Invasive Aquatic Plants

Aquatic Plants in Pitt Meadows

Parrot Feather is the common name for Myriophyllum aquaticum, an aquatic plant and very close relative of the Eurasian Watermilfoil (Myriophyllum spicatum).  Neither or these plants are native to British Columbia and both plants are considered to be an invasive weed species.  Their ability to colonize water bodies and drainage systems allows these plants to form dense, thick, obstructive layers in slow moving, fresh water sources.  These species create a stagnant water source, choking our ditches of the natural flow of water, severely impacting our agricultural and drainage infrastructure. 

Parrot Feather forms a dense mat on the water surface while Watermilfoil thrives below surface as its fragile stems are not able to support themselves above water.  Both plants cause severe negative impacts to native aquatic vegetation, insect, and fish populations.  

Parrot Feather     Watermilfoil
Leaves are above surface and resemble a small fir tree     Leaves rarely emerge from water due to their inability to support the stem
Found in aquariums, fresh water lakes, ponds, streams, and canals     Found in fresh water bodies with a sand or silt covered bottom
Most commonly spread by plant fragments which are quite hardy and will easily root in the ideal conditions     Primarily dispersed from one body of water to another by water currents, boats/trailers, and fishing gear
Biocontrol – none known      Biocontrol – There’s been suggestions that weevils or midge larva helps control the infestation, however, neither has been deemed effective.


Prevention and Control

Both of these invasive species are easily spread through transport.  If you are boating, take note of any signs advising that the waters you are occupying may contain Parrot Feather or Watermilfoil.  If they do, before you pull your boat out of the water, CLEAN off any leftover vegetation that may have tangled in your propeller or caught on your fishing gear.  DRAIN any remaining water and DRY off any gear that may have been exposed to these weeds.  

When selecting aquatic vegetation for your aquariums, there are a number of non-invasive plant options to choose from.  Visit for more information.

 More information relating to Parrot Feather, Watermilfoil, and other aquatic plants can be found on the following sites: