Eichhornia crassipes - Water-hyacinth
Inland surface waters
The water hyacinth is a free-floating aquatic plant native to the Amazon basin. It has thick, rounded, glossy leaves with swollen bases, and a flower spike with pale purple flowers.
Origin and Distribution:
It is native to the Amazon Basin, and has since invaded river basins in France, Italy, Portugal and Spain.
The plant grows extremely fast and develops into thick floating mats which, if uncontrolled, can cover entire water bodies. These mats block out the light and deplete the water of oxygen, smothering out all other native plants and animals. It also hinders water circulation, clogs up navigation routes, and causes immense damage to agriculture through increased water loss. It has serious impacts on agriculture due to increased water loss due to evapotranspiration. It can also suppress crops and inhibits germination. The plant also disturbs drainage, it damages hydropower plants, hampers recreation and disrupts fisheries.
How could it get here:
It was imported into Europe as an ornamental plant with attractive flowers and it became popular in horticulture, from where it easily spread into the environment.
Is it in Ireland:
Not present in Ireland
Methods for prevention:
EU-level action includes a ban on sales and planting or keeping the plant, including in isolated ponds.
Early detection and eradication:
Given the costs of management, a prompt response to newly establishing populations will be important to avoid later management costs.
Images courtesy of Q Bank and GBNNSS
Current Legislative Position (Listed on 03 August 2016)
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.
For further queries, you can contact the Non Native Invasive Species Team in the Northern Ireland Environment Agency on 028 9056 9558.