Several readers contacted The Buteman on Wednesday and Thursday to report that large numbers of dead worms had been seen on the beach at Ettrick Bay at low tide.

Alison Ramsay told us: "The tide was pretty far out on Wednesday afternoon, and as we walked out we realised that the beach was covered in hundreds and hundreds of dead lug worms, just lying on the beach, and no birds feeding on them either.

"As you walk further out towards the sea they are lying all over the sand, everywhere you look. There is also a strong fishy odour in the air - you don't notice it when you arrive, but of course as you go further out you notice it.

"It just shows how finely tuned nature is!"

Alison immediately contacted SEPA, who advised that the situation was likely to have been created by a 'toxic algal bloom', created by the warm weather, which poisons lug worms, sea urchins, some shellfish and other mollusc-type creatures which ingest the water.

Similar discoveries were reported on beaches at Ayr, Prestwick and West Kilbride.

In a statement, SEPA said that microscopic examination of the water had shown a high concentration of a plankton species called Karenia mikimotoi. This plankton bloom reduces the oxygen in the water.

No harmful effects on humans or other mammals have been reported.

SEPA's David Wilbraham said: "We would like to take this opportunity to thank members of the public who contacted us about this.

"Understandably people were worried that this was the result of a pollution incident, but it appears that this is a natural phenomenon.

"This plankton was linked to similar problems elsewhere in Scotland in 2006. The bloom is likely to disperse naturally with tidal movement and under the influence of changing weather patterns."

SEPA has also advised the Food Standards Agency, which is responsible for the safety of shellfish harvested in the area and the Scottish Association for Marine Science, who are carrying out research into this organism.

Any concerns about suspected marine pollution can be passed directly to SEPA via their 24-hour reporting telephone hotline on 0800 08 70 60.

Meanwhile, there is good news for Ettrick Bay on another front after bathing water samples found excellent water quality at the beach.

Five out of six samples taken between May 28 and June 25 found the water was of an 'excellent' quality, with 'good' quality water detected from the other sample.

As an officially designated bathing beach, Ettrick Bay is subjected to 20 water samples during the bathing season, which runs until mid-September.

The bay has failed to meet minimum European quality standards on eight out of ten years since testing at the beach began in 1999.