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"Biological, climatological, and hydrological data were collected from Clear Creek-Hogatza River from 1995 to 1997. A counting tower and partial weir were constructed to estimate chum salmon (Oncorhynchus keta). Partial hour counts were tested to see if they adequately estimated full hour counts. Chi-square tests indicated all estimates based on partial hour counts differed significantly from hour counts. ANOVA indicated no partial hour count differed significantly from the hour counts. Relative error analysis showed counts greater than 20 minutes produced unbiased estimates of hour counts. The three year estimated average was 96,932 salmon with the average peak occurring on 3 July. A 1:1 sex ratio existed with...
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Recent declines in the number of sockeye salmon Onchorynchus nerka returning to Lake Clark, Alaska have caused economic hardship in the region and raised resource concerns among local subsistence users and Federal managers. A lack of information regarding the distribution of spawning habitats in the glacially turbid Lake Clark watershed instigated this research. Radio telemetry was used to 1) determine the in-lake movement patterns of adult sockeye salmon and 2) identify sockeye salmon spawning locations. Sockeye salmon were radio tagged at they entered Lake Clark and tracked to spawning locations. After entering Lake Clark, sockeye salmon usually migrated to a region of the lake that was within 15 km of their spawning...
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Understanding processes and mechanisms resulting in observed ecological patterns is critical information for biologists charged with effectively managing and conserving wildlife populations. In many areas across North America woodland caribou (Rangifer tarandus caribou Gmelin) populations are declining, as are caribou and reindeer populations globally. Why these declines are occurring is a key research question of biologists and managers. I investigated factors influencing recruitment of mountain-dwelling woodland caribou using long-term time series from ten herds (populations) in the Yukon Territory, Canada (Yukon). Recruitment was indexed by the calf:cow ratio observed during the fall breeding season using data...
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Survey data for trumpeter swans were collected throughout Alaska since 1968, but due to design difficulties and past analytical limitations, previous analyses were limited to simple summary statistics. The main purpose of my work was to rigorously analyze these data using advanced methods and determine rates of population change, the effects of environmental change on habitat use, and the influences of habitat features on habitat occupancy. I estimated that the adult population grew at a rate of 5.9% (95% credible interval = 5.2% to 6.6%) and production of cygnets increased at 5.3% (95% credible interval = 2.2% to 8.0%) annually. I also found evidence that variation in occupancy was positively related to average...
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Wildfire is ubiquitous to interior Alaska and is the primary large-scale disturbance regime affecting thawing permafrost and ecosystem processes in boreal forests. Since surface and near surface hydrology is strongly affected by permafrost occurrence, and wildfire can consume insulating organic layers that partially control the thickness of the active layer overlying permafrost, changes in the active layer thickness following fire may mark a distinct change in surface hydrology. In this study, we examined surface area dynamics of lakes following wildfire in four regions of Interior Alaska during a 25-year period from 1984 - 2009. We compared the surface water dynamics of lakes in burned areas relative to lakes in...
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We isolated luminous bacteria from drying chum salmon, Oncorhynchus keta, reported by Alaska native fishermen to be 'glowing in the dark.' The salmon were harvested for subsistence use from the Yukon River, Alaska. We identified our luminous bacterial isolates as Photobacterium phosphoreum based on nutritional versatility, and 16S rDNA and luxA gene sequences. P. phosphoreum has previously only been isolated from the marine environment. We tested whether our strains, isolated from fish harvested in freshwater, represent cold-adapted, freshwater-tolerant strains of P. phosphoreum. We also analyzed lux operon composition and organization, and examined the 5' promoter region of the lux operon for shared genes and regulatory...
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"Habitat selection by calving caribou (Rangifer tarandus granti) of the Central Arctic Herd, Alaska, was assessed in relation to distance from roads, vegetation type, relative plant biomass (NDVI; Normalized Difference Vegetation Index), accumulation of plant biomass during early lactation (NDVIrate), snow cover, and terrain ruggedness. From 183 calving sites of 96 radio collared- females, 1980-95, calving distribution was estimated in reference (no development) and treatment (oilfields present) zones east and west of the Sagavanirktok River, respectively. In the reference zone, caribou regularly selected wet-graminoid vegetation, above-median NDVIrate, and non-rugged terrain; concentrated calving remained in habitats...
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Hatcheries play an important role in the enhancement of Pacific salmon (genus Oncorhynchus) as a resource, but genetic and phenotypic divergence trom wild populations may occur as a result of founder effects, genetic drift and/or domestication. In this study, agonistic behavior, ability to establish dominance, and morphology were compared among juveniles of chinook salmon (Oncorhynchus tshawytscha) that have experienced five generations of hatchery ranching culture, juveniles derived trom the wild founding stock, and second generation hybrids of the two lines. The parent generation of all lines was cultured in the same hatchery environment as the juveniles tested. Behavioral observations were conducted in replicate...
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Summary: "Puccinellia arctica is a species of arctic grass that is unpalatable to Canada geese, Branta canadensis, and may be an effective and non-lethal means of controlling the growing populations of urban Canada geese that are problematic in many areas of North America. The secondary metabolite profile of P. arctica was compared to the metabolite profiles of three palatable grass species to determine the plausibility that P. arctica is chemically defended. The volatile and non-volatile secondary metabolite profiles of both P. arctica and the palatable grasses were the same. No alkoloids were detected in any of the grasses. Condensed tannin levels were similar in all of the grasses. Gallotannin levels were higher...
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A spruce bark beetle (Dendroctonus rufipennis) epidemic in the Copper Basin of Alaska beginning in the late 1980's has infested over 200,000 ha of white spruce forests in the region. The impact of spruce beetle-induced habitat changes on the northern red-backed vole (Clethrionomys rutilus) was investigated using mark/recapture techniques for 2 field seasons. Vole abundance and recruitment was significantly greater on low versus heavily infested sites but a large vole survival response was lacking. Vole food resources and protective vegetative cover did not vary substantially in areas with different levels of spruce mortality. Male movement distances were influenced by sex ratio, and females appeared to respond to...
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Chum salmon (Oncorhynchus keta ) are important for subsistence and commercial harvest in Alaska. Variability of returns to western Alaskan drainages that caused economic hardship for stakeholders has led to speculation about reasons, which may include both anthropogenic and environmental causes in the marine environment. Mixed stock analysis (MSA) compares genetic information from an individual caught at sea to a reference baseline of genotypes to assign it to its population of origin. Application of genetic baselines requires several complex steps that can introduce bias. The bias may reduce the accuracy of MSA and result in overly-optimistic evaluations of baselines. Moreover, some applications that minimize bias...
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The Lower Ship Creek Fishery in the city of Anchorage, Alaska is one of the state's most popular sport fisheries. After years of channelization and development, this social-ecological system (SES) continues to experience the effects of urbanization and is struggling to achieve robustness. I apply a robustness framework to the management of this fishery because of its semi-engineered nature. This framework uses interdisciplinary methods to study the interrelationships between its socio-economic and ecological components. Robustness is more appropriate than resilience as an analytical framework because of the relative insensitivity of the engineered components to ecological feedbacks. On Lower Ship Creek, the engineered...
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"A region of concern for persistent organic pollutants (POPs) contamination is the Arctic, because of POPs' ability to migrate long distances through the atmosphere toward cold regions, condense out of the atmosphere in those regions, deposit in sensitive arctic ecosystems and bioaccumulate in Arctic species. Thus, monitoring of POP concentrations in the Arctic is necessary. However, traditional active air monitoring techniques for POPs may not be feasible in the Arctic, because of logistics and cost. While these issues may be overcome using passive air sampling devices, questions arise about the interpretation of the contaminant concentrations detected using the passive air samplers. In this dissertation semi-permeable...
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In order to evaluate the impact of natural organic matter (NOM) on drinking water, the hydrology of the Caribou-Poker Creeks Research Watershed (CPCRW) was considered. The CPCRW provided an excellent opportunity to investigate contaminant transport as it relates to hydrology in a well studied, discontinuous permafrost environment. The seasonal variation of organic chemistry of three different water sources (i.e. ground water, artesian spring and stream) was studied during the course of the year 2001. This thesis comprises three chapters, each of which seeks to gain a better understanding of the contaminant transport pathways in a boreal watershed, Caribou Poker Creeks Research Watershed. The hypothesis of Chapter...
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Gynodioecy, the co-occurrence of females and hermaphrodites, is considered an intermediate step in the evolution of separate sexes in flowering plants. Highly variable female frequencies among populations suggest structuring of sex determining genes and differences in the relative fitness of females and hermaphrodites as seed parents. I investigated spatial variability in sex ratio and the effects of inbreeding on offspring quality in Silene acaulis. Female frequencies varied among populations from 0.32 to 0.69, and most were at temporal equilibrium. Females were significantly clumped within two of six populations. Females produced from 4 to 27 times as many fruits as hermaphrodites. Self-pollination of hermaphrodites...
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Winter browsing of birch leads to chemical changes in leaves of the following growing season, potentially generating differences in the quality of leachates derived from leaf litter and in leachate use by stream microorganisms. The effects of moose browsing were tested on leachates from leaves collected from browsed and unbrowsed trees and inoculated with microbial communities. Respiration and bacterial abundance were used to assess qualitative differences in leachates. Microbes cultured in leachates derived from leaves of browsed trees had significantly higher rates of oxygen uptake. There were no significant differences in bacterial abundance between treatments. The basis for the qualitative difference in leachates...
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Summary: "I studied marten (Martes americana) abundance and ecology in the Yukon-Charley Rivers National Preserve during 1991-1993. Using a multiple sample, mark-recapture estimator, I estimated marten densities to be 0.69, 0.41, and 0.45 martens/km2 during each August for 1991-1993, respectively. Density estimates were derived with the boundary-strip method to address the edge effect inherent in live-trapping studies. During the study, marten density declined 43% between 1991 and 1992 and remained low during 1993. I hypothesize that a decline in primary prey (i.e., microtine rodents) and increased environmental stress (i.e., cold temperatures and snow cover) contributed significantly to the decline in marten abundance....
map background search result map search result map Phytochemical comparison of Puccinellia arctica to Poa pratensis, Puccinellia langeana, and Puccinellia phryganodes for evidence of chemical defense Winter vertebrate browsing of birch: effects on the use of leaf litter leachates by stream microorganisms Abundance and ecology of martens (Martes americana) in Interior Alaska An analysis of using semi-permeable membrane devices to assess persistent organic pollutants in ambient air of Alaska The effects of climate change on the population dynamics of trumpeter swans Urban stream management: An interdisciplinary assessment of the Ship Creek fishery Spatio-temporal recruitment dynamics of mountain-dwelling caribou in the Yukon Territory, Canada Breeding ecology and fasting tolerance of scaup and other ducks in the boreal forest of Alaska Habitat selection by calving caribou of the Central Arctic Herd, 1980-95 The ecological genetics of gynodioecy in Silene acaulis L. (Caryophyllaceae) : spatial sex structure and inbreeding depression Predicting contaminant transport pathways in the Caribou-Poker Creek Research Watershed Response of northern red-backed vole (Clethrionomys rutilus) populations to a major spruce beetle infestation in the Copper River Basin, Alaska Abundance and timing of summer run Chum salmon (Onchorhynchus keta) and water quality in Clear Creek-Hogatza River, northwestern Alaska Isolation and characterization of photobacterium phosphoreum from migrating Alaskan salmon Variation of agonistic behavior and morphology among juvenile chinook salmon (Oncorhynchus tshawytscha) of hatchery, wild, and hybrid origin under common rearing conditions Surface water dynamics of shallow lakes following wildfire in Boreal Alaska Yukon Water Availability Analysis: An Assessment of the Potential Impacts of Climate Change on the Balance between Precipitation and Potential Evapotranspiration in the Yukon, Canada The migration and spawning distribution of sockeye salmon within Lake Clark, Alaska Socio-ecological drivers of resource selection and habitat use by moose in interior Alaska Urban stream management: An interdisciplinary assessment of the Ship Creek fishery Phytochemical comparison of Puccinellia arctica to Poa pratensis, Puccinellia langeana, and Puccinellia phryganodes for evidence of chemical defense Breeding ecology and fasting tolerance of scaup and other ducks in the boreal forest of Alaska Winter vertebrate browsing of birch: effects on the use of leaf litter leachates by stream microorganisms Predicting contaminant transport pathways in the Caribou-Poker Creek Research Watershed Response of northern red-backed vole (Clethrionomys rutilus) populations to a major spruce beetle infestation in the Copper River Basin, Alaska Abundance and ecology of martens (Martes americana) in Interior Alaska The migration and spawning distribution of sockeye salmon within Lake Clark, Alaska Abundance and timing of summer run Chum salmon (Onchorhynchus keta) and water quality in Clear Creek-Hogatza River, northwestern Alaska An analysis of using semi-permeable membrane devices to assess persistent organic pollutants in ambient air of Alaska Habitat selection by calving caribou of the Central Arctic Herd, 1980-95 Socio-ecological drivers of resource selection and habitat use by moose in interior Alaska Surface water dynamics of shallow lakes following wildfire in Boreal Alaska The effects of climate change on the population dynamics of trumpeter swans The ecological genetics of gynodioecy in Silene acaulis L. (Caryophyllaceae) : spatial sex structure and inbreeding depression Spatio-temporal recruitment dynamics of mountain-dwelling caribou in the Yukon Territory, Canada Yukon Water Availability Analysis: An Assessment of the Potential Impacts of Climate Change on the Balance between Precipitation and Potential Evapotranspiration in the Yukon, Canada Variation of agonistic behavior and morphology among juvenile chinook salmon (Oncorhynchus tshawytscha) of hatchery, wild, and hybrid origin under common rearing conditions Isolation and characterization of photobacterium phosphoreum from migrating Alaskan salmon