Freshwater Stream and Lake Ecosystems

U.S. only. The North Atlantic, the St Lawrence and the Ontario major drainage basins.

Pogy Brook, Baxter State Park, Maine.
Photo: Josh Royte.

The Northern Appalachian—Acadian ecoregion is as well known for its aquatic features as for its mountains and coast. With snowy winters and humid summers, the once glaciated region boasts over 18,000 miles of streams and over 14,000 lakes. Split by the Appalachian mountains, large scale patterns of freshwater diversity correspond to huge drainage basins, the North Atlantic draining south and the St. Lawrence draining north, which have internally similar climatic and historical freshwater linkages. A portion of a third, the Lake Ontario basin, drains west from the Tug Hill plateau in New York.

Portfolio Streams: 3407 miles (U.S. only)
Stream Reaches: 380 miles identified or connectivity purposes
Impervious Surfaces: less than 2% of watersheds and stream buffers around portfolio streams
Agricultural Cover: less than 7% of watersheds and stream buffers around portfolio streams
Dams: over 150 dams fragment all sizes of portfolio streams and river mainstems
Portfolio %: 24% of portfolio river buffers secured against conversion
Protection: 14% of portfolio riparian land protected for biodiversity in GAP 1or 2. 10% is secured from conversion (GAP 3).

Conclusions for U.S. Streams

Our portfolio identifies the most significant and intact stream networks, representing all stream types and biophysical settings within eight major drainage basins (EDU) within the US portion of the ecoregion. The comprehensive classification and review of all size 2 and 3 watersheds and stream examples should help conservationists become more comfortable considering entire watersheds as the focus for conservation strategies rather than focusing only on aquatic species.

About planning methods used for freshwater aquatic ecosystems (pdf).
More about the U.S. portion of the assessment of streams and lakes in the: Freshwater Results chapter of the Ecoregional Report.