Every year the introduction of harmful, non-native species into Canadian waters has been increasing. These nuisance species make tremendous impacts to your boat, fishing and industry.

Originally native only to Europe, the zebra mussel was inadvertently introduced into the Great Lakes some time in the 1980s, probably in the ballast water of a foreign ship using the St. Lawrence Seaway.

The Great Lakes provides a good example of the extent of aquatic nuisance species impacts. Tens of millions of dollars on zebra mussel control every year. This freshwater mollusc can be found in lakes, rivers and even brackish lagoons. It is most abundant on hard surfaces, particularly rocks.

One of the zebra mussel’s most striking characteristics is the huge areas it can cover . Because of its extraordinary capacity for invading aquatic habitats, the zebra mussel has been deemed a nuisance species throughout much of North America. It damages and clogs underwater conduits, such as pipelines and tunnels. It also corrodes the hulls of ships, covers shipwrecks and destroys habitats by re-structuring the ecosystem.

Impacts to fishing are that the zebra mussel acts as a filter by removing microscopic particles such as algae from the water. After consuming the algae, it deposits its feces on the lake floor. This fertilizer provides nutrients for bottom-feeding species and ultimately for the fish that feed on them.

While this process may appear helpful by increasing water clarity and reducing pollution, it actually starves native species that rely on the algae as a food source. It also allows more sunlight to penetrate the water column, forcing some fish to find a new habitat.

Impacts to boating are that the Zebra mussels frequently attach themselves to boat hulls, but they also infiltrate water cooling systems and intakes, engine compartments, and bilges. Any part of a boat that comes into contact with waters infested with these mollusks is capable of retaining zebra mussels.

You can help deal with Zebra Mussels with the following measures –

• Thoroughly clean and scrape the hull of your boat. An alternative is to leave the boat out of the water for 10 days or more, as zebra mussels cannot live long without water.
• All live wells, bilge areas, etc. should be drained and dried. Chlorine bleach added at the rate of one part bleach to 10 parts water is recommended for areas where trapped water remains. A chlorine/water mixture at the above recommended dilution will not affect the aquatic environment.
  Caution: Chlorine bleach is corrosive to electronics. Do not use chlorine/water mix in areas housing electronics or electrical circuits.
• Other items to disinfect: anchors and anchor ropes, out drive units, trailer frames, raw water engine cooling systems, minnow buckets, etc.
• Approved anti-foulants should be applied to boat hulls to discourage zebra mussels from attaching.