A routine fish salvage exercise last fall on the Rideau Canal at Edmunds Locks found a new and unwelcome species in the Rideau River — round gobies.
During the exercise, 17 were captured and promptly removed from the population. Professor Steven Cooke of Carleton University said this is not good news. Round gobies are an aggressive invasive species that reproduce quickly.
“Although round gobies are often attributed to great smallmouth bass fishing on the Great Lakes and the St. Lawrence River, their impacts on the broader fish community are often more insidious,” he said. “The introduction of such a pervasive species often displaces native small-bodied benthic species such as darters and log perch, which can lead to unpredictable and often unwanted cascading effects throughout the food web.”
Prevention is key
The closest known population of round gobies is over 100 kilometres away, so the suspected source of transmission is either water from a boat’s bilge or bait bucket release.
The number of gobies found in such a small area leads Cooke to believe the invasion is already too far gone to warrant any hope of effectively removing them entirely from the system. He is considering tagging some to learn more about their spread through the Rideau River.
There is already an array of existing telemetry receivers associated with ongoing fisheries research on the Rideau River. Adding a few round gobies to the data-set could provide valuable insights into their movements.
“The most effective means of controlling aquatic invasive species is through prevention, such as education and enforcement, because once they are established, there is literally no way of getting them all out,” said Cooke.
Ontario Federation of Anglers and Hunters Invading Species Awareness Program Coordinator Sophie Monfette echoed that comment.
“Preventing the introduction of invasive species is critical for the conservation of Ontario’s natural resources because, once established, they are difficult and costly to eradicate or control, and their effects are often irreversible,” she said.
For more information about invasive species in Ontario or to report a new sighting visit www.eddmaps.org/ontario or call the Invading Species Hotline at 1-800-563-7711.