On the basis of monitored natural inland wetlands (including peatlands, marshes, swamps, lakes, rivers and pools, among others), 35% of wetland area was lost between 1970 and 2015, at a rate three times faster than that of forests. Of the remaining wetland habitats, 65% are under moderate-to-high levels of threat and 37% of rivers over 1,000 km are no longer free-flowing over their full length. Declines are continuing, generally out of sight and out of mind, despite the importance of the freshwater realm. Freshwaters support over 10% of all known species, including approximately one-third of vertebrates and one-half of fishes, while only covering less than 1% of the surface of the Earth.

The numbers above each column refer to the total numbers of species assessed and the best estimates of the proportion of species threatened (Methods). The black lines represent the best estimates of the proportion of species threatened. Red List categories are as follows: extinct (EX), extinct in the wild (EW), critically endangered (CR), endangered (EN), vulnerable (VU), data deficient (DD), near threatened (NT) and least concern (LC).

Missing As of December 2022, 3,804 freshwater fishes (21% of the formally described species), 169 odonates (3% of the formally described species) and 622 freshwater decapods (19% of the formally described species) were omitted from the study.