Recent SFOS Student Theses and Dissertations
Spring Semester 2009
Total Serum Immunoglobulin Y in Stellers Eiders and Surrogate Species as a Marker of Humoral Immune Status and Viral Response
Maryann Bozza, M.S. Marine Biology Degree Candidate
Faculty Advisor: Dr. Tuula Hollmen
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 larger study to investigate the role of disease in sea duck population declines, we further characterized Steller's eider humoral immunity by quantifying total serum immunoglobulin Y (IgY). We developed species-specific assays to quantify total serum IgY and determined baseline values for a captive flock of Steller's eiders housed at the Alaska SeaLife Center. There were no significant differences in total serum IgY between males and females or between molt (August-September) and winter (January-March) seasons for captive birds. For free-ranging Steller's eiders sampled from 2004-2006 at Izembek Lagoon and Unalaska Island, mean total serum IgY was significantly higher during the molt (August-September) and mid-winter (January) compared to captive baseline values. Free-ranging Steller's eiders had significantly higher levels of IgY in mid-winter in 2005, the only year sampled for this time frame, as compared to late winter (February-March, 2005-2006) or molt (2004-2005). To investigate the humoral immune response in mallards as a surrogate species to experimental avian influenza and adenovirus isolates from sea duck and sympatric duck species, samples from three experimental inoculation studies were analyzed. Mean total IgY levels were hypothesized to increase in response to viral infection, and although results in these studies were inconclusive, they suggest challenges to and opportunities for further research on the humoral immune response to viruses. By quantifying total serum IgY from captive Steller's eiders, we have created a relevant context for total serum IgY data from free-ranging Steller's eiders that will contribute to our further understanding of population-level immune status in Alaska's sea ducks throughout their annual cycle.
Abundance, Recruitment, and Environmental Forcing of Kodiak Red King Crab
William Bechtol, Ph.D. Fisheries Candidate
School of Fisheries and Ocean Sciences, Fisheries Division
Faculty Advisor: Dr. Gordon Kruse
Commercial harvests of red king crab Paralithodes camtschaticus around Kodiak Island, Alaska increased rapidly in the 1960s to a peak of 42,800 mt in 1965. Stock abundance declined sharply in the late 1960s, moderated in the 1970s, and crashed in the early 1980s. The stock has not recovered despite a commercial fishery closure since 1983. To better understand the rise, collapse, and continued depleted status of the red king crab stock around Kodiak Island, I conducted a retrospective analysis with three primary objectives: (l) reconstruct spawning stock abundance and recruitment during 1960-2004; (2) explore stock-recruit relationships; and (3) examine ecological influences on crab recruitment. A population dynamics model was used to estimate abundance, recruitment, and fishing and natural mortalities. Three male and four female "stages" were estimated using catch composition data from the fishery (1960-1982) and pot (1972-1986) and trawl (19862004) surveys. Male abundance was estimated for 1960-2004, but limited data constrained female estimates to 1972-2004. Strong crab recruitment facilitated increased fishery capitalization during the 1960s, but the high harvest rates were not sustainable, likely due to reproductive failure associated with sex ratios skewed toward females. To examine spawner-recruitment (S-R) relationships for the Kodiak stock, I considered lags of 5-8 years between reproduction and recruitment and, due to limited female data, two currencies of male abundance as a proxy for spawners: (I) all males = 125 mm carapace length (CL); and (2) legal males (= 145 mm CL). Model selection involved AICc, the Akaike Information Criterion corrected for small sample size. An autocorrelated Ricker model using all males and a 5-year lag, with the time series separated into three productivity periods corresponding to different ecological regimes, minimized AlCc values. Depensation at low stock sizes was not detected. Potential effects of selected biotic and abiotic factors on early life survival by Kodiak red king crab were examined by extending the S-R relationship. Results suggested a strong negative influence of Pacific cod Gadus macrocephalus on crab recruitment. Thus, increased cod abundance and a nearshore shift in cod distribution likely impeded crab stock rebuilding.
Nutrition and Technique for Large Scale Larval Culture of the Red King Crab (Paralithodes Camtschaticus) and Blue King Crab (Paralithodes Platypus)
Celeste Leroux, M.S. Marine Biology Degree Candidate
Faculty Advisor: Dr. Ginny Eckert
This presentation will outline a progression of knowledge in large-scale king crab culture through the first two years of the Alaska King Crab Research, Rehabilitation and Biology Program, a collaborative research initiative designed to develop and investigate the feasibility of this technology for the purpose of stock rehabilitation. We collected red king crab (Paralithodes camtschaticus) and blue king crab (Paralithodes platypus) ovigerous females from the wild and reared their larvae in a series of experiments designed to addresses the fundamental role of diet in larval health, growth, and survival. Paralithodes camtschaticus larvae were fed newly hatched Great Salt Lake strain Artemia sp. alone or in conjunction with one of three algae species commonly used in aquaculture which yielded low survival (0.35% [plus or minus] 0.33) to the glaucothoe stage. Mass culture of P. platypus larvae fed newly hatched Great Salt Lake strain Artemia sp. and the algae Isochrysis galbana yielded low survival overall (3.27% [plus or minus] 3.86) with or without the imposed stress of handling for survival assessments. Investigation of the low survival observed in 2007 larval rearing experiments led to biochemical analyses of crab larvae. These results provided baseline data on the proximate composition and fatty acid profiles of newly hatched P. camtschaticus and P. platypus zoeae. Additionally, P. platypus in later larval stages were analyzed for fatty acid composition which elucidated potential concerns regarding the effectiveness of using Great Salt Lake strain Artemia sp. nauplii as a diet, namely low values of EPA and DHA. In 2008, we tested a revised method of enriching San Francisco Bay strain Artemia sp. with DC DCHA SELCO. We observed higher survival for larvae fed enriched (62.19% [plus or minus] 19.4) versus newly-hatched Artemia sp. (1.18 [plus or minus] 0.89). Feeding I. galbana algae did not present a significant effect in zoeal survival. Along the way, many lessons were learned in the mechanical setup of a king crab hatchery and how to effectively conduct scientific research on this scale.
River Features Associated with Chinook Salmon Spawning Habitat in Southwest Alaska
Deena Jallen, MS Fisheries Degree Candidate
Faculty Advisor: Dr. Joe Margraf
Chinook salmon are a highly valued traditional, subsistence, and commercial resource in Southwest Alaska. Stream habitat availability is a major component of salmon productivity. The objective of this study was to identify river features associated with spawning habitat, and describe upper and lower boundaries of Chinook salmon spawning on the Tuluksak River. River distances, elevation, salmon locations, spawning sites, and habitat observations, were collected along 75 rkm of the Tuluksak River primarily within the Yukon Delta National Wildlife Refuge. Habitat and salmon observations were grouped into strata along the length of the river for comparison and analysis. Chinook salmon were observed spawning in the upper 45 rkm of the study area. Map based observations of elevation and channel sinuosity were found to correlate better to Chinook salmon spawning than in stream habitat measurements along the Tuluksak River. This project indicates that the upper boundary of Chinook salmon spawning in the Tuluksak River was outside of our study area. The lower boundary for Chinook salmon spawning habitat on similar rivers might be determined by examining elevation, sinuosity, and channel features from remote images or maps prior to conducting field studies.
Quantifying diet to tissue stable carbon and nitrogen isotope fractionation factors in captive spectacled eiders (Somateria fischeri): Creating a resource for nutrient allocation and foraging ecology studies
Rebekka Federer, SFOS M.S. Marine Biology Candidate
Faculty Advisor: Dr. Tuula Hollmen
Stable isotopes can be used to evaluate foraging ecology and nutrient allocation to reproduction in migratory birds that travel between isotopically distinct habitats (e.g., marine and freshwater). Many sea ducks, including spectacled eiders (Somateria fischeri), spend much of their annual cycle at-sea and travel to freshwater habitats for the breeding period. Spectacled eiders were listed as threatened on the Endangered Species List in 1993, and potential threats affecting their reproductive success and population recovery include changes in the marine prey abundance and availability. Little is known about sources of nutrients and energy required during reproduction, and therefore the development of diet assessment techniques has been listed as a recovery task by the spectacled eider recovery team. Stable isotope analyses of diet and tissues can be incorporated into mixing models to estimate the contribution of different nutrient resources to animal tissues. However, application of stable isotope analyses in dietary or reproductive nutrient allocation models requires knowledge of how the stable isotope signatures of animal tissues differ from their diet, referred to as isotopic fractionation. Captive populations offer an important contribution to these types of models by determining isotopic fractionation factors experimentally. In this thesis, I established the isotopic fractionation factors for diet to egg components using captive spectacled eiders, which had not been previously determined for any sea duck species. Sensitivity analyses indicated that using isotopic fractionation values from different species can considerably alter the results and conclusions. I also determined the isotopic fractionation values for down feathers. These values have not been previously reported for any avian species and could provide an alternate tissue to consider in future studies of nutrient allocation to reproduction. Additionally, I established the isotopic fractionation factors for diet to adult tissues (i.e., cellular blood, blood plasma, adult contour feathers, and subcutaneous fat) in captive spectacled eiders, which will enable researchers to evaluate diet sources/variability and movement patterns across biomes. Finally, I evaluated the effects of incorporating the newly derived diet to egg isotopic fractionation factors into two published sea duck nutrient allocation models that previously used isotopic fractionation values from falcons (Falco spp.). Results from these studies provide further resources to understand foraging ecology and reproductive nutrient allocation modeling in threatened spectacled eiders and may offer more accurate estimates for other sea duck models.
Analysis of Adult Lesson Choices and their Application to Outdoor Education Program Development
Shann Jones, M.S. Interdisciplinary Program Degree Candidate
Faculty Advisor: Dr. Terry Johnson
The physical benefits of recreation across the life span are well documented. Other related research indicates adults also desire to learn throughout life. Such has been the demonstrated by the growth of innovative post-secondary weekend outdoor education events throughout North America that meet both of these human development needs. More specifically, adult fly-fishing programs experience enrollment fluctuations largely due to popular culture. I noticed vast variations in North American fly-fishing curriculum as I developed my own collegiate program the University of Alaska Fairbanks (UAF). Therefore, I asked, "am I teaching adults the fly-fishing topics they want or think they should learn in the post-secondary environment?" I distributed a comprehensive questionnaire distributed to the public to gauge their fly-fishing educational wants and requirements. By analyzing the surveys' results, I created a science-based fly-fishing program that includes these components. This thesis reviews that data analysis and program development. To gauge, whether or not my course offerings met my students' expectations, pre-and post angler/aquatic education questionnaires were distributed, filled out by my class participants and qualitatively analyzed. These questionnaires were distributed to my UAF fly fishing-related program participants from Fall 2005 through Summer 2007 and subsequently analyzed.
An Exploration of the Life History of Broad Whitefish (Coregonus nasus) in Alaska Yukon River
William Carter III, MS Fisheries Degree Candidate
Faculty Advisor: Dr. Trent Sutton
Broad whitefish Coregonus nasus have long been an important subsistence resource for people 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 tries to illuminate 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. Fishwheels were used to capture individuals at a site 1200 km from the mouth of the Yukon River. The CPUE data covers six years and indicates a consistent increase in daily broad whitefish numbers through mid-September. Our 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 near by. Ages of 79 individual ranged from 5 to 16 years (mean=10, median=9). Microchemical analysis using a wavelength-dispersive electron microprobe showed amphidromy in 10 of 12 individuals by examining otolith strontium (Sr) concentrations. These findings provide a platform for further research into the complex life history of broad whitefish.
Fall Semester 2008
The Status of Pacific Walrus (Obobenus rosmarus divergens) Foraging Habitat and Diet Around St. Lawrence Island
Tracie Merrill, M.S. Marine Biology Candidate
School of Fisheries and Ocean Sciences Graduate Program in Marine Science and Limnology
Faculty Advisor: Dr. Brenda Konar
With ongoing climate change, reduced food resources may be negatively impacting Pacific walruses (Odobenus rosmarus divergens). Significant changes in walrus foraging habitat (benthic communities) or diet might indicate changes in prey quality or quantity. In this study, benthic infaunal biomass, abundance, and composition were compared between 1970-1974 and 2006 southwest of St. Lawrence Island. Sediment grain size also was compared because it strongly determines benthic community structure. Additionally, wet weights, counts, and composition of prey items found in walrus stomachs collected near the island were compared between the 1980s and 2007. Contrary to other studies, benthic invertebrate biomass and abundance significantly increased (mainly due to increases in the family Nuculidae). Silt fractions increased within the region. However, no significant dietary changes were detected in walruses. Walruses may have undergone population redistribution or decline in response to benthic community changes that would not be expressed in stomach content analyses.
Characterization of Annual Sex Steroid and Behavioral Profiles in Spectacled Eiders (Somateria fischeri)
Abigail Ellsworth, M.S. Marine Biology Degree Candidate
SFOS, Seward Marine Center, and Alaska Sealife Center
Faculty Advisor: Drs. Shannon Atkinson and Tuula Hollmen
The spectacled eider (Somateria fischeri) population in western Alaska declined by 96% from the 1970s though the 1990s, which led to their listing as threatened under the Endangered Species Act in 1993. Since listing, the breeding population in western Alaska has stabilized, but has not recovered to pre-decline numbers. Little is known about reproductive endocrinology and, more specifically, how sex steroids initiate and modulate reproductive efforts in spectacled eiders. Furthermore, longitudinal assessment of sex steroid profiles in this, and any species, is inevitably difficult using traditional blood sampling methods. In recent studies, measurements of sex steroids in excrement have been shown to reflect circulating hormone levels and provide a non-invasive method to frequently sample and monitor endocrine patterns in avian species. Samples from captive spectacled eiders were used to validate the use of excrement to longitudinally monitor sex steroids in this species. Additionally, fluctuations in annual endocrine profiles were compared to major breeding events and behavioral patterns in order to characterize the breeding season and explore the synchrony of physiology and behavior in these animals. Radioimmunoassay (RIA) techniques measured excreted male testosterone and female total estrogens accurately. The female total estrogen profile indicated that defining the breeding season solely by behavioral landmarks artificially truncated the season, leaving out an important ramp up (i.e. physiological preparation for breeding). The profile also revealed peak total estrogen levels that correspond with the laying period, as well as a non-breeding season peak in mid September. The male testosterone profile revealed peak values only occurring during the breeding season, with elevated levels beginning in mid February and continuing through the end of the laying period in early July. Male courtship and aggressive behaviors were higher during the breeding season than the non-breeding season, indicating a behavioral shift post-lay, however only courtship and male testosterone during post lay were related. These data suggest that excreted sex steroid levels correspond to major breeding landmarks within the annual cycle and this noninvasive method is a valuable research tool for future investigations of hormonal and behavioral correlates in threatened spectacled eiders.
Thermal limitations on Chinook salmon spawning habitat in the northern extent of their range
Samantha Decker, M.S. Fisheries Degree Candidate
Faculty Advisor: Dr. Joe Margraf
Salmon are highly valued ecologically, economically, and culturally; yet some populations are threatened due to habitat alteration and management priorities. Simplifications inherent in many harvest management models often overlook regional habitat influences and typically require long and expensive time series of stock abundance data. Additionally, most salmon habitat modeling research has been conducted in the southern end of the species range; therefore, transferability of this research may be compromised at the northern edge of their distribution. This study investigated the importance of water temperature on the spatial and temporal limits of Chinook salmon spawning on the Chena River, Alaska. While an absolute upstream thermal boundary to spawning was not discovered, thermal limitations in the habitat range during the spawning season were documented. These limitations suggest not only that a thermal boundary exists, but also that thermal limitations influence the overall size of Chinook salmon spawning habitat a the northern edge of their range. This project broadens the geographical range of Chinook salmon habitat research and contributes to the understanding of the geomorphological processes behind salmon habitat. It also provides a baseline for further investigations into water temperature for other species and in other thermal regimes.