Water lettuce

• It is found across most regions in tropical and subtropical habitats
• Major native populations in South and Central America, Africa and south-east Asia
• It is also native to the Northern Territory in Australia, with self-controlling regulations
• It has been introduced to Europe, including Spain, France, Italy and England

• Dense mats of P. stratiotes can block waterways, limit the transport of irrigation and drainage water and can hinder the recreational use of waterways
• It can alter water chemistry by increasing ammonium, nitrate, and phosphorus, and decreasing water pH and dissolved oxygen
• Plankton and fish species decline due to the change in water chemistry, increased water siltation, and decreased water velocity
• It creates a favourable habitat for the transmittance of water-borne diseases 

• It could get here by living in moist soil or through the horticultural/aquarium trade, and associated accidental releases

• It is not currently present in Northern Ireland

• Report sightings
• Prevent spread by ensuring that equipment (e.g. kayaks, fishing poles, Wellington boots) are free from fragments to prevent spread elsewhere See Check Clean Dry for further information
• Checking soil, as it can survive for extended periods in moist soil
• Avoid dumping unwanted plants, or waste water into rivers, ponds as other waterways
• Removing plants from infested waterbodies – may be used as part of a long term maintenance programme
• Chemical control is advised against, as these chemicals are indiscriminate in what plants are affected

• This species must not intentionally be brought into the Union; kept; bred; transported to, from or within the United Kingdom, unless for the transportation to facilities in the context of eradication; placed on the market; used or exchanged; permitted to reproduce, grown or cultivated; or released into the environment.

Species Related Files:

NIEA-ID-Guide-Pistia-stratiotes-Water-Lettuce

RA_Pistia_stratiotes_Water_lettuce