Scientific Research on Adirondack Loons

Adirondack Loons - Sentinels of Mercury Pollution in New York's Aquatic EcosystemsAdirondack Loons – Sentinels of Mercury Pollution in New York’s Aquatic Ecosystems

The newly released scientific report, Long-term Monitoring and Assessment of Mercury Based on Integrated Sampling Efforts Using the Common Loon, Prey Fish, Water, and Sediment, details scientific findings that span the Adirondack region of New York State over a period of nearly ten years. This extensive study confirms that mercury contamination is harmful to the health of the iconic bird.

A summary report designed for a general audience, Adirondack Loons– Sentinels of Mercury Pollution in New York’s Aquatic Ecosystems, provides an overview of Common Loon natural history, a section on the conservation concerns affecting their populations, and a summary of the scientific research we conducted, which highlights the impact of mercury pollution to the Adirondack loon population.

In the four-page condensed summary brochure, we showcase the results of this long-term study in the Adirondack Park to assess the effect of mercury contamination on wildlife and aquatic ecosystems, using the Common Loon as an indicator species. We traced mercury contamination throughout the food web, from zooplankton to loons, and found mercury in Common Loons that increased their risk of reproductive harm.

Mercury is an environmental pollutant released through a variety of industrial processes, such as coal burning, waste incineration, and metal production. Mercury emitted into the atmosphere can travel
great distances on air currents before being deposited in aquatic systems. Once in waterways, this contaminant is taken up by fish, which makes it a problem for all fish-eating species, including loons and humans alike.

The research effort was a joint project between BRI, the Wildlife Conservation Society’s (WCS) Adirondack Program, the New York State Department of Environmental Conservation, and other collaborators. The research was supported by the New York State Energy Research and Development Authority (NYSERDA)’s Environmental Monitoring, Evaluation, and Protection program and numerous foundations and private donors.

Common LoonEach summer, the haunting call of the Common Loon resounds through New York's Adirondack Park. They mystical icon of
our northern waterways helps inform us about the hidden risk of contaminants
in our local waters. Photo © Nina Schoch

Ongoing Adirondack Loon Research

BRI’s Adirondack Center for Loon Conservation conducts research to assess the impact of threats to the Common Loons breeding in New York’s Adirondack Park. Through collaboration with its partners and various organizations, BRI’s ACLC scientific research has resulted in a long-term dataset regarding the health of the Adirondack loon population and its aquatic habitat. Our research has focused on

Our loon mercury research expands upon a study conducted by BRI in the Adirondacks from 1998-2000, which provided a preliminary assessment of the impact of environmental mercury pollution to the Adirondack loon population. The report from this study is available on our Reports and Publications section.

Upcoming research will assess additional human-related impacts to Adirondack loons, including such threats as lead poisoning from ingestion of fishing tackle, entanglement in fishing line, and human disturbance of breeding loons.

Capturing and Banding Loons

Loons are captured on their breeding lakes using playbacks of their calls, and night lighting techniques.

Blood and feather samples are collected for laboratory analyses to determine the overall health of the loon, the status of its immune system, its contaminant levels, and genetics analysis.

The birds are banded with aluminum U.S. Fish and Wildlife Service bands and with a unique combination of plastic colored bands. The unique combination of bands helps us to identify loons from a distance and enables our field staff to monitor these individuals during successive years. We have followed some Adirondack loons for more than a decade!

The banding program provides valuable data about loon behavior, levels of contaminants in Adirondack loons, and the health and breeding success of the Adirondack loon population. By comparing populations of banded loons across North America, threats affecting behavior, reproduction, and survival can be identified. This data informs the implementation of management efforts and regulations to minimize or eliminate the effects of such threats to this species throughout its home range.

Adirondack Loon Census

An annual census of loons on lakes in and around the Adirondack Park is conducted on the third Saturday in July. The number of adult loons, chicks, and immature loons observed in a one-hour period (from 8-9 AM) are recorded. his citizen science project is a collaborative effort between BRI’s Adirondack Center for Loon Conservation and the Wildlife Conservation Society’s Adirondack Program. These data provide a quick glimpse of the status of the breeding loon population in the Park and the summering loon population in New York. Results of the Annual Loon Census over time enable researchers to determine trends in the Adirondack and New York State loon population. The NYS Dept. of Environmental Conservation will use this data to better monitor the New York loon population and to implement management efforts where needed.

Similar loon counts are also conducted in other states throughout the Northeast at the same time on the same day. Thus, a regional overview of the current status of the loon population in northeastern North America is obtained.

The census is only possible with the help of numerous observers throughout the Adirondack Park and New York. Observations from areas throughout New York State are most welcome! Please join us!

Sign up now for the 2014 Census, July 19

A New York Annual Loon Census observer counts a loon on an Adirondack lake. Photo © Nina Schoch

Adirondack Satellite Telemetry Research

In the summers of 2003 and 2004, the partners of the former Adirondack Cooperative Loon Program collaborated with Kevin Kenow, a scientist from the U.S. Geological Survey (USGS) to equip a few Adirondack loons with satellite transmitters to record the birds’ southerly migrations. Additional birds in New Hampshire were also outfitted with transmitters. Information retrieved helped us identify the loons’ year-round habitat use and requirements.

The study complemented research conducted by the U.S. Geological Survey in the Midwest to determine migration, staging, and wintering areas significant to North American loon populations.

This research contributes to a broader understanding of the year-round distribution of Common Loon populations, and provides information to better assess the impact of factors (e.g., oil spills, botulism, environmental contamination) affecting loons throughout their range. The full report can be viewed here.

This project was funded in part by the New York State Department of Environmental Conservation, including federal funding from the U.S. Fish and Wildlife Service’s State Wildlife Grants Program, grants from the New York State Biodiversity Research Institute and the G.E. Foundation to the Natural History Museum of the Adirondacks, and the U.S. Geological Survey. The Wildlife Conservation Society’s Global Health Program provided assistance with transmitter implantation. Satellite transmitters were manufactured for this project by Microwave Telemetry, Inc.


Scientific Reports and Publications

Evers, D.C., K. A. Williams, M. W. Meyer, A. M. Scheuhammer, N. Schoch, A. Gilbert, L. Siegel, R. J. Taylor, R. Poppenga, and C.R. Perkins. 2011. Spatial gradients of methylmercury for breeding Common Loons in the Laurentian Great Lakes region. Ecotoxicology. 20(7):1609-1625.
Schoch, N., A. Jackson, M. Duron, D.C. Evers, M. Glennon, C.T. Driscoll, X.Yu, and H. Simonin. 2011. Long-term monitoring and assessment of mercury based on integrated sampling efforts using the common loon, prey fish, water, and sediment. Biodiversity Research Institute, Gorham, Maine. Report BRI 2011-28 to the New York State Energy Research and Development Authority for NYSERDA EMEP Project #7608. 116 pages.
Schoch, N. and A. Jackson. 2011. Adirondack Loons–Sentinels of Mercury Pollution in New York’s Aquatic Ecosystems. BRI Report #2011-29, Biodiversity Research Institute, Gorham, Maine. 60 pages.
Yu, X., C.T. Driscoll, M. Montesdeoca, D.C. Evers, M. Duron, K.A. Williams, N. Schoch, N.C. Kamman. 2011. Spatial patterns of mercury in biota of Adirondack, New York, lakes. Ecotoxicology 20(7): 1543-1554.
Kenow, K.P., D. Adams, N. Schoch, D. C. Evers, W. Hanson, D. Yates, L. Savoy, T. J. Fox, A. Major, R. Kratt, J. W. Ozard. 2009. Migration patterns and wintering range of Common Loons breeding in the Northeastern United States. Waterbirds 32(2): 234-247.
Schoch, N. 2008. Common Loon (Gavia immer). In: McGowan, K.J. and K. Corwin, eds. The Second Atlas of Breeding Birds in New York State. Cornell University Press, Ithaca, NY.
Schoch, N. 2006. The Adirondack Cooperative Loon Program: Loon Conservation in the Adirondack Park. Adirondack Journal of Environmental Studies. 13(2): 18-22.
Schoch, N. and D. C. Evers. 2002. Monitoring Mercury in Common Loons: New York Field Report, 1998-2000. Report BRI 2001-01 submitted to U.S. Fish Wildl. Serv. and New York State Dept. Environ. Conservation. Biodiversity Research Institute, Gorham, ME.