Butter and salt: How you can take advantage of Edmonton's crustacean invasion

In this Wednesday, May 30, 2018 photo, invasive American Crayfish lay in a container after being caught in small river in the Britzer Garden park in Berlin on May 30, 2018. (Markus Schreiber)

If you're looking for fresh shellfish in Edmonton, you need not look further than the North Saskatchewan River.

Northern crayfish can be found in several of Edmonton's waterways, and like lobster or crab, they taste great with a bit of butter and salt.

While the species is native to the Beaver River watershed on the eastern Alberta border, it is listed as an invasive species by the Government of Alberta. 

It's suspected that the prawn-sized crustacean made its way into other Alberta watersheds, including the North Saskatchewan, in the 1990s as live bait being dumped into rivers and lakes.

Wild food guide Kevin Kossowan said crayfish first appeared on his radar around 10 years ago.

"I learned that they were an invasive species and weren't where they were supposed to be, and that you could catch them as much as you'd like," Kossowan said. "In fact, you were doing the ecosystem a favour if you did."

Unlike other aquatic species, crayfish can be harvested without a licence everywhere in Alberta except Beaver River, as long as you're using nets, traps or – if you're brave – your hands.

"(It's) a bold move, because they do have pincers on them like a little mini-lobster," Kossowan said. "I've found tongs quite useful as a way to grab them."

In this Wednesday, May 30, 2018 photo, An American Crayfish captured at a small river in the Britzer Garden park in Berlin on May 30, 2018. (Markus Schreiber)Crayfish traps or instructions on how to make them are readily available online as well, as they're a common food in many places, including the U.S. They've even been featured as a battle ingredient on the classic cooking show Iron Chef.

Known there as crawdads, crawfish or mudbugs, they're served in seasoned boils, and they're so popular in some regions that entire festivals are dedicated to cooking and eating them. 

In Kossowan's opinion, they're best served simply.

"I'm not a big fan of all the mixing of flavors like in a boil," he said. "I would be picking some wild onion from the river valley or from my yard … Wild onion, butter, crayfish, salt, that's it.

Kossowan said there are plenty of other ingredients awaiting anyone looking to score supper from our city's wild places. To book a foraging class or learn more, visit From The Wild. 

What you need to know before you go

There are a few things to keep in mind when hunting crayfish, and where you hunt is a big one.

Crayfish are scavengers, said Mike Jenkins, a senior scientist with the City of Edmonton, and accumulate contaminants and toxins from the surrounding environment.

"The condition of crayfish is going to be heavily influenced by the quality of water where they have been raised," Jenkins said. "Caution should be taken before consuming any wild meat."

Kossowan said the best bet for a tasty, safe crayfish supper (if you don't want to leave the city) is the North Saskatchewan River.

"The creeks in the Edmonton area would be one of my last choices," he added. "I would feel good about eating crayfish out of the North Saskatchewan.

"I think the flow rates are heavy enough and steady enough that you're in a pretty clean scenario."

Runoff from city streets can enter local waterways, Jenkins said, and eating any unregulated food carries risks.

"For public safety, any activity that may result in direct contact with water in stormwater management facilities is prohibited," Jenkins said.

It is illegal in Alberta to travel with live crayfish or to use crayfish, even dead ones, as bait. So, you need to be ready to cook them right away.

"If you're going to be playing with crayfish, you have to have a camp pot handy," Kossowan said.

Salt the water and boil them for three to five minutes, and eat them right away if you like. Kossowan said you can devein like a shrimp as well, if you want.

"(It's) basically removing the digestive tract," Kossowan said. "We found that to be not necessary, but of benefit if you want a cleaner favour."

Or you can let them cool down, take them home and fix up your favorite shellfish snack.

Mitigation efforts

According to the province, northern crayfish impact local ecosystems by reducing and changing the diversity of insect and macroinvertebrate populations, which affect native species that rely on them.

"The crayfish will also graze on new emergent vegetation, reducing the habitat and cover available for other species," Jenkins said.

In 2022, northern Crayfish were reported to have reached six Alberta river drainages. That includes Banff National Park's Bow Lake, which is unusual given crayfish's preference for warmer waters. 

• 'Suspect there are more': Parks Canada captures invasive crayfish
• Crayfish make unwelcome appearance in Nose Creek

A study published the same year by the journal Freshwater Science suggests management of the species could become more difficult as average water temperatures in the North Saskatchewan Rivershed rise.

A Nashville crayfish is counted during an annual census in Nashville, Tenn., where the species is endangered, on June 11, 2024. (Travis Loller)Jenkins said Edmonton's crayfish population can thrive when the river is warmer and lower, but there are currently no programs to monitor the local population.

There aren't any current mitigation efforts either.

"They are well established, and any attempts at eradication would be costly and likely unsuccessful," Jenkins said, adding that crayfish don't need to be reported to the city.

"The public is encouraged to report any other suspected invasive species, in particular goldfish/Prussian carp and quagga mussel," he said.

For more information on invasive species in Edmonton, or to report a sighting, visit the City of Edmonton website.