Scientists tag carp in Ottawa to measure river cleanup success

US Geological Survey researchers completed a tagging session in Allen Park in Ottawa on Wednesday, collecting data to evaluate their removal strategy for invasive silver carp in the Illinois River.

The team focused on the Starved Rock field, an area where scientists are working to determine how effective ongoing removal efforts are. They left the boat ramp on the west side of the park to enter the river, returning with approximately 15 to 20 carp per trip. For each fish, the scientists recorded its length, sex, and weight before releasing it back into the water.

Scientist Jessica Stanton explained the tracking method used to gauge success. “We tag 1,000 fish, and then commercial fishermen report those tags as they encounter them over the next couple of weeks and months when they’re out doing removals,” Stanton said. “Then, we know how many tags we put out and depending on how many we get back, we can estimate the percentage of the removal rate.”

Stanton noted that while large numbers of silver carp are removed annually, the agency lacks precise data on what portion of the total population this represents. She described silver carp as invasive species that compete with native fish for resources. These carp consume more food and reproduce faster than most North American native species, which affects both commercial and recreational fishing industries.

The immediate next step for the team is to calculate an estimate of the current silver carp population. Once that figure is established, the US Geological Survey will adjust its current management plans based on the new data.