NOTE: This download link includes Fish Regions, Freshwater Ecoregions, and Freshwater Resilience.
Freshwater ecoregions provide a global biogeographic regionalization of the Earth's freshwater biodiversity. These units are distinguished by patterns of native fish distribution resulting from large-scale geoclimatic processes and evolutionary history. The freshwater ecoregion boundaries generally, though not always, correspond with those of watersheds. Within individual ecoregions there will be turnover of species, such as when moving up or down a river system, but taken as a whole an ecoregion will typically have a distinct evolutionary history and/or suite of ecological processes (Abell et al. 2008). The WWF defined 76 freshwater ecoregions in North America, based largely on the USDA Forest Service mapping project (Maxwell et al. 1995), which used native fish distributions to delineate subregions. Maxwell et al.'s subregion boundaries were modified by biodiversity experts to better represent the distributions of a greater range of freshwater species. Boundaries in this dataset are revised as of 3/31/2006 by WWF. Note there is a new release of freshwater ecoregions from 2010, but TNC Eastern Division Science continues to use this 2006 version because we prefer/agree with the Chesapeake Bay Ecoregion boundary as represented in the 2006 version.
