Saltmarshes hold great ecological value due to their range of associated plants and animals. The diversity of flora and fauna reflects the interactions between the marine and terrestrial environment. Saltmarshes provide an essential habitat for a range of bird species to feed, roost and nest. Their creeks provide vital spawning and nursery areas for many fish species. They hold an essential function in the exchange of nutrients and sediments within estuarine and coastal ecosystems. Saltmarshes are also recognised for their flood defence benefits as they provide an effective buffer between land and sea.
The saltmarsh tool enables an assessment of the ecological health of the biological quality element "angiosperms". Seagrasses are the only true marine angiosperms (and are considered in a separate guide), however within the WFD, saltmarsh is also considered as part of this biological element.