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Publications—Fact Sheet 064–98

Walden Pond, Massachusetts: Environmental Setting and Current Investigations

By John A. Colman and Marcus C. Waldron

U.S. Geological Survey Fact Sheet 064–98


This report is available in Portable Document Format (PDF):

FS 064–98 (904 KB)  – 6 pages


Introduction

Walden Pond, in Concord, Massachusetts, is famous among lakes because of its unique social history. Walden was the setting for American naturalist Henry David Thoreau’s well–known essay "Walden; or, Life in the Woods," first published in 1854. Thoreau lived and wrote at Walden Pond from July 1845 to September 1847. In "Walden," Thoreau combined highly admired writing on Transcendental philosophy with pioneering observations of aquatic ecology and physical aspects of limnology, the study of lakes. Because Thoreau also defended so effectively the value of living close to nature in the Walden woods, the pond is considered by many to be the birthplace of the American conservation movement. Visitors come from all over the world to the pond, which has been designated a National Historic Landmark, and its fame has resulted in a major fund drive to preserve the surrounding woods.

Walden Pond has no surfacewater inflow or outflow, and much of its ground–water contributing area likely is preserved within the Walden Pond Reservation area (fig. 1). Only 15 miles from Boston, the pond is unusually clear and pristine for an urban–area lake. However, point sources of nutrients near the pond, and a large annual visitor attendance, concentrated during the summer when the swimming beach (fig. 2) is open, may contribute a nutrient load sufficient to change the pond environment. The occurrence of nuisance algal species, a recent beach closing, and an awareness of water–quality problems suffered by other ponds in the region raise concerns about the risk of ecological change at Walden Pond.

Despite the role of Walden Pond as a cultural and environmental icon, little is known about the pond’s ecological features, such as its internal nutrient cycling or the structure of its food web, nor have consistent measurements been made to determine whether these features are changing or are stable. Production rates of aquatic plants in lakes and ponds naturally undergo a slow increase as plant nutrients, organic matter, and soil are leached and eroded from the surrounding watershed. This process is known as eutrophication. The term "cultural eutrophication" refers to an accelerated form of the natural process in which extra soil and nutrients are derived from people’s use of fertilizer, rerouting of surface drainage, and disposal of domestic and industrial waste. Cultural eutrophication can lead to excessive growth of aquatic plants, pond filling by decayed plants and eroded soils, reduced water clarity, and depletion of dissolved oxygen in deep water with subsequent loss of cold-water fish habitat.

In order to document the longterm ecological health of Walden Pond, the U.S. Geological Survey (USGS), working in cooperation with the Massachusetts Department of Environmental Management (MDEM), is investigating factors that could contribute to cultural eutrophication of Walden. Through measurements of mass balance of nutrients and oxygen in the pond’s deep water, the investigation will establish a baseline data set on Walden’s trophic state, which is a measure of the pond’s ability to support plant growth. The baseline data will be used to detect trends and give early warning of trophic changes or trophic response to pond remediation projects.

This Fact Sheet provides background information on the environmental setting, limnological features, and cultural eutrophication of Walden Pond, and describes the joint USGS⁄MDEM study.

 


This report is available online in Portable Document Format (PDF). If you do not have the Adobe Acrobat PDF Reader, it is available for free download from Adobe Systems Incorporated.

Document Accessibility: Adobe Systems Incorporated has information about PDFs and the visually impaired. This information provides tools to help make PDF files accessible. These tools convert Adobe PDF documents into HTML or ASCII text, which then can be read by a number of common screen-reading programs that synthesize text as audible speech. In addition, an accessible version of Acrobat Reader 8.0 for Windows (English only), which contains support for screen readers, is available. These tools and the accessible reader may be obtained free from Adobe at Adobe Access.


Suggested Citation:
Colman, J.A., Waldron, M.C., 1998, Walden Pond, Massachusetts: Environmental Setting and Current Investigations: U.S. Geological Survey Fact Sheet 064–98, 6 p.


For additional information write to:

Director,
USGS Massachusetts–Rhode Island Water Science Center
10 Bearfoot Road
Northborough, MA 01532

or visit our Web site at:
http://ma.water.usgs.gov



U.S. Department of the Interior, U.S. Geological Survey
Persistent URL: https://pubs.water.usgs.gov/fs06498
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Last modified: Tuesday, 29-Nov-2016 18:09:48 EST
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