Proposals to protect Europe's longest chalk reef have been criticised for not going far enough to safeguard its future.
A new Marine Conservation Zone has been put forward to the government and would include a 20-mile long reef off the Norfolk coast.
In summer 2011, a species of purple sponge which is new to science was discovered there.
A proposal to ban fishing on part of the main reef - a "no-take zone" - has not been included in the plan.
Rob Spray, who runs a project to map the reef, said the plan did not guarantee any degree of protection.
Chalk reefs are unusual off the UK, and provide a vital habitat for plants, algae and a wide variety of sea creatures.
Mr Spray, of Seasearch East, said: "Despite evidence from highly protected no-take zones around the world, and the disappointingly small sizes suggested, it was not possible to identify such a zone for the north Norfolk chalk reef.
"No one can deny that the North Sea has been over fished in comparison with the spectacular productivity it could demonstrate in the first half of the 20th Century."
The reef is in a fishing area for the north Norfolk coast and any restrictions have been strongly opposed.
Cromer fisherman John Davies is the eighth generation of his family to fish for crabs off the coast.
He argued that the voluntary ban on trawling on the reef, which has been in place for some time, is enough to protect the chalk. Instead, fishermen use pots to fish for lobsters and crabs.
"The chalk and flint sea bed is why we are here; that's where we get the majority of our living from.
"We've still got a reasonably buoyant fishery, and they're trying to take it away.
"[The no-take zone] is not a bad thing but why do they want it right in the middle of our grounds where we fish?"
Marine Conservation Zones have been designed to conserve a mixture of nationally important wildlife, habitats and geology.
For two years, negotiations have been taking place between conservationists, fishermen, energy companies and other sea users to try to agree the position of the zones.
Organisers of the project, called Netgain said this gave a unique insight into a broad range of opinions.
Final recommendations will be reviewed by the Joint Nature Conservation Committee and Natural England.
In 2012, all final recommendations will be put forward to the government which, following a public consultation, will make the final decision on all Marine Conservation Zones and the activity allowed within them.
Britain's Great Reef will be broadcast across the East at 19:30 BST on Monday.