The water in this lake at the University of Surrey is usually a muddy brown, but for the last few days it's turned green.

"Many have noticed the in the last few days the lake on campus has transformed in colour. This has been the result of action taken by the Estates and Facilities Management department to combat the spread of Blanket Weed across the water.

Blanket Weed is an environmentally damaging form of algae that under ideal conditions can grow up to a foot a day, rapidly clogging the lake and destroying any and all animal life in the vicinity.

Nigel Hodge, Horticultural and Landscape Manager commented: 'We don't usually have such a problem with it, but several factors have contributed to its growth. The lake was cleaned last summer which has resulted in a higher level of natural Nitrogen in the water; pruning of trees around the edge of the lake has reduced shade which means light and temperature levels have increased which all helps to create the perfect conditions for weed growth.

'We had several duckling deaths, so decided to take action. After consultation with a variety of experts, a harmless dye was put into the lake to cut down the amount of sunlight that reaches the weed and slowly reduces its spread.'

The dye does not affect wild life or fish in any way, and was specifically chosen over a traditional Blanket Weed killer as this type of control may have affected the fish.

The dye was added to the lake last Thursday and the work was carried out by a trusted contractor."