Article - Minimising the Spread of Invasive Species

Aquatic invaders are like uninvited house guests who refuse to leave. Recent invaders in the southern Gulf of St. Lawrence have become serious pests. This problem affects everyone using our waters - recreational boaters, cottage owners, commercial harvesters, aquaculturists and others.

Important invaders in the Gulf Region include green crab, clubbed tunicate, and oyster thief. These invaders can compete with, or even prey on, native fishes, invertebrates and plants.

Oyster thief		Green crab

They can spread through natural processes such as drifting with the current, but by far the greatest potential for spreading these species is through human activities.

It may be true that "they'll get there eventually" but by following some simple precautions you may be able to delay the arrival of invaders. A delay of several years, or more, may allow the time needed for the development of effective treatments.

Also, this delay means more years of use of the water body for fishing, aquaculture, etc., before having to cope with the effects of a harmful invader. These effects tend to be costly both in terms of economics and environment.

Invasive species can be introduced in several ways: by moving ships and boats, by accidental release, and by intentional introductions. Getting rid of these species is next to impossible. Keeping them out in the first place is the best approach.

To minimise the risk of spreading species, some simple procedures should be followed even in bodies of water where invaders haven't been detected - just because we haven't seen them yet doesn't mean they aren't there.

Before trailering a boat to a different body of water:

• Pick off any plants or animals visible on the boat, anchor, trailer or other equipment and discard on shore or in the garbage - not near another body of water.
• Drain water from the motor, bilge, and wells.
• Wash boat, anchor, trailer and other equipment such as nets or fish crates with fresh water (power wash if possible) or spray and scrub with undiluted vinegar.
• Let equipment dry completely, if possible, before launching at a new site.

For larger vessels:

• Use anti-fouling paint to reduce settlement of organisms on the hull.
• Don't take on or release ballast water in port, near aquaculture facilities, or at night (many organisms stay near or on the bottom during the day but swim up into the water at night).

When collecting clams or other shellfish:

• Clean them in the water where they were collected.
• Move them with a minimum amount of water.
• Dispose of that water on land, away from other water bodies that may become contaminated.

Learn to identify invasive species in your area and report sightings.

Clubbed tunicate

If you see invasive species such as tunicates, green crabs, oyster thief, or other "weird stuff" you can't identify or haven't seen before, DFO would like to hear about it.

This information is important, so scientists can get a complete picture of what invaders are present in the southern Gulf of St. Lawrence and where they're distributed.

Please contact DFO by phone, fax, or email with your observations or questions. You can also request copies of our brochure Aquatic Invaders - Uninvited Guests.

For more information:
1-866-759-6600 (toll-free bilingual phone line)
Fax: 506-851-2079 (attention: Aquatic Invaders)
Email: invaders.glf@dfo-mpo.gc.ca

DFO in Charlottetown (902-566-7812) and the PEI-DFAE (902-368-6330) are other numbers you can call for information or with your observations.