British Columbia

B.C.'s invasive species warriors tackle turtles, knotweed, climate change and critics

Invasive species experts have gathered in Richmond to strategize strikes against everything from Japanese knotweed to American bullfrogs with the only weapon that works — cooperation.

Irish expert offers tools to help weed out destructive invaders from bullfrogs to hogweed

Red-eared slider turtles sold as pets have been able to establish themselves in B.C. freshwater and breed as winters have warmed and now pose a threat as an invasive species. (CBC)

Invasive species experts have gathered in Richmond to strategize strikes against everything from Japanese knotweed to American bullfrogs with the only weapon that works — cooperation.

The Invasive Species Council of B.C. (ISCBC) works to stop foreign plants and animals from taking over ecosystems in the province.

With increased trade and travel and warmer winters, organizers say they face more challenges than ever controlling destructive invaders.

A green frog peeks out from under a leaf, in some water.
American bullfrog (Lithobates catesbeianus) is native to North America, east of the Rocky Mountains, but has spread in past decades to other regions of the US and Canada, and to numerous countries around the world. It is a voracious predator that eats almost anything it can fit into its mouth. (Angel DiBilio/Shutterstock)

The biggest tool in their arsenal is cooperation.

"You can't fight invasive species on your own," said executive director Gail Wallin.

Nobody can tackle a knotweed invasion if neighbours ignore it.

So they've called in experts from as far away as Ireland — a leader in biosecurity worldwide.

This week, the ISCBC council is hearing from Joe Caffery, with Ireland's INVAS Biosecurity, the agency which helped the European Union settle on the top 37 invasive species that should be targeted — an issue that's growing due to globalization.

"You can imagine the mayhem that ensued in trying to come up with one coherent list," said Caffery. "They haggled and haggled."

It took 18 months to finalize the list.

The keynote speaker, Tim Readman with the Stroke Association of B.C., has been invited as an expert on partnerships, because not all invasive species experts agree on non-native species control.

Partnerships key

Not everyone agrees with the effort and cost of eradicating non-native species and the battle against invasive species has come under fire from others in the ecological movement.

Authors like London environmental writer Fred Pearce claims in his book,The New Wild: Why Invasive Species will be Nature's Salvation that the dangers of introduced plants and animals is "hopelessly hyped" and understudied.

"I'd find that laughable, but it's a bit scary. We should not poo-poo it," said Caffery, who has seen firsthand the devastation done by non-native species.

Wallin says the threat is more prevalent than ever in B.C., as more people than ever before flock to the province, putting native species and environments at risk, though she agrees that not all non-native species are problematic.

"Daffodils in your garden are not creating a problem. But the giant hogweed in your garden is actually sending kids to hospital," said Wallin.

Warmer winters in B.C. are compounding the issue. Species are now surviving in Canada that would have been frozen out in the past.

Furry, rodent-like nutria are disturbing ecosystems across North America and Europe. (Robin Loznak/News-Review/File/AP)

Wallin pointed out that red slider turtles were found last year for the first time thriving in the Fraser Valley.

The turtles, once sold as pets, are native to southern U.S. states like Texas and were never established in B.C. until now.

While some non-native species arrive as pets, many other plants and animals are brought in by travellers.

"Plants grab easily onto tires, so you will see them spread along hydro lines, utility corridors," she said. — describing seeds transferring from truck tires to soil.

Giant hogweed only flowers once in its lifetime. When it does, the plant will undergo aggressive growth and is capable of reaching heights of 13 to 15 feet. Until then, hogweed (left) is often mistaken for its smaller, more benign cousin, Queen Anne's Lace (right). (Colin Butler/CBC News)

Other species were failed business opportunities.

American bullfrogs were bred to market frog legs after World War II.

"[It was a] delicacy that people weren't used to, so it was a commercial business and it didn't take off as well."

But the frogs did.

American bullfrogs are so ravenous, they can decimate an ecosystem, even eating fledgling birds.

Nutria — a beaver-like rodent with less of a tail — was bred to harvest fur but some of the animals got away.

However, most of the invasive species threat are plants such as Japanese knotweed or giant hogweed, said Wallin, which may not look that villainous but can wreak havoc, taking over and destroying natural habitat.

The Invasive 2017 forum is being held Feb. 7 to 8 in Richmond B.C.

Ashphalt is no challenge for knotweed that can grow through everything from concrete to brick walls and destroy a yard. (wiseknotweed.com)
Japanese knotweed can reach three metres in height with two thirds of its size remaining underground. The roots are able to grow through concrete, cement and asphalt. (Paula Noel)