Browsing by Author "Copeland, John R."

Now showing 1 - 12 of 12
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    Analysis of Grass Carp Dynamics to Optimize Hydrilla Control in an Appalachian Reservoir
    Weberg, Matthew Aaron (Virginia Tech, 2013-11-20)
    The primary objectives of this study were: 1) to evaluate the movement patterns, habitat use, and survival of triploid grass carp Ctenopharyngodon idella stocked to control hydrilla Hydrilla verticillata in a riverine reservoir (Claytor Lake, Virginia), 2) to examine grass carp population dynamics and hydrilla growth dynamics in Claytor Lake to guide long-term management efforts, and 3) to describe the aquatic plant community in the New River upstream of Claytor Lake to assess the potential for alterations due to potential grass carp herbivory. Only 3% of radio-tagged grass migrated out of Claytor Lake during the 2-year study. Grass carp movement patterns were significantly correlated with temperature-, weather-, and habitat-related variables. Grass carp selected specific cove, shoal and tributary habitats colonized by hydrilla. First-year survival of grass carp was 44% in 2011, and 25% in 2012. Grass carp growth rates were rapid in 2011, but declined in 2012 concurrent with significant reductions in hydrilla abundance. Based on grass carp population dynamics observed in Claytor Lake, our stocking model predicted that hydrilla could be controlled through 2030 by a grass carp standing stock of 5-6 metric tons. We documented 12 plant species in the New River upstream of Claytor Lake, 9 of which are preferred plants for grass carp suggesting that the plant community could be altered if migration rates increase. Grass carp can be effective for managing hydrilla in riverine reservoirs; however, continued monitoring of grass carp population dynamics, migration rates, and vegetation abundance could facilitate greater precision in management efforts.
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    Assessment of the Response of Piscivorous Sportfishes to the Establishment of Gizzard Shad in Claytor Lake, Virginia
    Bonds, Charles Craig (Virginia Tech, 2000-02-07)
    Gizzard shad were illegally introduced to Claytor Lake in the late 1980s and soon established a thriving population. This study assessed 1) the degree to which gizzard shad were utilized by piscivores (pelagic - striped bass Morone saxatilis, hybrid striped bass M. chrysops x M. saxatilis, and walleye Stizostedion vitreum, and three littoral black basses Micropterus spp.), 2) the availability of gizzard shad as potential prey as determined from age and growth analysis, and 3) the performance (growth rates, relative weight, and relative abundance) of piscivores before versus after gizzard shad establishment. Gizzard shad were more highly utilized by pelagic predators (especially striped bass and their hybrids) than black basses. Rapid growth of gizzard shad (mean back-calculated length at age-1 = 155 mm TL) meant that almost all morphologically available shad were age-0. The reliance on one edible age class of gizzard shad resulted in an unstable food supply as evidenced by much greater striped bass shad consumption in Summer 1998 (63 % by weight) when age-0 shad were more abundant than in Summer 1997 (7 % by weight). Striped bass was the only species to exhibit faster growth rates and mean relative weight (Wr) values in the 1990s versus pre-shad years. Walleye (except age-1) and black bass growth rates declined, and mean Wr values either remained consistent or declined. Largemouth bass and walleye were the only sportfish to show increases in relative abundance. Benefits of gizzard shad as a forage fish appear to be limited to striped bass and its hybrid species. It is possible that gizzard shad have had, directly or indirectly, an adverse impact on the black basses of Claytor Lake, but explanatory analysis of these relationships was beyond the scope of this study.
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    Back to the Future: The TIA Alliance as a Student Recruitment Tool
    Copeland, John R.; Smith, A. Kirk; Murphy, Brian R. (New River Symposium, 2019-04-12)
    Future natural resource management success depends on a workforce of well-trained, motivated, and relevant conservation professionals. Today’s high school students need to ‘rub elbows’ with inspirational natural resource managers doing field work culminating in meaningful experiences. Over the last six years, a James Madison High School club in Vienna, VA piloted a successful program. Urban students traveled to the Blue Ridge Mountains, conducted basic headwater drainage basin assessments and identified release sites for brook trout raised in Northern Virginia Classrooms. They were rewarded with fishing trips sponsored by a local Trout Unlimited (TU) chapter, potentially recruiting them as nontraditional anglers. In November 2018, TU joined the Izaak Walton League of America (IWLA) and the American Fisheries Society (AFS), creating the TIA Alliance, pledging to work together to expand the Madison club approach, potentially creating a nationwide program. One local area where this work may happen is the New River Valley, Virginia area, where the primary author is the Virginia Department of Game and Inland Fisheries fisheries biologist, an IWLA member and an active AFS member. Meaningful outdoor experiences will be enhanced by leaders providing quality mentorship to propel us ‘Back to the Future’ by creating new natural resource managers.
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    Characterizing a Hidden Fishery: Setline Fishing in the New River, Virginia
    Dickinson, Benjamin David (Virginia Tech, 2013-12-19)
    Catfishes Ictaluridae are important food fish that are harvested from the New River, Virginia by multiple methods, yet standard creel survey approaches do not accurately sample setline effort, a popular fishing gear for catfish. I characterized the New River setline fishery by estimating setline effort and catch rates of catfish and by-catch in 2011, and by investigating the attitudes and opinions of setline users during 2012. Setline effort was highest during June-August, and declined significantly by mid-September. Several dedicated setline users accounted for a significant portion of total setline effort. Experimental setlines baited with live minnows Cyprinidae proved to be an effective method for catching catfish but caught few walleye Sander vitreus, smallmouth bass Micropterus dolomieu, and muskellunge Esox masquinongy. Estimated by-catch of these species by setline fishers is small compared to catch by hook-and-line anglers, though walleye experienced high setline hooking mortality, and catch rates increased in autumn months. Setlines appear to be part of a larger "way of life" for some rural individuals, who may also hunt, trap, and garden as part of activities to supplement their diet or income. New River setline fishers strongly believe that setline fishing has declined significantly in the New River Valley due to improving socioeconomic status of the region, changing recreational values (such as focus on catch-and-release fishing and paddle sports), increasing recreational traffic and law enforcement presence, and decreasing participation in setline fishing by younger generation.
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    Comparative Ecology of Juvenile Striped Bass and Juvenile Hybrid Striped Bass in Claytor Lake, Virginia
    Rash, Jacob Michael (Virginia Tech, 2003-12-08)
    Since the introduction of hybrid striped bass M. chrysops x M. saxatilis to Claytor Lake, Virginia in 1993, relative abundance of striped bass Morone saxatilis has dropped disproportionately to stocking density. Potentially deleterious interactions between the two fishes that may limit recruitment to age 1 were considered in terms of trophic relationships, physiological indices of health, overwinter survival, and post-stocking predation. Both fishes preferred habitat types characterized by structure-free sand or gravel substrates, but striped bass and hybrid striped bass did not exhibit significant diet overlap during the growing season. At a total length of approximately 120 mm, the juvenile moronids shifted from a mixed diet of zooplankton and invertebrates to a diet comprised primarily of age-0 fishes. However, after becoming piscivorous striped bass preyed primarily upon age-0 alewife Alosa pseudoharengus, while hybrid striped bass consumed age-0 sunfishes. Striped bass achieved mean total lengths of 229 and 173 mm by the end of the growing season in 2001 and 2002, respectively. Stocked into the reservoir three months later than striped bass, mean hybrid striped bass total lengths reached 133 mm at the end of the 2002 growing season. Condition factor, relative weight, and lipid index values were low, but nearly equivalent for both striped bass and hybrid striped bass throughout this study. Overwinter starvation of smaller (< 150 mm total length) striped bass was observed for the 2001-2002 sampling season. Predation upon stocked fingerlings was not considered significant in limiting juvenile survival; only three fingerling moronids were found in the examination of stomach contents of 200 potential predators captured near stocking sites. It does not appear that resource competition with hybrid striped bass during the growing season resulted in increased overwinter mortality of juvenile striped bass. Delayed stocking of hybrid striped bass lessens the potential for trophic competition between striped bass and hybrid striped bass at this early life-stage.
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    Habitat Use, Movements, and Exploitation of Striped Bass and Hybrid Striped Bass in Claytor Lake, Virginia
    Kilpatrick, John Matthews (Virginia Tech, 2004-04-26)
    The comparative performance of striped bass Morone saxatilis (STB) and hybrid striped bass M. saxatilis x M. chrysops (HSB) was evaluated in Claytor Lake, Virginia. This study assessed: 1) habitat use versus habitat availability for STB and HSB; 2) seasonal movement patterns, movement rates, and emigration rates of STB and HSB; and 3) angler catch rates of STB and HSB in Claytor Lake. In general, STB and HSB used similar habitats throughout this study. However, HSB used warmer (2-3'aC) water than STB during spring of 2001 and 2002. During the summer months, fish selected the coolest water temperature available that contained adequate (> 2.0 mg/L) dissolved oxygen. Striped bass habitat was more degraded than HSB habitat during summer stratification of both years. Both moronids exhibited similar seasonal movement patterns. Upstream spawning migrations took place in March at 9-10'aC. Summer habitat was restricted to the lower 1/3 of Claytor Lake, whereas fish used the entire reservoir during other seasons. Minimum daily movement rates were similar between species and seasons (0.2-0.5 km/h). Hourly movement rates were also similar between species (0.2-0.3 km/h). One tagged fish from the reservoir was recovered below the dam, suggesting low rates of emigration. Poor tag return rates by anglers limited confidence in estimation of exploitation rates. However, based on estimated natural and handling mortality rates and tag-reporting rates, estimated annual fishing mortality was 26% for STB and 14% for HSB, lower than rates found in Virginia′s Lake Gaston and Smith Mountain Lake.
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    Managing Muskellunge in the New River, Virginia: Effective Regulations and Predation on Smallmouth Bass
    Doss, Sasha Stevely (Virginia Tech, 2017-04-21)
    Potential predation between fishes of recreational interest has incited many bitter conflicts between angler groups. Large predators, such as esocids, are often at the center of these conflicts because of their capacity to alter fish populations. Such a conflict certainly exists between the Muskellunge Esox masquinongy and Smallmouth Bass Micropterus dolomieu fisheries of the New River, Virginia. Following the institution of a 42-in minimum-length limit (MLL) on Muskellunge, bass anglers feared that increased Muskellunge abundance might be negatively affecting Smallmouth Bass via increased predation. In order to ascertain the impacts of the 42-in MLL, I estimated the demographics, abundance, and food habits of Muskellunge combined with bioenergetics modeling to assess changes (i) in the quality of the Muskellunge fishery and (ii) in Muskellunge predation on Smallmouth Bass. Additionally, given the likelihood of future regulations to incite similar concerns from bass anglers, I modeled alternative length-limit regulations (iii) to assess their potential to improve fishery quality, thereby laying the groundwork for managers to address angler concerns before they arise. I found substantial increases in population size structure and in average adult density of Muskellunge since the institution of the 42-in MLL, but bioenergetics modeling did not indicate a notable increase in the consumption of Smallmouth Bass. I also found that high MLLs (e.g., 48-in) were likely to promote the largest increases in trophy production of Muskellunge compared to low MLLs or protected-slot limits (PSLs). This study suggests that the current Muskellunge population likely plays a small role in shaping Smallmouth Bass population dynamics and production in the New River; and lays the groundwork for predicting how the impact of Muskellunge on Smallmouth Bass might change under alternative regulations.
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    Marker-assisted restoration of native New River walleye
    Harris, Sheila; Copeland, John R.; Palmer, George Caleb; Hallerman, Eric M. (New River Symposium, 2017-05-16)
    Walleye (Sander vitreus) is an important game fish in the Upper New River, with March and April walleye fishing effort from Buck Dam to Claytor Lake increasing from 49 to 66% of total fishing effort between 2007 and 2016. Population genetics research has shown the persistence of the presumptive native stock in the New River. Although the river had been stocked from sources in the Great Lakes region, unique genetic markers (microsatellite alleles at the Svi17 and Svi33 loci and mitochondrial restriction fragment haplotype 43) were observed, indicating that the native stock had persisted. Native walleye is of conservation interest due to their adaptation to a southern river system and their large ultimate size. Genetic marker-assisted selection of presumptive native walleye has been carried out since 2000, and has led to an increase in native allele frequencies from 16% and 14% in the 1997 and 1999 genetic surveys to 46% and 58% in the 2004 and 2006 surveys. Walleye abundance and angler catch increased over this time period in relation to annual stocking success. Ongoing work is aimed at deepening our understanding of population genetics and natural history of walleye in the southeast.
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    Mucking Around with Aquatic Plants in Claytor Lake: What Have We Learned?
    Copeland, John R.; Blankenship, Joan; Walters, Laura (New River Symposium, 2019-04-12)
    Aquatic vegetation is an important habitat component in southern reservoirs, but native vegetation in these important fisheries is often displaced by unwanted non-native species, creating less desirable habitat conditions. Claytor Lake, a 1,764 ha mainstem reservoir of the New River in Pulaski County, Virginia, contained a number of native aquatic plants historically, but was colonized by hydrilla (Hydrilla verticillata) in the early 2000’s. Hydrilla control during the early 2010’s using triploid grass carp (Ptenopharyngodon idella) resulted in hydrilla suppression and the loss of remaining native aquatic vegetation beds in Claytor Lake. While the management plan guiding hydrilla control discussed native vegetation restoration as an outcome, additional partnerships were created and grant funding was awarded to make the dream a reality. After 5 years of native vegetation restoration work on this reservoir, we share our story as an example of what can be accomplished when diverse constituencies converge in natural resource management. Potential impacts of the Claytor Lake triploid grass carp stocking on native aquatic plants in the Upper New River will be discussed, as well as spin-off effects on the aquatic integrity of the New River, as well as the potential for native plant reintroduction in the Upper New River.
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    Trophic interactions between larval gizzard shad and resident zooplanktivores in Claytor Lake, Virginia
    Small, Ron (Virginia Tech, 2002-09-20)
    Anglers unlawfully introduced gizzard shad Dorosoma cepedianum into Claytor Lake, Virginia in the late 1980s, apparently with the intention of improving the sportfishery by adding an additional clupeid prey resource. This study examined the trophic interactions between larval shad and resident zooplanktivorous fishes, in an attempt to discover the potential for trophic competition and negative impacts to these fish species. Ichthyoplankton sampling in 1997 and 1998 showed that peak abundances of larval shad overlapped temporally and spatially with both larval Lepomis spp. and larval alewife Alosa pseudoharengus. Peak larval shad density (0.04-0.06 fish/m3) was two to three orders of magnitude less than that reported from other reservoir systems, slightly less than that of larval alewife in Claytor Lake (0.05-0.07 fish/m3), and significantly less than that of larval Lepomis spp. in Claytor Lake (0.28-0.51 fish/m3). Diet overlap values indicated potential resource overlap among all three larval taxa. Diet of larval shad did not overlap with that of either age-0 Micropterus spp. or adult alewife. All species of limnetic larvae examined showed feeding preferences for Diaphanosoma and copepod nauplii. Crustacean zooplankton densities did not respond negatively to peak larval fish abundances, and never dropped below 250-400 organisms/L. In Claytor Lake, the impact of trophic competition with larval gizzard shad on other zooplanktivores currently appears to be minimized by low densities of larval shad and abundant crustacean zooplankton.
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    Virginia master naturalist basic training course Ichthyology
    (Virginia Cooperative Extension, 2019)
    Diversity and distribution of fishes and their role in the Virginia ecosystem. Characteristics used to identify fish and fish taxonomy. Biology and natural history of fishes and how this relates to environmental factors. Threats and issues related to fish in Virginia. Fishery management
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    Virginia Master Naturalist Basic Training Course. Ichthyology
    Averett, Adrienne; Bandolin, Larry; Bugas, Paul E., Jr.; Copeland, John R.; Devlin, George; Duncan, Michael Bennett; Gowan, Charles; Herrmann, Scott; Kirk, Dawn; Murphy, Brian R. (Virginia Cooperative Extension, 2013-03-21)
    Describes the diversity and distribution of fishes in Virginia and their role in Virginia ecosystems, key characteristics used to identify fish and basic fish taxonomy, the biology and natural history of fishes, threats and issues relating to fish in Virginia, rare of special species that indicate habitat quality, appropriate methods for studying fish, and basic principles of fisheries management.