Toxics Release Inventory (TRI) Program
Large Aquatic Ecosystems:
Introduction
A watershed is the land area that drains to a common waterway. Rivers, lakes, estuaries, wetlands, streams, and even the oceans are catch basins for the land adjacent to them. Ground water aquifers are replenished based on water flowing down through the land area above them. These important water resources are sensitive to chemicals and other pollutants released within or transferred across their boundaries.
A large aquatic ecosystem (LAE) is comprised of multiple small watersheds and water resources within a large geographic area. The Large Aquatic Ecosystems Council was created by the U.S. Environmental Protection Agency in 2008 to focus on protecting and restoring the health of critical aquatic ecosystems. Currently there are ten program LAEs in this program, which are listed below and shown in the following map:
- Chesapeake Bay [Español]
- Columbia River Basin
- Great Lakes Basin
- Gulf of Mexico [Español]
- Lake Champlain Basin
- Long Island Sound [Español]
- Pacific Islands
- Puget Sound-Georgia Basin
- San Francisco Bay Delta [Español]
- South Florida [Español]

Large Aquatic Ecosystems Map
Water pollution, surface runoff, contaminated sediment, toxic discharges, and air emissions can impact the environmental quality of the land, water, and living resources within an aquatic ecosystem. Persistent toxic pollutants can be especially problematic in aquatic ecosystems because pollutants accumulate in sediments and may bioaccumulate in the tissues of fish and other wildlife at the top of the food chain to concentrations many times higher than in the water or air, causing environmental health problems for both humans and wildlife.
The TRI program has profiled each of these ten LAEs. Each profile includes information on the toxic chemicals released or otherwise managed as wastes, the sources of the toxics chemicals, and the potential impacts of these chemicals on the ecosystem and human health. The total quantity of toxic chemicals managed as wastes varies greatly among the LAEs along with the types and sizes of industrial facilities. How facilities dispose of or release toxic chemicals within the LAEs-whether to the land, air, or water-also varies greatly among the LAEs, as shown below.


