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The Squam Lake Loon Initiative

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Between the fall of 2004 and the spring of 2005, Squam Lake lost seven of its loon pairs. The decline from 16 to 9 pairs represented 44% of Squam’s loon population, a drop unprecedented on Squam or any other large lake in more than 40 years of LPC’s history of monitoring loons throughout New Hampshire. It also brought Squam’s loon population to its lowest level since LPC began to survey Squam Lake in 1975.

Like loons throughout New Hampshire, Squam Lake’s loons face multiple stressors; however, unhatched loon eggs collected by LPC (under state and federal permits) from Squam between 2005 and 2007 revealed high levels of a number of contaminants, including PBDE (flame retardants), PFOS (stain guards), PCB (industrial insulating/cooling agents), and chlordane (a pesticide). Levels of contaminants from Squam eggs during 2005-2007 were two to nine times higher than levels found in eggs collected from the other lakes. Our knowledge of the effects of these contaminants, especially combinations of contaminants, on loons is limited. However, some of these contaminants were present in loon eggs at levels that have been shown to affect the physiology, health, and/or reproductive success of other bird species.

Squam’s loon population has also experienced extremely high levels of mortality from lead fishing tackle. Since the opening of the reconstructed public boat launch in 2001, the rate of mortality from lead fishing tackle on Squam Lake has doubled and is twice the overall statewide rate of lead mortality during the same period. From 2001-2012, Squam lost on average 1.9% of its adult loon population annually due to lead fishing tackle. Although it is not possible to demonstrate causation, it is worth noting that, since 2001, the number of boats counted during an annual boat census of Squam, the number of fishing tournaments, and the number of boats participating in fishing tournaments has increased at a statistically significant level.

Population rates of lead mortality on Squam vs. statewide
Fig 1. Population rates of lead mortality on Squam vs. statewide rates of lead mortality.

The Squam Lake Loon Initiative (SLLI) includes an increased monitoring, research, management, and outreach effort in order to achieve the following goals:

    1. Determine the overall survival and reproductive success of Squam’s remaining loon population.
    2. Assess causes of nest failure and collect inviable eggs from failed nests for analysis of a wide range of contaminants and pathogens.
    3. Rescue sick or injured loons to increase loon survival whenever possible.
    4. Find and collect loon carcasses, determine causes of death, and test liver samples from dead loons for contaminants and pathogens
    5. Band loons to allow us to identify and track individual bird and collect blood and feather samples for analysis
    6. Determine survival and breeding success of previously banded and sampled loons, and related survival and breeding success of individuals to their levels of contaminants and pathogens
    7. Incorporate results into a systems dynamics or other explanatory model to determine the relative contributions of a wide range of possible stressors on the mortality and reproductive failure of loons on Squam Lake
    8. Restore and maintain a healthy and stable population of loons on Squam Lake as a component of a healthy statewide population of loons
Loon Preservation Committee