The Long Island Sound Watershed

The Long Island Sound is a tidal estuary in the northeastern United States. It has an area of 1,194 square miles, drains about 17,000 square miles, ranges from freshwater to saltwater, and encompasses almost 600 miles of shoreline (Long Island Sound Study, 2024). Several major rivers contribute to the sound, including the Connecticut, Housatonic, and Thames Rivers. These rivers and their tributaries make up most of the Long Island Sound watershed, or the area of land from which water drains into the sound. The watershed spans parts of Connecticut, Massachusetts, New Hampshire, New York, Rhode Island, and Vermont in the United States and Quebec in Canada that are populated by nearly 9 million people (Long Island Sound Study, 2024; Parker, 2024). Land use in the Long Island Sound watershed includes urban areas along the Connecticut River and the coast of the Long Island Sound and mostly forested and agricultural areas in western Massachusetts, New Hampshire, and Vermont (fig. 1). Land use can greatly affect the quality and quantity of stormwater runoff, groundwater recharge, flooding, and overall ecosystem health, making it an important factor within the watershed.

Past and current studies of the Long Island Sound and its watershed by Federal, State, Tribal Nation, academic, and community organizations include topics such as water quality, nutrient loading, fisheries, flora and fauna, groundwater supply and quantity, spatial coverages and land use, infrastructure, climate change, sediment and geology, flooding, forestry, and energy (Latimer and others, 2014). The goal of these efforts is to provide up-to-date science relevant to the Long Island Sound and its watershed.

Map Application Purpose

The abundance of data produced from studying the Long Island Sound and its watershed across many disciplines prompted the U.S. Geological Survey (USGS) to work with the U.S. Environmental Protection Agency (EPA) and the Long Island Sound Study to compile information from various monitoring projects through an interactive online map-based application (fig. 2). Many States and other organizations conducting studies in the Long Island Sound watershed have publicly accessible data repositories (table 1); however, this information is spread across several databases. The spatial display of information in this application provides a single platform where the details of projects throughout the watershed can be accessed to promote collaboration, identify data gaps, reduce duplicated efforts, and allow for more efficient use of resources.

The Long Island Sound and Watershed Metadata Map Application

The Long Island Sound and Watershed Metadata map application (U.S. Geological Survey, 2024; https://apps.usgs.gov/liswmetadata/) does not host data or maintain data repositories. Instead, it compiles and presents metadata from publicly accessible databases managed by State and other organizations (table 1). As of August 2024, there are 707 data layers composed of 12 categories and 33 subcategories within the application (fig. 3). These layers include metadata from the USGS and EPA Water Quality Portal, which enables advanced filtering options, such as site type, sample media, characteristic group, State, and start and end dates.

The application provides tools to visualize and filter metadata in an online interactive map and includes several features that allow users to search and filter available layers to visualize and export metadata (fig. 4), including: