Water monitoring group finds 16 invasive crayfish in Nose Creek in less than 60 seconds
Save Nose Creek caught 16 critters in its last screening, up from the usual 3 to 5
A record number of invasive northern crayfish has been counted in one of Calgary's northeast water bodies this past week by a volunteer advocacy group, Save Nose Creek.
The group has been testing Nose Creek each week since June for water quality, chemicals and invertebrates, as part of their training with CreekWatch Alberta.
Usually, they catch three to five of the mini-lobster looking critters in a span of 30 seconds to one minute.
But on Aug. 3, volunteers tallied up 16 northern crayfish — their biggest count yet, according to Save Nose Creek founder Andrew Yule.
Watch | Volunteer advocacy group catches crayfish in Nose Creek
"Every time we've gone out, it's just more and more and more…. It just shows that there's nothing really stopping this crawfish from multiplying," said Yule.
"It's not a great thing to see an invasive species thrive in a creek that you're trying to preserve."
Alongside other teams in other areas of the city, Yule says the group will continue its weekly monitoring of Nose Creek until about October, as CreekWatch works on a report with its findings.
Expanding to southern Alberta
Under provincial regulations, northern crayfish are considered an aquatic invasive species of concern.
They're native to Alberta, but not Calgary. They've historically been found between Wainwright and Ryley in the Beaver River watershed, southeast of Edmonton.
But through the years, they've scuttled their way south through the province, all the way down to Montana. One was even captured in Banff National Park for the first time last year.
Nicole Kimmel, aquatic invasive species specialist for Alberta Environment and Protected Areas, says no others have been found in Banff since then.
She says she's trying to figure out how the critters have been spreading so vastly.
"We think people are helping it move along," said Kimmel. "We think some folks like to use them as bait, and they might not be ensuring that they're dead."
"Once they're introduced, they have very limited predators or prey to keep their population in check and they really disrupt food webs."
Remove and kill
Nose Creek is one of Calgary's known hotspots for crayfish, says Kimmel.
Under current regulations, since they're managed as a pest species, Kimmel says the province encourages citizens to remove and kill crayfish when they find them.
She says Albertans are only allowed to have live crayfish within five meters of the water body they took it from.
Some people also eat the crustaceans.
Kimmel says she has no concerns for consumption with a natural body of water like Nose Creek, but doesn't recommend "consuming out of those man-made water bodies" that work as collection points for household fluids.
But Yule with Save Nose Creek said he'd think twice about that "just because of the pollution that we're dealing with," though he notes the creek's health has significantly improved over the years.
Yule says he'd like to see governments work to help improve the health of the creek so residents can comfortably fish for crayfish as much as they want.
Kimmel is also asking residents to report any possible sightings of crayfish, ideally with pictures, to 1-855-336-BOAT(2628).
She says it's because they're keeping an eye out for other species of crayfish popping up throughout the country.
"One of them is marbled that's able to clone itself," she said.
ABOUT THE AUTHOR
