When a mere documentary inspires a respectable film star to appear naked with nothing but a fish in her arms you have to credit its makers with chutzpah. Let’s hope it works and the fish enjoyed itself.

Filmed over a two-year period in settings as far apart as the Straits of Gibraltar, Alaska, Senegal and Tokyo, Rupert Murray’s film is a warning that there may be no fish in the sea by 2050. It points out that man, “the most efficient predator our oceans have ever known”, is allowed to fish in 99 per cent of the seas, which has led to the near extinction of bluefin tuna, used in sushi, and a vast over-population of jellyfish. Anyone who doesn’t eat sustainable fish is doing our children no favours.

Scientists, fishermen and enforcement officials state the case, and Murray has applied a professional gloss but visually and emotionally The End of the Line understates its case. If what it says is true, it does not seem angry enough. And does it really provide enough facts to underline its argument?

Perhaps its chief purpose is to interest those who know very little about the devastation caused by deep sea trawlers without putting them off with pessimism. If so, it does a good job — but a tougher argument might have done an even better one.