Diet of and Prey Availability for Reintroduced Juvenile Lake Sturgeon (Acipenser Fulvescens) in Ft. Loudoun Reservoir, Tennessee PDF Download
Are you looking for read ebook online? Search for your book and save it on your Kindle device, PC, phones or tablets. Download Diet of and Prey Availability for Reintroduced Juvenile Lake Sturgeon (Acipenser Fulvescens) in Ft. Loudoun Reservoir, Tennessee PDF full book. Access full book title Diet of and Prey Availability for Reintroduced Juvenile Lake Sturgeon (Acipenser Fulvescens) in Ft. Loudoun Reservoir, Tennessee by Todd Michael Amacker. Download full books in PDF and EPUB format.
Author: Todd Michael Amacker
Publisher:
ISBN:
Category : Lake sturgeons
Languages : en
Pages : 63
Get Book Here
Book Description
After fifteen years of reintroducing juvenile Lake Sturgeon (Acipenser fulvescens) in the Upper Tennessee River Basin, fisheries biologists are researching basic ecological traits of subsistent organisms. I set out to seasonally assess whether Lake Sturgeon forage opportunistically or selectively in Ft. Loudoun Reservoir. After anesthetizing individual juvenile Lake Sturgeon caught on trotlines in a 13-km reach of the reservoir, I used colonic flush and gastric lavage techniques to describe diets quantitatively. I also used two methods to assess available prey items in the study area by 1) taking systematic benthic grabs along several transects across the width of the reservoir and 2) opportunistically deploying rock cages filled with various types of hard substrate to assess potential prey that colonize hard surfaces. After identifying macroinvertebrates to their lowest taxonomic level, the foraging modes of Lake Sturgeon were determined by comparing the relative abundances of invertebrate taxa in the gut contents of each sturgeon specimen to the relative abundances of the same invertebrate taxa collected from the resource base. Indices that quantify resource overlap or segregation were used to determine how selective Lake Sturgeon in Ft. Loudoun Reservoir were with respect to diet. I conclude that Lake Sturgeon in Ft. Loudoun Reservoir forage primarily in the benthos where they utilize a relatively narrow niche consisting mostly of larval chironomids, some genera of which they prey upon selectively. Comprehensive conclusions regarding Lake Sturgeon foraging patterns, niche utilization, and selective predation can only be drawn if researchers a) determine the seasonally available prey base by identifying macroinvertebrates to genus/species level b) analyze diet composition (again, identifying prey items to genus/species) from both stomach and intestinal contents and c) use a combination of indices that determine how selective, if at all, Lake Sturgeon are when utilizing the available prey base.
Author: Todd Michael Amacker
Publisher:
ISBN:
Category : Lake sturgeons
Languages : en
Pages : 63
Get Book Here
Book Description
After fifteen years of reintroducing juvenile Lake Sturgeon (Acipenser fulvescens) in the Upper Tennessee River Basin, fisheries biologists are researching basic ecological traits of subsistent organisms. I set out to seasonally assess whether Lake Sturgeon forage opportunistically or selectively in Ft. Loudoun Reservoir. After anesthetizing individual juvenile Lake Sturgeon caught on trotlines in a 13-km reach of the reservoir, I used colonic flush and gastric lavage techniques to describe diets quantitatively. I also used two methods to assess available prey items in the study area by 1) taking systematic benthic grabs along several transects across the width of the reservoir and 2) opportunistically deploying rock cages filled with various types of hard substrate to assess potential prey that colonize hard surfaces. After identifying macroinvertebrates to their lowest taxonomic level, the foraging modes of Lake Sturgeon were determined by comparing the relative abundances of invertebrate taxa in the gut contents of each sturgeon specimen to the relative abundances of the same invertebrate taxa collected from the resource base. Indices that quantify resource overlap or segregation were used to determine how selective Lake Sturgeon in Ft. Loudoun Reservoir were with respect to diet. I conclude that Lake Sturgeon in Ft. Loudoun Reservoir forage primarily in the benthos where they utilize a relatively narrow niche consisting mostly of larval chironomids, some genera of which they prey upon selectively. Comprehensive conclusions regarding Lake Sturgeon foraging patterns, niche utilization, and selective predation can only be drawn if researchers a) determine the seasonally available prey base by identifying macroinvertebrates to genus/species level b) analyze diet composition (again, identifying prey items to genus/species) from both stomach and intestinal contents and c) use a combination of indices that determine how selective, if at all, Lake Sturgeon are when utilizing the available prey base.
Author:
Publisher:
ISBN:
Category : Fishes
Languages : en
Pages : 105
Get Book Here
Book Description
The lake sturgeon (Acipenser fulvescens) historically occurred throughout the Tennessee River system but was extirpated by the 1960's due to over-consumption, and habitat destruction and alteration from pollution, and dam construction. In response to improvements in water quality and other improvements made by the Tennessee Valley Authority (TVA), a multi-agency partnership was formed to reintroduce lake sturgeon in the Upper Tennessee River system. The initial re-introduction occurred in 2000, and to date over 45,000 fish from multiple age classes have been released. Little is known about the behavior of the hatchery-reared juvenile lake sturgeon in this system. A biotelemetry study of hatchery-reared juvenile lake sturgeon released into the French Broad River was conducted to determine if patterns exist in their dispersal, persistence, and use of the upper Tennessee River system. Radio transmitters were surgically implanted into 20 juvenile lake sturgeon that were released into the French Broad River in the fall of 2004. Persistence within the system was 50% for the 90-day battery life of the transmitters. The mean dispersal from the release site was 10.6 river miles (sd=7.9). The mean linear range was 7.3 river miles and ranged from 1.0-20.3 total river miles. Directional movement was correlated with changes in flow; distances traveled, dispersal distances, and depth selection exhibited slight linear relationships to daily temperatures and mean daily discharges from an upstream hydroelectric dam. Juvenile lake sturgeon exhibited aggregation and used core areas in the French Broad River, a tributary to the Tennessee River. Areas of aggregation and core use were located within the bend of the river, with sand substrate, and corresponding mean depth of approximately 6 meters.
Author: Daniel James Walker
Publisher:
ISBN:
Category : Lake sturgeon
Languages : en
Pages : 141
Get Book Here
Book Description
The Lake Sturgeon Acipenser fulvescens historically occurred throughout the United States and Canada. However, due to widespread overfishing and habitat loss it was extirpated from much of its range, especially in the lower latitudes. Since the year 2000, fisheries managers have been working to restore this species to the Tennessee and Cumberland Rivers where it has been extirpated since c. 1961. This reintroduction is comprised of annual releases of young-of-the-year Lake Sturgeon reared in head-start aquaculture facilities around the Southeastern U.S., and annual monitoring efforts that track the spread and growth of reintroduced individuals. In 2015, a management plan guiding this reintroduction effort was drafted which included a variety of research needs to assist with and improve the ongoing restoration of this species. Two of these research needs are an assessment of habitats available to and occupied by Lake Sturgeon in the Upper Tennessee River, and a quantitative assessment of population size.In this dissertation, I explain how I addressed these two research needs, and based on the results, I offer management recommendations for the continued success of Lake Sturgeon recovery in the Southeastern U.S. I characterized two important types of habitat relevant to different life stages of the species: spawning habitat and summer holding areas. I also used 5 years of mark-recapture data to generate the first quantitative assessments of population density and size-specific survival. My results indicate that there is ample suitable spawning substrate within the tailwaters I surveyed. I collected detailed measurements of various physical habitat variables from an area suspected to be important summer refugia for this species and describe in detail the physical habitat characteristics of this important area of habitat. I used a population model to evaluate the mark-recapture data, and found that while Lake Sturgeon are persisting in the Upper Tennessee River, many fall into the slowest-growth category. Finally, I used simulations to show that without natural recruitment, current stocking rates are unlikely to reach stated population goals through stocking alone. The information I provide here will be instrumental in aiding the adaptive management of this population.
Author: Martin Jay Brown
Publisher:
ISBN:
Category : Fishes
Languages : en
Pages : 80
Get Book Here
Book Description
Author: Stephen Slongo
Publisher:
ISBN:
Category : Forest management
Languages : en
Pages : 52
Get Book Here
Book Description
"The habitat preferences of Lake Sturgeon (Acipenser fulvescens) were compared by literature review of 24 study areas across three major North American watersheds in five categories: depth, substrate, current, home range size and preferred prey items. Comparisons focused on differences in adult and juvenile habitat preferences. Patterns and trends were used to test evidence of a size structure in spatial distribution by life stage. Juveniles are encountered in deeper water more often than adults are. Both adults and juveniles exhibit similar prey and substrate preferences. Adults and juveniles both prefer areas with low to medium current velocities with some evidence that adults prefer slightly higher currents. Home ranges of adults are much greater than home ranges of juveniles. These patterns are confounded by the wide variation in preferences in all categories for both adults and juveniles. Studies comparing both adults and juveniles in the same area provide stronger support for size structured separation in Lake Sturgeon. These types of studies are most effective for illustrating site-specific variation in habitat use, as well as adult and juvenile habitat differences."-- abstract.
Author: J. Marty Holtgren
Publisher:
ISBN:
Category :
Languages : en
Pages :
Get Book Here
Book Description
Author: Forrest Bjornson
Publisher:
ISBN:
Category :
Languages : en
Pages : 0
Get Book Here
Book Description
Hatchery supplementation of declining fish populations is often used as part of population enhancement and recovery programs. However, fish produced from the sterile hatchery environment often develop maladaptive behavioural phenotypes that can result in high post-release mortality. Lake Sturgeon (Acipenser fulvescens) are reared in hatcheries for conservation purposes, yet little is known of their early life behaviour. Here, I investigate the influence of body size on resource holding potential (RHP) and boldness, and the potential for predator conditioning to influence risk assessment and the physiology of juvenile Lake Sturgeon. Results indicate condition factor, rather than body size, increases RHP and bold responses in juvenile Lake Sturgeon. Additionally, conditioning did not influence risk assessment behaviour. However, foraging remained paramount, and chronic conditioning had an effect on whole body cortisol concentrations, suggesting a sensitive stress response. These results indicate the complex early life behaviour of juvenile Lake Sturgeon, both behaviourally and physiologically.
Author: James S. Diana
Publisher:
ISBN:
Category : Lake sturgeon
Languages : en
Pages : 18
Get Book Here
Book Description
Author: Ramon Martin
Publisher:
ISBN:
Category : Sturgeons
Languages : en
Pages : 136
Get Book Here
Book Description
Author: Earl L. Bozeman
Publisher:
ISBN:
Category : Alewife
Languages : en
Pages : 28
Get Book Here
Book Description
