MARINE nature reserves could be set up along the Westcountry coastline in a bid to protect basking sharks and other under-threat sea creatures.

The world's second biggest fish, which can be more than 30ft long and weigh several tonnes but feed only on plankton, are a regular visitor to the region's coastline, especially Cornwall where they are increasingly spotted by holidaymakers and wildlife enthusiasts. Watching them as they come inshore in the summer is beginning to rival whale-watching in popularity.

An international conference beginning this Sunday on the Isle of Man will attempt to identify potential areas of the British coastline in most need of marine conservation. These sites could then become included under the evolving Marine Bill currently before Parliament.

Basking sharks are in particular need of protection as they are increasingly threatened by boat collisions and entanglement in fishing nets. In some parts of the world, they are hunted for their fins, often to be used in shark fin soup.

Now the conference will discuss formal proposals for UK protection zones with the resulting recommendations feeding into the South West's marine partnership project Finding Sanctuary, which aims to safeguard the region's marine wildlife and habitats.

Basking shark hotspots such as The Lizard and Land's End are expected to be raised at the conference.

Joana Doyle, communications officer for Finding Sanctuary, said: "The aim of the Marine Conservation Zone is to establish a network that is ecologically coherent and can function to become equally beneficial for the nation's coastline as a whole."

All coastal areas would have to work together to offer marine protection because it is predicted that some of the conservation zones could extend out to sea by as much as 200 nautical miles.

The basking shark has become renowned in Westcountry waters as the ultimate gentle giant. Despite a bumper year for sightings in 2009, in recent years sightings have diminished dramatically, with the disturbance from marine ecotourism actually being blamed for disrupting breeding and feeding grounds visited by basking sharks.

The marine conservation areas would impose restrictions such as water-speed limits at certain times of the year and rules to inhibit harassment of marine wildlife in an attempt to introduce a more sympathetic relationship.

Dr Lissa Goodwin, marine policy officer for the Wildlife Trusts involved with the conference, told The Independent: "There are definite threats to the basking shark in Britain, such as boat collisions and entanglement in nets, but we don't know what the level of threat is to the population as a whole, so we need to err on the side of caution."

Basking sharks are considered a "mobile species" and cover large distances across the world's oceans, so it has been difficult to protect them in international waters - especially from hunters targeting them for their elusive dorsal fins, which fetch large sums of money on the black market.

As such, the Isle of Man conference has attracted experts from across the globe in an attempt to highlight the need for the protection of basking sharks and other protected species from a local to international level.