Bits & Pieces: Hand‑Fishing, Habitat Projects, and Bass Handling Science

Field Research: Hand-Fishing and Flatheads

At The Third International Catfish Symposium held earlier this year, Texas Parks and Wildlife Department (TPWD) fishery biologist Kristopher Bodine presented results of recent TPWD research conducted by him and his colleagues evaluating the effects of hand-fishing on a flathead catfish population.*

The legalization of hand-fishing in Texas prompted the TPWD to evaluate potential impacts on population characteristics and dynamic rates of flathead catfish in Lake Palestine, Texas, Bodine reports. Results of that 2014 study indicated that the effects of hand-fishing would be minimal and the current regulation was sufficient to maintain the population.

Despite these findings, concerns of potential overharvest remained, and the TPWD conducted a follow-up evaluation in 2018 to determine if population characteristics such as relative abundance, size structure, or recruitment had changed since the previous evaluation in 2014. Flatheads were sampled with low-frequency electrofishing, following similar procedures used in the previous study.

The researchers found no statistically significant changes in any metric examined. Total catch rates and catch rates of trophy-sized flatheads were not different, length-frequency distributions were similar, no differences in size structure were observed, and recruitment patterns were similar. These findings suggest the addition of hand-fishing has indeed had no measurable effects on the flathead population in Lake Palestine.

*Bodine, K. A., R. A. Ott, D. L. Bennett, and J. D. Norman. 2020. Round 2: A four-year follow-up evaluation of a flathead catfish population exposed to hand fishing. Presentation abstract. The Third International Catfish Symposium, Little Rock, Arkansas.

Conservation in Action: Union Apprentices Help Improve Fisheries

A new generation of conservationists is helping improve America’s fisheries and expand fishing opportunities. Participants in labor union apprenticeship programs are a potent source of skilled volunteer labor in conservation, access, and outreach projects organized by the nonprofit Union Sportsmen’s Alliance (USA) Work Boots on the Ground (WBG) program.

Launched in 2010, the program has completed 237 projects in 31 states. The value of volunteer labor donated through WBG exceeds $1.5 million, while outreach events have engaged more than 13,000 participants, including over 6,000 in 2019. Apprentices—who spend the work week on the job earning a living while advancing their careers in a variety of skilled trades—play a vital role in these efforts, as do their seasoned coworkers.

The long list of USA conservation projects involving apprentices includes the rehabilitation of a large public fishing pier on Tennessee’s Lake Chickamauga; a kayak launch dock and other enhancement projects at John Heinz National Wildlife Refuge in Pennsylvania; and a public weigh-in pavilion at Smith Lake, Alabama. In Gloucester City, New Jersey, apprentices at the Plasterers’ and Cement Masons’ Local 592 training center are working with the Coastal Conservation Association-Maryland Chapter (CCA-MD) to enhance fisheries habitat in Chesapeake Bay by setting molds and pouring concrete to make “reef ball” habitat structures.

 Carpenters Local 318 apprentices in Pelham, Alabama, are building “spider block” fish attractors for Alabama’s Department of Conservation and Natural Resources. The attractors help replace natural cover, which deteriorates over time in a manmade reservoir, and quickly become home to aquatic plants, insects, baitfish, and crustaceans, providing forage for crappies, bass, and other gamefish. Attractors also are being constructed in Florence, Alabama, by Millwright and Machinery Erectors Local 1192 apprentices.

State fishery biologist Kyle Bolton said the volunteers’ efforts are a boon to Alabama’s aquatic habitat recovery program, which lacked the manpower to build the spider-blocks. “We and the angling public are very fortunate to have union members and the Union Sportsmen’s Alliance help us with that.” For details, visit unionsportsmen.org.

–Dan Johnson

Select Science: Bass Out of Water

Bass anglers often wince when they see pros, TV hosts, and other anglers hold bass out of water for minutes at a time to build tournament interest, for photographs, or to promote tackle. Recent studies provide a better evaluation of potential harm in doing this.

In an extensive study of blood chemistry, post-release mortality, and behavior of largemouth bass following release at tournaments, researchers found significant changes in blood chemistry as a result of stress, and that air-exposed fish took significantly longer to regain equilibrium or to leave release sites.* After five days, however, no released bass had died, even those exposed to air for as long as 13 minutes. This study was done at temperatures of 70°F or below so these findings do not suggest that largemouth bass can survive such treatment in warmer conditions. They do suggest that they can survive air exposure better than previously believed.

A parallel study at similar water temperatures simulated angling and subsequent air exposure of largemouth and smallmouth bass for up to 10 minutes.** Again, no mortality occurred. There were similar changes in blood chemistry for the two bass species, but the behavior and recovery time of smallmouths were more affected by both exercise and air exposure than largemouths.

An earlier experiment of oxygen deprivation in largemouth bass and smallmouth bass indicated that smallmouths suffered more stress symptoms than largemouths and are more sensitive to hypoxia in all ways.*** Reducing time out of water is a good handling practice, but not as critical as once thought, particularly for largemouths.

–Ralph Manns

*Thompson, L. A., and six co-authors. 2008. Physiology, behavior, and survival of angled and air-exposed largemouth bass. N. Am. J. Fish. Mgmt. 28:1059-1068.

**White, A. J., J. F., Schreer, and S. J. Cooke. 2008. Behavioral and physiological response of the congeneric largemouth (Micropterus salmoides) and smallmouth bass (Micropterus dolomieu) to various exercise and air exposure durations. Fish Res. 89:9-16.

***Furmisky, M, S. J. Cooke, C. D. Suski, Y. Wang, and B. L. Tufts. 2003. Respiratory and circulatory responses to hypoxia in largemouth bass and smallmouth bass: Implications for “live-release” angling tournaments. Trans. Am. Fish. Soc. 132:1065-1075.

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