Although there are several factors that enable and facilitate the rapid spread of certain EEIs, in the case of water hyacinth and other plant species such as water fern, Mexican water lily, etc., it is important to note the presence of a high content of nutrients in the water and sludge of the Guadiana, especially in its Extremadura section. This abundance of nutrients is the basis of the food of this group of EEIs, so that once they are extended it is very difficult to eradicate them or to control them completely if there is no action to reduce the presence of so many nutrients in the river in the long run.

The water hyacinth is a phytoremediator, it can obtain from water all the nutrients it requires for its metabolism, being nitrogen and phosphorus, together with potassium, calcium, magnesium, iron, ammonium, nitrite, sulfate, chlorine, phosphate and carbonate ions, the most important ones. It has a root system, which may have associated microorganisms that favor the purifying action of the plant and are capable of retaining in their tissues a wide variety of heavy metals (such as cadmium, mercury and arsenic). The mechanism to do this is by means of complex formations between the heavy metal with the amino acids present inside the cell, prior absorption of these metals through the roots.

To be more informed about how nutrients affect EEIs you can consult the following document.