Report a discovery in an unlisted area
If you think you’ve seen or caught a Common Cordgrass:
- Do not release it into the water.
- Catch it and keep it frozen. If you can’t do that, destroy it.
- Note the location (with GPS coordinates if possible) as well as the observation date.
- Contact Fisheries and Oceans Canada.
Common Cordgrass is a hybrid, perennial, salt-tolerant grass with a distinct 45 to 90 degree angle between the leaf blade and the stem. Round, hollow stems grow in roundish clumps up to two metres in height. The leaf blades, 36 to 46 centimetres in length and up to 12 millimetres wide, are flat, rough and green-gray in colour. Cordgrass sprouts in the spring and blooms from July through November. The seeds resemble wheat and are found on one side of the stem.
Where it has been found
It was discovered in the summer of 2003 in Boundary Bay and Roberts Bank, near the Fraser River estuary. It has recently been discovered in Baynes Sound and Courtenay on Vancouver Island.
Common cordgrass can grow rapidly in intertidal zones, such as mudflats and beaches.
Ecological and economic impacts
Three species of Spartina, commonly known as cordgrasses, have invaded coastal estuaries of B.C. As these species proliferate, they trap sediment with their large root masses, raise the elevation of intertidal areas, fill drainage channels, and replace natural mud and sand flats, native eelgrass and algae beds. It is extremely aggressive and will displace existing habitat as it spreads over mudflats via seeds and/or rhisomes and move upwards into natural salt marshes.
The results can be serious:
- A loss of critical rearing habitat for fish such as juvenile salmon, clams, oysters and crab.
- A loss of valuable habitat for migrating shorebirds and waterfowl. Boundary Bay is a major resting and feeding area for more than 320 bird species
- An increase in the risk of flooding
- A loss of water access from shoreline areas and beaches and for boats
- A loss of more diverse, native plant species
- Disruption of saltwater ecosystem structure and function
- Competition with native marsh species
- May negatively impact native wildlife
- Competition with other plant species
Mode of dissemination
The plants can spread in B.C. by birds, animals, humans, and water currents. This species was introduced to some locations intentionally to stabilize banks/shorelines and seeds have been transported unintentionally with oyster transplants.
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