Bits & Pieces: Live-Scanning Invasives and Tourney Bass Dispersal

Technology In Action: Live-Scanning for Invasive Carp 

Invasive carp conjure up mental images of flying fish and hyperabundance. Millions are spent annually to control and curb the spread of black carp, silver carp, and bighead carp. Specifically, bigheaded carps (silver carp and bighead carp) are highly-publicized, abundant, and their impacts are well understood in established regions such as in the Mississippi River basin.

In the Grand Lake/Neosho River system, invasive carp are in low abundance, and thus locating and removing them are difficult. Over the last 20 to 30 years, only less than 10 have ever been captured by traditional fishery sampling despite extensive effort. Recently, biologists from Oklahoma Department of Wildlife Conservation, Kansas Department of Wildlife and Parks, and Missouri State University joined forces with anglers to combat invasive carp.

Using live-viewing sonar, anglers are locating and capturing bighead carp. By targeting individual fish, bighead carp are effectively being hunted and removed from the system. During spring 2023, 40 large bighead carp have been captured by guides and anglers. Several 100-pound-plus fish have been caught, including a 118-pound 3-ounce female caught on May 5, 2023, by Bryan Baker. To our knowledge, this is the world-record bighead carp caught on rod and reel and confirmed as largest in the state of Oklahoma.

-Hae Kim and Dr. Quinton Phelps, Missouri State University

Field Science: Largemouth and Smallmouth Bass Dispersal at Tournaments

One question that often arises among anglers and fishery managers involves the length of time it takes for fish released at a tournament site to return to parts of the lake where they’d been caught, often called dispersal. Recently, a team of Ontario scientists used acoustic telemetry to assess post-tournament movement of largemouth and smallmouth bass caught in events held at Big Rideau Lake, a large lake in eastern Ontario that’s a popular tournament location.* They implanted transmitters in 88 bass of both species that averaged a bit over 16 inches. Receivers placed at the release site, neckdown areas, and at the entrance to the main basin recorded fish moving past.

The team compared behavior of 30 “control” bass caught and tagged prior to the season to movements of bass after tournaments held early in the season (June), mid-season (August), and late-season (October). They tagged only bass that anglers were able to describe the catch location on a map, which covered the lake from one end to the other.

While bass typically lingered near the release site, all eventually departed. Though half of the largemouths evacuated the site in less than 5 days, it was 40 days until all were gone. Half the smallmouths left the site within the first day, though some lingered for up to 18 days. This suggests that short-term stockpiling occurred, but all fish eventually left without mortality or harvest, though the authors noted that other tournaments are held at that site as well, so there may be some accumulation of bass during the tournament season.

In general, smallmouths left the release site faster than largemouths in all months, which agrees with results of several earlier studies. Fall-caught largemouths left faster than those caught earlier in the season. Largemouth bass all returned to the main-lake basin, passing a receiver located at a neckdown about 11 miles to the south, though some took well over a year to do so. All smallmouth bass had passed into the main basin in three months. But it remained unknown if fish returned to the capture locations.

-Steve Quinn

*Abrams, A. E. I., A. J. Zoldero, E. J. I. Ledee, M. J. Lawrence, P. E. Holder, and S. J Cooke. 2021. Dispersal patterns of largemouth bass and smallmouth bass following early-, mid-, and late-season fishing tournaments in an eastern Ontario lake. N. Am. J. Fish. Mgmt. 41:1454-1464.

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