• Learning to work and think for life

      Sprankle, Elizabeth; Daku, Mike; Duke, J. Robert; Boldt, Frank (2019-08)
      This paper explores literature related to the use of restorative discipline and restorative practices in school communities. It draws heavily on the ideas presented in Ron and Roxanne Claassens’ book, Discipline that Restores, in order to illustrate why students, staff, administrators, families and the community connected to a traditional public high school, such as West Valley High School, in Fairbanks, Alaska, would benefit from shifting to a restorative approach to discipline. The paper also examines numerous sources to demonstrate why embedding lessons related to social justice and restorative practices into content areas is logical and beneficial and attainable and that both these embedded courses and this approach to discipline support and foster content related to a Career Technical Education pathway focused on Education, Public & Human Services.
    • Leaving Centralia and other stories

      Small, Sarah; Brightwell, Geri; Kamerling, Leonard; Harney, Eileen (2018-05)
      In the eight short stories within this collection, we encounter characters against a variety of backdrops, from the mundane--middle school shop class, and a short road trip--to the more bizarre--a town with an underground fire predicted to burn for two hundred years, and a forbidden island potter's field. Many of the protagonists are adolescents, positioned between their childhood, when they played a more passive role in their own lives, and adulthood, when they more deliberately make decisions about their own actions and lives. However, in all of these settings and regardless of age, the characters find that it is not under exceptional circumstances but through the course of the ordinary moments in their daily lives that they encounter testing points for their maturity and integrity.
    • Leaving King Island: The Closure Of A Bureau Of Indian Affairs School And Its Consequences

      Braem, Nicole M.; Schneider, William (2004)
      By 1966, the King Island Inupiat had moved from their island village and lived at Nome. Little has been written about the de facto relocation of the King Islanders---and how and why it happened. What follows is an ethnohistory of the relocation based on the anthropology and history of the Bering Strait region, archival records of the Bureau of Indian Affairs and interviews with King Islanders in Nome. The heart of the matter was the village's school. Based on the evidence, the BIA closed the school because of the expense and inconvenience of operating at King Island. This accomplished what the BIA had been unable for decades to do by persuasion---to move the village to the mainland. The immediate result of the closure, the resettlement of the villagers in Nome, fits within the established pattern of BIA policy over time, one that had assimilation as its ultimate goal.
    • The legacy of shamans? Structural and cognitive perspectives of prehistoric symbolism in the Bering Strait region

      Qu, Feng; 曲, 枫; Potter, Ben; Schweitzer, Peter; Plattet, Patrick; Koester, David (2013-08)
      This research explores the meanings of prehistoric artistic artifacts discovered in the Bering Strait region. The research focuses on the prehistoric period between AD 100 and 1700, including Okvik culture, Old Bering Sea culture, Punuk Culture, Birnirk Culture, Thule culture, and Ipiutak Culture. My archaeological data in this research were collected from the archaeological collections of the Okvik site on Punuk Islands, the Kukulik site on St. Lawrence Island, and the Nukleet site at Cape Denbigh at the University of Alaska Museum of the North. Based on abundant ethnographic records from the Bering Strait region, this research relies on ethnographic analysis as methodology to approach prehistoric symbolism. Applying ethnographic analysis results in diverse interpretations of the archaeological artifacts, which bear potential spiritual or secular meanings. Theoretically, the research provides an assessment of contemporary archaeological theories such as cognitive archaeology, structural archaeology, and shamanism theory (general shamanism theory and the neuropsychological model) in order to examine the reliability of these theories in the study of prehistoric art. Due to the problems of cognitive, structural, and shamanism theories, the conclusion of this research builds on practice theory and animist ontology to interpret the variants of art productivity, cosmological structures, and relationship between humans and materials.
    • Length-based models and population analyses for northern shrimp Pandalus borealis Krøyer

      Fu, Caihong (2000-08)
      The lack of basic knowledge on stock dynamics o f northern shrimp Pandalus borealis, a protandric hermaphrodite, has caused difficulty in regulating fishing effort on a scientific basis and in understanding potential causes behind population fluctuations and collapses. Previous length-based population models (LBMs), developed for other species, are undesirable primarily for two reasons: (1) individual cohort dynamics are masked; (2) variations in annual natural mortality (M) are ignored. This research was primarily aimed at developing a more advanced LBM that provides estimates of parameters such as recruitment (R), fishing mortality (F) and especially annual M. Simulation-estimation experiments were conducted to evaluate model performance. Despite model complexity, annual M can be well estimated provided measurement errors in survey biomass estimates are low. The common assumption of constant M created biased parameter estimates. Estimated M of P. borealis in Kachemak Bay, Alaska increased steadily in the 1980s. Retrospective projections showed that the increasing trend in M in the 1980s resulted in the population collapse. The ultimate goal o f stock assessment is to develop sound harvest strategies. With the widely observed abundance fluctuations in shrimp populations, it is impossible to manage solely based on conventional methods, such as maximum sustainable yield (MSY). Thus, harvest strategies were compared under various situations o f M and R. With M increasing over time, it is important to execute threshold management, i.e., closing the fishery at population levels below a threshold value. Simulations indicated that overfishing caused by underestimated M or overestimated R can be greatly alleviated if the population is sampled once every year. Life history aspects of sex change, growth, M, and their seasonal variations were also incorporated into the LBM. Populations with protandrous animals are likely to be subject to recruitment overfishing; merely protecting older females while allowing high exploitation on younger males can lead to population collapse. Fishing after spring egg hatching is superior to fishing after mating and egg extrusion in fall when F is high. In summary, the length-based model developed here provided a convenient framework for understanding population processes and harvest strategies and should be useful for a variety of hard-to-age species.
    • Lesson plans for the seventh grade Alaska State standards in language arts

      Gieser, Kenneth E. (2014-04)
      The SBE (standards-based education) reform movement calls for clear, measurable standards for all school students. Rather than norm-referenced rankings, a standards-based system measures each student against the concrete standard. Curriculum, assessments, and professional development are aligned to the standards. However, many teachers find standards burdening and restrictive, and it has been challenging for teachers to infuse them with her, or his personal passions. The purpose of this project is to demonstrate that not only can these new standards be taught effectively, but that teachers can find them accommodating enough for their passions. This project's outcome will include lesson plans, activities, and assessments, along with my personal reflection as to the efficacy of using these new standards without losing the passion for teaching with them.
    • "Let us die trying": a post-colonial reading of Velma Wallis

      Myers, Seth G. (2006-05)
      This essay explores the work of Velma Wallis from the perspective of post-colonial theory. Her works, Two Old Women and Bird Girl and the Man who Followed the Sun are read within this theoretical framework as volatile and resistant texts, in opposition to readings that might limit their meaning as ethnographic or otherwise. I outline the generalities of my theoretical framework with reference to Edward Said and Homi K. Bhabha, before I approach a discussion of Native American literature and Velma Wallis specifically. Within this theoretical framework, I find that Wallis resists, not only generic definition, but the larger structures of colonialism, through an exploration of resistance within so-called colonized groups. She performs this resistance by demonstrating the power of language, that survival is itself resistant, the resistance of feminism, and the importance of positive dialogue in a world of cultural contact.
    • Letters as literature: semantic and discursive features of irony in "Letters to Howard"

      Cook, Corinna Jo; Schneider, William; Koester, David; Ruppert, James (2011-12)
      This thesis examines the literary features of the Letters to Howard, a series of letters to the editor of the Alaskan newspaper, the Tundra Times. Published over the course of several months in 1973, the letters were signed by two semi-fictional characters: an old Eskimo man, Naugga Ciunerput, and a lost VISTA volunteer, Wally Morton, the two lone inhabitants of the imagined Land's End Village, Alaska. Naugga and Wally had a pointed agenda: they were addressing editor Howard Rock and his readership with their concerns regarding the newly-passed Alaska Native Claims Settlement Act, or ANCSA. In truth, Naugga and Wally's letters were written by two graduate students, Fred Bigjim (an Inupiaq from Nome studying education) and James Ito-Adler (a law student who had switched to anthropology). The use of irony in these letters is the subject of my analysis here; I focus first on the semantic layers of irony and second on its discursive dimensions. This thesis' ultimate goal is to illuminate the ways in which these letters contest history, frame the nature and distribution of power, and examine the myriad tensions at play between Native peoples' historic, cultural, and political ties to the land.
    • Leveraging Alaska North Slope satellite oil field design with networked instrumentation and control systems architecture - Foundation Feldbus

      Chouinard, Brian A. (2000-05)
      Since 1988, oil production rates on Alaska's North Slope have faded. The West Sak oil field in the Greater Kuparuk Area was a satellite field targeted to help slow the production decline. The nature of West Sak oil made it prohibitively expensive to produce using conventional methods. Drastic changes in field production design and operational philosophy were required to make West Sak oil economically viable. The instrumentation and controls network architecture leveraged the implementation of this new design and philosophy. This paper examines the technological requirements, establishes evaluation criteria, compares competing options, outlines the design and implementation, and discusses future prospects. In addition, a functional description of the selected technology, Foundation Fieldbus, is presented from the users perspective.
    • A lexical transducer for North Slope Iñupiaq

      Bills, Aric R.; Tuttle, Siri; Levin, Lori; Berge, Anna; Kaplan, Lawrence (2011-05)
      This thesis describes the creation and evaluation of software designed to analyze and generate North Slope Iñupiaq words. Given a complete lñupiaq word as input, it attempts to identify the word's stem and suffixes, including the grammatical category and any inflectional information contained in the word. Given a stem and list of suffixes as input, it attempts to produce the corresponding Iñupiaq word, applying phonological processes as necessary. Innovations in the implementation of this software include Iñupiaq-specific formats for specifying lexical data, including a table-based format for specifying inflectional suffixes in paradigms; a treatment of phonologically-conditioned irregular allomorphy which leverages the pattern-recognition capabilities of the xfst programming language; and an idiom for composing morphographemic rules together in xfst which captures the state of the software each time a new rule is added, maximizing feedback during software compilation and facilitating troubleshooting. In testing, the software recognized 81.2% of all word tokens (78.3% of unique word types) and guessed at the morphology of an additional 16.8% of tokens (19.4% of types). Analyses of recognized words were largely accurate; a heuristic for identifying accurate parses is proposed. Most guesses were at least partly inaccurate. Improvements and applications are proposed.
    • Liberation dreamin’ (a good time holiday eight-track for the real American)

      Sanders, Craig S.; Brightwell, Geraldine; Farmer, Daryl; Schell, Jennifer (2016-05)
      The eight short stories that make up Liberation Dreamin’ follow protagonists who yearn to be heroes, saviors, caretakers, and liberators. These are characters fueled by the power of metaphor, lost in the idea of America as they expose the fabulism of reality itself through their absurd attempts to realize their often idealistic wishes and longings. They hunt treasure in the forest of northwestern Pennsylvania, shoot hot air balloons out of the sky, run major celebrities down with their cars on nights of blinded judgment, and even kidnap roadrunners. They stage protests for bigots’ funerals, wage strange wars with dairy farm animals, have misguided epiphanies in checkout lanes, and write urgent letters to Santa Claus himself. These pieces seek to render the biblical commonplace and highlight the profundities of everyday trivialities. As is suggested by the collection’s parenthetical subtitle, A Good Time Holiday Eight-Track for the Real American, these are stories that strive to be musical. In this book of satire and ridiculous narratives, imaginary human beings are at home in their preoccupation with holidays and anniversaries. A sociopolitical commentary on the American Dream and dreams in general, Liberation Dreamin’ runs on anger, humor, foreign policy, and ultimately hope.
    • Lichen Availability on the Range of an Expanding Caribou (Rangifer tarandus) Population in Alaska

      Fleischman, Steven J.; Klein, David R.; Thompson, Steven K.; Viereck, Leslie A.; White, Robert G.; Regelin, Wayne L. (1990-05)
      Terrestrial lichen abundance, lichen availability as affected by snow, and winter fecal composition were investigated for the Delta Caribou Herd (DCH), which recently quadrupled in size and expanded its early winter range. Mean lichen abundance was relatively low (10-85 g/m2). However, even on heavily-used range, caribou ate only 7% of lichen standing crop annually. Snow affected lichen availability only slightly on peripheral tundra ranges, since lichens predominated on xeric sites with little snow. On traditional ranges, lichens were shorter and rarely found in high-density patches; disproportionate grazing and trampling of exposed lichens had caused reduced lichen availability. This was reflected in lower fecal lichen for caribou on traditional ranges, however DCH population growth or seasonal movements probably were not substantially affected. A model of caribou cratering energetics indicated that loss of potential foraging time may influence energy balance more than does cratering energy expenditure.
    • Lidar and radar studies of turbulence, instabilities, and waves in the Arctic middle atmosphere

      Li, Jintai; Collins, Richard L.; Newman, David E.; Simpson, William R.; Thorsen, Denise L.; Williams, Bifford P. (2019-08)
      This dissertation presents new studies of gravity waves and turbulence in the Arctic middle atmosphere. The studies employ lidars and radar to characterize wave activity, instability and turbulence. In the lidar-based studies, we analyze turbulence and wave activity in the MLT based on lidar measurements of atmospheric temperature, density and sodium density, temperature and wind. This combination of measurements provides simultaneous characterization of both the atmospheric stability as well as material transport that allow us to estimate the eddy diffusion coefficient associated with turbulence. We extend the scope of previous studies by developing retrievals of potential temperature and sodium mixing ratio from the Rayleigh density temperature lidar and sodium resonance density lidar measurements. We find that the estimated values of turbulent eddy diffusion coefficients, K, of 400-2800 m²/s, are larger than typically reported (1-1000 m²/s) while the values of the energy dissipation rates, ε, of 5-20 mW/kg, are more typical (0.1-1000 mW/kg). We find that upwardly propagating gravity waves accompany the instabilities. In the presence of instabilities, we find that the gravity waves are dissipating as they propagate upward. We estimate the energy available for turbulence generation from the wave activities and estimate the possible turbulent energy dissipation rate, εGW. We find that the values of εGW are comparable to the values of ε. We find that the estimate of the depth of the layer of turbulence are critical to the estimate of the values of both ε and εGW. We find that our method tends to overestimate the depth, and thus overestimate the value of ε, and underestimate the value of εGW. In the radar-based study, we conduct a retrieval of turbulent parameters in the mesosphere based on a hypothesis test. We distinguish between the presence and absence of turbulence based on fitting Voigt-based and Lorentzian-based line shapes to the radar spectra. We also allow for the presence and absence of meteoric smoke particles (MSPs) in the radar spectra. We find examples of Poker Flat Incoherent Scatter Radar (PFISR) spectra showing both the presence and absence of turbulence and the presence and absence of MSPs in the upper mesosphere. Based on the analysis, we find that relatively few of the radar measurements yield significant measurements of turbulence. The significant estimates of turbulence have a strength that is over a factor of two larger than the average of the estimates from all of the radar measurements. The probability of true positives increases with the quality factor of the spectrum. The method yields significant measurements of turbulence with probabilities of true positives of greater than 30% and false positives less than 0.01%.
    • Lidar and satellite studies of noctilucent clouds over Alaska

      Alspach, Jennifer H.; Collins, Richard; Bossert, Katrina; Thorsen, Denise; Fochesatto, Javier (2020-05)
      This thesis presents studies of noctilucent clouds (NLCs) occurring in the summer polar mesosphere over Alaska. Lidar observations of NLCs conducted at Poker Flat Research Range in Chatanika, Alaska (65° N, 147° W) from 1998-2019 are analyzed. The NLCs detected by lidar are characterized in terms of their brightness properties and duration. NLCs were detected on ~51% of the nights when lidar observations have been conducted during NLC season. The brighter NLCs are found to exist at lower altitudes, indicating a growth-sedimentation mechanism. Cloud Imaging and Particle Size (CIPS) data from the Aeronomy of Ice in the Mesosphere (AIM) satellite is used to examine NLC occurrence and brightness over the Alaska region (60-70° N, 130-170° W). In general, high frequency and brightness in the CIPS data corresponds to positive detections of NLCs by the lidar. Microwave Limb Sounder (MLS) temperature and water vapor data from the Aura satellite is used to investigate the meteorological environment of the NLCs observed by lidar at Chatanika. The occurrence of NLCs at Chatanika is found to be driven by the temperature relative to the frost point. Low temperatures relative to the frost point (> 4 K below) correspond to observations when NLCs were present. High temperatures relative to the frost point (> 8 K above) correspond to observations when NLCs were absent. The MLS data is also used to investigate the stability of an ice cloud at different latitudes (64.7°-70.3° N) relative to the equilibrium water vapor mixing ratio. The stability study suggests that the weakest NLCs detected by lidar at Chatanika were in subsaturated conditions, and it is likely that the NLCs formed over several hundred kilometers to the north of Chatanika. The Rayleigh three-channel receiver system was used to conduct NLC measurements during 2019. A technical overview of the three-channel system and the density and temperature retrieval methods is presented at the end of the thesis using observations from the winter of 2018 and the summer of 2019.
    • Life after CHOPS: the Alaskan heavy oil reservoir perspective

      Mathur, Bakul; Dandekar, Abhijit; Khataniar, Santanu; Patil, Shirish (2017-05)
      The heavy oil reservoirs in Alaska offer major production challenges, including proximity to the permafrost layer, very high viscosity oil and low mechanical strength pay zones. The Ugnu deposits of the Alaska North Slope (ANS) hold more than 6 billion barrels of oil. The dead oil viscosity at reservoir temperature ranges from 1,000 to 1,000,000 cp1. In an effort to sustain well life, this research focuses on the unique set of challenges occurring in the Ugnu reservoir and presents the best possible way to maximize production. The present research accentuates observations derived from the field data, which shows that deliberate sand production with the hydrocarbon stream while employing a Progressive Cavity Pump (PCP) as an artificial lift method has a favorable effect on primary oil recovery. The developments have led to the advent of a technique called Cold Heavy Oil Production with Sand (CHOPS) as an initial production method for shallow heavy oil reservoirs. Sand production leads to the formation of high porosity channels or wormholes that can range up to hundreds of meters. The co-mingling of heavy oil and sand develops foamy oil by creating a bubbly flow inside the reservoir. The combination of these wormholes with the foamy oil behavior are the primary factors that result in enhanced production during CHOPS. One of the major hindrances to its successful application is the selection of the post-CHOPS production method, which is addressed in this study with the help of modeling and simulation. Alternative recovery techniques following the primary cold production include water flooding, polymer injection, miscible gas injection and thermal recovery methods. Water flooding is unviable because of the mobility contrast between the highly viscous oil and water. The high permeability zones provide a bypass for water, consequently producing elevated water cuts. Another aspect unique to Alaskan heavy oil reservoirs is the proximity to the permafrost layer, with the hydrocarbon bearing zone making thermal recovery methods unappealing. Polymer injection and miscible gas injection become the favorable non-thermal secondary and tertiary recovery methods in this case. This study is based on modeling one of the wells drilled into the M80 sands of the Ugnu formation followed by the analysis of post-CHOPS recovery for the well. The CHOPS well modeling is done with the help of a wormhole fractal pattern and a foamy oil model. Simulation of the polymer injection is then employed from a nearby well. The results indicate almost 12% increment in recovery with polymer flooding as compared to the natural depletion. The recovery obtained from the simulations have been analyzed to provide a basis for designing the polymer injection job as an Enhanced Oil Recovery (EOR) method after CHOPS. With the promising results of this study, it can be determined that the Ugnu reservoir sands can be exploited for heavy oil with the help of polymer flooding. It can also be combined with miscible gas flooding or alkali-surfactant flooding to obtain even higher hydrocarbon recoveries.
    • Life history and management of the grayling in interior Alaska

      Wojcik, Frank J. (1955-04)
      Field work on the Arctic grayling was conducted from September, 1951, to May, 1953; data on movements, spawning, food habits, sex ratios, and population dynamics were obtained. Returns on 1,222 tagged grayling varied from 0 to 20 per cent with areas. No returns were obtained from 165 fin-clipped fish. Fish entered the streams in the spring as soon as water started flowing, the dates varying from March 15 to May 9, 1952. Spawning in the Little Salcha River during 1952 is believed to have occurred between June 12 and June 16, Of 262 grayling checked for maturity, 18.7 per cent were mature in their fourth summer, 45 per cent in their fifth summer, and all by their sixth summer. Sex ratios obtained for adults varied with areas. The average sex ratio found for all areas was 79 males per 100 fem ales. The rate of growth was determined for grayling from six areas. The average increment for class V fish varied from 2.7 to 4.6 cm. per year. Aquatic insects were the main food organisms taken by grayling. Some terrestrial insects, fish, fish eggs and vegetable, matter were also taken. In view of the findings made in this study, overfishing appears to be the major cause of the decline in the sizes of grayling populations along the highways in the Fairbanks area. A twelve-inch minimum size limit is apparently the best management procedure, although an area closure is advisable for overfished spawning runs.
    • Life history characteristics, management strategies, and environmental and economic factors that contribute to the vulnerability of rockfish stocks off Alaska

      Patt, Jacqueline; Criddle, Keith; Gharrett, Anthony; Love, Milton; Heifetz, Jonathan (2014-12)
      This study explored the extent to which variations in biological characteristics, environmental and economic factors, and management strategies have affected the tendency for rockfish to become overfished. The analysis used data on 5 species of rockfish that account for more than 95% of commercial catch of rockfish in the Gulf of Alaska (GOA) and Bering Sea and Aleutian Island (BSAI) management regions. These species are: Shortraker Rockfish (Sebastes borealis), Pacific Ocean Perch (Sebastes alutus), Northern Rockfish (Sebastes polyspinis), Dusky Rockfish (Sebastes variabilis), and Shortspine Thornyhead (Sebastolobus alascanus). Fishery management models often treat BMSY, the biomass level that maximizes sustainable yield, as a critical reference point; whenever the biomass of a federally managed fish or shellfish stock is estimated at less than 0.5×BMSY, the stock is declared "overfished" and managers are required to develop a recovery plan that will restore stock abundance above BMSY within about one generation length. Because estimates of BMSY are unavailable for some GOA and BSAI rockfish stocks included in this analysis and because we were interested in developing a model that could be applied to data-poor stocks, we explored two proxies for BMSY. The mean of past estimates of exploitable biomass (avgExpB) was used as a proxy for BMSY for the better-studied stocks. The mean of past catch (avgC) was used as a proxy for BMSY for data-poor stocks. These values were used to scale time series estimates of exploitable biomass (ExpBt) or catch (Ct). A systems estimation approach, seemingly unrelated regression (SUR), was used to estimate parameters of linear and nonlinear models that included available numerical and categorical variables (biological, management, environmental, and economic factors) thought to contribute to increases or decreases in ExpBt / avgExpB or Ct / avgC. Goodness-of-fit statistics and tests of individual coefficients and groupings of coefficients were used to guide model refinement. The modeling approach worked well for better-studied stocks but not for data-poor stocks. The preferred 5-stock model (Pacific Ocean Perch in the GOA and BSAI, Northern Rockfish in the GOA and BSAI, and Dusky Rockfish in the GOA) had an excellent fit to the overall system (R² = 0.922, P << 10⁻⁶) and statistically significant coefficient estimates of the variables included. The model indicated that the past values of ExpBt / avgExpB can be accounted for through time and across stocks by nonlinear variation in: spawning biomass, intrinsic growth rates (k), maximum age, exploitation rates, habitat preferences, Pacific Decadal Oscillation, and ex-vessel price. Because some of these factors are subject to management control and others are predictable, it should be possible to take account of anticipated changes in these factors when setting harvest targets and harvest limits, selecting spatial management strategies, or considering changes to harvest control rules or fisheries governance systems.
    • The life history of Effie Kokrine through personal recordings

      Freiburger, Annette J.; Schneider, William S.; Morrow, Phyllis; Mangusso, Mary C. (2013-08)
      This thesis is a combination of tape transcriptions and research to document the life history of Athabascan leader Effie Folger Kokrine. Effie Kokrine was well known in the Interior of Alaska, but her impact reached much farther, and in many directions, as she loved to travel and share her stories with people in many different states and in several other countries. Sharing stories was only one of her many talents. She was an Alaska Native culture educator, a champion dog musher, an expert seamstress, skin sewer and beader, hunter, fisher, cook and bottle washer. Effie stayed active and busy right until her sudden death from heart failure. She believed that every person should contribute to the well-being of the community, and she did her part by volunteering with the Junior Dog Musher's Association, the American Legion Post #11 Women's Auxiliary, the Badger Lion's Club, and speaking to almost every group that invited her, which was many. The only reason that she would turn someone down who invited her to speak was if she had a prior commitment. She was a favorite speaker of various groups, especially those involving children, because of her history, and because of her humor. The intent of this thesis is to attempt to capture some of that history and share some of the stories.
    • The life history of the intertidal barnacle, Balanus balanoides (L.) in Port Valdez, Alaska

      Rucker, Tami Louise (1983-09)
      The life history of the boreo-arctic barnacle Batanus balanoides was examined at three study sites in Port Valdez. Ovarian tissue development began in early summer. Fertilized eggs, evident by September, were brooded throughout the winter. Larval release was synchronous with the spring phytoplankton bloom. Settlement was observed in April and continued until June. Maximal shell growth occurred immediately subsequent to assimilation of organic material from the spring bloom. Seasonal fluctuations in body weight were noted and reflect feeding, spermatogenesis, and energy transfer to other biological processes (i.e., shell growth and reproduction). Mortality, greater for juveniles than adults, resulted from seasonal stresses (lowered salinity and heightened sedimentation), spatial competition, predation, and pollutants (hydrocarbons). Once life-history events were confirmed for barnacles in Port Valdez, comparisons of trends observed at the three sites were possible. Differences between populations were evident and were attributed to the unique micro-habitats of the study sites.
    • Life History, Demography, And Ecology Of The Spiny Dogfish "Squalus Acanthias" In The Gulf Of Alaska

      Tribuzio, Cindy A.; Kruse, Gordon; Fujioka, Jeff; Gallucci, Vince; Hillgruber, Nicola; Lowe, Chris; Woodby, Doug (2010)
      The spiny dogfish (Squalus acanthias) is a small, cosmopolitan shark species, common in sub-tropical and sub-arctic waters. The species is often targeted commercially in most areas of the world throughout its range, and in some cases it is overfished or the subject of conservation concern. In the Gulf of Alaska, spiny dogfish are not targeted and not generally retained, but incidental catches can be high for this schooling species. Previously, biological parameters for spiny dogfish in the Gulf of Alaska were assumed from estimates for this specie's neighboring areas, including British Columbia and Washington State. The purpose of this study was to examine spiny dogfish in the Gulf of Alaska and estimate important parameters for stock assessment in four stages: (1) general biology, distribution, and life history; (2) modeling age and growth; (3) population demographic modeling; and (4) ecological interactions revealed by diet analysis. Spiny dogfish are similar in length in the Gulf of Alaska to neighboring regions, but mature at larger sizes and have a greater fecundity than reported elsewhere. There is high natural variability in estimated ages for the species, which is reflected in the poor fit of the growth models, possibly owing to measurement error from using the dorsal fin spine as the aging structure. A two-phase growth model provided the statistical best fit. However, questions were raised about the biological interpretation of the model and whether more traditional models (e.g., von Bertalanffy and Gompertz) may be more appropriate. Using the life-history and growth data, Leslie matrix type age- and stage-based demographic models were created to estimate sustainable fishing mortality rates and to examine the risk of harvest scenarios. Female Gulf of Alaska spiny dogfish can support up to a 3% annual harvest rate; fisheries that target juveniles have the greatest risk of population decline below threshold levels. Spiny dogfish are generalist opportunistic feeders that feed on whichever prey is available, however shrimp are the most important prey type, followed by cephalopods. Results of this study will be used in future ecosystem modeling and stock assessments for this species. Taking into account the history of targeted fisheries for the species on the U.S. east coast and in British Columbia and Washington, as well as the susceptibility of the species to overfishing, fishery managers will need to take a cautious approach should a target fishery develop in the Gulf of Alaska.