Widespread chemical contaminants found in failed Loon eggs from 24 Lakes


MOULTONBOROUGH — The Loon Preservation Committee has released a report documenting the widespread presence of chemical contaminants in inviable Common Loon eggs taken from failed loon nests on lakes throughout New Hampshire. As fish-eaters, loons are important sentinels of the health of aquatic ecosystems, especially when measuring contaminants that magnify at higher levels of aquatic food webs.

LPC tested 81 eggs from 24 lakes for per- and polyfluoroalkyl substances (PFAS), flame retardants (polybrominated diphenyl ethers or BDEs), polychlorinated biphenyls (PCBs), and organochlorine pesticides, including DDT and chlordane. The effects of these contaminants on loons are unknown, but up to 60 percent of eggs tested exceeded levels documented to cause negative health or reproductive effects in other bird species in at least one of the contaminant classes.

Lakes with notably elevated levels of contaminants included Arlington Mill Reservoir (PFAS), Canobie Lake (PFAS), Lake Francis (PCBs), Merrymeeting Lake (PCBs), and Squam Lake (BDEs, PCBs). Where present in fish, effects of these contaminants could, together with other stressors, negatively affect loon health and/or reproductive success and also potentially affect other lake wildlife and human health. After LPC’s discovery of elevated contaminant levels in loon eggs on Squam Lake, New Hampshire Department of Environment Services tested fish on Squam and found high levels of PCBs in smallmouth bass and yellow perch, leading to an advisory in March 2020 to limit consumption of fish from the lake due to the presence of this likely carcinogen.

LPC’s report details recommendations to address the issue of contaminants in New Hampshire’s lakes, including increased testing of fish and wildlife high on the aquatic food web, inviable loon eggs, or other species known to consume fish. LPC is the only organization systematically testing lake wildlife for many of these contaminants in the state.

“Our limited testing has already turned up concerning levels of contaminants in several lakes, as well as documenting the presence of these contaminants in lakes throughout New Hampshire. We hope that more can be done to identify additional areas where there may be impacts on wildlife or human health,” said Tiffany Grade, Squam Lakes Biologist for LPC.

“The Loon Preservation Committee has contributed a tremendous service to the state by collecting and publishing these data,” said Ted Diers, Administrator of the Watershed Management Bureau at New Hampshire Department of Environmental Services. “Their diligence in following up on the loon egg sampling has opened a number of critical questions about the health of these amazing birds and the humans who recreate on the lakes. Because of LPC’s work, NHDES has followed up on a number of lakes to determine if the fish are safe to eat, and has issued fish consumption advisories as a result.”

“We applaud the efforts of NHDES and New Hampshire Department of Fish & Game (NHF&G) to address the issue of contaminants in New Hampshire. We are all limited in what we can do by limited funding, and we hope that more state agency resources will be made available to identify and mitigate areas of elevated contaminants in the state,” said Harry Vogel, Senior Biologist and Executive Director of LPC.

LPC will continue to monitor contaminants in loon eggs in New Hampshire and report results to NHDES and NHF&G. LPC biologists will also be conducting further research to investigate potential impacts of contaminants on loon productivity as they continue to work with NHF&G and NHDES for the health of New Hampshire’s loons and aquatic ecosystems.

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