Green groups in Australia have found an ally in the United National Educational, Scientific and Cultural Organisation (UNESCO) in protecting the country's Great Barrier Reef.

UNESCO, which released over the weekend its assessment of the reef's state of conservation, was critical of Australia's management of the 2,300-kilometre long reef which was listed in 1981 by the agency as a World Heritage site. It asked Canberra not to allow the development of new ports along the Great Barrier Reef.

There are liquefied natural gas (LNG) plants at Curtis Island in Gladstone Harbour which sparked a UNESCO mission to visit the area in the early part of 2012. The report pointed out the potentially significant impact of the unprecedented scale of development being proposed or affecting the reef.

UNESCO pushed for the conduct of an independent review of the management arrangements of the Gladstone Harbour to ensure the harbour's development of port infrastructure is consistent with best practices globally.

Environmental groups have blamed the harbor dredging at Curtis Island and the LNG developments for mass fish deaths and diseases at Gladstone Harbour and water turbidity problems, but the accusations have not yet been proven.

UNESCO had expressed alarm that in the past five years, 60 per cent of 67 of 108 development proposals were approved, mostly coal and LNG export ventures.

In view of the UNESCO report, green groups said the federal government must turn down a Cape York coal mine under plan. The project, also known was the Wongai proposal, includes building and dredging of a jetty or port facility at Bathurst Heads, the Wilderness Society's campaigner Gavan MacFadzean said.

In May, Queensland granted the Wongai proposal significant project status pending final approval from Australia's federal government.

Because of the UNESCO report, the Queensland cabinet will discuss the study on Monday. Queensland Environment and Heritage Protection Minister Andrew Powell said the state government is implementing many of the report's recommendations.