Ottawa

Invasive round goby fish found in Rideau Canal

An invasive species of fish native to the Caspian Sea has been found swimming in the Rideau Canal. Now, researchers from Carleton University are trying to figure out how they got there, and how to prevent them from getting to the Ottawa River.

Carleton University researchers tracking how they got there, and how to stop them

This is one of the round goby fish caught by researchers at Carleton University. It will be tagged and returned to the Rideau Canal so the team can track its movements. (Jean Delisle/CBC)

An invasive species of fish originally from the Caspian Sea has been found swimming in the Rideau Canal.

Now, researchers from Carleton University are trying to figure out how the fish got there, and how to prevent them from reaching the Ottawa River.

Round goby fish were found this spring at the Edmonds lockstation in Smiths Falls, Ont. When it was drained, 17 of the invasive fish were spotted.

The discovery caught the attention of researchers at Carleton University, who want to understand their movement patterns through lock systems as part of a larger project about how locks and dams affect the ecology of the Rideau Canal.

Jordanna Bergman, a PhD student at Carleton University, is part of a team studying fish movement and connectivity in the Rideau Canal.

Jordanna Bergman, a PhD student at Carleton's Fish Ecology and Conservation Physiology Lab, is leading the field research and said understanding round goby movement is vital to stopping them from continuing all the way to the Ottawa River.

"Once invasive species have established themselves in an area, it's relatively impossible to eradicate them," Bergman said.

Round goby common in Great Lakes

The round goby is native to Eurasia, particularly the Black and Caspian seas, and was spotted in Lake Ontario in 1998. The species was introduced to the Great Lakes through the ballast water of ships.

It's been destructive because it is more aggressive than native fish and competes for the same food source. It also is known to eat the nest eggs of bass fish, which has negative consequences on bass populations.

Bergman's three-person team has now located 11 round goby fish downstream from the Edmonds lockstation, and she said there's a good chance the fish are upstream as well.

"That means that they probably have come here all the way from Lake Ontario, which would be a very impressive feat for such a small benthic fish," she said. Benthic fish live and feed on or near the bottom of waterways.

The round goby fish is a species native to Eurasia, particularly the Black and Caspian seas, but it is now common in Lake Ontario. The species was just recently discovered in the Rideau Canal. (Jean Delisle/CBC)

The team is also tracking another invasive species — the common carp — and two native species, the northern pike and largemouth bass.

By comparing their movements, the researchers are hoping to find ways to optimize the movements of the native fish while minimizing the movements of invasive species.

Tracking round goby isn't easy

Originally from the Caspian Sea, round goby fish have been found swimming in the Rideau Canal. Jordanna Bergman and her team from Carleton University are using a unique method to catch the fish in order to track their movements. 1:08

But finding round goby fish to tag and track hasn't been an easy task. According to Bergman, traditional methods of angling and using minnow traps weren't working.

"Because goby are relatively new to the system, we believe they are just in lower densities right now and those two techniques are used for higher-density areas," Bergman said.

On Tuesday, her team started a different approach that has them looking a bit like Ghostbusters.

"We're gobybusters," Bergman joked.

From left, researchers Jordanna Bergman, Brenna Gagliardi and André Kileen are tagging and tracking round goby fish in the Rideau Canal. Kileen is holding the electrofisher they're using to help catch the fish more easily. (Jean Delisle/CBC)

They're using a piece of equipment called an electrofisher. It gets strapped to one person's back and sends electrical shocks into the water, which stuns, but doesn't hurt, all the fish nearby.

The stunned fish are then easily captured in a net.

On their first day of "e-fishing" the team found a round goby.

"So much screaming and shouting, so much excitement," Bergman recalled.

An invasive fish originally from the Black and Caspian Seas is now swimming in the Rideau Canal. 6:48

The tagged fish will be tracked for a total of 87 days, just long enough to get through the rest of the navigation season.

"So if we do want to see if they're moving through lockstations, this is our chance to do it right now. We've just captured them in time," Bergman said.

Comments

To encourage thoughtful and respectful conversations, first and last names will appear with each submission to CBC/Radio-Canada's online communities (except in children and youth-oriented communities). Pseudonyms will no longer be permitted.

By submitting a comment, you accept that CBC has the right to reproduce and publish that comment in whole or in part, in any manner CBC chooses. Please note that CBC does not endorse the opinions expressed in comments. Comments on this story are moderated according to our Submission Guidelines. Comments are welcome while open. We reserve the right to close comments at any time.