The 900-page report, Charting Progress: An Integrated Assessment of the State of UK Seas, was released yesterday by the Department of Food, Environment and the Regions (Defra).

It took 18 months to prepare, and is regarded as the most detailed assessment of Britains territorial waters ever carried out by the Government.

Analysis threw up evidence in three key areas - fishing, pollution and the effects of climatic change. The results are expected to have an important influence on the Governments forthcoming Marine Bill, and to strengthen its argument for global reductions in climate-affecting gases.

To put the report in perspective, Defra states that UK seas are productive, supporting a wide range of fish, mammals, seabirds and other marine life.

It says that the open seas are generally not affected by pollution and levels of monitored contaminants have decreased significantly. Pollution detected is generally in industrialised estuaries or areas local to the activity.

But the report has raised key concerns, and will directly assist with the development and evaluation of policy in creating an effective, co-odinated system of marine management.                                                                           
A major problem is that of overfishing. A number of species are seriously depleted and seabeds badly damaged, says the report.
Cod, haddock, herring, blue whiting and sole are being fished at an unsustainable rate - with cod, in particular, in danger of elimination. The angel shark and the magnificantly large (up to 2m-span) common skate have nearly disappeared from the English Channel and Irish Sea.

High rates of accidental bicatch continue, many dolphins and porpoises drowning in nets. Other bicatch victims are known to include elasmobranchs - sharks, skates and rays.

While general pollution is down, the effects of some industrial releases are not sufficiently understood or monitored. In the Mersey, Clyde and Tees estuaries, dab and flounder have shown evidence of cancer and sex-change due to contamination from heavy metals and chemicals.

Farm fertiliser run-off continues to encourage algal blooms and excessive seaweed growth in relatively closed areas, such as ports and estuaries.

Worrying evidence, because it may soon be irreversible, concerns the effects of climatic change. Sea levels are rising and temperatures increasing, says the report.

Levels around Britain are rising by 2mm a year, due to the worlds melting icecaps and more rainfallt. And the average yearly sea temperature has risen by 0.6 degrees C in the past decade. The biggest change has been in winter, with temperatures up by 1.5 degrees C.

About 50 non-native species are known to have arrived in Britains warmer seas in recent years. At the bottom of the food chain, for instance, an increase in warm-water plankton is pushing cold-water plankton, a food for young cod and other species, north.

The sea is becoming more acidic due to increased carbon dioxide levels in the air. Absorbed by the sea, this converts to carbonic acid, which is known to harm plankton and organisms, such as corals and sea urchins, which use calcium to make a shell or skeleton.

Commenting on the report, the Environment Minister, Elliot Morley, said: This new approach [to marine research] will hopefully give us the answers we are looking for and help us plan for the long term.

But what I can say with some certainty is that we are having an adverse effect on our marine life, and climate change is clearly evident in our seas.

Conservationists will be relieved that, with its Marine Bill pending, the Government has so clearly identified areas of high concern in marine affairs.

The Defra announcement comes a month after the release of another report on the state of Britains seas. The WWFs Marine Health Check 2005 study has already concluded that the seas are in crisis, and tallies closely with the Governments lastest findings.

As part of its ongoing programme of marine research, the Government plans the Marine Data and Information Partnership, which will establish a national framework for pooling and processing research information.

It also plans the Marine Climate Change Impacts Partnership, to generate a better undertstanding of how climatic change is affecting Britains seas.

Defras Charting Progress: An Integrated Assessment of the State of UK Seas report was prepared with the assistance of the Scottish Executive, the Welsh Assembly Government, and the devolved administration in Northern Ireland.