(Canadian Press)

(Canadian Press)

Spread of invasive species in Canada costs billions, changes environment

Experts say the plight of the spotted frog is one of many examples of how invasive species can overtake an area

For two decades experts have been carefully nursing a community of endangered northern leopard frogs in B.C.’s Kootenay region but invasive bullfrogs and fish threaten to muscle in, potentially swallowing years of work.

Purnimia Govindarajulu, a small mammal and herpetofauna specialist at B.C.’s Ministry of Environment, said disease and invasive fish already mean the endangered frogs aren’t thriving as they should be in a wetland in Creston.

More concerning to her is that a mass of bullfrog eggs was recently missed in a lake just 15 kilometres away, and Govindarajulu said teams in Canada and the United States are preparing to do battle with the voracious bullfrog to prevent its spread.

“We call it the American bullfrog action team,” she said, lowering her voice with mock authority.

“The defenders of the northern leopard frog,” she added with a chuckle.

Bullfrogs are native to parts of Central and Eastern Canada and are even on the decline in some areas, but they have overtaken parts of southern B.C. and are known to eat native fish, frogs, salamanders, snakes, birds and turtles.

Experts say the plight of the spotted frog is one of many examples of how invasive species can overtake an area, squeeze out existing plants or animals, create a lasting scar on the landscape and impose huge costs on the Canadian economy.

A common thread to the threat to many of Canada’s species at risk are invasive species, said Gail Wallin, executive director of the Canadian Council on Invasive Species.

“So not only do invasive species take over our natural environment, they actually threaten species at risk. They have a major environmental impact.”

Invasive species like giant hogweed, zebra mussels and knot weed can overwhelm entire ecosystems, stripping lakes, valleys and cities of wildlife and vegetation.

A 2008 report by the Canadian Food Inspection Agency said there were at least 486 invasive alien plant species alone in Canada.

The cost of battling or holding back invasive species is incalculable, Wallin said, pointing out that every level of government, homeowners, farmers, businesses and other groups spend money on the fight.

The annual economic impacts on agriculture, crops and forestry is estimated at $7.5 billion, she said.

“When we look at these huge economic costs, we have to recognize that we’re only looking at samples, we’re not looking at all the costs of the total number of invasive species in Canada,” Wallin said.

David Nisbet, manager of partnership and science at the Invasive Species Centre in Sault Ste. Marie, Ont., said putting a price tag on the issue is difficult because an invasive species can set off all kinds of actions and reactions. When pests kill trees it can change the oxygen supply, prompt flooding, reshape the neighbourhood canopy and cost homeowners or a city for replacements, he said.

Recent surveys by the centre on spending in Ontario shows an average municipal cost of $381,000 a year.

The Canadian Food Inspection Agency classifies invasive species as plants, animals and micro-organisms in an area where they’ve never been before. They can adapt, spread quickly and don’t have natural predators in their new environment.

Insects like the emerald ash borer, which kills ash trees, have ravaged hundreds of thousands of hectares of Ontario’s forests. Giant hog weed with its highly toxic sap has taken over entire valleys in B.C. and nematodes have had devastating impacts on Canadian crops.

Most invasive species are moved by people, Wallin said, adding that’s where they’re aiming education.

Hogweed was brought in as a garden plant. Firewood moved between campsites also transports pests. Boaters carry Eurasian milfoil or zebra and quagga mussels with them when they change lakes, she said.

Some of the largest factors in the spread and introduction of invasive species are trade and travel, Wallin said. Bugs can hide in untreated pallets and tourists may bring something back intentionally or not.

“We’ve got way more trade coming in now so we need to be more conscious of that. Other countries have new regulations in place, making sure that before you ship into our countries that your cargo is clean of invasive species,” Wallin said.

“We can do more than what we do now. It’s a big world and we’re all travelling. So yes, regulation will be really important.”

The problems spread because people aren’t aware of the risks, said Nisbet.

“They don’t have a negative intent in mind, we should try not to place the blame on Canadians who just aren’t aware, we try to place a lot of effort in raising that awareness.”

Govindarajulu said many people don’t realize it’s illegal to move or remove frogs from their environment and it’s also against the Wildlife Act to bring them back because they could be introducing disease into the rest of the population.

“Often it’s children and often people mean well. It’s not like they’re being vindictive, they want to help frogs and they think they are.”

The Invasive Species Centre runs a citizen science program in Ontario, training those interested to identify a problem before it spreads. Nisbet said the program has been helpful with people reporting their suspicions and findings around the province.

The lesson is to take action, he said.

“Whether it’s cleaning you gear after you go boating, or if you go hiking, cleaning your boots, cleaning your pets, getting all the seeds and plant material off, buying local firewood, buying native plants, just taking these sorts of actions to prevent the spread of invasive species further.”

The Canadian Press

Like us on Facebook and follow us on Twitter.

Just Posted

Police officers and their dogs undergo training at the RCMP Police Dog Services training centre in Innisfail, Alta., on Wednesday, July 15, 2015. Mounties say they are searching for an armed and dangerous man near a provincial park in northern Alberta who is believed to have shot and killed a service dog during a police chase. THE CANADIAN PRESS/Jeff McIntosh
RCMP search for armed man in northern Alberta after police dog shot and killed

Cpl. Deanna Fontaine says a police service dog named Jago was shot during the pursuit

Alberta now has 2,336 active cases of COVID-19, with 237 people in hospital, including 58 in intensive care. (Black Press file photo)
Red Deer down to 73 active cases of COVID-19, lowest since early November

The Central zone has 253 active cases of the virus

The Sylvan Lake Gulls show off the home jerseys (white) and their way jerseys at the Gulls Media Day on June 17, before the season opener. Following the media day, the team took to the field for their first practise. (Photo by Megan Roth/Sylvan Lake News)
Sylvan Lake Gulls ready to throw first pitch as construction continues

The Gulls inaugural season kicks off June 18 with a game against the Edmonton Prospects

People line up to get their COVID-19 vaccine at a vaccination centre, Thursday, June 10, 2021 in Montreal. THE CANADIAN PRESS/Ryan Remiorz
Vaccines, low COVID case counts increase Father’s Day hope, but risk is still there

Expert says people will have to do their own risk calculus before popping in on Papa

Canadian Prime Minister Justin Trudeau is seen during a joint news conference following the EU-Canada Summit, in Brussels, Belgium, Tuesday June 15, 2021. Trudeau says Canada is on track now to have 68 million doses delivered by the end of July, which is more than enough to fully vaccinate all 33.2 million Canadians over the age of 12. THE CANADIAN PRESS/Adrian Wyld
Vaccine deliveries enough to fully vaccinate all eligible Canadians by end of July

Three in four eligible Canadians now have their first dose, nearly one in five fully vaccinated.

Chief Public Health Officer Theresa Tam listens to a question during a news conference, in Ottawa, Tuesday, Jan. 12, 2021. The number of confirmed COVID-19 cases attributed to the highly contagious Delta variant grew in Canada this week. THE CANADIAN PRESS/Adrian Wyld
Canada’s public health agency reports spike in confirmed cases of Delta variant

More than 2,000 cases of the variant confirmed across all 10 provinces and in one territory

The federal government says it wants to ban most flavoured vaping products in a bid to reduce their appeal to youth. THE CANADIAN PRESS/AP-Craig Mitchelldyer
Health Canada proposes ban on most vaping flavours it says appeal to youth

If implemented, the regulations would restrict all e-cigarette flavours except tobacco, mint and menthol

The Montreal Police logo is seen in Montreal on Wednesday, July 8, 2020. Some Quebec politicians are calling for an investigation after a video was released that appears to show a Montreal police officer with his leg on a young Black man’s neck during an arrest. THE CANADIAN PRESS/Paul Chiasson
Probe called for after video appearing to show Montreal officer’s knee on Black youth’s neck

Politicians call for investigation after clip evokes memories of George Floyd incident

Thousands of protesters make their way through the downtown core during a Black Lives Matter protest in Ottawa, Friday June 5, 2020. THE CANADIAN PRESS/Adrian Wyld
MPs’ study of systemic racism in policing concludes RCMP needs new model

Chair of the House public safety committee says it’s time for a reckoning on ‘quasi-military’ structure

A case filled with packages of boneless chicken breasts is shown in a grocery store Sunday, May 10, 2020, in southeast Denver. THE CANADIAN PRESS/AP-David Zalubowski
One million chickens euthanized during labour dispute at Quebec slaughterhouse

Premier says waste amounts to 13 per cent of the province’s chicken production thrown in the garbage

A section of the eastern slopes of the Canadian Rockies is seen west of Cochrane, Alta., Thursday, June 17, 2021. A joint federal-provincial review has denied an application for an open-pit coal mine in Alberta’s Rocky Mountains, saying its impacts on the environment and Indigenous rights aren’t worth the economic benefits it would bring. THE CANADIAN PRESS/Jeff McIntosh
Panel says Grassy Mountain coal mine in Alberta Rockies not in public interest

Public hearings on the project in southern Alberta’s Crowsnest Pass region were held last fall

The border crossing into the United States is seen during the COVID-19 pandemic in Lacolle, Que. on Friday, February 12, 2021. THE CANADIAN PRESS/Paul Chiasson
U.S. border restrictions to remain in place until at least July 21

Safety minister says Canada, U.S. extending restrictions on non-essential international travel

Most Read