The government has launched its long-awaited Marine Bill which aims to protect Britain's seas and marine life.
Protected areas could help to regenerate valuable fish stocks
As well as creating protected areas, ministers plan to improve the regulation of inshore fisheries and ease planning for offshore industry.
Environment groups have generally given the move a guarded welcome.
The bill, a manifesto commitment at the 2005 general election, goes out for consultation with the aim of passing legislation next year.
"Protecting our seas is one of the biggest environmental challenges after climate change, and the two are closely linked," said Environment Secretary David Miliband.
"The proposals in the Marine Bill White Paper are a first for the UK, and would raise planning for the management and protection of our seas to a world-leading level."
The bill would create up to eight new Special Areas of Conservation, including features such as the Dogger Bank in the North Sea which are important spawning grounds for fish and dolphins.
Other projected conservation areas include the Darwin Mounds, an exceptional cold coral reef to the north-west of Scotland, and the Scanner and Braemar Pockmarks in the North Sea where methane seeps from the sea floor, sustaining communities of worms and other organisms.
Protected areas can bring benefits to the fishing industry by creating places where young fish can grow. The UK's only "no-take zone" around the Isle of Lundy has brought local shellfish populations back from their overfished state.
Meanwhile, companies wanting to exploit non-protected zones of the sea would find their progress eased.
Environmental groups began campaigning for a bill like this more than five years ago.
They were delighted when Labour included it in its manifesto for the last general election, but dismayed when it did not make the 2006 Queen's Speech.
Climate change is making creatures like the flat topshell migrate
"There is a lot in the Marine Bill White Paper that we are excited about," said WWF's campaign director Paul King.
"It is a vital tool for restoring our seas to good health, and it is now crucial that the government introduces legislation in the 2007 Queen's Speech if it is to meet its national and international targets on biodiversity and climate change."
Those targets include the commitment, made by every government signed up to the UN biodiversity convention, to halt the global loss of biodiversity by 2010.
On climate change, the renewables industry has been lobbying hard for streamlining of the planning process for offshore wind farms, and the Marine Bill promises to meet that need.