Wednesday, March 22, 2017

New netting method leading changes in crappie management

LITTLE ROCK – Managing a fishery isn’t just stocking, creating habitat, fertilizing and adjusting harvest regulations. Biologists must have a true picture of what a population of a certain fish species in the lake looks like before they make changes, and they have to keep tabs on that population to determine if the management changes have the desired effect. Monitoring crappie populations can be a challenge. But a new method of netting may help biologists take a snapshot of the population when conditions are less than ideal.

Traditionally, biologists would set up trap nets to catch crappie as they moved toward shallow water for spawning or following shad in fall. Essentially, a large hoop net was placed in the water, and a long, fence-like runner was attached to cover a section of water and guide crappie to the net.

“Crappie bump into the runner and follow it to deeper water and the net, where we collect them,” said Jon Stein, fisheries biologist in the Arkansas Game and Fish Commission’s Beaver Lake regional office. “From there we are able to look at the size of different year classes of fish in the population to help make future management decisions.”

Trap-netting does have its shortcomings, however. To be effective, the net must be placed in fairly shallow water. But crappie spend the majority of their time in water deeper than trap nets can reach.

“Trap nets really hinder our ability to sample crappie in areas with steep shorelines like Beaver Lake,” Stein said. “The crappie stage and hold and spawn in deeper water than lowland lakes and reservoirs, and trap nets are ineffective tools for sampling at those depths.”

Always in search of a better mouse (or crappie) trap, biologists throughout the U.S. have dabbled with different ways to sample crappie populations and replace the trap net in challenging areas. Thanks to communication with Louisiana Department of Wildlife and Fisheries, AGFC fisheries biologists may have found the solution to trap-netting troubles.

Andy Yung, regional fisheries biologist at the AGFC’s Camden regional office, says Louisiana and Arkansas have a partnership meeting every other year to share information and learn from each other. During a recent meeting, Louisiana biologists gave a presentation on a new type of netting technique called a lead net, that can overcome the barriers of trap nets.

“In a lot of our lakes, we know that crappie are holding along creek channel swings and deep flats, but we can’t get to them through conventional means,” Yung said. “But these lead nets let us go to the crappie instead of waiting for a relatively brief window when they come up shallow.”

Yung says AGFC biologists have been experimenting with the new net style for a few years and comparing them alongside results of trap nets. In some cases, the trap nets would indicate very few fish in areas where biologists knew healthy crappie populations existed. Lead nets placed in deeper water in the same lakes yielded much better results.

“In some cases, lead nets were more than 40 times more successful,” Yung said. “That lets us spend less time running nets for crappie sampling and frees up more time to devote to habitat improvement and other fisheries efforts.”

Biologists in seven districts worked with the nets last fall and winter, collecting results on a monthly basis to determine the best times for sampling. Armed with this new information, Yung hopes to streamline the sampling process even further and use the new technique to make better decisions for crappie regulations and recommendations.

“Once we have fine-tuned the netting procedure, we’ll be able to have a standard sampling method across all our districts and really be able to compare the crappie fisheries around the state and develop trend data all of us can use,” Yung said.

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