern New Hampshire for PFAS, Diers said.

“They test small parts per trillion,” Diers said. “It’s very, very expensive.

“Our waters are generally very clean,” he added. “Yeah, there are some of those high levels here and there. In general, we have very good quality water in New Hampshire. “

Claire Potter is a member of the Report for America Corps. She can be reached at [email protected] or 603-727-3242.


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