The Weymouth Sealife Park is calling for visitors to sign a petition to help outlaw the practice of shark finning.

It wants to persuade the UN to help back their plight of banning the cruel trade worldwide.

The new campaign, in association with the Shark Trust, was launched in Weymouth with an underwater totaliser, which tracks the number of signatures. The park is aiming to gather more than 250,000 signatures over the next two years.

Shark finning involves the hacking off of the fin of a live shark, which is thrown back to face a slow and painful death. The fins are very profitable as they can be sold to make soup, oriental medicines or they are sold as trophies. A single fin from the Whale Shark can make as much as £15,000.

Mitchel Hird, Curator at Sealife Biological Services in Weymouth, said: "Sharks are the top predators in the marine life food chain. However, as they only breed in later life and have few young, their breeding population has been damaged by the shark fin trade. This industry is threatening the survival of all shark species."

It is hoped that the petition will generate as much success as last year's effort calling for greater protection for sea turtles. Within weeks of the petition being presented to an EU parliament, the Greek government was sanctioned for failing was to enforce legislation to protect the turtles.