The Gearagh is primarily of interest and importance due to its rich and rare diversity of wildlife, and it represents the only extant extensive alluvial woodland in Western Europe. It hosts numerous rare plant species including marsh marigold, meadowsweet and nightshade, and 62 species of moss and liverwort. While oak and ash trees once pre-dominated, today there are a number of willow and alder trees on the higher islands and inlets. It hosts a large diversity of birds and wildfowl and attracts both summer and winter migrants. Examples include mallards, wigeon, Greylag geese, herons and coots. It also hosts Atlantic salmon and the near extinct freshwater pearl mussel. The area is protected under the international Ramsar Convention.