SESSION B:

Title: The Nature Conservancy’s Approach to Stratifying and Prioritizing Lakes and Streams for Conservation Action

Authors: Arlene Olivero¹, Joshua L. Royte², Barbara Vickery², Peter Vaux³, and Kathy Jensen^2
1The Eastern US Conservation Region Office of The Nature Conservancy, Boston
²The Maine Chapter of The Nature Conservancy, Brunswick and
³Senator George J. Mitchell Center for Environmental and Watershed Research, U. of Maine, Orono.

Abstract:

The Nature Conservancy works with partners in our mission to protect the full spectrum of life were it occurs in each of the Earth’s habitat types. Over the past five years the Conservancy developed tools and approaches for setting priorities for aquatic conservation. The assessment relies heavily on data from the Maine Aquatic Biodiveristy Project which includes the known freshwater data collected by state, federal, tribal, and other available partner organizations available in a digital database and digital map data.

The Conservancy developed a classification system and a qualification system to assess freshwater biodiversity, uniqueness, landscape condition, and water quality. Stream watershed types were based on elevation, gradients, bedrock and surficial geology. Ponds types were based on size, elevation, depth, connectivity, and buffering capacity. We stratified the selection by broad watersheds (8-digit HUC) in which we listed the highest quality systems known based on the occurrence of rare or uncommon species, species assemblages, and both water and watershed condition. The result is a list of lakes (>10 acre) and stream drainages (>30 square miles) that represent the highest quality examples of their type in each of Maine’s broad watersheds.

We are in the process of determining which systems are most at risk, where and from what threats. While land protection is one strategy others are needed to ensure ecological integrity of aquatic ecosystems from threats such as invasive plants and animals, point and non-point source pollution, atmospheric pollutants, persistent historic pollutants, altered stream channels, and barriers to migratory species.