Tourists are being warned to stay away from the beaches in northern France because the rotting seaweed may be lethal. Researchers blame Intensive agricultural practises.
A green seaweed known as sea lettuce is spreading across the beaches of Brittany. The warning to tourists to stay away came after a horse died and his rider lost consciousness due to the overwhelming smell from the putrefying algae.
Vincent Petit, 27 is a veterinary surgeon and he said rotting seaweed a metre deep had killed his horse last week as he rode across St-Michel-en-Grève beach.
Petit lost consciousness.
When an autopsy was performed on the horse, it was found the horse had died of pulmonary oedema caused by inhaling hydrogen sulphide given off by the rotting seaweed.
Intensive agricultural practises are being blamed for pumping excessive nitrates into the water system and causing the seaweed to die and drift ashore.
There is a possibility that the problem may spread in Britain, as similar farming methods are used, environmental scientists warned.
'This is a very toxic gas, which smells like rotten eggs,' added Alain Menesguen, director of research at the French Institute for Sea Research and Exploitation.
'It attacks the respiratory system and can kill a man or an animal in minutes.
'It is likely to be a feature of any area where intensive farming methods are employed."
Environmentalist Jean-Frangois Piquot said. "There is no doubt that farming is to blame. Brittany has 5 per cent of French agricultural land but 60 per cent of the pigs, 45 per cent of the poultry and 30 per cent of the dairy farms. As our rivers are not long, the pollution does not have time to clear before the water reaches the sea. If it enters a closed bay and the sunlight produces the seaweed. "