Sharks, seals and other marine life risk harm from leisure boats and even eco-friendly wildlife-watching tours, experts told an Earthwatch meeting in London, UK.

Vessels from jet skis to motor boats can cause harm to marine life. They can damage individual animals and their combined used upsets the acoustic balance of the marine ecosystem vital for the survival of these noise-sensitive animals.

People in boats are often too focused on leisure pursuits and not enough on the marine life, says Colin Speedie, who heads an Earthwatch programme to protect Britain's basking sharks.

He says that awareness and some simple precautions can reduce injuries and death. This will help stop population reduction.

Dr Kevin Robinson, who runs an Earthwatch field research programme aimed at protecting whales and dolphins on Scotland's coastline, says he strongly advocates watching these animals from the shore.

If you do choose to see marine creatures from a boat, WiSe is a UK training and accreditation scheme for operators of registered passenger and charter vessels who wish to view marine wildlife.

The WiSe logo on a boat or brochure means the tour operator understands how to approach marine wildlife, and how to minimise any disturbance to the animals.