Nuttall's waterweed
Elodea nuttallii
Nuttall's waterweed is a perennial herbaceous aquatic plant native to North America. It grows entirely submerged, forming long, branched stems that can create dense mats on the water bed or in the open water column. Its leaves are narrow-lanceolate, typically arranged in whorls of three, and often characteristically spirally twisted or recurved. In Europe, it is considered an invasive neophyte that displaces native species through its rapid growth and can significantly alter aquatic ecosystems.
Details
Oxygen production
Very high during daytime photosynthesis phases.
Habitat function
Important refuge for aquatic invertebrates and spawning site for fish.
Nutrient uptake
Very high efficiency in absorbing nitrogen and phosphorus directly from the water column.
Food source for
Food source for various waterfowl and phytophagous fish.
Human use
Formerly used as an aquarium plant and for biological wastewater treatment.
Ecology
Ecological role
Provides habitat and shelter for juvenile fish and macrozoobenthos, but can cause problems due to oxygen depletion during mass developments.
Natural predators
Waterfowl (e.g., coots), herbivorous fish (e.g., rudd, grass carp), and invertebrates.
Competitor species
Elodea canadensis, Myriophyllum spicatum, Potamogeton pectinatus.
Ecosystem service
Oxygen production, nutrient sequestration, and stabilization of sediment conditions.
Threats
None; the species itself is a threat to biodiversity in non-native areas.
Scientific profile
Profile
Reproduction
In Europe, reproduction occurs almost exclusively vegetatively through fragmentation. Even tiny stem fragments can grow into new individuals. Dispersal occurs via water currents, waterfowl, or human activities (boats, angling).
Protection & threats
Main threats
Not threatened in its native range (North America). In Europe, it is itself a threat to aquatic biodiversity.