‘We’re doomed’: New invasive fish species detected in Quebec lake

tubenose goby underwater Photo by Rostislav Stefanek/Shutterstock

The Quebec Ministry of the Environment and the Fight Against Climate Change has detected a new species of invasive fish in Montérégie’s Saint-François Lake, an hour west of Montreal.

The western tubenose goby (Proterorhinus semilunaris), native to the Black and Caspian sea basins, is believed to have been first brought to North America in the late 1980s after ocean-going ships dumped ballast water into the Great Lakes, according to Ontario’s Invasive Species Awareness Program. It’s a voracious eater, preying on sea snails, fish eggs and larva on the lakebed in great enough quantities that it can single-handedly reduce a waterway’s biodiversity. 

Annick Drouin is responsible for the MELCC’s aquatic invasive species division. She says the ministry first caught a tubenose goby in St. François Lake during an annual research fishing expedition on Aug. 25, 2022. Testing confirmed the species a few weeks later, but the ministry waited until July 2023 to announce that researchers detected the fish.

“It was more (worthwhile) for us to announce it to the public when recreational fishing was more active, so fishers would be more vigilant in detecting tubenose goby,” Drouin says, adding that they will continue monitoring the lake and its surrounding bodies of water.

The tubenose goby has a thin, cylindrical body with an average length of nine centimetres according to the Government of Quebec. It has a fused pelvic fin on its stomach that looks like a suction cup, slate gray, olive green, or brown scales with occasional brown or black spots, and two nostril tubes, which Drouin calls atypical. It’s usually found in waterways with a sandy lakebed.

People often confuse the tubenose goby for another invasive fish, the round goby (Neogobius melanostomu), says Julien Poisson, director of conservation for the Nature Conservancy of Canada in Southern Quebec. This sister species has a similar appetite and appearance, save for its more curved back. Round gobies also thrive more in waterways with rocky lakebeds, but they have been found in sandy Quebec environments for the last 30 years according to Fisheries and Oceans Canada.

Poisson says these two invasive fish are also similar to a few native species, including the mottled sculpin (Cottus bairdii) and the at-risk deepwater sculpin (Myoxocephalus thompsonii). Because of these similarities, the ministry requires anglers who catch gobies to put them back in the water.

“It’s kind of counterintuitive to re-release gobies into the water,” Poisson says. “But I understand the ministry just doesn’t want to make it worse since people will take all the goby-like fish and kill them.”

Anglers who catch fish for consumption are exempt from this restriction, but there’s so little meat on these gobies that they’re not worth the time, and they have to be fully cooked to be edible. They only have a few predators as a result, including the yellow walleye (Sander vitreus) and large or smallmouth bass. Drouin says this is one of several factors that contributed to the round goby’s overabundance and density in some Quebec lakes. “The goby is too prolific for predators and hides well,” she says.

To combat the spread of the tubenose goby, Drouin recommends washing fishing equipment with warm water, emptying ballast water before removing a boat from a lake, and not using live or dead bait fish prohibited by the Quebec government. On a larger scale, however, she says there’s little the ministry can do. Any chemicals that would kill tubenose gobies could also threaten native wildlife, and installing dams that could stop them would also stop local fish from traversing waterways.

Now that the tubenose goby is here, Poisson says it’s likely to travel east of Montreal to Two Mountain Lake. The worst-case scenario is that it follows the river down to Lac Saint-Pierre, which will give it access to many of the province’s large rivers.

“My guess is in two to three years there’s going to be a tubenose goby at the pass going up the Richelieu,” he says. “After that, we’re doomed.”

Clarification: The tubenose goby originated in the Black and Caspian sea basins. According to the Invasive Species Awareness program website, it’s believed the tubenose goby was first brought to North America through the ballast water of ocean-going ships.

Featured Video