Today’s post is from Amanda Reed, Digital Media Organizer in our main office.
Did you know that the European water chestnut is an invasive species?
This destructive plant gained a foothold in Voyageur Provincial Park and, without the continued efforts of park staff, would take over the beaches and destroy our wetland.
How did it get here?
The European water chestnut originated in (surprise) Europe and is in fact considered endangered in many European countries. It arrived in North America in the late 19th century and has only been seen in a few places in Ontario.
One of those places is Voyageur Provincial Park.
The water chestnut must be thrown in the correct place in order to grab the seed.
Since water chestnut populations are found in only a few locations in Ontario, it is very important that we do everything we can to remove this plant before it spreads to other locations.
What’s wrong with water chestnut?
Invasive species are non-native species that are harmful to the environment or human health.
Water chestnut grows densely above water, creating floating layers of vegetation that reduce light penetration into the underwater ecosystem. Water chestnut outcompetes and chokes out native plants.
Reduced light penetration and plant growth beneath the water chestnut canopy, combined with a large amount of decaying vegetation beneath, can cause decreased dissolved oxygen levels, which can impact native species. and even kill the fish.
Their pointed nuts are a danger to swimmers and bathers. In fact, it grows so thick that without the park’s efforts to control it, Voyageur’s beaches would not be accessible to swimmers, fishermen and boaters.
But I put water chestnuts in my stir fry!
The European water chestnut is completely different from what you put in your stir fry. Those water chestnuts are native to Asia, not Europe.
Closeup of a European water chestnut seed
See those spikes? They are a sure sign that you have got your hands on this invasive species of water chestnut.
The inside of a European water chestnut is also a little dirtier than what goes into stir-frying. Does it look like this:
Voyageur’s Battle of the Water Chestnuts
For several years, Voyageur staff have been working to get rid of water chestnuts growing in the park’s wetlands and in the Ottawa River. People like Jean Malboeuf and Oliver Rondeau have been present in the operation from the beginning. They occasionally travel to Hawkesbury to get rid of this species!
The operation begins every spring.
The staff, wearing hip and chest waders, extract water chestnuts by hand in areas that cannot be accessed by boats. It takes a lot of patience, but you can move forward very quickly.
Staff working hard removing water chestnuts
The water chestnut is an annual plant that overwinters as seed. This means that preventing the current year’s plants from setting seed will stop the infestation. Seeds can remain dormant in the river for eight to ten years, so multi-year monitoring is necessary to manage the population.
The most important thing is to get the root of the water chestnut; You have to grab it in the right place to get the seed. The Voyageur team is professional, but it is almost impossible to get the root. each time, so it is an ongoing battle.
The other way to get rid of water chestnuts is much more fun. Boats can rake the plants and collect them in nets.
Jean shows us how to use the rake machine on the front of a boat.
Without these workers, the areas where you swim and boat would be covered in this annoying plant. Luckily, part of the operation has barriers in the bathing area.
If you are ever swimming in the park and see orange barriers it is because the area has been blocked off so that the water chestnuts cannot enter. This will allow you to swim without pricking your toes.
Is all this work paying off?
So far, Voyageur’s efforts have contained this invasive species, preventing it from spreading to other parts of the province.
By actively controlling and eventually eradicating the population, Ontario Parks is preventing the spread of water chestnut in the province’s waterways, maintaining the ecological integrity of the increasingly rare coastal wetland habitat.
Thanks to all the hard-working staff looking for a solution to this thorny problem!
Be part of the solution
As Voyageur staff work to eradicate this invasive species from the park, we need your help to prevent it from spreading to other areas.
This is especially important for boaters. Remember:
- Clean your boat and equipment
- Drain before leaving
- Dry or disinfect your boat before going out on the water again.
- Avoid running the engine through aquatic plants.
- Never transport or release a prohibited invasive species.