Invasive Plants

“The National Biodiversity Data Centre is a national organisation for the collection, collation, management, analysis and dissemination of data on Ireland’s biological diversity.”

The NBDC also tracks invasive species, including the location of aquatic invasive plants like New Zealand Pigmy weed (Crassula helmsii) Curly waterweed (Lagarosiphon Major) and Nuttall’s waterweed (Elodea Nuttallii).

“Biodiversity data are a key requirement for understanding our natural surroundings, for tracking change in our environment and for gaining a greater insight on how we benefit from, and impact upon, the ecosystem goods and services provided by biological diversity; a national asset which contributes at least €2.6 billion to the Irish economy each year.  The Data Centre was established by the Heritage Council in 2007 and is funded by the Heritage Council and the Department of Culture, Heritage and the Gaeltacht.”

During 2018 and 2019 boaters have recorded large swathes of Coon’s Tail or Hornwort (Cerotophyllum demersum) in the canals.  The descriptions available state this plant is sold to discourage growth of native weed in garden ponds.  It appears to be spreading rapidly in the wild, as it was considered ‘rare’ in Ireland in 2007.  During cold weather, it will sink to find warmer water but does not die.  It likes still water between 15c and 30c and spreads when cut.  In other words, the Grand and Royal canals are its ideal habitat.  Currently, it is not deemed invasive in Ireland.

This plant is one of the most problematic to boaters, as it wraps around the shaft behind the propellor, slowing down the boat, eventually stopping it and sometimes damaging it. It is impossible to kick off by going astern, as the stems are long and it wraps tightly, like a rope.

Also recorded during 2018 and 2019 is a variety of Eelgrass, growing along the Grand and Royal Canals.  As with Coon’s Tail, Eelgrass is growing in large swathes. 

Work continues on identifying the weeds spreading along the canal and preventing boat passage especially during the warmer months. Sightings on Kildare Canals can be recorded on the Nav-Watch system and at NBDC Invasive Species.