GPS-enabled kayaks deployed at Emiquon offer new hope in struggle to keep multiple species of invasive carp at bay, TNC officials say.
LEWISTOWN, Ill. Unmanned kayaks equipped with side-scanning sonar gathering data in the dark of night at The Nature Conservancy in Illinois’ (TNC) Emiquon Preserve could be a game changer in wetlands invasive carp management, including the potential large scale removal of silver, bighead, and even the elusive common carp.
With new innovative practices utilizing recreational grade sonar, researchers with the U.S. Geological Survey are using semi-autonomous kayaks to map Emiquon, a wetland outdoor laboratory, of sorts, managed by TNC, and capture detailed information about the invasive carp living there, revealing how they react to disturbances and, perhaps most importantly, where they hide – information TNC and their partners plan to use to remove them.
“Invasive carp, including common carp, absolutely wreak havoc on high quality wetlands,” said Randy Smith TNC’s Illinois River Project Director. “If this works, it will be a really big deal for wetland managers.”
Approximately four times per year during the next two years, USGS will deploy four kayaks with pre-programmed GPS-enabled trolling motors to collect all of the data they can on the fish, which will then be analyzed using artificial intelligence.
“Our goal at USGS is to provide cutting-edge research that allows land and water managers to make the best decisions possible for the environments under their care,” said Robin Calfee, USGS research biologist. “In partnership with The Nature Conservancy, Emiquon is an ideal wetland area for getting our newer technologies into the field.”
Once USGS researchers are confident in their understanding of the fish’s behavior patterns at Emiquon, TNC will use that information to remove what they hope will be multiple semi-truckloads of invasive fish in one event, which could take place as soon as 2025.
“It would take many, many years to achieve the same level of fish removal using traditional methods that we’re hoping to achieve in one event,” Smith said. “It’s extremely labor intensive, but we think it will be worth it.”
TNC currently does not have a formal removal process for invasive fish but does allow some commercial fishermen to remove large quantities of mostly silver and bighead carp. Commercial methods typically include making a ruckus in the water and spooking the fish into nets. Smith said the startle tactics result in the removal of 5,000-to-8,000 pounds of fish in a day, an amount considered miniscule to the Emiquon fish population. Overall, he estimates, one-to-two percent of the invasive silver and bighead carp at Emiquon have been removed by commercial techniques. There are no successful strategies in place to remove significant numbers of common carp.
“The problem is the carp are much more sensitive to their environments than we give them credit for,” Smith said. “When there is even a small disturbance, most fish hide and are able to avoid the collection entirely. It’s just not efficient, and it doesn’t address common carp, which are even less susceptible to traditional commercial capture techniques.”
This potentially groundbreaking USGS methodology is the result of work currently led by USGS Fish Biologist Josey Ridgway, who has been using sonar technology to survey fish for about six years, and is now adding unmanned kayaks to the mix as his team explores affordable and efficient techniques. Similar trials are underway in Missouri and Minnesota.
“Research grade sonar systems can be cost-prohibitive, but recreational technology has come a long way and does not require advanced technical training,” Ridgway said. “Kayaks cost less than a traditional survey vessel, can be deployed in multiples to scale coverage, and are quieter.”
The kayaks are so quiet, in fact, Ridgway believes deploying them after sunset when there are fewer disturbances from other watercraft will result in more accurate data collection. Thus far, the team has conducted two outings with four kayaks to complete the route-programming process. TNC hopes that information will support a 2025 removal event.
Based on their experience with other carp removal events, USGS indicated a great deal of planning will need to take place to secure transport equipment, work with the fishery industry, and determine the most suitable outlets for the removed fish, which may include human consumption, pet products, and fertilizer.
“There’s much still to be done, but we’re extremely excited about the possibilities for the future of wetlands management,” Smith said.