In 1985 harvest regulations on crappies Pomoxis spp. were changed from no limits to a 254‐mm minimum‐length and a 25‐fish daily bag limit at three Texas reservoirs. The objective was to increase the proportion and relative abundance of large crappies and thereby increase harvest rate, yield, and mean weight of harvested fish. Changes in the stock structure and harvest of white crappies P. annularis were monitored after the limits were imposed. The proportion of stock‐size (≥127 mm) white crappies that were of preferred size (≥254 mm) (RSD‐P) increased significantly at Lake Palestine and Lake Meredith (where growth overfishing had occurred), and remained at acceptable levels at Lake Whitney (where growth overfishing did not occur). Mean weight of harvested white crappies increased at one of the two sites where RSD‐P increased. Total yield (kg/ hectare) increased at all three reservoirs. Few anglers harvested 25 white crappies/d either before or after the limits were imposed. Results indicate minimum‐length limits can alleviate growth overfishing. Where growth overfishing is not occurring, length limits can maintain yield in spite of increased pressure. In addition, a minimum‐length limit may moderate or eliminate the variability or cyclicity inherent in crappie fisheries. By preventing harvest of small crappies, which are attractive to anglers only when abundance of larger fish is low, minimum‐length limits may help maintain a more stable supply of preferred‐size crappies.

The recent legalization of hand fishing in Texas has prompted concern for the potential overharvest of catfish. Large (≥600 mm) Flathead Catfish Pylodictis olivaris are thought to be vulnerable to this angling method, and the potential effects of selectively harvesting large fish are not well understood. Therefore, in April 2013 we quantified size‐ and gear‐specific exploitation of Flathead Catfish in Lake Palestine, Texas, by tagging 255 fish within three size‐groups (457–599, 600–761, and ≥762 mm) with reward tags. We also quantified abundance, mortality (total and natural), and growth to simulate the effects of exploitation (particularly of size‐groups targeted by hand fishing) on the Flathead Catfish population. Exploitation was low (3.2%), and size‐specific harvest was less than 5% for all size‐groups. Trotlines and hand fishing accounted for 100% of observed harvest (50% for each gear). Our models indicated that maximum sustainable yield would be achieved at 10% to 15% exploitation. Recruitment overfishing and growth overfishing were evident at about 15% to 20% exploitation. When we simulated increased exploitation by hand fishers only (achieved by only increasing exploitation of fish ≥762 mm), recruitment overfishing was not evident until 55% exploitation, and growth overfishing never occurred. These results indicate that the current low harvest by hand fishers will have little impact on yield or size structure of Flathead Catfish, and, in most scenarios, the current 457‐mm minimum length limit can maintain a sustainable fishery. Undoubtedly, any additional harvest of trophy fish (≥762 mm) will reduce trophy fish abundance; however, exploitation of trophy fish (alone) would need to exceed 55% before populations become unsustainable.Received February 9, 2016; accepted June 29, 2016 Published online November 10, 2016

The routine assessment and monitoring of aquatic habitat characteristics, such as submerged aquatic vegetation (SAV), is a fundamental tool in fisheries management. The relative low cost and availability of recreation‐grade side‐scan sonar (SSS) systems has made capturing high‐resolution (<10 cm) underwater imagery a practical and viable tool for improving these assessments. Using Humminbird SSS and a boat‐mounted transducer, we determined our ability to produce classified maps of SAV within three reservoirs in Texas. Sonar recordings of photic zone habitat were collected and processed into georeferenced mosaic images by using SonarTRX SSS software for use in geographical information systems (GISs). The resulting raster images were interpreted to identify and map SAV, and a classification scheme was developed. Random‐point data was also used to develop a traditional error matrix and an accuracy assessment for each classified map. In the three reservoirs, 485 ha were classified, including 298 ha of SAV. The area estimates for 11 of 12 classes fell within the 95% CIs that were estimated from concurrent random‐point surveys. Overall classification accuracy ranged from 78% to 88% for the three reservoirs. The methods that were developed demonstrate an accurate procedure for calculating SAV coverage and producing a high‐quality map product for distribution to stakeholders.

The 2011 legalization of hand fishing for catfishes in Texas prompted the Texas Parks and Wildlife Department (TPWD) to conduct a model‐based evaluation of the potential impacts on size structure and dynamic rates of the Flathead Catfish Pylodictis olivaris in Lake Palestine, Texas. Results predicted that impacts by hand fishers would be minimal and that the preexisting harvest regulation of 5 fish/d with a 457‐mm minimum length limit was sufficient to maintain fishery quality. Despite these findings, TPWD fisheries staff continued to have concerns about potential overharvest. In response to this concern, we conducted a follow‐up evaluation in April 2018 to determine whether population characteristics, such as relative abundance or size‐related metrics, had changed since the previous evaluation in 2014. Sampling was conducted with low‐frequency electrofishing via similar procedures used in the previous study. We found no significant changes in any metric examined. Total catch rates and the catch rates of trophy‐sized fish were not significantly different. Length frequency distributions were also similar, and no differences were observed in mean TL or any proportional size distribution measurement. These findings corroborate those from the 2014 study and also suggest that hand fishing has had no measurable effect on Flathead Catfish abundance or size‐related metrics in Lake Palestine from 2014 through 2018.

We evaluated the efficacy of trap nets fitted with a batteryoperated, submersible light in the net mouth in increasing the catch rates of white crappies Pomoxis annularis by comparing the catch rate and size structure of white crappies collected by these nets with those of fish collected by standard (i.e., unlighted) trap nets in six Texas reservoirs. The catch rates of standard (mean = 16.3/netnight) and lighted trap nets (12.1/net-night) did not differ significantly. We found no significant difference in the catch of stock-size white crappies (≥130 mm total length [TL]) by standard (12.7 fish/net-night) versus lighted trap nets (9.9 fish/net-night); however, significantly fewer preferred sizes (≥250 mm TL) were taken by lighted (1.9 fish/net-night) than by standard sets (2.9 fish/netnight). The length-frequency distributions of the white crappies collected by each trap net treatment were similar and did not significantly differ in four of the five lakes tested. Our results suggest that trap nets fitted with artificial lights in the net mouth do not effectively increase catch rates for white crappies and may favor the collection of smaller size-classes than standard trap nets.