AGFC biologists round up Lake Erling catfish in rodeo for new study

July 8, 2020

Jim Harris

Managing Editor Arkansas Wildlife Magazine

TAYLOR – Biologists from the Arkansas Game and Fish Commission spent a week in June getting a good look at the size and scope of the flathead and blue catfish swimming the waters of Lake Erling, in the southwest corner of the state. The verdict from the study is yet to be determined until samples are analyzed, but the initial view is that Lake Erling has some big catfish, to be sure.

By using electrofishing – passing pulses of electric current through the water from a boat to temporarily stun the fish, allowing them to be netted – the biologists, led by Andy Yung of the agency’s Fisheries Division District 6 in Camden, were able to take pectoral fin spine samples, which can be used to determine the age of fish, along with measurements of the length of about 400 specimens of blues and flatheads caught over a five-day period.

“We certainly hit our goals on numbers for blue catfish, and I would have liked to have caught a few more flatheads,” Yung said, indicating that 70 flatheads made up the total haul. “But the good thing was, they were very spread out as far as length is concerned. That’s good for us when we’re doing our age-and-growth surveys. If everyone was in one size inch-group, it only tells us about that small portion of the population. But we saw flatheads from 4 inches long out to 3 feet long. We saw a nice spread. We’ve also learned a lot for the next time we go out and do something like this.”

Spine samples taken will be studied under a microscope by the biologists to determine the fish’s age – like trees, a fish’s spines develop a ring each year and can be cross-sectioned in the lab.

Some areas yielded some impressive flatheads, including a few in the high 600 millimeters (which ciphers out to about 25-27 inches). In another area, over a channel running through the middle of the lake, an amazing number of blue catfish surfaced, many of them weighing about a pound, in a matter of moments of the current being applied. The crew saw a few pop the surface before suddenly dozens of blues began bouncing around both boats, with skilled biologists netting six at a time in just seconds.

The shocking doesn’t harm the fish, and the taking of a spine for the study does not cause any long-term damage; the break in the skin where a spine is removed will soon heal once the fish is returned to the water.

Lake Erling, which covers about 7,000 acres and is situated a couple of miles from the Arkansas-Louisiana border, or 14 miles south of Lewisville to its northern tip, is owned by the Shreveport-based American Gamebird Research Education and Development Foundation. It’s previous owner for six decades was International Paper Co., which built it to provide a water source for a former mill in Springhill, Louisiana, just across the state line. This study of flathead and blue catfish was the first there since the AGFC took a look in 2014, according to Yung.

Electrofishing is not a new concept for the AGFC’s Fisheries Division, but the equipment now being used is. A high-tech machine called “The Infinity Box,” a newer version made by a different company than previous equipment has literally infinite frequency settings to control current output for electrofishing. The 2014 study at Erling didn’t have that equipment, and it was also conducted as a random sampling of the lake ostensibly to determine density as well as size and age of fish, but few fish were caught, including just 10 flatheads. This study, by comparison, collected more than six times the total number of fish, Yung said. But the new study was in search of raw data rather than a density of fish in the lake, hence areas of Erling were not randomly selected.

“At some point you have to sacrifice random site selection to go out and get enough fish to gather some data,” Yung explained. “If you have a baseline data set and you say, ‘This is where the growth is at,’ then you can progress to some of these random samples and we can use our catch rates and say, ‘We need to do this many electrofishing runs when we’re random sampling to get the amount of the fish we need.’ And you can build from there.

“This is kind of the first stepping stone to just let us get a handle on what’s going on. We haven’t been out there for five years or so, six years, and we’re just trying to get baseline information on some fish that we know are popular. There are a lot of catfish anglers out there.”

When Yung says “out there,” he means statewide and beyond, not just at Lake Erling. He notes that the research of catfish has taken a big leap in recent years with the AGFC and nationally. Jason Olive, AGFC’s assistant chief of Fisheries, said, “Due to the sampling methods required to collect catfish being much different than those used for most scaled fish like bass and crappie, there has been a lag nationwide in studying and understanding catfish populations as well as we do some other popular sportfish species. AGFC Fisheries Division communicates regularly with surrounding states on all sorts of issues, and catfish sampling has been a hot topic in those discussions over the last 10 years.”

So, the AGFC since about 2012, Olive said, has put much more effort into its catfish program and research. Also, earlier this year, Little Rock played host to the 3rd International Catfish Symposium, a conference held every 10 years, where fisheries managers and researchers from across the U.S. and Mexico came together for two days to share the latest research on catfish. Most of the attendees were biologists from state game and fish agencies who were there to share findings from work in their state and to learn from biologists from other states.

“Almost all of our management biologists attended this conference, not because they had to, but because they wanted to learn about the latest science and techniques to make sure that we are on the cutting edge of catfish management,” Olive said.

The research and reports are helping to change the public’s long-held perception of catfish as merely bottom feeders, but longtime catfish anglers already know what a great meal they can provide, particularly flatheads, and many enjoy the sport of fishing for catfish just like bass and crappie anglers do.

Bass and crappie have long been randomly electro-fished in Arkansas lakes for density estimates and other studies that required large samples in a short amount of time. Bass and crappie are electro-fished with a higher frequency rate of pulse; because they don’t have scales, catfish are given a low-frequency current, Yung said. A large number of bass or crappie can be collected in a day; catfish are often deeper and don’t come up as frequently.

Catfish, particularly channel catfish, are also regularly sampled with hoop nets. While the particular low-frequency pulses now used for electrofishing catfish do not appear to stun channel catfish, they affect flatheads and blues. The biggest difference, though, between bass or crappie electrofishing and using the method for flatheads and blues is that these catfish species will disperse away from the shocking boat rather than surfacing and being netted right in front, the biologists say.

Hence, fishing for flatheads and blues requires a “chase” boat trailing the shocking boat, to help net catfish popping up sometimes as far as 50-75 yards away.

As Colton Dennis, one of the AGFC biologists in the sampling, described it: “It’s a rodeo out there.”