Weevils to clear water weed

Published: Friday, 06 August 2010

TINY weevils have just been released into the the Bridgwater & Taunton Canal in Somerset in an attempt to eradicate the problematic North American Water Fern.

British Waterways have released 5,000 of the creatures at Maunsel Lock in the waterway in order to eat the invader weed that is a voracious grower and can multiply rapidly, covering the surface of a waterway with thick mats in a matter of weeks. This reduces light and oxygen levels in the water, killing fish and other wildlife.

Robert Randall, British Waterways Ecologist, explains:

"Water fern was first introduced to the UK by the Victorians as an ornamental plant for ponds. Despite looking nice, this weed is actually a serious threat to waterway wildlife in the UK.

"As the warm weather continues, there's a danger that it will take over completely, so introducing weevils to the canal acts as a natural pre-emptive strike in getting rid of this weed. The weevils breed extremely rapidly and only eat water fern so are very effective in destroying the plant without causing further damage to other species. If we don't act now there is a danger that birds may inadvertently transfer the weed to the the rest of the canal. Then it will be much harder to contain the spread."

The advice to anyone who is thinking of buying plants for their pond to consider the effect that certain, generally non-native, species can have on waterway wildlife, and if there is a need to dispose of them, don't put them down the drain or in the rubbish. Instead, compost, burn or bury them.