Freshwater Ecoregions of the World, (FEOW) provides a new global
biogeographic regionalization of the Earth's freshwater biodiversity.
Covering virtually all freshwater habitats on Earth, this first-ever
ecoregion map, together with associated species data, is a useful tool
for underpinning global and regional conservation planning efforts,
particularly to identify outstanding and imperiled freshwater systems;
for serving as a logical framework for large-scale conservation
strategies; and for providing a global-scale knowledge base for
increasing freshwater biogeographic literacy. The freshwater ecoregion
map encompasses 426 units, whose boundaries generally - though not
always - correspond with those of watersheds (also known as drainage
basins or catchments). 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 ecological processes. Ecoregions are
delineated based on the best available information, but data describing
freshwater species and ecological processes are characterized by marked
gaps and variation in quality, and improved information in the future
may warrant map revisions.