Many Manitobans enjoy our lakes, rivers and beaches but are not always aware of little critters that might be hitching a ride.  Currently, Manitoba has 17 Aquatic Invasive Species (AIS) in our waterways and river systems. 

According to the Manitoba AIS website, aquatic invasive species are ‘organisms (animals, plants, parasites, viruses etc) not native to a region that when introduced, either intentionally or accidentally, out-compete native species for available resources. Invasive species become successful in their new environments due to their high reproductive rates and absence of native predators and diseases.’ 

Candace Parks is the Province’s Aquatic Invasive Species Specialist and works through the Department of Agriculture and Resource Development. 

Of the 17 different AIS species, Parks says the zebra mussels are the most well-known, but there are 16 other AIS that we should be aware of so that we don’t accidentally spread their detrimental effects to other areas. 

Zebra mussels, spiny water fleas, rusty crayfish and a whole host of these critters came from Europe and Asia on ocean-going transport ships in the ballast tanks some 30 years ago. “When these ships came over the ocean with cargo to the Great Lakes, the cargo got unloaded but they also dumped this water from the ballast tanks into the Great Lakes,” says Parks. 

Zebra mussel and spiny water flea populations thrived and has since spread throughout the country. “So now unfortunately humans are moving the zebra mussels and the spiny water fleas from the Great Lakes to other water bodies mostly by the overall movement of watercraft.”  

Parks says the ‘Big 3’ aquatic invasive species in Manitoba’s water systems are zebra mussels, the spiny water flea, and the rusty crayfish. 

Zebra Mussels 

Parks says zebra mussels, which resemble miniature clams, are the most well-known AIS in our province, making their way from the Great Lakes over the past 30 years.  Zebra mussels were confirmed in Lake Winnipeg in 2013, moving into the Red River and Cedar Lake by 2015.  

Despite the successful eradication of zebra mussels in the four treated harbours in Lake Winnipeg in 2014, they were found elsewhere in the south basin and are successfully reproducing. Eradication of the zebra mussel is no longer an option. 

Depending on temperature and humidity, adult zebra mussels can survive out of water for 7-30 days, and attached themselves to watercraft, water-based aircraft and other water-related equipment. 

Zebra mussels in their larval stage, called veligers, passively move downstream by water movement and are invisible to the naked eye. Veligers rely on water to survive thus they can be inadvertently carried in small amounts of water transported by a wide variety of sport and leisure water equipment and items. 

Once Zebra Mussels become established, they cannot be eradicated, so it is extremely important to stop their spread. 

 

Spiny Water Flea 

Like the Zebra mussels, the spiny water flea hailed from Eurasia but it has also come into Manitoba from Lake the Woods and the Winnipeg River system into Lake Winnipeg.  They are as far north as Playgreen Lake, MB. 

“What makes the spiny water flea detrimental to Manitoba is that it eats the zooplankton, the base of the food chain, and our native fish don’t want to eat the spiny water flea because they have a very long spine and a big spiny tail. These fleas are growing out of control.”  These too, are transported from lake to lake through the movement of watercraft. 

Rusty Crayfish 

The Rusty Crayfish is found mostly in southeastern Manitoba and is believed to have been brought over as live bait from the United States into Falcon Lake.  One theory is these fishers dumped their bait bucket into the lake, thus introducing this new species of crayfish into those waters. 

Parks explains how the rusty crayfish has been detrimental to the native species of crayfish that used to thrive in those water, and how the rusty crayfish affects the natural habitat. 

 

“Because the rusty crayfish is now in Manitoba there is now a zero-possession limit for crayfish,” explains Parks.  “That means you cannot possess any crayfish in the province of Manitoba. So that hopefully handles the spread of rusty crayfish.” 

 When it comes to zebra mussels and the spiny water flea, due to their microscopic size, water enthusiasts might be transporting these AIS unknowingly. 

 

To counter-act the accidental transport of these invasive species, the Province has implemented laws (as of 2015) to target surface water users to educate them on AIS. 

“We want them to know that whenever you use a water body in Manitoba you must clean, drain and dry everything that comes out of that water - and that’s across the board in any water in Manitoba,” adds Parks. 

This means that if you’re spending the weekend at Lake Winnipeg’s Grand Beach, everything that touches the lake water can hold the microscopic zebra mussel veliger, and the spiny water flea – including beach toys, life jackets & kids floatation helps (like water wings), fishing lures, anchors and nets, wet swim suits, kayaks, ropes, the list goes on. 

The slogan, CLEAN, DRAIN and DRY applies to everything that comes in contact with affected waters. 

 

How do we decontaminate these items?   

Whatever fits into your freezer, keep it there for 3 days and you will have killed all the critters that don’t belong.  Unfortunately, just simply washing isn’t good enough, as water temperatures need to be 60 degrees Celsius to kill the zebra mussel larva and spiny water flea. 

Candace Parks explains the life cycle of the zebra mussel and why it’s so easy to miss. 

 

To decontaminate your watercraft, trailers and vehicle tires that might carry critters simply by loading and unloading your boat, Manitoba has 6 decontamination stations scattered across the province, specifically located on the roadways of AIS-affected lakes and rivers. 

Visit the following link to find out more about Aquatic Invasive Species in Manitoba: 

www.gov.mb.ca/sd/environment_and_biodiversity/invasive_species/fish_and_wildlife/index.html

  

To learn more about AIS, the public is invited to join Candace Parks on Tuesday, July 28th in Killarney for Level 1 AIS Inspection Training from 9:00 am-1:00 pm, and/or an evening of information & demonstration from 7-9 pm – hosted by the Killarney Lake Action Committee. 

The two sessions will be held at the Killarney Ag Society building and grounds on Water Ave, across from Erin Park, in Killarney MB 

Call Betty at 204-726-3410 or Rick at 204-523-1545 to register.  COVID-19 social distancing guidelines will be followed at both events.