Bits & Pieces: Dutch Super Pike and Walleye Revival Success

Notable Catches: Super Pike

Longtime In-Fisherman friend and European correspondent on pike Jan Eggers shared with us news of recent catches of giant European pike. Eggers reports that on October 13, 2019, his good friend Siegfried Schön caught the new Dutch record pike, a 138-cm (54.3-inch) toothy giant.

Eggers has seen hundreds of huge pike and more and more of them being caught in his own country of Holland. “I recently heard rumors about a 20-kg (44-pound) pike caught in Haringvliet Lake, but it was only 121 cm (47.6 inches) long, so I had some doubt,” he  says. “With the help of Raubfisch editor Thomas Wendt, I managed to get more information and a nice picture. It’s one of the nicest photos of a big pike I have seen in my life and I’d like to share it with In-Fisherman readers. It was caught by Enrico di Ventura from Minden in Germany on December 12, 2019. He was fishing a contest organized by Fisch und Fang magazine and fished from the bank of Haringvliet using a 14-cm (5.5-inch) Westin Shad Teez.”

–In-Fisherman with Jan Eggers

Science in Action: Creating a Void for Walleyes

The 2,000-acre Lake Metonga in Wisconsin’s north woods had been a successful walleye fishery for decades, but by the late 1990s, natural reproduction and walleye recruitment had slowed. To make matters worse, by 2004, the adult walleye population had sharply declined. Spawning habitat was excellent, but young fish, either stocked or natural, were not surviving to adulthood.

Mike Preul, fishery biologist for the Mole Lake Sokaogon Chippewa Community, has been involved with fisheries work on Lake Metonga for 20 years. The fish community in Lake Metonga had always included black bullheads, but now fishermen were telling him how often they were catching them. “While electrofishing one day and when the stunned fish floated to the surface, all we saw were yellow bellies,” he says. “That’s when I knew there was a problem.” The abundance of bullheads had become enormous.

“The theory was they were outcompeting walleyes for important forage at critical times when walleyes need an abundance of specific-sized food,” he says. “We knew walleye stocking wasn’t working, so the idea was that if we could create a kind of void, walleyes might rush in to fill it.”

Preul’s plan was to create conditions where walleyes could thrive, and that meant reducing the lake’s bullhead biomass. In spring 2008, he began an annual bullhead removal program on the lake. “At first we set fyke nets, but they weren’t catching sufficient numbers so we went to electrofishing.” By summer’s end, they’d removed 13,337 pounds of bullheads. All the fish were donated to the public, to food banks, and to nearby wildlife rehabilitation centers for the feeding of raptors. Into the newly created void, Preul stocked 5,000 large fingerling walleyes.

The next spring, another 6,216 pounds of bullheads were removed and over 2 million walleye fry were stocked. This time, substantial numbers of young walleyes survived from the two years of stocking and began to show up and be counted in fall recruitment surveys.

At first there seemed to be no end to the steady stream of electroshocked bullheads, but gradually fewer appeared and by 2012 the catch rate had dropped by 87 percent. During the same time, the abundance of walleye fingerlings steadily increased.

During 2011, there was a large year-class consisting of naturally reproduced fish, and stocking was no longer needed after 2012. With bullhead numbers reduced and in better balance with other fish, walleye production in Lake Metonga boomed. Eventually, both natural recruitment and adult walleye density reached historic highs. For Preul, this felt like the kind of victory that fishery managers rarely experience. “It was a lot of hard work, but the results have been amazing.”

Today, Preul spends only a few days each spring shocking for bullheads. It’s become maintenance now, like mowing his lawn. “As long as they don’t get out of control, I think we’re good,” he says. Walleye production has it’s up and down years but has remained reliable overall.

Preul’s biomanipulation method of removing bullheads to rebuild embattled walleye populations was successfully used on Patten Lake in nearby Florence County and worked well. When that lake’s over-abundant population of bullheads were severely reduced, the walleyes quickly came back in record-setting density.

Keeping walleye lakes healthy and productive is an ongoing issue, and all lakes face their own unique challenges. Overall, there likely aren’t a great number of walleye lakes affected by bullhead populations, but where such lakes exist, biomanipulation might be the answer.

–Eric Engbretson

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