The marine habitats of the South West support some of the richest plant and animal communities in the world. The region's waters mark a boundary between warm southern and cool northern seas, resulting in an abundance of species living at or near the limit of their distribution. The UK populations of some warm water wildlife are restricted to this region.

The seabeds around our coast are made of a wide variety of different rocks, from soft chalk to hard granite. Of particular note are the mudstone reefs in Lyme Bay, the best known examples of this substrate type in the country. In addition, the presence of rocky seabed to considerable depths on the open coast, and extending far into some marine inlets, is of considerable importance.

The physical and biological processes responsible for maintaining the diversity of marine life on the rocky seabed are still poorly understood. The habitats we see around us have been managed for generations, and rely on continued human activity to maintain and enhance the richness of their wildlife. In contrast, much of the rocky seabed can be thought of as being as a real wilderness, with human interference tending to reduce the diversity of the communities it supports.

The following table gives the location of our top seabed sites (out to 6 nautical miles from baselines or to the 50 m depth contour, whichever is the greater).

The following are examples of species that depend on rocky sea beds, some of which are of conservation concern:

The wilderness areas beneath our seas, while out of sight, are extremely fragile places, susceptible to even the slightest human impact.

However, humans rely on the sea for many products, not the least as a source of fish. This can bring us into conflict with this fragile environment. For instance fishing gear (towed gear including beam trawls/dredges) dragged along the sea bed quite clearly cause direct damage to habitats and species, especially in boulder fields and areas of softer bedrock.

The sea is also used as a place to get rid of waste. Pollution causes major problems for a wide range of communities and species sensitive to different contaminants. In addition the direct dumping of dredge spoil and other materials leads to a smothering of habitats at the dump site and in the adjacent area. Alongside this we must count oil spillage as an ever present threat.

We also extract sand and gravel from the sea bed for use in building. This disturbs the sea bed and stirs up the sediment which damages the delicate balance of the marine ecosystem.

Beyond pollution, our coasts are also subject to recreational pressure at popular sites with large numbers of visitors, especially divers, anglers and yachtsmen. These people can, often inadvertently, cause damage and somtimes lack awareness of the wildlife value of the sites they are visiting.

Lastly, as with other coastal habitats, climate change, if it affects seasonal water change, will have an unpredictable, and possibly detrimental effect on the habitat.

A variety of official designations contribute to the effective management and protection of key areas in the region, including England's only statutory Marine Nature Reserve around Lundy and Voluntary Marine Conservation Areas at Purbeck, Durlston and Charmouth, North Devon, Wembury, Looe, Helford, St Agnes, Polzeath, and Isles of Scilly.

Management of fishing practices within the region's waters is carried out by the Devon, Cornwall, Isles of Scilly, and Southern Sea Fisheries Committees and in some areas by the Environment Agency. Regulations which have a direct effect on the rocky seabed include seasonal and area closures and control of scallop dredging.