A critically-endangered shorebird once seen regularly along NSW's coastline is facing extinction, wildlife conservationists have warned.
The NSW government is being urged to strengthen its environmental protection laws as habitat destruction threatens the Eastern Curlew and the Curlew Sandpiper along the state's coastline, BirdLife Australia says.
Both were declared critically endangered in 2015.
The conservation group said the Eastern Curlew's population has collapsed because of overdevelopment in coastal areas.
"Eastern Curlews were once seen regularly along the coast between Newcastle and Wollongong, including sites around Sydney," project officer Mick Roderick said in a statement last Thursday.
"Sightings of these wonderful shorebirds are becoming increasingly rare and the current legal framework is allowing it to happen by allowing large-scale development to destroy its habitat."
Mr Roderick wants all areas along their migration route to be protected to ensure they do not become extinct.
Landing Lights Wetland at Arncliffe is a remnant of the extensive wetlands which used to stretch from the area occupied by Sydney Airport to the Georges River.
It was used by shorebirds from Siberia and Alaska, including the curlew sandpiper, who migrated south during the northern hemisphere winter.
The wetland is under threat from the proposed Cooks Cove project. The Sydney South Regional Panel will determine the development application for the $100 million first stage which is a new golf course on the area occupied by Barton Park and the old St George Stadium.
The Towra Point Nature Reserve on the southern shores of Botany Bay is another crucial habitat for endangered migratory birds including the Pied Oystercatcher and Little Tern.
Mr Roderick called on NSW and the Commonwealth to strengthen their environmental laws to ensure the protection of wildlife.
"State and federal governments are ignoring the science and putting commercial interests ahead of our unique and threatened species," he said.