Discovery of zebra mussel in N.B. raises alarm over spread of invasive species

Aidan Cox · CBC News

· Posted: Mar 10, 2025 5:00 AM EDT | Last Updated: 12 minutes ago

The caller find of a unrecorded zebra mussel adjacent Mactaquac, westbound of Fredericton, is raising concerns the invasive taxon is spreading successful New Brunswick, with perchance damaging impacts connected ecosystems, infrastructure, boats and adjacent beaches.

The Department of Fisheries and Oceans recovered an big zebra mussel connected a dock successful the St. John River conscionable northbound of the Mactaquac Dam in December, said Terry Melanson, squad pb for the department's aquatic invasive species program.

The azygous mussel doesn't needfully mean the taxon has taken clasp successful that portion of the river, but it does suggest the mollusc has dispersed from the Edmundston region, wherever it was archetypal discovered successful the state successful 2023, Melanson said.

"Now, volition it get bad? That we don't know," Melanson said successful an interview.

"We could spot localized impacts and we could spot precise small [impact]. That's benignant of the enigma down this ... that though we're employing respective methods to observe the zebra mussels, there's nary mode to know to what grade they're going to found successful the St. John River."

A creeping threat

Zebra mussels are autochthonal to eastern European waters but entered the Great Lakes successful the precocious 1980s done ballast h2o discharged from ships, according to the Department of Fisheries and Oceans.

They've since dispersed done overmuch of eastbound Canada and the United States.

The menace to New Brunswick archetypal came successful 2022, erstwhile zebra mussels were detected successful Quebec's Lake Temiscouata, which drains into the Madawaska River, a tributary of the St. John River.

WATCH | Why spreading zebra mussels could wounded infrastructure:

As feared, the mussels were discovered the pursuing twelvemonth successful the Madawaska River, including connected infrastructure connected to Edmundston's Madawaska Dam, said Melanson.

Last summer, samples by the Department of Fisheries and Oceans recovered zebra mussel larvae successful respective locations successful the St. John River arsenic acold southbound arsenic the Mactaquac Dam, Melanson said..

Danger to autochthonal species

Melanson said erstwhile zebra mussels instrumentality clasp successful an environment, they tin propagate successful clusters numbering into the thousands.

If that happens successful New Brunswick, the taxon could airs a superior hazard to the yellowish lampmussel, which has been labelled a taxon of "special concern" by the Committee connected the Status of Endangered Wildlife successful Canada.

"They're filter feeders, mussels, so they would filter the aforesaid organisms or integrated substance arsenic the yellowish lampmussels. So successful that respect [zebra mussels] risk impacting negatively that species."

According to the Fisheries and Oceans, the yellowish lampmussel is lone recovered successful 2 Canadian watersheds, the St. John River and Sydney River successful Nova Scotia, making it peculiarly susceptible to changes successful those ecosystems.

Damaging to humans

Aside from the menace they airs to New Brunswick's aquatic ecosystem, zebra mussels are besides known to wreak havoc successful spaces affecting people.

Melanson said municipal intake and drainage pipes along the St. John River could go clogged by clusters of zebra mussels and the aforesaid tin hap to infrastructure for hydroelectric dams.

"And erstwhile they bash instrumentality to these hardened substrates, they truly signifier dense mats," helium said.

"We're talking thing possibly [the size of] the extremity of your tiny fingernail, but instrumentality hundreds oregon thousands of those successful dense clumps, you tin already imagine the impacts that tin hap conscionable on, connected infrastructure alone."

Melanson said zebra mussels person been recovered connected the Madawaska Dam, but the twelve oregon truthful that were recovered are considered a tiny number.

Melanson said swimming spots could besides go hazardous if zebra mussels dispersed and multiply successful the St. John River, fixed their signifier and size.

"The shells being tiny by their precise quality are precise sharp, and ... a idiosyncratic walking barefoot, it could chopped their feet."

Stopping their spread

Once zebra mussels person entered a h2o body, there's not overmuch that tin beryllium done to eradicate them, said Sarah Cusack, a task co-ordinator with the New Brunswick Invasive Species Council.

Cusack said portion of what makes them truthful proliferous is that successful their larval stage, zebra mussels tin question agelong distances connected their own just using the earthy travel of a assemblage of water.

On apical of that, the larvae are intolerable to spot with the bare eye and tin get accidentally transported from 1 waterway to different by boaters and kayakers.

Cusack said successful airy of that, her enactment emphasizes to recreational boaters to thoroughly cleanable their boats, drain immoderate captured water, and fto them adust retired earlier putting it backmost successful the h2o — particularly if they're going to beryllium successful a antithetic h2o body.

"I bash judge that this is thing that should beryllium taken precise seriously," Cusack said.

"Zebra mussels person caused billions of dollars of damages and absorption requirements elsewhere wherever they've been introduced," she said.

"They're not autochthonal to North America. So we are going to spot perchance changes successful our ecosystem, successful our freshwater systems, and a cascading effect that volition hap due to the fact that of that due to the fact that they bash determination truthful quickly."