The world's fish will be extinct by the middle of this century if we continue to plunder the oceans, a new film has claimed.

Dubbed "An Inconvenient Truth for fish", the two-year global documentary, The End Of The Line, highlights the fact around 75% of the world's fish stocks are severely depleted.

It blames increasing demand from consumers, supermarkets and restaurants, fishermen breaking their quotas and politicians ignoring the problem.

The film's executive producer, Christopher Hird, told Sky News online: "There are three things people need to do. They need to change their eating habits so they only eat sustainably-caught fish.

"They need to put pressure on politicians to make sure the law that already exists is enforced and extended.
"And they need to join the campaign to create great reserves of the oceans which will for a period of time be completely free of commercial fishing."

Every year around 7m tonnes of unwanted fish - or bycatch - is thrown back into the sea. In UK waters, stocks of some fish, like cod, have been reduced to less than 10% of what they were 100 years ago. Despite the problems though, the vast majority of us do not bother buying sustainable fish.

According to a YouGov survey carried out for Waitrose, 78% of us ignore the labelling on fish packaging which is a sign of sustainable stock - such as the Marine Stewardship Council's stamp.