Securing the Future of Coastal Plain Ponds
Written by Juliana Quant, Town of Southampton Community Preservation Department
There is exciting news in the Long Pond Greenbelt! An ecological study is launching to help protect the coastal plain ponds and their shores in Sag Harbor, NY.
The coastal plain ponds and shores of the Long Pond Greenbelt Preserve are unique habitats, home to a wealth of rare species. These include many species of dragonflies, rushes, sedges, fascinating aquatic plants, and elegant flowers.
The lands around the ponds are mostly preserved, public, and/or forested. Nevertheless, human land use can have significant negative impacts on these precious natural communities. Water quality, hydrology, and invasive species are all key concerns for the health of these habitats.1 Invasive species have been introduced to the ponds from other regions through human actions. This habitat alteration must be kept in check to keep the coastal plain ponds in balance. Otherwise, the rare species populations may dwindle.
What is the best way to make conservation decisions to protect the coastal plain ponds?
The Town of Southampton is working with expert Lake Managers from GEI Environmental Consulting to answer that question. This work is possible thanks to a grant from the NYS Environmental Protection Fund, administered by the Department of Environmental Conservation. (Note that the opinions, results, findings and/or interpretations of data do not necessarily represent the opinions, interpretations, or policy of the State.)
The researchers are in the data-collection phase: examining water quality, depth profile (bathymetry), and vegetation in Long Pond and Little Long Pond (Sag Harbor). With this information and years of expertise, they will have the power to make science-based conservation recommendations. They will compile and analyze this information to create a strategic approach in a Lake Management Plan.
As of August 2025, we have a peek at some of their preliminary data (see below). The maps below show Little Long Pond is up to 19 ft. deep in some places, while Long Pond is 10 ft. at its deepest. Little Long Pond has a prominent trend of dense vegetation in the deepest areas, while Long Pond has denser vegetation closer to shore. These are just the beginnings of the data the researchers will analyze as they formulate a lake management plan.
Many thanks to the Friends of the Long Pond Greenbelt, the South Fork Natural History Museum, and the Southampton Town Trustees. These organizations are committed advocates for the Greenbelt, and their partnership and support makes this project possible. Thanks also to the Long Island Invasive Species Management Area (LIISMA) for their guidance and assistance with invasive species management in the ponds.
- New York Natural Heritage Program. 2025. Online Conservation Guide for Coastal Plain Pond. Available from: https://guides.nynhp.org/coastal-plain-pond/. Accessed August 18, 2025.
