This wide variety of bird species has led to the estuaries being officially designated as a Special Protection Area and as a Ramsar site.

[2] The Ramsar wetlands extend to 13,464 ha (33,270 acres) and include an area of sand dunes which has interesting vegetation and provides habitat for important populations of amphibians.

[1] Birds that breed at the site include common tern (Sterna hirundo), lesser black-backed gull (Larus fuscus) and ruff (Philomachus pugnax).

[3] Migratory species that visit in spring and autumn include ringed plover (Charadrius hiaticula) and sanderling (Calidris alba).

[3] Birds that over-winter here include bar-tailed godwit (Limosa lapponica), black-tailed godwit (Limosa limosa islandica), Bewick's swan (Cygnus columbianus bewickii), dunlin (Calidris alpina alpina), golden plover (Pluvialis apricaria), grey plover (Pluvialis squatarola), knot (Calidris canutus), oystercatcher (Haematopus ostralegus), pink-footed goose (Anser brachyrhynchus), pintail (Anas acuta), redshank (Tringa totanus), sanderling (Calidris alba), shelduck (Tadorna tadorna), teal (Anas crecca), whooper swan (Cygnus cygnus) and Eurasian wigeon (Anas penelope).