By David Eastman, Country Ecology
When visiting the Loon Preservation Committee’s headquarters in Moultonborough, you might notice a new informational placard in their meeting room where videos are shown daily to audiences. Necropsies from dead loons in the past have previously shown some disturbing evidence about toxic contaminants spreading from chemicals into the ecosystem. These reach into water bodies and then become part of the loons’ physical life in eggs and feathers, following concentrations in fishy prey. The chemical properties of many environmental contaminants cause them to accumulate in loons’ body fat and egg contents. In 2005, the Loon Preservation Committee (LPC) recorded a dramatic single-year decline of seven pairs of loons on Squam Lake (from 16 pairs in 2004 to nine pairs in 2005). A single year decline of this magnitude (44 percent) is unprecedented in LPC’s years of state-wide efforts, and brought loons to their lowest numbers ever recorded on Squam. This was shocking information; after all we have felt so good about recovery efforts for the “great Northern diver,” as the common loon has been called. We had comfortably gotten used to repeated improvement for the species, therefore holding the line for New Hampshire’s loon population over the 34 years of LPC’s monitoring. We slowly had regained lakes left vacant by historic declines, up to 247 pairs in 2008, with 160 of those pairs nesting. But, breeding success last season was especially low on the state’s biggest lakes: Squam, Umbagog, and Winnipesaukee. Only four chicks survived on Lake Winnipesaukee, two on Squam, and one on Umbagog in 2008. State-wide, reproductive success was only 0.39 chicks per territorial loon pair. For the past three years, the combined documented numbers have been below the rate required to sustain a stable population. To investigate the possibility that this upsetting decline was caused in part by the impact of environmental contaminants on the health of the loons, LPC tested the contents of 13 in viable loon eggs from Squam and other New Hampshire lakes in 2007 and 2008 to quantify the amount and types of contaminants present. This can be quite extensive at the close of the birds’ reproductive season, even stinky in its work, but clinics such as Tufts University’s are utilized by this institution to pursue these scientific results with considerable intensity. Eggs that didn’t hatch were gathered up by environmental interns, called “loon rangers” from various colleges who fl oat around during summers, monitoring nesting sites. In an industrialized society like ours, a wide variety of chemicals are released into the environment every-day from residential, commercial, and industrial sources. Of particular concern are chemicals known as persistent organic pollutants. These chemicals do not breakdown in the environment, and therefore can bioaccumulate through the food web and pose significant health threats to wildlife. Examples of persistent organic pollutants listed on this new poster at the LPC include: Polychlorinated Biphenyls (PCBs), Poly-brominated Diphenyl Ethers (PBDEs), Polychlorinated Dibenzop Dioxins (PCDD), Polychlorinated Dibenzofurans (PCDF), and Perfluorooctanesulfonate (PFOS). Whew, glad I don’t have to pronounce such names. These effects can come from fl ame retardants or stain preventing chemicals in our household furnishings and upholstery. So, in the future, loon biologists will test liver samples for contaminants that are known from egg samples to date, or suspected (from literature) to occur in loons. And then, identify potential sources of contaminants in the watershed. It seems the reason these things unfortunately don’t break down in the environment in that they are synthetic in their ori-gins. PBDEs etc. Are probably coming from point sources or aerial deposition into our waters. The Loon Preservation Committee plans to expand this year’s monitoring to look for late-season mortality of loons. It will collect data on a wide range of stressing factors, including boating, angling, precipitation and weather events, fish populations, and predators. These analyzed results will be integrated into a systems dynamic model. This model will determine the relative contributions of a wide range of possible stressors on the mortality and reproductive failure of loons on Squam Lake. Then, LPC intends to report these results to the public and to New Hampshire’s legislators through articles, educational presentations, and meetings. Eventually, the Loon Center’s people will expand sampling of in viable loon eggs and carcasses state-wide to determine the extent and severity of contaminants affecting loons in New Hampshire. Already, the Squam Lake Loon Study has provided invaluable baseline data on contaminants and other environ-mental stressors on loons. Impressively, in the center of this new poster are various bar graphs from other bird species’ research such as terns, herring gulls, wood ducks, and ospreys that vividly show problems that result from ingestion of these chemicals on their behavior and otherwise. While much of this research is preliminary and fast moving, it reveals some disturbing effects we should begin to worry about at this point in time for waterfowl and aquatic species.
Dave Eastman also broadcasts “Country Ecology” four times weekly over WMWV 93.5 fm. As Vice President of the Lakes Region Chapter/ASNH, he welcomes you to monthly programs at the Loon Center in Moultonborough. He is available at: www.countryecology.com for consultation.
To learn more about the Loon Preservation Committee, become a member, or make a donation to help save the loons click here.
Reprinted with permission of the author.