The multibillion-dollar project will be affected by much environmental legislation that will require it to be assessed by both state and federal governments.

Dozens of flora and fauna species have been recorded in the area, which adjoins the internationally recognised Hunter Estuary National Park.

Of particular concern is Deep Pond, an area of about 26hectares shorebirds and ducks favour as a roosting site.

‘‘Bird populations have been increasing in the area because of the destruction of other parts of the Hunter estuary,’’ Hunter Bird Observers Club member Ann Lindsey said.

‘‘The ambitions of the coal industry appear to be overriding the legislation designed to protect the environment.’’

Another sensitive environmental hurdle is the possibility that another rail line may be built on land partly owned by the Department of Environment, Climate Change and Water.

Much of this land has been earmarked for inclusion into the Hunter Estuary National Park.

Port Waratah Coal Services, the organisation behind the T4 plan, was working to tackle the project’s potential environmental effects, PWCS general manager Graham Davidson said.

‘‘We’ve already engaged with environmental experts, government agencies and local groups to work out possible ways forward, and we’re obligated to step up those consultations,’’ Mr Davidson said.

‘‘We’re pretty confident that some highly effective bird and frog protection and relocation strategies can be implemented once everyone’s views have been taken into account.”