Children warned not to eat swordfish

Popular dishes of swordfish, shark and marlin have been found to contain dangerous levels of chemicals.

Pregnant women and children under 16 are being told to stop eating the exotic fish altogether. Food watchdogs also believe that everyone else should limit their intake of the species to only one portion a week.

In a survey of 336 types of fish by the Food Standards Agency, swordfish, marlin and shark were all found to contain high levels of methylmercury which can harm the nervous system of an unborn child. Britain's most popular fish dishes of cod, haddock and plaice were given a clean bill of health.

Exotic fish are becoming more popular at restaurants thanks to their meaty consistency and simple flavour. About 1,506 tonnes of the fish are consumed each year compared with 244,366 tonnes of cod and haddock.

A spokeswoman for the Sea Fish Industry Authority said the news would not affect many consumers.

"People should listen to this advice. But overall, these fish make up less than one per cent of all fish sales in Britain," she said. "It is important to remember that fish is still an important part of a healthy diet and on the whole, fish is a good food to eat."

The Food Standards Agency has already warned consumers not to eat too much fish each week because of their dioxin content. They believe one portion of oily fish and another portion of normal fish will provide sufficient health benefits.

On average, UK consumers eat only three quarters of a portion of white fish and one quarter of a portion of oily fish a week. The independent expert Committee on Toxicity of Chemicals in Food, Consumer Products and the Environment will consider the findings and issue further advice if necessary.