Research is under way at Toledo Bend Reservoir and Lake Fork where biologists Todd Driscoll and Jake Norman are following tagged bass.
The study is outside the realm of traditional fisheries research such as evaluations of length and bag limits, habitat enhancements, fish stockings, etcetera.Typical research looks at ways to improve fish quality to make fishing better. This study is geared more toward catch rates.

Helping anglers better understand bass movement and behavior to increase their angling efficiency is important.

The study calls for at least 20 fish to be collected on each lake. Ten are from 10 feet of water or less and 10 from 15 to 30 feet. When they were caught a transmitter was surgically implanted into the fish. They are easily identified by the long antenna that extends from their belly and a tag identifying them as a TPWD project fish.

The bass weigh 2 pounds and up and were released back into the depths they were originally caught and are being followed weekly.
At Fork the fish are in Birch Creek. They are in the somewhat larger Housen Bayou on Toledo Bend.

The biologists will be able to get information from anglers who catch them. They will also be using equipment like Garmin’s Livescope for underwater behavioral observations.

“Our transmitters should last 1½ to 2 years, and we will track fish for the duration of the transmitter lifespan,” Driscoll said.

“What initially led us into this study was the decline in bass fishing quality at Toledo Bend. No doubt, bass fishing was exceptional from 2011-2016. In fact, the Bassmaster organization ranked Toledo Bend Reservoir as the best black bass fishery in the world for both 2015 and 2016.

As expected, angling effort increased substantially during 2016-2018 following the national publicity the bass fishery received.
Beginning in 2018, complaints from bass anglers were frequent regarding declines in catch rates and lack of bass observed while idling and searching with high-end sonar on historically productive off-shore structure.

The biologist said fishermen blamed the reduction on harvest, and TPWD surveys did a show a decline in the population.

“However, we wondered if the high angling effort could be causing alterations in fish behavior and also be contributing to the fishery-related declines,” Driscoll said. The changes might include movement and habitat use in avoiding areas with boats and anglers.

The study could answer if fish move deep to avoid popular fishing areas and how much do they move with changing seasons. It will also look at engine and whether the noise new sonar equipment is changing fish habits.

“Anglers utilizing these GPS/sonar units, which are capable of displaying individual fish throughout the water column, frequently idle potentially productive structure, only fishing when fish are observed.
Potential effects of boat motor noise on largemouth bass behavior such as boat avoidance and catchabilty outside of the spawning season has not been studied,” Driscoll said.

At Lake Fork it is the perceived lack of bass moving into the slot in recent years.

After the drought in 2010-2011 everyone was excited when the lake filled back up about the new lake affect. Everyone had been catching small fish, and then fast-forward to when the lake filled back up and everyone expected there to be a big slug of fish in the slot, but they were not seeing them.

“Are they going to different areas and avoiding common areas, or not biting, or learning noises of boat motor and fleeing,” fishery biologist Jake Norman asked.

Driscoll said about half have the fish stayed where they were caught. The majority of the others moved up to a mile.

“One fish traveled over three miles from the south bank of Housen to the north bank in a 10-day period, and now is no longer located in Housen Bayou. Another fish initially captured on the south bank in the middle part of Housen moved two miles to the extreme back of Housen over two weeks. During the next two-week period, it moved 5.5 miles to the main-lake mouth of Housen,” Driscoll said.

Two tagged fish, a 3½ and an 8, have been caught by fishermen. At Fork, eight of the 23 bass tagged have already been caught by anglers. Two of them, one 14-inch fish and another 18-inch, have been caught twice.

Norman said only one of the Fork fish was holding tight to the bank while most of the others had moved to 10-feet of water. One had gone to deeper water and was integrated into a school.

“We have had a few take off from boat noise and others haven’t. There was one we could see on a stump in 6 to 7 feet of water. I took the boat around him, bumping off the stump, I dropped a worm in front of him and he didn’t show any reaction. There was another one and whenever got close he would haul off,” Norman said

Photo courtesy Lake Fork guide, Andrew Grills