AN ARMY of 2mm-long insects are being called onto save the Gloucester & Sharpness Canal from being overcome by a problematic water weed.

Ecologists from the Canal and River Trust, the charity that cares for the canal, are releasing 3,000 weevils into the water at locations along the 16.5 mile canal, in the hope that they could eat the invading water fern, Azolla.

Azolla 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, as well as affecting how boaters and anglers can use the canal.

Individually the weevils consume a relatively small amount of the vegetation but soon breed into very large populations which will feed extensively, until sections of Azolla start to die and sink, where it is further broken down by other feeders.

Given time to reproduce and spread throughout a mat of Azolla, the weevil is capable of clearing entire lakes or canals within a matter of weeks.

Canal and River Trust ecologist, Laura Plenty said Azolla could be a serious threat to water wildlife.

“With the hot weather there’s a danger that it can grow really quickly and completely take over sections of the canal, so we’re getting the weevils in to combat it,” she said.

“The weevils breed really quickly and only eat Azolla, so should be extremely effective. The Gloucester and& Sharpness Canal is a great place to visit at this time of year, excellent for boaters, walkers, families and people with an interest in wildlife, so I’d encourage you to come and have a look for yourselves.”