Written by:

A Small Big Problem

Issue 2NatureNature Issue 2Species

It’s surprising how the tiniest things can have the biggest impact. A single microscopic larvae can be the beginning of a mushrooming, pervasive infestation that colonizes a body of water, starves out local aquatic life, increases algal blooms, and affects man-made infrastructure and recreational equipment. Although they’re only around an inch long as adults, Zebra Mussels invade waterways and squelch out native wildlife.

Zebra Mussels (Dreissena polymorpha) are small freshwater mussels named for the distinctive dark striped pattern on their shells. They’re an invasive species to Ontario, originating from the Black Sea region of Eastern Europe and Western Asia. It’s believed that they possibly travelled from Europe to North America in ballast water from transoceanic ships. The Great Lakes and other waterways within Ontario are freshwater and especially vulnerable to infestation, as they provide optimal habitat conditions for Zebra Mussels to populate at an incredible rate. They can live from four to six years, and a single female can lay around a million eggs in one year. The larvae are microscopic so you can’t see them with the naked eye. For an infestation to take over, all it needs is one larvae to drift downstream. Unfortunately Zebra Mussel larvae can be moved upstream, or to any body of water, from human activity. If recreational equipment (either a boat or water from a live well or bait bucket) has been in infected waters, larvae can attach and hitch a ride to the next destination.

In addition to the Great Lakes, they’ve been observed in Lake Simcoe, the Thames River, and now Sixteen Mile Creek. Zebra Mussels were first seen in Kelso Reservoir in the fall of 2013 attached to a boat. They have since spread along the rocky shorelines, onto logs and trees, and also board walk piers. Some people have even seen Zebra Mussels on tree branches dangling over the water, after being submerged in the water.

Bivalvia_Dreissenidae_SXM-30_KOotjers (9)

Zebra mussels affect the entire food chain. They consume large amounts of plankton and as part of their feeding nature filter additional contaminants from the water.Those contaminants travel up the food chain when fish or ducks eat them. If the infestation is large enough, Zebra Mussels will colonize on the stream bottoms and can prevent fish from spawning. The sharp shells can easily cut the foot of a swimmer and infrastructure and recreational equipment can also be impacted resulting in potentially costly damage and maintenance.

We don’t suggest you chow down on zebra mussels either: they don’t taste good, and since they accumulate contaminants in their bodies, you could unknowingly ingest contaminants yourself. It’s best you keep them off your menu.

What can you do to stop the spread of zebra mussels?

  • Inspect all recreational equipment that is submersed in water (boats, canoes, paddleboards, trailers, paddles and bait buckets) after each use. Remove all plants, animals and mud before leaving the area
  • Drain water from motor, bilge, live wells, and buckets while on land and away from a water source. Flush equipment with hot tap water. There is a boat washing station you can use at Kelso near the Boat Rentals.
  • Do not re-use bait from infested waters. Any live bait should be disposed of properly in the garbage to prevent introductions of Zebra Mussels or other invasive species into new areas.
  • Rinse all recreational equipment used in infested waters with high pressure hot water, or let it dry in the sun for at least five days.
  • If you find Zebra Mussels or other invasive species in the wild, please contact the toll-free Invading Species Hotline at 1-800-563-7711.

For more detailed information on Zebra Mussels, please refer to our website for more on what Conservation Halton is doing to monitor and manage the spread of Zebra Mussels in the Halton watershed.


Share Button

Last modified: September 5, 2017

Leave a Reply

Your email address will not be published. Required fields are marked *

Subscribe to our Newsletter