The Site is comprised of extensive intertidal mud and sand flats and open subtidal waters, as well as beach and dune systems and salt and freshwater marshes, which make it significant for the maintenance of regional biodiversity. The Site supports an area of eelgrass (Zostera noltii). Over 1% of the global populations of light-bellied brent goose (Branta bernicla hrota) and black-tailed godwit (Limosa limosa islandica) are found, as well as nationally important populations of numerous species including dunlin (Calidris alpina), golden plover (Pluvialis apricaria) and bar-tailed godwit (Limosa lapponica). Wintering waterbirds of high conservation concern at local, European or global level include shoveler (Anas clypeata), barnacle goose (Branta leucopsis) and red knot (Calidris canutus). Dungarvan Harbour is the largest area of oyster cultivation in Ireland and is also important for recreation, tourism and scientific studies of its wintering birds. The local community and stakeholders from industry, business, tourism, recreation, nature and heritage have developed the Dungarvan Harbour Partnership to help protect its water quality and biodiversity and initiate climate actions. Major threats include urbanization, and aquaculture and fishing.