Thermal shock caused fish deaths

May 14 2008 By Chris Clements

EXPERTS have confirmed that the large number of dead fish found floating in the loch at Strathclyde Park died as a result of a naturally-occurring phenomenon.

There were fears of water pollution when members of the public raised the alarm with the Park Ranger service, who promptly informed the Scottish Environmental Protection Agency.

However, following tests on the water, it became clear that there appears to be no pollutants or waste in the water that pose a serious threat to wildlife. The tests suggest that the fish suffered from a combination of thermal shock, due to the sharp rise in temperature over the past week, and the negative effects of a "late diatom algal bloom". This can irritate the gills and result in death.

John Turnbull, Countryside and Landscape Manager with North Lanarkshire Council, said:

"It’s not at all unusual for thermal shock to cause some numbers of dead fish to appear after a sudden change in water temperature, either up or down.

"The fish affected are usually weak and diseased specimens from the previous year’s fry, and that seems to be the case here.

"However, to be absolutely certain there is no cause for concern, a number of days ago the Countryside Rangers asked SEPA to examine both the water and some of the fish from the loch."

A spokesperson from SEPA said today:

"An officer went to investigate and noticed that the water was an unusual colour, although the South Calder, which flows into the loch, was clear, with no signs of discharge.

"However, it appears that this has been a natural occurrence."