Tourists have been warned to avoid blooms of toxic microalgae that have been propagating in the hot weather off Spain’s Canary Islands.
Beachgoers have emerged from the warm sea waters scratching themselves after brushing against the tiny algae, also known as sea sawdust.
“Since the end of June, we have seen episodes of massive efflorescence (or bloom) of microalgae, sometimes reaching as far as bathing beaches,” said Juan Aleman, director of public health for the Canaries.
He said its proliferation was a “natural, temporary phenomenon” which would eventually disappear.
But he warned the bacterium contained a toxin which can lead to skin irritation and dermatitis.
“Hence one must avoid coming into contact with it in the water and on the sand,” said Mr Aleman.
He added no beaches had been closed because of the algae.
However, AFP reported that it had found several have been closed to swimmers in recent weeks, including the popular Teresitas beach at Santa Cruz de Tenerife.
Marta Sanson, professor of plant biology at the University of La Laguna in Tenerife, said ideal conditions, including an increase in water temperature, were allowing proliferation of the microalgae.
This includes a dust cloud sweeping in off the Sahara which is rich in iron, a nutrient which micro-organisms like, she said.
Earlier this week, an Australian teenager was bitten by flesh-eating bugs during a night-time dip in the ocean at Brighton Beach in Melbourne.
He emerged with blood streaming from his feet and ankles after being attacked by what are believed to have been sea lice.