Elodea canadensis (Canadian pondweed).

Abstract Elodea canadensis is a submerged aquatic plant of slower flowing rivers, native to North America. It has been intentionally introduced into areas outside of its native range as an ornamental aquarium species. This species has a wide ecological tolerance and grows relatively fast. It is a perennial, overwintering in the deeper water, and reproducing asexually. Disturbance increases the dispersal of numerous propagules and the vigorous re-growth is enhanced through changes in availability of nutrients. E. canadensis can form dense mats which can interfere with recreational activities, navigation and port infrastructure. In addition to this, the dense mats outcompete native plant species and therefore decrease the biodiversity in an area. It also accentuates the accumulation of finer organic silts which enhances its growth further as nutrients are released. E. canadensis is considered invasive in Australia, New Zealand, Cuba, Alaska and the majority of European countries where it is present. Control is complicated and loss of fragments should be minimized to prevent further spread. It is included in the IUCN Red List, categorized as being of Least Concern. Thus, no conservation action is proposed or is necessary for this species.