This study assessed exploitation and evaluated management options for walleye, Sander vitreus (Mitchill), in Glen Elder Reservoir, Kansas. A total of 2429 walleye varying from 240 to 687 mm was tagged with Carlin dangler tags during 2000-2003. After correcting for tag loss and non-reporting, exploitation of walleye was estimated as 68.3%. More than 85% of the tagged walleye were harvested during April to June and 75% were harvested within 6 months after tagging. A Beverton-Holt yield-per-recruit model was used to evaluate six minimum length limits varying from 250 to 610 mm. Given current exploitation rates, population demographics and harvest regulations (381-mm minimum length limit), the walleye population is probably experiencing recruitment overfishing. Model results suggested that a 610-mm minimum length limit would be required to prevent growth overfishing and a 533-mm or longer minimum length limit would prevent recruitment overfishing. K E Y W O R D S : growth overfishing, partial-year minimum length limit, recruitment overfishing.

Saugeyes (Walleye Sander vitreus × Sauger S. canadensis) are stocked by natural resource agencies to provide angling opportunities and biological control of abundant small‐bodied fishes. Concern has been raised regarding the stocking of fertile diploid saugeyes in Kansas waters due to potential genetic introgression into wild parental stocks and unintended natural reproduction in ecologically sensitive systems. As such, triploid saugeyes have been stocked in Kansas since 2006 but with minimal evaluation. We compared relative recruitment, growth, and condition of diploid and triploid saugeyes after stocking equal numbers of 3–6‐d‐old diploid and triploid saugeye fry in four Kansas reservoirs for 3 years. Saugeyes were sampled from study reservoirs annually (2014–2016) with autumn night electrofishing, and flow cytometry was used to determine the ploidy of sampled fish. Throughout the study, diploid fish composed approximately 80% of sampled saugeyes. Age‐0 year‐classes consisted of 67–100% diploid fish, depending on the study reservoir and sampling year. As saugeyes reached ages 1 and 2, similar patterns in relative recruitment were indicated, with diploids outnumbering triploids by approximately four times. At individual study impoundments, diploid saugeyes composed 75–87% of fish from all study year‐classes. Mean length of diploid saugeyes was generally greater than that of triploids at age 0, whereas mean lengths at ages 1 and 2 were similar for the two groups. Our results indicate that diploid saugeye fry represent a more efficient stocking option than triploid fry and that managers should carefully balance consideration of the relative recruitment of diploid and triploid saugeyes with potential genetic integration between Sander spp. when conducting supplemental stockings.

The saugeye (walleye [Sander vitreus] x sauger [S. canadensis]) has been stocked across the midwestern United States to provide large-bodied percid fisheries in systems that are unsuitable for walleye or sauger. Although the saugeye often exhibits faster growth than sauger and better stocking survival than walleye in warm, turbid reservoirs, a common justification for stocking saugeye is the belief that it is more vulnerable to angling than the walleye, particularly during summer. Direct comparisons of walleye and saugeye harvest have not been conducted, therefore, patterns of walleye and saugeye harvest were evaluated in Glen Elder Reservoir, Kansas. We tagged 1,438 walleyes and 289 saugeyes with Carlin dangler tags during [2001][2002][2003]. The percentage of tags returned was nearly identical between taxa; 44.6% of the tagged walleyes and 46.0% of the tagged saugeyes were harvested. Similarly, 8 1

The CPUE (fish/6,000 m3) of Silver Carp Hypophthalmichthys molitrix obtained by using an electrified butterfly trawl (paupier) was evaluated among various temporal (time of day and season) and spatial (location, habitat [shoreline and open water], and water depth) factors that are likely to be influential in large lentic habitats. The paupier sampled the upper water column (1.5 m) in three locations (Kentucky Lake, Kentucky [two embayments]; Lake Barkley, Kentucky [forebay]; and upper Illinois River, Illinois [two backwaters]). Sampling commenced 2 h prior to sunset and continued into the night, not exceeding 5 h beyond sunset. Model selection showed that all temporal and spatial factors were important. Post hoc analysis revealed that Silver Carp CPUE was higher at night (beyond 1 h after sunset), in shoreline habitat, and in water generally no deeper than 5 m. Seasonal variation in CPUE occurred, but in general the CPUE was high in the fall for all locations. Considering these results for management application, we estimated the sampling effort required to reach precise CPUE and adequately assess size structure (125 stock‐length fish) in shoreline habitat at night. These sampling objectives were attainable in the spring and fall seasons for all locations (4–31 deployments) but were more variable in summer. We recommend consideration of the paupier as a standard method to sample Silver Carp in large lentic habitats by using the guidelines provided herein (i.e., sampling of the shoreline beyond 1 h after sunset during the fall season). An important next step to strengthen this method is to validate CPUE as an index of density.

Silver Carp Hypophthalmichthys molitrix are elusive fish that can be difficult to capture with conventional management tools. New tools must be developed to help increase the capture of Silver Carp, thereby improving the understanding and management of the species. An electrified dozer trawl was developed in an attempt to increase the capture of Silver Carp while reducing the amount of sampling effort needed to successfully assess a population and inform management actions. We compared Silver Carp catch rates, sample run time, and Silver Carp length frequency distributions from the electrified dozer trawl with those from conventional boat electrofishing. Silver Carp capture was greater and sample time was shorter for the electrified dozer trawl compared to conventional boat electrofishing. Length frequency distributions were similar between gears. The electrified dozer trawl can shorten sample run times and potentially improve Silver Carp capture, thus facilitating management. Use of the electrified dozer trawl should be expanded beyond Missouri River tributaries to further understand the gear's potential for sampling Silver Carp in a diverse array of environments.