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Full-Text Articles in Physical Sciences and Mathematics
Production Of Triploid Rainbow Trout For Evaluation In South Dakota Waters, Jeff C. Dillon
Production Of Triploid Rainbow Trout For Evaluation In South Dakota Waters, Jeff C. Dillon
Electronic Theses and Dissertations
In September 1986, approximately 50,000 rainbow trout (Salmo gairdneri) eggs were fertilized and subjected to heat shocks to prevent expulsion of the second polar body, theoretically resulting in triploid embryos. Heat shocks were at 26 and 28°c, began 10, 20, 30, or 40 min after fertilization, and lasted for 10 or 20 min for a total of 16 treatments. Another 25,000 eggs served as controls and were handled identically but at a normal water temperature of 12°c. Cumulative hatching rates for eggs that were heat-shocked at 26 and 28° were 64 and 50%, respectively, compared to control eggs which had …
Growth, Survival, And Vulnerability To Predation Of Stocked Walleye (Stizostedion Vitreum) Fingerlings, James D. Wolters
Growth, Survival, And Vulnerability To Predation Of Stocked Walleye (Stizostedion Vitreum) Fingerlings, James D. Wolters
Electronic Theses and Dissertations
In laboratory tanks, largemouth bass (Micropterus salmoides) and northern pike (Esox Lucius consumed fathead minnows (Pimephales promelas) 2.6 times more frequently than walleye (Stizostedion vitreum) and 5.7 times more than lepomids. Prey were more vulnerable in circular than rectangular tanks. In field studies, walleye fingerlings averaging 35 mm and 53 mm (mean total length) were stocked in two ponds (3- and 7- hectares) respectively: both contained largemouth bass, northern pike, yellow perch (Perca flavescenes), green sunfish (Lepomis cyanellus), and fathead minnows. Aquatic insects dominated the diet of largemouth bass for 3 days after walleye were stocked, indicating that walleye fingerlings …
Waterfowl Production On Three Types Of Artificial Nesting Structures In South Dakota Wetlands, Marcy Haworth
Waterfowl Production On Three Types Of Artificial Nesting Structures In South Dakota Wetlands, Marcy Haworth
Electronic Theses and Dissertations
Artificial nesting structures are currently being used by various agencies to offset the decline in waterfowl production due to predation losses and degradation of nesting habitats. However, the various structure types available are not equally attractive to nesting waterfowl. This study looked at 3 types of artificial nesting structures – open topped cone baskets, round hay bales, and concrete culverts – and evaluated their used, success, and production in South Dakota. Structure type and site characteristics were correlated to occupancy rates and nesting success. Sixty-eight baskets and 205 bales were monitored during 1986, and 154 baskets, 200 bales, and 20 …
Seasonal Habitat Use, Home Range, And Dispersal Of Wild Turkeys In Southcentral South Dakota, Scott L. Laudenslager
Seasonal Habitat Use, Home Range, And Dispersal Of Wild Turkeys In Southcentral South Dakota, Scott L. Laudenslager
Electronic Theses and Dissertations
Seasonal movements, home range, and habitat use of wild turkeys in south-central South Dakota were investigated using radio telemetry from summer 1984 to winter 1986. Spring dispersal from wintering sites ranged from 0.2 to 5.8 km (x = 2.8 km). Non-nesting females moved significantly (P ~ 0.05) farther than males. Fall movements from summer to winter habitat ranged from o.o to 5.0 km (x = 2.2 km). Marked birds always returned to summer areas used in previous years. In contrast, wintering areas changed yearly among some individuals. Home ranges for all birds in summer ranged from 46. 7 ha to …
Conservation Of Least Terns And Piping Plovers Along The Missouri River And Its Major Western Tributaries In South Dakota, Monica Jean Schwalbach
Conservation Of Least Terns And Piping Plovers Along The Missouri River And Its Major Western Tributaries In South Dakota, Monica Jean Schwalbach
Electronic Theses and Dissertations
Interior least terns (Sterna antillarum) and piping plovers (Charadrius melodus) are listed as endangered or threatened over all of their breeding range, including South Dakota (SD). Investigations were made into the status, distribution, production, habitat characteristics, and factors limiting productivity of least terns and piping plovers in SD. The study area included the Missouri River from the North Dakota state line to Ponca State Park, Nebraska, and the lower 1/3 of the Grand, Moreau, Cheyenne, and White rivers. Least tern numbers increased substantially (253; 367) between 1986 and 1987, but plover numbers increased only slightly (187; 197). Terns and plovers …
Wetland Characteristics Of Avian Cholera Outbreaks And Surface Water Transfer In The Nebraska Rainwater Basin Area, Brian J. Smith
Wetland Characteristics Of Avian Cholera Outbreaks And Surface Water Transfer In The Nebraska Rainwater Basin Area, Brian J. Smith
Electronic Theses and Dissertations
Avian Cholera (Pateurella multocida) has infected and killed thousands of migrating waterfowl each year since 1975 in Nebraska’s rainwater basin area. Disease outbreaks in migrating waterfowl populations just prior to the nesting season are of concern to biologists. Feedlots and itner-wetland basin surface water transfer mechanisms of the avian cholera causative agent, P. multocida, were investigated using remote sensing techniques. Wetland basin characteristics (classification type, adjacent landuse, basin landuse, and basin densities) were also investigated for relationships to 1981 avian cholera outbreaks. No surface drainage relationships were found that would permit the transfer of P. multocida from one wetland basin …
The Effect Of Grass Carp Introduction On Aquatic Vegetation And Existing Fish Populations In Two Small Prairie Lakes, David L. Bauer
The Effect Of Grass Carp Introduction On Aquatic Vegetation And Existing Fish Populations In Two Small Prairie Lakes, David L. Bauer
Electronic Theses and Dissertations
Within two years after triploid grass carp introduction in 2.3 hectare Prior Lake in South Dakota, aquatic vegetation coverage and height in the water column were significantly lower (P<0.005). During the same two year period, triploid grass carp did not significantly reduce aquatic vegetation coverage or height in the water column in 11.4 hectare East Lake Eureka, also in South Dakota. Stocking densities were 49 fish/hectare and 61 fish/hectare (229 mm mean total length) in Prior Lake and East Lake Eureka, respectively. The biomass of prey fish in East Lake Eureka in 1986 was quite high with 88.3, 85.3 and 17.3 kg/hectare for black bullhead (Ictalurus melas), yellow perch (Perea flavescens), and bluegill (Lepomis macrochirus), respectively. The biomass of northern pike (Esox lucius) was also high at 13.8 kg/hectare. A Proportional Stock Density (PSD) of 11 and Relative Weight (WK) of 117 indicated a relatively healthy bluegill population in East Lake Eureka. However, the PSD value for black bullheads was lower (8) while their condition was relatively good (K=l.58). The yellow perch population appeared to be over-populated in East Lake Eureka with a PSD of only 5 and a relatively low condition factor (K=l.14). The northern pike population in East Lake Eureka had a PSD value of 53, but a slightly low Wr of 94. Available prey/predator ratio indicated that there was an excess of prey fish for most size classes of predators. Because no significant vegetation reduction occurred in East Lake Eureka, no changes in existing fish populations could be attributed to grass carp introduction or aquatic vegetation reduction. Data gathered on existing fish populations in East Lake Eureka will serve as a pre-treatment data set to be compared to future conditions if aquatic vegetation is reduced. Fish sampling in Prior Lake was greatly reduced due to a winterkill which occurred in the late winter of 1986. Bluegill and largemouth bass (Micropterus salmoides) were the most abundant fish species found in Prior Lake in 1987. Bluegill appeared to be overpopulated as their PSD value was 1; a high Wr of 109 may have indicated improved conditions immediately following the winterkill. Results for the largemouth bass in Prior Lake were similar with a low PSD (7) and a high w~ (112). Winterkill (Prior Lake) and lack of aquatic vegetation control by grass carp (East Lake Eureka) prohibited making conclusions about the effect of grass carp introduction on the existing fish populations in the two lakes. Further research needs to be conducted in South Dakota to determine appropriate grass carp stocking rates for South Dakota waters, and to evaluate what effect grass carp introduction and aquatic vegetation reduction has on existing fish populations.
Electrophoretic, Morphometric, And Meristic Comparisons Of Walleye Broodstock In South Dakota, Chantel M. Waltner
Electrophoretic, Morphometric, And Meristic Comparisons Of Walleye Broodstock In South Dakota, Chantel M. Waltner
Electronic Theses and Dissertations
Electrophoretic and morphological variability among walleyes collected from three upper Missouri River tributaries and a glacial lake in South Dakota was investigated, and an upper Mississippi River stock was electrophoretically compared to the South Dakota stocks. Allele frequencies of two (MDH-3, GMP-3) of the twenty-one loci examined differed significantly (P<0. 05) between South Dakota and Mississippi River walleyes. Contingency chi-square tests of allele frequencies showed homogeneity among walleyes from the Missouri River tributaries, and significant (P<0.001) heterogeneity (P<0.001) at the GMP-3 locus between Missouri River and glacial lake stocks. A dendogram derived from Nei unbiased genetic identity values produced separate branchings for the South Dakota and Mississippi River walleyes. All four walleye stocks in South Dakota were morphologically variable, although no one character could be used as a diagnostic tool to separate the stocks visually. Discriminant function analysis of eight of the most powerful discriminatory characters was successful in correctly classifying walleyes by origin with 83-97% accuracy.
Forage Potential Of Seasonal Wetlands, Daniel Edward Hubbard
Forage Potential Of Seasonal Wetlands, Daniel Edward Hubbard
Electronic Theses and Dissertations
Investigations on aspects of seasonal wetland forage potential were conducted in eastern South Dakota. The quantity and quality of the standing crop of vegetation in 6 seasonal wetland communities were assessed at the end of the growing season in 1983 and in 2 seasonal-wetland-dominated basins and their associated uplands (native mixed-grass prairie) over the growing season in 1985. Crude protein (CP), ash, detergent fiber, and in vitro digestible dry matter (IVDDM) values were measured on the above-ground material of whitetop [Scolochloas festucacea (Willd.) Link], slough sedge (Carex atherodes Spreng.), burred (Spargnaium eurycarpum Engelm.), and smartweed (Polygonum amphibium L. var. emersum …
Productivity, Movements, And Habitat Use Of Nesting And Brooding Wild Turkey Hens In Gregory County, South Dakota, Keith Stephen Day
Productivity, Movements, And Habitat Use Of Nesting And Brooding Wild Turkey Hens In Gregory County, South Dakota, Keith Stephen Day
Electronic Theses and Dissertations
Radio-equipped wild turkey (Meleagris gallopavo) hens (n=53) were monitored in a prairie river breaks environment in south-central South Dakota during 1986 and 1987. Seventy percent (36 of 47 adults and 1 of 6 juveniles) of the monitored hens nested. Hens that nested prior to 7 May selected nest sites in woodland habitats, while hens nesting later than 7 May selected nest sites in grassland habitats. Hens nested at sites with higher (P<0.05) percent visual obstruction, percent shrub cover, presence of overhanging vegetation, and habitat diversity than found at random control sites. Nest sites also allowed greater field of vision and opportunities for escape than random controls. Discriminant models developed from variables measured at nest and control sites were effective in distinguishing between the 2 categories. Seventeen of 39 (43.6%) clutches hatched, and 11 broods survived to mid-August. Poult survival in 1986 was 42.9%, with all poult mortality occurring during the first 2 weeks post-hatch. Accurate data for poult survival was not obtainable during 1987, but survival appeared to be similar to 1986. Broods moved up to 3.5 km from nest sites before establishing definite ranges. Broods ranges were composed of ≥50% woodland types, while woodlands comprised only 30.8% of the study area. Mean range size increased 3-fold from the 0-4 week age class (Age 1) to the 4+ week age class (Age 2). Broods used habitats in proportion to availability within ranges. However, grasslands were used more than expected (P<0.05) between 0631 hr and 1130 hr over the summer, and less than expected (P<0.05) by Age 2 broods between 1131 hr and 1630 hr. Woodlands were used more than expected between 1131 hr and 1630 hr over the summer, but not significantly so. Seventy-seven percent of all brood sightings made between 0631 hr and 1130 hr, and 67% of all sightings made between 1631 hr and 2030 hr were in grassland habitats. Seventy-two percent of all brood sightings made between 1131 hr and 1630 hr were in woodlands. Grassland brood use sites had greater forb cover, less grass cover, and were closer to habitat edges than random control sites (P<0.05). Discriminant analysis effectively reclassified grassland brood use sites, but not control sites. Age 1 broods sued grassland sites with greater overhead (> 30 cm) shrub cover, and nearer habitat edges than sites used by Age 2 broods (P<0.05). Woodland brood use sites were nearer (P<0.05) habitat edges than random controls. No significant differences could be found between woodland sites used by Age 1 and Age 2 broods. Discriminant analysis was ineffective in distinguishing between classes for woodland brood use sites or between ages for either woodland or grassland brood use sites.