Canal closed due to New Zealand plant predator

an invasive New Zealand predator has hit Kildare’s waterways forcing the closure of part of the Grand Canal.

an invasive New Zealand predator has hit Kildare’s waterways forcing the closure of part of the Grand Canal.

No, it’s not the All Blacks rugby team - but it is just as dominant and as menacing - it’s a weed which has appeared for the first time ever in our canals in Ireland.

The closure of the stretch between Kilpatrick bridge (Lullymore) and Ticknevin Lock has been extended from February 29 to April 5 to allow the professionals eradicate this plant.

Spokesperson for Waterways Ireland, Katrina McGirr said; “New Zealand Pygmyweed (Crassula helmsii) is a highly invasive aquatic plant which can form dense carpets in canals and alter native communities/habitats and impact fish and invertebrate communities, block boat movement and inhibit angling activities. It has been known to cause significant problems internationally and, as such, is a priority invasive species to control. The likely introduction mechanism for this plant into Ireland is through the ornamental/horticultural/aquarium trade.”

The weed has been found within 2.2 Km of the Grand Canal from Lullymore Bridge to Hartley Bridge in Ticknevin. Waterways Ireland said it has no evidence to verify the source of the infestation.

“On advice from, and with the help of, Inland Fisheries Ireland, Waterways Ireland is taking the necessary measures to eradicate it from this section of the canal. This is particularly important to ensure the navigational and ecological interests of the Grand Canal are protected,” she added.

In order to remove the green pest, Waterways Ireland, carried out a trial using matting to cover the bed of the canal. This was unsuccessful. Then they de-watered and applied herbicide to this section of the stretch of water. The top layer of sediment (silt and weed) was removed across the full width of the canal to a depth of 10cm using a long-reach digger.