HOLIDAYMAKERS should wear flip-flops on sandy beaches to protect them from an explosion in the numbers of a poisonous fish in Scotland, marine biologists warned last night.
The lesser weever fish, which inflicts an "excruciating" wound from poisonous barbs on its back, has amazed scientists by increasing its population by four-fold in the last year.
The native species, which grows to 15cm, lies buried in wet sand at low tide or shallow water. If it is stood on, it causes the person's foot to turn red and swell and is painful for up to two weeks.
Scientists now fear the surge in numbers of the species in Scotland's waters could lead to more beach-goers being stung if they fail to take precautions.
Geoff Swinney, curator of fishes at the National Museum of Scotland, said the dangers had to be brought to people's attention so they could treat the sting in the correct way. "People ought to be alerted about the dangerous species along our shoreline of which the Weever fish is one," he said.
"This fish gives an extremely painful sting. If someone is stung by one they should not pour vinegar on it like you do for a jellyfish sting, but instead they should allow the wound to bleed to wash the poison out.
"They should also put their foot into as hot water as they can stand without scalding themselves as this breaks down the proteins in the poison and stops it from working. They should then seek medical attention.
"People can die if they go into anaphylactic shock after being stung by the weever fish so people should take precautions and not paddle barefoot."
He added that fishermen should also beware of grabbing fish from nets because the greater weever fish found in deeper Scottish waters would inject venom into their hands from the barbs on their backs.
The lesser weever lives on shrimps and comes in shore to feed during the summer months. They are a golden-brown colour with silvery underbelly and have sharp black fins which are filled with venom.
Dr Mike Burrows, shore ecologist at the Association For Marine Science near Oban, said the weever fish had been thriving this year.
"They have been very successful this summer. Our teams during sampling along the shore have been finding about three or four times more Weever fish in their nets than ever before.
"This is good news for the species but bad news for paddlers. The spike on its back produces a very painful sting far worse than a bee sting so I would advise people to wear flip flops.
"If a weever fish is disturbed by someone walking about near them they will erect their spines."
Chris Rowe, marine biologist at Deep Sea World in South Queensferry, said people can easily stand on them because they bury into the sand.
"I have heard of people standing on them and it isn't pleasant, so I would definitely recommend wearing flip-flops. A lot of people don't know about them so they don't know to put their foot into hot water for at least thirty minutes if they are stung by a weever fish.
"A sudden explosion of a species like this indicates an imbalance in the food web and if it continues it would be a worry. It is also bad news as far as playing on the beach is concerned."