Boaters reminded to clean, drain and dry watercraft after invasive plant found for 1st time in Ontario

As people with boats and other watercraftget ready to pack them away for the season this fall, experts are reminding them to properly clean, drain and dry their equipment.

It's particularly important after an invasive aquatic plant called Hydrilla verticillatawas discovered for the first time in the wildin Ontario.

The Essex Region Conservation Authority said hydrilla was found at the Hillman Marsh Conservation Areain Leamington, Ont., at the end ofJune.

The authority says the plant can grow up to 2.5 cm per day and to lengths of 7.5 metres, and can choke native species, clog water intake pipes and impact recreational activities like swimming or boating.

Hydrilla is a prohibited invasive species under Ontario's Invasive Species Act.

Rebecca Rooney is an associate professor at the University of Waterloo who does research in wetland ecology and is a world expert on biomonitoring and wetland assessment.

She and her team were in Hillman Marsh this summer when they discovered the hydrilla.

It's unknown how the plant, believed to have made its way to North America for aquariums, got into the marsh. Rooney says the plant can spread seeds. It also produces tubers, similar to really tiny potatoes, that a new plant can grow from.

"If you're walking through the wetland and you get mud on your boots, you can spread it that way by picking up tubers," she said.

"If you're boating through there and you break up the plant, the little plant fragments can actually grow whole new plants. And so it's really important to not come into contact with hydrilla and that if you do that, you really thoroughly clean, drain and dry your equipment to make sure that we're not accidentally spreading it."

WATCH|Hydrilla invasive species found in Canada for 1st time:

Hydrilla invasive species found in Canada for 1st time

1 month ago

Duration 1:11

Rebecca Rooney, an associate professor at the University of Waterloo and a wetland expert, and Tim Byrne, CAO of the Essex Region Conservation Authority, talk about hydrilla, an rapidly growing invasive species found at the Hillman Marsh Conservation Area in Leamington, Ont.

Clean, drain, dry responsibilities

That's a message Rick Layzell, CEO of the Boating Ontario Association, said they've worked to actively promote

"We have distributed over 100 educational and informative signs that have been installed at launch ramps across the province," he said of telling people about their "clean, drain, dry responsibilities."

He said they also share resources through their website and social media accounts.

"For close to 30 years we have also led and managed the Clean Marine program, offering guidance and best practices to marinas and boat dealers throughout the province."

The Ontario government said that before people transport a boat overland, they must clean mud, vegetation, algae, mussels or any animals from the boat, motor, trailer, vehicle or equipment.

"Some aquatic invasive species can survive up to two weeks out of water and not every invader attached to your boat can be seen with the naked eye," said the provincial website about invasive species action plans. It saidpeople should dry their boat in the sunlight and/or clean the boat with hot or pressurized water.

The federal department of fisheries and oceans also says "in some cases, decontamination may also be needed." Rooney saidher team used bleach on their equipment after being in the water.

Plants 'extremely good' at spreading

Joe Ackerman, a professor of physical ecology and aquatic sciences at the University of Guelph, has studied invasive species including zebra mussels.

He saidhe was "saddened" to hear about hydrilla in an Ontario marsh, "but I wasn't surprised."

Hydrilla does exist in some waterways in the U.S., including in the Finger Lakes region of New York state andthe Niagara River south of the border.

"It's just across the river to get to Ontario, so it's not very far," he said.

"How it got into the marsh itself, I don't know. These plants are extremely good at dispersal, and humans are extremely good dispersal agents, which is a fancy way to say that people spread them."

He said it could be something as simple as the plant being wrapped around a prop on a boat or a trailer or sticking to a paddle.

It's not just boats and watercraft that can spread them. Ackerman saidit's believed hydrilla was first introduced to water in North America in Florida in the 1950s when someone dumped aquarium water and plants into a canal and the plants spread to the wild.

"You just need a small piece and that's good enough to get stuff started."

He said it's important people don't dump aquarium water or plants into any local ponds or waterways to prevent these kinds of plants from entering the ecosystem.

Costly clean-up

Tim Byrne of the Essex Region Conservation Authority said a single herbicide treatment against hydrilla will cost $125,000.The process will be complicated and could take five to 10 years, Byrne said earlier this month.

Rooney said the area covered by the hydrilla is equivalent in size to about 64 football fields.

Rooney saidit appears the hydrilla is fully contained in the marsh, which is not directly connected to Lake Erie. Efforts are now underway to remove it, but comprehensive monitoring will be required to make sure it doesn't reappear. Her research will continue to look at hydrilla in this area.

"There's the hope that we can eliminate it and go back to being a hydrilla-free Ontario," she said.

People who spot what they believe might be hydrilla can report it on environmental monitoring apps like iNaturalistand report it to the ministry.