Northern crayfish continues its Alberta invasion, this time, in mountain parks

If you haven't spotted a northern crayfish in Alberta already, there's now one more spot where you might see one swimming about. 

Parks Canada recently caught one of the mini-lobster looking critters near a stream flowing into Bow Lake in Banff National Park. 

It's the first time they've seen the aquatic invasive species so far upstream in the Bow River or in the mountain national parks.

"We are continuing our efforts to try and detect whether or not there are more or if there's an established population in the area," said Megan Goudie, ecosystem scientist with the Lake Louise, Yoho and Kootenay field unit with Parks Canada.

"We still have traps set in the area and are doing visual inspections frequently." 

Parks Canada received a report detailing a possible crayfish sighting in the area earlier this month, which caused Goudie and her colleagues to explore nearby tributaries. 

After several days of searching, netting and setting minnow traps, they found one crayfish on Aug. 6. Unfortunately, Goudie says, where there's one, there's likely more.

Under provincial regulations, northern crayfish are considered an aquatic invasive species of concern. 

Historically, they've been found in between Wainwright and Ryley in the Beaver River watershed south of Edmonton, but today, they're all over the province, including in Calgary.

"We're finding them all the way up to Grand Prairie, Whitecourt, Athabasca, Cold Lake regions, and then basically pretty consistently all the way down to the Montana border," said Nicole Kimmel, aquatic invasive species specialist with Alberta Environment and Parks.

"So it's not alarming that they jumped over into the national parks, but still disappointing."

It's unclear exactly what changes the crayfish are causing in their new ecosystems, but Kimmel says an initial study does point to impacts on native fish and wildlife.

Crayfish can alter the food web, changing the abundance and diversity of food that's available for different species.

"We do have two species at-risk in this section of Banff National Park, the Bull Trout and the Westslope Cutthroat Trout," Goudie said.

"So our concern is that this could adversely affect these species at-risk."

'Open season on crayfish'

Both groups suspect the crayfish have spread through human activities, whether it be using them as fish bait or releasing them into other water bodies — which are both illegal in Alberta.

"It is also possible, but not quite as likely in this case, that it could be attached to watercraft or aquatic recreational gear that people are bringing into the park," Goudie said.

Parks Canada is continuing to monitor for crayfish through the use of environmental DNA. It's a new tool being used to better understand the distribution of crayfish throughout the parks.

"As species go about their normal lives, they are shedding little bits of themselves into the water system, and so by filtering water through very special filters, we're able to pick up these little bits," Goudie said.

The agency is also requiring non-motorized boat users to complete a self-certification permit that confirms the user has cleaned, drained and dried their watercraft for at least 48 hours before it's used in Banff National Park.

Kimmel says the Alberta government has also changed its sportfishing regulations to allow for unlimited angling of the crustaceans.

"We're pretty restricted on any response control measures ... they're too widespread at this point," she said.

"It's pretty much an open season on crayfish."

Residents can fish for crayfish using a net — or if they have a fishing license, with a rod — but they cannot be kept or transported.

"We have laid charges on some in that aspect in recent years, so we do know that folks are trying to move these alive, and that's probably why they're being so widely distributed so fast," Kimmel said.

Some people also eat them, but before you do, consider where you caught them.

Any crayfish caught in natural water bodies should be fine, Kimmel says, but "some of these crayfish are being found in storm water management facilities like in the urban towns and cities. We don't recommend consuming any crayfish from those water bodies."

Both groups are asking residents to report any possible sightings of crayfish.

The northern variety is the only species known to be in Alberta at this point, but others such as the rusty crayfish and the red swamp crayfish are located in surrounding provinces.

Pictures of the sightings also help, if possible.

Reports can be submitted to the Alberta Environment and Parks hotline at 1-855-336-BOAT (2628).