What's cooking? Three invasive species you can eat
They're nutritious and delicious (so we've heard).
Canada is home to an estimated 1,440 invasive species — and that’s bad news for the environment.
A recent report says invasive species subtract around $35 billion from Canada’s economy each year, adding pressure to our forest, agricultural, and fishing industries.
You can help by planting native plants in your garden (this stops the spread of invasive plant species and provides native animals and insect with suitable habitat and food sources). In the water, you can help prevent the spread by thoroughly cleaning recreational equipment before and immediately after use. And authorities always appreciate when you call in a sighting.
There’s another thing you could do, if you’re feeling up to it.
Some of Canada’s invasive species are edible. Here are three examples.
Asian carp
In the 1960s and 70s, Asian carp were introduced to the southern U.S. to control algal blooms. A series of unfortunate events, including floods and human error, helped the fish escape into the Mississippi River system, and their population has been exploding ever since.
The term "Asian carp" collectively refers to four species: bighead, silver, grass, and black. The voracious eaters out-compete native fish and destroy local environments, accounting for 90 per cent of all fish biomass in parts of the Upper Mississippi.
The bighead, silver, black, and grass carp, are in Ontario waters and threaten the Great Lakes ecosystem, although they do not appear to be present in large numbers.
Carp has long been consumed in parts of Asia, but in North America, its reputation as a destructive invasive species has limited its popularity as a food choice.
Back in 2021, Illinois officials introduced a campaign to rebrand the carp as a tasty treat.
Experts continue to share this message. In a February 2025 press release, the U.S. Fish & Wildlife Service again included carp on its list of edible invasive species.
The release, titled 'Eat the Invaders,' reminds the public that the fish are "surprisingly tasty."
"Try them grilled, blackened, or turned into crispy fish cakes," the agency suggests.
Other health benefits of carp
Carp is a flaky fish that's low in iron and high in omega-3 fatty acids.
Dirk Fucik, owner of Dirk's Fish and Gourmet Shop in Chicago, told USA Today in 2021 that carp isn't a bottom-feeding fish. It's actually a plankton feeder, with "cleaner, sweeter-tasting meat."
People remain reluctant to eat carp
Hundreds of thousands of dollars were poured into Illinois’ 2021 campaign to entice the public to eat invasive carp, going so far as to rename the fish copi, a marketing ploy to diminish any unappetizing perceptions about the fish.
Garlic mustard
Garlic mustard is an invasive and 'aggressive forest invader' that's overtaking green spaces in parts of Ontario and Quebec. It it also found in small pockets in B.C., Nova Scotia, PEI, and New Brunswick.
In its first year of growth, the plant is fairly inconspicuous, but by the second year, it can grow up to a metre high, posing a significant threat to surrounding biodiversity.
You might come across it in your neighbourhood, especially in April and May when it is flowering.
Garlic mustard threatens several native species, the Government of Ontario says on its website, including American ginseng, drooping trillium, false rue-anemone, hoary mountain mint, white wood aster, wild hyacinth, and wood poppy.
Crushed leaves of garlic mustard (pictured here) give off a distinct garlic smell.(Cheryl Santa Maria for The Weather Network)
Garlic mustard was intentionally brought to North America by European settlers in the 1800s_.
Local foraging groups encourage curbing the plant's spread by eating it. Like the name suggests, its crushed leaves have a distinct, garlicky smell and light, garlicky taste. Just make sure you know where you're foraging. Plants on public property may have been treated with pesticides that make them unsafe for consumption. But if you find garlic mustard on private property, it's likely safe to eat.
According to a 2015 report written for the CBC by Jonathan Pinto, it can replace basil to make a "really delicious" pesto. Garlic mustard is also nutritious, with high concentrations of vitamins A and C.
But be careful, because there are some lookalikes lurking about, like dame’s rocket. Key differences are the colour of the flowers: Dame's rocket flowers are different shades of purple, whereas garlic mustard produces white flowers. Also take note of the shape of the leaves: Dame's rocket leaves tend to be elongated and narrow, while garlic mustard leaves are triangular and jagged.
Dame's rocket (pictured above) resembles garlic mustard, but its flowers range in colour from light to dark purple. (Huw Williams/Wikipedia/Public domain.)
Rusty crayfish
A rusty crayfish. ([Government of Ontario](Doug Watkinson,)/Doug Watkinson for the DFO]
Originating in Ohio, Kentucky, and Tennessee, this aggressive crayfish was introduced into Ontario waterways by fishermen who used it as bait.
The fish are damaging to Canadian waterways because, without any natural predators, they:
Severely reduce aquatic vegetation by reducing available habitat, food, and spawning grounds for native fish.
Consume the eggs and young of native fish populations, resulting in reduced numbers.
Demonstrate aggressive behaviours towards other fish.
Spawn in large numbers and can hybridize with native crayfish.
Once established, they are costly to eradicate, according to the Government of Manitoba
Not only are rusty crayfish edible, they’re considered a delicacy in Cajun cuisine and pair well with a jambalaya.
But catching them could be tricky in parts of Canada due to local regulations regarding their capture and possession.
For example, in Ontario, it is illegal to transport rusty crayfish over land, whether dead or alive. This law is in place to prevent further spread of the species.
It’s also imperative to source from a clean water source to prevent the risk of illness.
VIDEO: Canada loses billions annually to invasive species
Header image: File photos and elements sourced from Canva Pro. Rusty Crayfish image: DFO