The Government publishes its draft Marine Bill today amid concerns from environmentalists that it may not be tough enough to adequately protect wildlife.
The proposed legislation is intended to better protect, regulate and manage the seas around the UK and will include a nationwide marine planning system for developments such as offshore wind farms.
It is also expected to include measures giving people the freedom to walk around the whole English coast for the first time, for coastal and estuary management, fisheries management and an "ecologically coherent network" of marine protected areas.
The Government has said it wants to see a new extended network of marine conservation zones in place by 2012, with varying levels of protection for individual sites.
But while conservation groups are welcoming the long-awaited publication of the Marine Bill, they fear the new proposed legislation will not provide sufficient protection for marine species and ecosystems.
Ahead of the Bill's publication, the RSPB's senior marine policy officer Dr Sharon Thompson, said: "We are very excited that the Marine Bill is finally published, even if it is in draft form, and would anticipate new, robust laws to protect the UK's fabulous sealife.
"However, we are gravely concerned that in reality all we will get is a rehash of the current, ineffective legislation."
The RSPB said the UK Government must commit time, money and effort to surveying the seas to see what is needed in terms of protection, and that conservation zones should be designated on environmental grounds, rather than economic ones.
The conservation charity wants to see serious and enforceable penalties for damaging protected areas.
The Marine Conservation Society (MCS) said the draft Bill heralded a new approach to managing the seas, but called for it to be toughened up to establish a network of fully protected marine reserves.
The MCS said existing protected areas did not have sufficient controls, and in some, damaging practices including dredging for scallops and bottom trawling were still allowed.
Dr Jean-Luc Solandt, MCS biodiversity policy officer, said: "We fear the proposals set out in the draft Bill will only repeat the errors of the past, with Government allowing short-term commercial interests to compromise much-needed long term protection and sustainability."
More than 100 divers in diving gear are planning to march across Westminster Bridge today to hand in a 100,000-strong petition calling for a marine reserves network.
The MCS's Marine Reserves Now campaign, which is backed by BBC Springwatch presenters Bill Oddie and Kate Humble among others, is calling for a network of areas fully protected from damaging activities.
The MCS said the single highly protected marine reserve currently in existence at Lundy Island represented just 0.00195% of the UK's territorial seas - far less than the 30 per cent level of protection marine scientists are calling for.
In recent weeks, the RSPB identified some 70 areas around the country's coasts which it said were of importance to breeding birds and which would make suitable sites for marine conservation zones.
And last month, a report from WWF-UK outlined proposals for five experimental marine reserves covering more than 10% of the North Sea in a bid to improve the sustainability of fisheries and habitats.Reuse content