The spiny seahorses are one of two species in the British Isles

An underwater team is going to lay 750m of cable across the Salcombe and Kingsbridge Estuary, a marine site of Special Scientific Interest.

The site is home to the shy and vulnerable spiny seahorse.

BT has worked with environmental experts to ensure the work does not interfere with marine life.

'Excellent sanctuary'

An installation team of about 12 people, including four divers, will ease the cable into position through the eelgrass beds, as marine conservation officers from South Hams District Council look on.

Glenn Lipsham, BT's sub sea senior operations manager, said: "We are working closely with environmentalists and South Hams District Council to ensure the cable has minimal adverse effect on marine life in the estuary."

The cable is designed to improve phone and broadband links at East Portlemouth.

Nigel Mortimer, marine conservation officer for South Hams District Council, said: "The estuary's eelgrass beds are the marine equivalent of a tropical jungle and are known to be highly vulnerable and sensitive.

"They provide an excellent sanctuary for a rich diversity of wildlife, such as seahorses and other fish."