Elodea canadensis
Elodea
Family: Hydrocharitaceae
Origin: North America
Regional Pest Management Plan (RPMP) status
- Aotea — Exclusion
- Whole region — Sustained control
- Hauraki Gulf Controlled Area Notice pest
General description
Submerged, bottom-rooting freshwater, aquatic < 5 m tall. Leaves are in whorls of three. Flowers are small, white/purple, five-petalled and borne at water’s surface November – January.
What you need to know
To help protect our environment:
- You must not breed, distribute, release or sell elodea on Aotea/Great Barrier Island group, or outside of secure containment within the Auckland region.
- You must not plant elodea on Aotea/Great Barrier Island group.
- You must not plant elodea outside of secure containment within the Auckland region, unless you are transferring an existing plant on your land to another location within the boundaries of the same property.
- You must destroy any elodea on land that you occupy if it has been planted in breach of the above rules and you are directed to do so by an authorised person.
If you see elodea anywhere on Aotea/Great Barrier Island group, please report it to Auckland Council at pestfree@aucklandcouncil.govt.nz.
Habitats
Still and slow-moving water bodies < 10 m deep.
Dispersal
Vegetative spread from stem fragments. Human-mediated dispersal through contamination of machinery and fishing equipment and deliberate releases.
Impact on environment
Can reduce flow velocity and impede gas exchange in freshwater ecosystems, lowering dissolved oxygen levels and increasing sedimentation. May impede water flow in drains, exacerbating flooding.
Control
Site Management
Very difficult to control once established.
Recommended approaches
Do not attempt to undertake control of this species on Aotea/Great Barrier Island group. Please report to Auckland Council if seen on Aotea/Great Barrier Island group.
Physical control
Method: Pull out.
Plant parts requiring disposal: All parts.
Disposal options: Remove to greenwaste or landfill if practical.
Biocontrol
Biocontrol is currently not available for this species.
Caution: When using any herbicide or pesticide please read the label thoroughly to ensure that all instructions and safety requirements are followed.
