Conservation groups say a NSW government decision to open the Batemans Bay Marine Park to fishing is a blow to the critically endangered grey nurse shark.
NSW Fisheries Minister Adam Marshall last week announced five protected zones in the Batemans Bay Marine Park would be opened up for fishing.
The areas include Montague Island (east and south), Brou Lake (south), Clarks Bay (Freshwater Bay), Forsters Bay and Nangudga Lake.
NSW MP Andrew Constance described the sites as "low-hanging fruit and areas where it makes sense to wind back restrictions on recreational fishing activities".
But the Humane Society International and the Australian Marine Conservation Society said Montague Island was a critical habitat for the grey nurse shark.
"Sanctuary zones on the eastern and southern side of the island are critical habitat for the grey nurse shark and will now only be protected for six months of the year, leaving them exposed for the remainder," the groups said.
The grey nurse shark became the first protected shark in the world in 1984, after it was nearly hunted to extinction in the 60s and 70s.
The species is slow moving and slow to reproduce, meaning it was easy to target and takes a long time recover.
A NSW fisheries survey in 2000 estimated the number of grey nurse sharks on the NSW east coast could be as low as 292.
In 2014, there were estimated to be between 1131 and 2142 individuals in the east coast population.
But a report commissioned by the Humane Society International and the Australian Marine Conservation Society found there have been no measurable improvements in the conservation status for shark and ray species listed as threatened, despite many millions of dollars being spent on their protection.
None have been downgraded since being listed and several have had their threatened status upgraded by the International Union for the Conservation of Nature since they were listed under the Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act), the report said.
Conservation groups say the key threat to grey nurse sharks is recreational and commercial line fishing. Sharks that are accidentally hooked or that swallow prey with hooks can suffer septicemia or an inability to reproduce.
Humane Society International marine biologist Lawrence Chlebeck said the species would never have any hope of recovery if such threats were allowed in critical habitats.
"We must provide a sanctuary from hooks from which the species can rebuild," he said.