There are fears over shellfish poisoning

Opposition MSPs issued the warning as the Scottish Executive passed an order to block scallop fishing over fears that the shellfish can be poisonous at certain times of the year.

The Food Protection (Emergency Prohibitions) (Amnesic Shellfish Poisoning) (West Coast) (Scotland) Order was passed by 78 votes to 14 with one abstention.

But Scottish National Party MSP Fergus Ewing, said: "What is at stake here is the future of the scallop fishing industry in Scotland."

Shellfish are vulnerable to poisons of all sorts, whether naturally occurring or man-made, as they feed by filtering sea water.

Stricter tests for levels of toxins were introduced by the EU four years ago after potentially dangerous algae was discovered off the west coast.

Low doses of Amnesic Shellfish Poisoning can cause vomiting, stomach cramps, diarrhoea, dizziness and lethargy.

High doses can cause memory loss, seizures, coma and even death.

Mr Ewing, MSP for Inverness East, Skye and Lochaber, said scallop fisherman had estimated that 9.6 million meals containing three scallops had been eaten during the past four years of the tougher regime yet not a single case of poisoning had been recorded.

Public health

He said: "The only logical conclusion we can draw is that the existing regime is far more stringent than necessary to protect public health."

Deputy Health Minister Tom McCabe said the executive had to bring forward the order to comply with European laws and to protect public health.

He said: "But I want to stress that I don't underestimate for one moment how this impacts on this industry's ability to earn a living."

Tory list MSP for Mid Scotland and Fife MSP Ted Brocklebank said no one wanted to see diseased shellfish reaching the market place.

He said that whilst people "where I come from" ate more than three scallops per meal, someone would have to eat a lot to become ill.