Theses for the College of Fisheries & Ocean Sciences.

For departmental theses, see the following collections:
Theses (Fisheries)
Theses (Marine Biology, formerly Marine Science and Limnology)
Theses (Oceanography)


Recent Submissions

  • Habitat analysis of major fishing grounds on the continental shelf off Kodiak, Alaska

    Rooney, Sean Charles; Reynolds, Jennifer; Norcross, Brenda; Heifetz, Jonathan; Kruse, Gordon (2008-12)
    "The continental shelf and upper slope of the Gulf of Alaska support diverse and commercially important communities of demersal fishes. Twenty-eight video-strip transects conducted from a research submersible, together with habitat maps based on interpreted multibeam sonar data, were used to classify distribution and abundance patterns of fishes relative to seafloor substrate type and water depth on Albatross and Portlock Banks on the Kodiak Shelf in the Gulf of Alaska. These associations were examined across spatial scales: ranging from tens of kilometer centimeters in size. A total of 5,778 fishes were recorded from 33 taxa. Fish community distribution patterns were largely correlated with depth and to a lesser extent with substrate type. Individual fish species habitat associations were also influenced by depth and substrate type; however, the spatial scale at which these factors were relevant varied by fish species. There was strong regional concordance among observed fish species habitat associations and those previously documented in studies from central California to the northern Gulf of Alaska. Although integrating substrates classified at different scales was challenging, the resulting information of scale specific habitat associations provides a more comprehensive understanding of how demersal fishes utilize benthic habitats"--Leaf iii
  • Characterization of reproductive cyclicity of sex steroids by fecal analysis in Steller sea lions (Eumetopias jubatus)

    Litz, Beate (2008-08)
    "Steller sea lions (Eumetopias jubatus) have experienced a drastic population decline in the past several decades. Among hypotheses for the decline and failure of the population to recover is decreased reproductive success. Harsh environmental conditions within the species range and the large body size of the animals can limit sampling efforts to investigate these hypotheses. Three captive Steller sea lions were used as models to validate the use of fecal steroid analysis for this species. Their annual endocrine fluctuations were monitored over four years to gain a better understanding of their reproductive endocrinology and overcome sampling challenges typically associated with hormonal studies of large mammals. Radioimmunoassays (RIA) and enzyme immunoassays (EIA) reliably measured testosterone, total estrogens, and progesterone extracted from Steller sea lion feces. Lack of refrigeration for five days and freezing ( -20°C) for 8 weeks did not alter concentrations of fecal testosterone and total estrogens measured. The stability of fecal progesterone in the absence of cold storage was compromised by 4.5 days; however, it remained stable while frozen ( -20°C) for 8 weeks. Thus, for field research, there are two primary implications. Firstly, samples of freshly voided scat collected from rookeries and haulouts can reliably reflect hormone concentrations for <̲ 4.5 days and secondly, these samples can be stored for later analysis for at least 8 weeks. Long-term serial sampling demonstrated fecal progesterone may be more useful in providing information on reproductive function than fecal estrogens. Annual endocrine profiles suggest the females are seasonally monoestrus, supporting the general assumption for the species, and the male has a strong seasonal cycle in testosterone with maximum concentrations measured just prior to the natural breeding season. These data also suggest fecal testosterone reflects changes in testicular activity despite breeding status and proximity to females. Collectively, these data suggest this non-invasive endocrine monitoring technique has potential to provide a useful alternative method of sample collection"--Leaf iii
  • Age, growth and productivity of juvenile sockeye salmon in two high latitude lakes, Alaska

    Wilson, Lorna I.; Smoker, William W.; Adkison, Milo D.; Zimmerman, Christian E.; Volk, Eric C. (2009-12)
    "The growth of Seward Peninsula sockeye salmon (Oncorhynchus nerka) from Salmon and Glacial lakes is related to their physical environment. Dermal scales collected over many years were measured to document the annual age specific growth of smolts and adults. The effect of fertilization on fry growth was examined using the first year of growth. The growth histories of Salmon Lake sockeye salmon were compared to Glacial Lake sockeye salmon through smolting and in the marine environment. Annual age specific fry growth had no direct relationship to fertilization; however, there were interactions between biomass of salmon prey and fertilization, and between prey biomass and age of smolting. Glacial Lake age-1 smolts are the same size as Salmon Lake age-1 smolts, but age-1.3 Salmon Lake juveniles after their first year in the ocean are smaller than age-1.3 Glacial Lake juveniles suggesting lower size based mortality. The differences in growth histories show each population's response to lake production and mortality experienced by smolt between the rearing lake and the ocean"--Leaf iii
  • Analysis of adult sport fishing lesson choices and their application to post-secondary curriculum development

    Jones, Shann Paul; Hebert, Michele; Wipfli, Mark; Bomar, Charles R.; Johnson, Terry L.; Carlson, John (2009-12)
    "Post-secondary angler education offerings have increased nationally, but little is known about what sport fishing skills anglers desire. I noticed variations in such curricula while developing the University of Alaska Fairbanks course, Fundamentals of Fly Fishing. My study objectives were to 1) determine what fly-fishing skills potential students desire so they invest both time and money attending my education events; 2) refine my offerings; and, 3) determine if students gained angling-related knowledge. I developed a questionnaire gauging the public's fly-fishing educational desires and requirements, and distributed it from 2003 to 2005. After analyzing the results, I revised my class to include more science-based angler knowledge and practical skills. The target audience for my classes is people under 55 years of age with less than three years angling experience who fish less than twice monthly. They want preparatory topics that allow them to continue with the sport once they complete the educational event. After incorporating the results into my offerings, enrollments more than doubled from 2003 to 2008. Students made measurable advances in understanding the sciences behind sport fishing. By surveying potential participants' educational desires and needs, adult educators should be able to build sustainable personal enrichment programs as demonstrated here"--Leaf iii
  • The impact of sea kayak tourism and recreation on harbor seal behavior in Kenai Fjords National Park: integrating research with outreach, education, and tourism

    Jezierski, Caroline M.; Norcross, Brenda; Hoover-Miller, Anne; Wynne, Kate M.; Polasek, Lori (2009-12)
    "Increasing numbers of sea kayakers in Kenai Fjords National Park, Alaska prompted a study to evaluate human disturbance on harbor seals. Harbor seal behavior recorded during the molt from 2004-2006 via remotely controlled cameras and direct field observations were used to evaluate effects of human activities. Behaviors of the seals observed in the presence and absence of kayakers/walkers were contrasted by method of collection, year, presence of humans, presence of a guide, and guide training. Results demonstrated that harbor seals abandoned the ice and were more alert when kayakers were present than when humans were absent. Harbor seals became progressively sensitive to the presence of walkers. Sea kayak guides were advised to observe seal behavior and minimize contact by avoiding areas with high concentrations of hauled-out seals. Educational training provided to sea kayak guides effectively reduced the impact of human disturbance on harbor seals"--Leaf iii
  • Total serum immunoglobulin Y in Steller's eiders and a surrogate species as a marker of humoral immune status and viral response

    Bozza, Maryann; Hollmen, Tuula; Hofmeister, Erik; Polasek, Lori (2009-12)
    "Steller's eiders (Polysticta stelleri) and other sea duck species have undergone population declines in recent decades, and the causes for the declines remain largely unknown. As part of a study to investigate the role of disease in sea duck population declines, I further characterized Steller's eider humoral immunity by quantifying total serum immunoglobulin Y (IgY). Baseline values of total serum IgY were determined for a captive flock of Steller's eiders housed at the Alaska SeaLife Center using species-specific assays. There were no significant differences in total serum IgY between males and females or between seasons (molt and winter) for captive birds. For free-ranging Steller's eiders, mean total serum IgY was significantly higher during molt and mid-winter compared to captive baseline values, suggesting increased disease exposure. As a further investigation of the humoral immune response, experimental inoculations (low pathogenicity avian influenza and adenovirus) were conducted in mallards (Anas platyrhyncus) as a surrogate species. Quantification of total serum IgY from captive Steller's eiders provides a baseline for comparative studies of total serum IgY from free-ranging Steller's eiders. This study also provided first quantitative information about circulating IgY in free-ranging Steller's eiders"--Leaf iii
  • Environmental gradients and prey availability relative to glacial features in Kittlitz's murrelet foraging habitat

    Arimitsu, Mayumi L.; Hillgruber, Nicola; Piatt, John; Weingartner, Thomas; Mueter, Franz (2009-12)
    "The goal of this study was to characterize Kittlitz's murrelet (Brachyramphus brevirostris) foraging habitat relative to prey availability and oceanography in Kenai Fjords National Park, a glacial-marine system. I conducted oceanographic, hydroacoustic, trawl, beach seine, and marine bird surveys monthly from June-August in 2007 and 2008. High sediment load from glacial river runoff shaped the marine ecosystem, and this appeared critically important to Kittlitz's murrelets at sea. Submerged moraines influenced inner fjord habitat that was characterized by cool, fresh, stratified, and silt-laden waters. This silty glacial runoff limited light availability to chlorophyll near tidewater glaciers, but zooplankton abundance was enhanced in the surface waters, perhaps due to the absence of a photic cue for vertical migration. Zooplankton community structure was influenced by glacial features and varied along an increasing temperature gradient over the summer. Acoustic measurements suggested that low density aggregations of fish and zooplankton were available in the surface waters near glacial river outflows where murrelets typically forage. Dense fish aggregations moved into the fjords by August. Kittlitz's murrelets were more likely to occur in areas with higher acoustic biomass near glaciers, making these birds more susceptible to climate change than the congeneric marbled murrelet (B. marmoratus), which was most associated with shallow, ice-free areas"--Leaf iii
  • Balancing biological sustainability with the economic needs of Alaska's sockeye salmon fisheries

    Steiner, Erin M.; Criddle, Keith R.; Adkison, Milo D.; Kruse, Gordon H. (2009-05)
    "The total revenue of the Bristol Bay, Alaska sockeye salmon, Oncorhynchus nerka, fishery has continued to decline despite strong run sizes. This decline is primarily attributed to increases in production of farmed Chilean rainbow trout O. mykiss and coho salmon, O. kisutch. Although wild salmon managers have less control over production than salmon farmers, there may be some opportunity to regain value to the fishery by altering management strategies. To explore this potential, we first simulated three management strategies for sockeye salmon: a fixed escapement range strategy, a fixed harvest strategy and a fixed harvest rate strategy. Yields from these simulations were then combined with a forecast of farmed Chilean trout and salmon production and a model of international trade flows for Alaskan sockeye and Chilean coho salmon and rainbow trout to generate forecasts of exvessel price and total revenue for 2010. All three management strategies were able to achieve a run size equilibrium indicating biological sustainability. The highest median yield resulted from the fixed escapement strategy and the lowest median yield was generated by the fixed harvest strategy. Exvessel prices and total revenue were highest under the fixed harvest strategy. These results demonstrate a switch to an inelastic market environment and reveal the need to modify current management strategies to improve the economic health of the fishery"--Leaf iii
  • Recent paleoenvironmental changes recorded in three non-anadromous lakes in Southwest Alaska: effects of climatic and vegetation dynamics on lake productivity

    Cohn, Brian R.; Heiser, Patricia; Finney, Bruce; Whitledge, Terry; Wooller, Matthew (2009-05)
    "Paleolimnological investigations, landscape analyses, and repeat photographs were used to provide a long-term view (~150 yrs. BP to present) of nutrient dynamics and lake ecosystem change in southwest Alaska. Recent major changes in lake ecology and landscape are generally attributed to climate warming since the end of the Little Ice Age and to the recent warm phase of the Pacific Decadal Oscillation. Disturbances driven by climate, glacial retreat, and volcanism also contribute to changes in aquatic-driven processes. Sediment cores reveal a complex yet progressive set of changes that are expressed in the study lakes. Changes in the biogeochemical proxies began in the mid-19th to early-20th century, but major inflections occurred significantly later, most pronounced after 1950. Among these changes are increases in biogenic opal, and indicators of enhanced C and N cycling. These systems act as integrators of climatic, terrestrial, and aquatic processes without additions of marine-derived nutrient subsidies from spawning salmon and thus allow us to isolate and identify factors (e.g. productivity, spawning and rearing success of salmonids, or terrestrial nutrient inputs) important for interpreting sediment records in anadromous systems"--Leaf iii
  • Quantifying diet to tissue isotopic (δ¹³C and δ¹⁵N) fractionation factors in captive spectacled eiders (Somateria fischeri): implications for nutrient allocation and foraging studies

    Federer, Rebekka; Hollmén, Tuula; Esler, Daniel; Wooller, Matthew (2009-08)
    "The spectacled eider (Somateria fischeri) was listed as threatened under the Endangered Species Act in 1993, and potential threats to population recovery include changes in the marine prey abundance and availability. Therefore, development of diet assessment techniques has been listed as an eider recovery task. Stable isotopes have been used to evaluate foraging ecology and nutrient allocation to reproduction in birds. Application of this technique requires knowledge of how stable isotope signatures of animal tissues differ from their diet, referred to as isotopic fractionation, and these values can be determined experimentally using captive populations. I established stable isotopic fractionation factors for d¹³C and d¹⁵N from diet to egg components, down feathers, contour feathers, cellular blood, blood plasma, and fat of captive spectacled eiders. Sensitivity analyses indicate that choice of isotopic fractionation values from eggs of different species could considerably alter model conclusions. Therefore, I incorporated isotopic fractionation factors from spectacled eider eggs into two published sea duck nutrient allocation models that previously used these values from falcons (Falco spp.) to assess differences in model conclusions. Results from these studies provide further resources to understand foraging and nutrient transfer in eiders and may offer more accurate estimates for sea duck models"--Leaf iii
  • Ontogenetic considerations in the trophic level of commercial groundfish species in the Gulf of Alaska

    Marsh, Jennifer Marie; Hillgruber, Nicola; Foy, Robert; Kruse, Gordon; Wooller, Matthew (2010-12)
    "Trends in trophic level (TL) estimates of commercial fishery catches are used as ecosystem-based indicators for sustainability, but these estimates often do not incorporate species-specific interannual and ontogenetic feeding patterns. This study provides a finer resolution of ontogenetic and temporal variations in the trophic position of four groundfish species in the central Gulf of Alaska (GOA), walleye pollock (Theragra chaleogramma), Pacific cod (Gadus macrocephalus), arrowtooth flounder (Atheresthes stomias), and Pacific halibut (Hippoglossus stenolepis), using stable isotope analysis to assess TL and diet source. Samples were collected from the northeastern side of Kodiak Island, Alaska, from 2000-2004. Several Analysis of Covariance models were tested, allowing TL to co-vary with length, to detect possible variation among years and seasons and to estimate TL of catch for each study species. For each species, TL increased with length. Significant annual differences in [delta]¹³C and [delta]¹⁵N were detected for all groundfish, indicating a lower TL, pelagic diet in 2003 and a higher TL, benthic diet in 2001. Overall, TL of GOA commercial catches appeared to remain stable over 1990-2009, with the exception of walleye Pollack after 1999. This study shows that including length data could lead to an earlier detection of decline in TL estimates"--Leaf iii
  • Variation in the trophic position of spiny dogfish (Squalus acanthias) in the Northeastern Pacific Ocean: an approach using carbon and nitrogen stable isotopes

    Andrews, Alexander George III; Foy, Robert J.; Hillgruber, Nicola; Kruse, Gordon H.; Wooller, Matthew J. (2010-12)
    "Spiny dogfish (Squalus acanthias) are among the most abundant shark species in the Gulf of Alaska (GOA). An increase in relative biomass of spiny dogfish in 2003 and 2007 inspired interest in this species as a commercial resource. However, very little was known about the ecology of this species in the GOA. This study investigated the trophic role of spiny dogfish in the GOA, British Columbia (BC), and Washington using stable isotope analysis of carbon and nitrogen. Specifically, we examined the trophic position (TP) of spiny dogfish in relation to length, sex, and geographic region. Weathervane scallops (Patinopecten caurinus) were used as a stable isotopic baseline organism. Spiny dogfish between 52 to 113 cm length had [delta]¹⁵N values that ranged geographically from 10.8°/₀₀ to 15.6°/₀₀; [delta]¹⁵N was linearly related to length. In contrast, lipid-normalized [delta]¹³C, values ranged from -21.28°/₀₀ to -16.88°/₀₀ and were not linearly related to length. In the GOA, TP of spiny dogfish ranged from 3.3 to over 4.1, with Kodiak having the highest TPs for spiny dogfish of a given length. Our results indicated that size-based ontogenetic changes in TP of spiny dogfish are important and should be incorporated into mass-balance, food-web models such as Ecopath"--Leaf iii.
  • Life history and spawning movements of broad whitefish in the middle Yukon River

    Carter, William K. III; Sutton, Trent; Brown, Randy; Lopez, Andres; Margraf, Joseph (2010-05)
    "Broad whitefish Coregonus nasus have long been an important subsistence resource across its Arctic and sub-Arctic range. Despite its regional importance, little is known about the life history and ecology of this species. This research illuminates fundamental life-history information through the use of catch-per-unit-effort (CPUE) run timing, gonadosomatic index (GSI), radio telemetry, and aging and microchemical analysis of otoliths. From 2001 to 2006, fishwheels were used to capture individuals 1,200 km upstream from the mouth of the Yukon River. CPUE data indicated a consistent increase in daily fish numbers through mid-September. The GSI showed an increasing gonad weight over the sampling period, indicating preparation for spawning. Thirty-one of 41 radio-tagged fish were tracked to a 260 km long spawning area centered 350 km upstream of the tagging site. Thirteen of 17 fish found in the spawning area in 2003 overwintered nearby. Ages of 79 individuals ranged from 5 to 16 years (mean age = 10; median age = 9). Microchemical analysis showed amphidromy in 10 of 12 individuals by examining otolith strontium (Sr) concentrations. This information indicates that the broad whitefish captured in this study were mature, migrating to a spawning/overwintering area, and have a complex amphidromous life history"--Leaf iii
  • A review of the species status of the Angayukaksurak charr (Salvelinus anaktuvukensis) of northern Alaska: perspectives from molecular and morphological data

    Ayers, Scott David; Rosenberger, Amanda; Hillgruber, Nicola; Larsen, Amy; Taylor, Eric (2010-05)
    "The Arctic, known for its dynamic past, is a significant place to examine drivers of and spatial variation in diversity of life history strategies in fishes. Diversity in heritable life history traits can lead to speciation, as may be the case for the putative Angayukaksurak chair (Salvelinus anaktuvukensis). The goal of this study was to determine the species status of this fish, the only described freshwater species endemic to Alaska. I examined and compared the morphology and genetics of Angayukaksurak charr and its most closely related species, the Dolly Varden (Salvelinus malma). Meristic characters divided the specimens into three forms by major river drainage. Morphological analysis divided the specimens into two forms along nominal species lines based on differences that could also be attributed to differences between life history forms. Sequences from a 550 bp section of mitochondrial d-loop failed to segregate the putative Angayukaksurak charr into a separate lineage, rather placing specimens into two previously resolved lineages of holarctic Arctic chair. In addition, analysis of microsatellite loci showed no clear differentiation between species. Based on these results, I concluded that the Angayukaksurak charr is not a separate species, but rather a resident life history form of the Dolly Varden"--Leaf iii
  • A remote sensing-GIS based approach to identify and model spawning habitat for fall chum salmon in a sub-arctic, glacially-fed river

    South, Lisa; Rosenberger, Amanda; Margraf, F. Joseph; Prakash, Anupma (2010-08)
    "At northern extremes, fish habitat requirements are often linked to thermal preferences and the presence of overwintering habitat. The goal of this study was to identify spawning habitat for fall chum salmon Oncorhynchus keta and model habitat selection from spatial distributions of tagged individuals in the mainstem Tanana River, Alaska. I hypothesized that the presence of groundwater, which provides thermal refugia for overwinter incubation, would be most important for fall chum salmon. Models included braiding, sinuosity, open water surface area (indicating significant groundwater influence), and open water persistence (consistent presence of open water for a 12 year period according to satellite imagery). Candidate models containing open water persistence were selected as most likely. Persistent open water areas were further examined using forward-looking infrared (FLIR) imagery; marked differences between sites were observed in the extent of thermal influence by groundwater. Persistent open water sites with strong groundwater influence appear to serve as core areas for spawning salmon; the importance of stability through time suggests the legacy of successful reproductive effort in these areas for this homing species. This study indicates that not only the presence of groundwater is important for spawning chum, but its persistence and extent of groundwater influence"--Leaf iii
  • Humpback whale (Megaptera novaeangliae) numbers and distribution on their summer feeding grounds of the Eastern Aleutian Islands

    Riley, Heather; Hills, Sue; Straley, Jan; Matkin, Craig; Stockwell, Dean (2010-08)
    "In summer, Humpback whales (Megaptera novaeangliae) of the North Pacific stock feed in Alaska's nearshore waters. My research focused on the Bering Sea between Unimak and Samalga Pass with the objectives: 1) Estimate the number of humpback whales using the study area from 2001 through 2006; 2) Determine to what extent humpback whales exhibit site fidelity; 3) Describe the distribution of humpback whales and determine if depth, slope, and chlorophyll-a can predict the humpback whale presence. To investigate the degree to which whales return to the Eastern Aleutian summer feeding ground, 1,985 whale photographs were collected and an identity matrix was created; Humpback whales exhibited a 22 percent return rate with 181 whales out of 802 total whales seen in more than one year during the six year study. Program MARK (Mark and recapture parameter estimation) was used to estimate the number of humpback whales utilizing this area, resulting in an estimate of 500 to 1600 animals. Logistic regression and random forest classification determined that depth and longitude are significant predictors of humpback whale presence. These results support other studies in the Eastern Aleutians and North Pacific and further confirm the importance of oceanographic and biological features in concentrating prey and predicting humpback whale distribution"--Leaf iii
  • Larval transport of brachyuran crab in Kachemak Bay, Alaska

    Murphy, Megan M.; Iken, Katrin; Eckert, Ginny; Pegau, Scott (2010-08)
    "This study's primary goal was to understand the oceanographic effects on larval crab transport and distribution between an estuarine inner and more oceanic outer bay in the subarctic estuary of Kachemak Bay, Alaska. Plankton tows and hydrographic measurements (temperature and salinity) were taken along the boundary between the two bay parts from March - October on spring and neap tides. Summer water flow and in Kachemak Bay is predominantly freshwater-driven and density patterns vary inter-annually with the amount of freshwater supplied to the inner bay. Larvae of seven crab species occurred in a seasonal sequence and the crab larval assemblage was closely correlated to temperature in the upper 20 m. The influence of tidal forcing on larval transport was not clear even though most species exhibited peak abundances at spring tides. Larval distribution patterns across the inner/outer boundary indicated that Oregonia gracilis larvae may be transported into inner Kachemak Bay; however, late larval stages of the two commercially relevant species, Chionoecetes bairdi and Cancer magister, were never observed and may be exported from the inner estuary. These observations provide an important baseline for further studies to understand Kachemak Bay's role as a source or sink for larval crab"--Leaf iii
  • Growth rates of juvenile Scolelepis squamata (Polychaeta: spionidae) from the Chukchi Sea fast ice

    McConnell, Brenna; Gradinger, Rolf; Iken, Katrin; Bluhm, Bodil (2010-08)
    "Arctic coastal fast ice supports high densities of sea ice algae, and is thermally stable at the ice-water interface at around the freezing point of sea water, providing a suitable environment for sympagic meiofauna feeding on the sea ice algae during spring months. Changes in water temperature due to seasonality and climate change may affect physiological processes of these organisms. We tested the hypothesis that juvenile growth rates of a common sympagic polychaete, Scolelepis squamata (Polychaeta: Spionidae), would be significantly faster at typical spring sea ice algal concentrations compared to concurrent phytoplankton concentrations and at open water summer versus winter temperatures. Juvenile S. squamata from fast ice off Barrow, Alaska were fed three algal concentrations at 0°C and 5°C, simulating ambient high sea ice algal concentrations, concurrent low phytoplankton concentrations and an intermediate concentration. Growth rates, calculated using a simple linear regression equation, were significantly higher (up to 225 times) at the highest algal concentration compared to the lowest in all experiments, showing sea ice to provide more beneficial food situation compared to the under-ice water column. Additionally, juveniles grew over five times faster at 5°C compared to those feeding at 0°C, forecasting faster juvenile growth as Arctic temperatures warm"--Leaf iii
  • The relationship between rainbow trout stocking success and habitat variables in Interior Alaska Lakes

    Mansfield, Kelly A.; Skaugstad, Calvin; Rosenberger, Amanda; Sutton, Trent (2010-08)
    "Fish are stocked for a variety of reasons, including the providence of diverse angling opportunities. Rainbow trout Oncorhynchus mykiss are the most widely stocked sport fish species in North America. In Interior Alaska, over 90 of the 137 lakes chosen for stocking are stocked with rainbow trout. To optimize fish stocking programs, managers require a better understanding of the lake characteristics associated with success in meeting program objectives, for assessment of potential lakes proposed for stocking, and to address angler inquiries. For my project, I used a model-selection process with lake morphometric and biotic data from 36 stocked lakes in interior Alaska to develop a predictive model for rainbow trout stocking success defined by pre-set mean length-at-age standards. Average stocking density, lake surface area, and shoreline development explained 46% of the variation in rainbow trout lengths. Model cross-validation, however, called into question the predictive capabilities of the model. In addition, limnological data collected from 10 lakes in 2009 identified water temperature as a correlate with rainbow trout length. This study provided an approach that can be used by managers to evaluate rainbow trout length in stocked lakes, and serves the basis for improving stocking programs while providing satisfactory fishing experiences"--Leaf iii
  • Reproductive biology and movement patterns of humpback whitefish and least cisco in the Minto Flats-Chatanika River complex, Alaska

    Dupuis, Aaron Wayne; Sutton, Trent; Wuttig, Klaus; Seitz, Andrew (2010-08)
    "Humpback whitefish Coregonus pidschian and least cisco C. sardinella are two species of coregonids common to the interior of Alaska and are a food resource for rural and urban communities. These fishes exhibit variation in life-history characteristics throughout their range, and many basic life-history questions remain unanswered. My objectives were to describe the spawning movements and identify the current distribution of putative spawning areas for humpback whitefish, and to assess the reproductive biology of humpback whitefish and least cisco in the Minto Flats-Chatanika River complex. Observed movement patterns indicated that humpback whitefish exhibited complex dispersals to putative spawning areas. Two putative spawning areas were identified: one in the Chatanika River downstream of the Elliot Highway Bridge and the other in the Tanana River near Fairbanks. Mean absolute fecundity was 45,000 eggs female⁻¹ for humpback whitefish and 41,780 eggs · female⁻¹ for least cisco. This examination of reproductive biology suggested that larger-bodied females associated with higher gonadosomatic index values produce more and larger eggs per unit body weight than smaller females. This study increased our understanding of the life history and biology of whitefishes in Alaska and can assist managers with developing appropriate management strategies for these fishes in the future"--Leaf iii

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