The Western Channel and Celtic Sea region extends around south-west England from Dartmouth in the east to St Davids Head in the north-west and extends across the Celtic Sea to the continental shelf edge. Water depths are generally between 50 m and 200m, extending to 1000 m in the west. The coastline is predominantly rocky but with some areas of intertidal sediment occurring mainly in bays, inlets and around the coasts of the Bristol Channel. The main offshore habitats are largely sand and gravel with rocky outcrops. There are big seasonal variations in seasurface temperature, ranging from 8 °C in winter to 18 °C in summer. Some areas become stratified in summer and the strong tides generate tidal fronts, which influence water circulation.

Climate change

Sea level is rising, increasing the risk of coastal erosion and flooding. This is a particular concern for the soft sediment coasts especially around the Bristol Channel where high tides and storm surges increase the risk of flooding.

Sea temperature is rising and has contributed to significant changes in the balance of warm-water and cold-water species in intertidal rocky habitat, although part of the change is due to shellfish harvesting.

Maritime economy

The south-west corner of the UK is a key point of landfall for international telecommunication connections from America and Africa, providing a significant indirect economic value. The two most valuable fisheries are beam trawling for demersal fish and cuttlefish, and pot fishing for crabs and lobsters. The region also has important wave resources from which electricity could be generated, and is likely to become an important area for the testing of demonstrator devices over the next five years and deployment of commercial scale projects over the longer term. It also includes the Severn Estuary with the greatest potential tidal range energy in the UK and a number of options are being explored to harness this.

South Wales is particularly dependent on marine dredged sand due to shortages in local land won sources and there are currently no realistic alternatives. There are also two naval bases in the region, at Plymouth and Dartmouth, providing significant direct and indirect economic activity. There are also important ferry services from Swansea, Milford Haven and Pembroke dock linking with Ireland.

The region includes some attractive coastline ranging from exposed coasts to sheltered bays and inlets. As a result it is an important region for recreation particularly tourism, surfing and scuba diving.

Fishing pressure

This is the only region in which fishing effort has increased. With the exception of a sole stock, assessed commercial fish stocks are either not at full reproductive capacity or are not being harvested sustainably. There have been improvements in some aspects of the demersal fish community but there is evidence, including a shift towards smaller fish that indicates continuing pressure.

Mobile fishing gears may be causing damage to seabed sediment habitats (although we have low confidence in this assessment) and this may have led to the decline or disappearance of large, slowgrowing and/or fragile invertebrates from areas. Fishing is a pressure on grey seals through indirect effects on prey and habitat but directly through by-catch. By-catch is also significant for common dolphins and harbour porpoises and relates to the types of fishing gear deployed.

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