Lakecaster Online

Responsibilities of the TPWD Inland Fisheries Division
By Todd Driscoll
Texas Parks and Wildlife Department


While interacting with the public, I often get the question "What do fisheries biologists actually do?" or even better yet "Boy, I bet it is nice to get to fish for a living?". Even though it was my love for fishing that led me into being a biologist, very little of my actual responsibilities involve a rod and reel. In Texas, the job of a fisheries biologist is very diverse, but most of our time is spent monitoring and managing fish populations in public waters.

The Inland Fisheries Division of Texas Parks and Wildlife Department (TPWD) in Jasper is responsible for fisheries management of public waters in 15 local counties. This equates to approximately 30 water bodies in the area, ranging from 1 acre city ponds to 185,000 acre Toledo Bend Reservoir. Reservoirs smaller than 500 acres are sampled as the need arises. The fish populations of our larger reservoirs are investigated at least once every four years, but most of these are sampled annually.

Fish population sampling techniques utilized by TPWD include electrofishing, trap netting, gill netting, and creel surveys. With the exception of creel surveys, fish sampling takes advantage of the cooler water temperatures associated with the fall and spring seasons when fish frequent shallow water areas and are active for greater periods during the day. Increased accessibility in shallow water enable biologists to maximize the amount of information obtained about the fishery, as many fish are collected in a short amount of time. In addition, cooler water temperatures reduce the handling stress associated with sampling.

Electrofishing targets species that occupy shallow shoreline areas during the fall and spring, such as black bass, sunfish, and baitfish (primarily shad). Electrofishing is conducted with a boat-mounted generator and pulsator (shock box). The shock box allows the biologist to control the amount of volts and amperes of electricity produced. The electricity is transferred to the water by fiberglass booms that extend 7-8 feet ahead of the boat. The area conducting electricity varies from lake to lake due to changing water conductivity, but is relatively small (approximately 10 feet wide and 4-8 feet deep). Two people on the front deck dipnet stunned fish, which are held in a livewell. A widely believed misconception is that electrofishing either kills fish, injures them, or prevents them from reproducing. However, if used wisely and properly (i.e., proper volt-amperage range), scientific studies have shown that electrofishing is a safe, effective way to collect fish and their long-term health is not affected.
Trap netting is conducted in the fall and targets cover-oriented fish (in our area, primarily crappie). Trap nets are placed close to shore. Each net consists of a 4 ft by 60 ft leader attached to a 3 ft by 5 ft frame. Fish mistake the trap net for cover. Fish come in contact with the leader, follow it to the frame, enter the frame through a throat or slit, and become entrapped. These nets are set in the evening and are retrieved the following morning.

Gill netting is conducted during the winter or spring and targets species that inhabit offshore areas (i.e., catfish, white bass, striped bass, and hybrid striped bass). Each net is constructed of monofilament mesh of different sizes and is 125 feet long and 8 feet deep. These nets are also allowed to fish overnight.

Creel (or angler) surveys are conducted year-round. Anglers are intercepted on the reservoir while fishing and are asked various questions about their trip. We determine what anglers are fishing for, what they catch, keep, and release, and how much money they spent on their fishing trip.
Data obtained from all these sampling techniques are analyzed and compared to information from past years. Detailed reports are written and current fish stockings and regulations (length limits and bag limits) are evaluated; if necessary, changes are made to improve the quality of the fishery resource. Contact us with questions or concerns about area fisheries by phone (409-384-9572) or email ( Good luck and good fishing!

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