• Assessing the potential of Salix alaxensis for the rhizoremediation of diesel contaminated soil

      Starsman, Jessica; Leigh, Mary Beth; Schiewer, Silke; Schnabel, William (2016-08)
      Alaska has over 280 remote communities that rely on diesel as their main source of heat; as a result, there have been multiple diesel spills across the state. Research has shown that plants are able to assist in the degradation of diesel through rhizoremediation, relying on the interaction between microorganisms, plant roots, and other components of the soil environment. Greater attention is now being given to the potential role of secondary plant compounds released during fine root turnover and the stimulatory effects they may have on the rhizoremediation process. For this study the native plant species, Salix alaxensis (felt leaf willow) was chosen. Fine root turnover in the sub-Arctic was mimicked through a microcosm study performed with sub-Arctic soil contaminated with weathered and fresh diesel, incubated at 4 °C and 20 °C. The effect of adding crushed willow roots was compared against addition of pure salicylic acid, a secondary plant compound found in the salicaceae family, and/or addition of fertilizer. Results showed that the addition of crushed fine willow roots with or without fertilizer increased diesel loss. Overall, greater loss and higher respiration occurred at 20 °C. The addition of salicylic acid with or without fertilizer increased soil toxicity. Toxicity may have been the result of observed phenol production and/or fungal growth. Findings show promise for the use of Salix alaxensis for the rhizoremediation of diesel contaminated soils in the sub-Arctic.
    • Assessing the production of sockeye salmon (Oncorhynchus nerka) at Chilkat Lake, Southeast Alaska, using current trophic conditions and the paleolimnologic sediment record

      Barto, David (2004-12)
      Anadromous sockeye salmon are the only Pacific salmon that require an extensive rearing period in a lake environment. Recent studies suggest changes in lake nutrient inputs are directly related to the magnitude of annual spawning populations (escapement), and can be quantified by sediment stable isotope analysis of nitrogen ¹⁵N). Marine nitrogen supplied by returned salmon is enriched in ¹⁵N relative to the freshwater nitrogen, which is derived from atmospheric N₂ (ð¹⁵N=0 ⁰/₀₀). Recent (1987-1996) limnological investigations of Chilkat Lake, Alaska, matched to brood year escapement estimates, indicate that sockeye marine-derived phosphorus and nitrogen contributed up to 87% and 20%, respectively, of the lake nutrient pool. Since salmon populations fluctuate annually, the resulting marine derived nutrient (MDN) inputs and ð¹⁵N also fluctuate. Sedimentary ð¹⁵N is positively correlated (r²=0.8605, p=0.0076, df=5) with observed escapement. Additionally, ð¹⁵N is positively related to lake paleoproductivity and inversely correlated with high concentrations of CaCO₃ and glacial silt. The frequency and duration of these CaCO₃ inputs are believed to be the result of climate related glacial meltwater intrusions from the Tsirku River. Thus, fluctuations in MDN can be shown to influence the overall sockeye salmon production at Chilkat Lake by controlling lake productivity.
    • Assessing year to year variability of inertial oscillation in the Chukchi Sea using the wavelet transform

      Leonard, David (2016-05)
      Three years of ocean drifter data from the Chukchi Sea were examined using the wavelet transform to investigate inertial oscillation. There was an increasing trend in number, duration, and hence total proportion of time spent in inertial oscillation events. Additionally, the Chukchi Sea seems to facilitate inertial oscillation that is easier to discern using north-south velocity records rather than east-west velocity records. The data used in this analysis was transformed using wavelets, which are generally used as a qualitative statistical method. Because of this, in addition to measurement error and random ocean noise, there is an additional source of variability and correlation which makes concrete statistical results challenging to obtain. However, wavelets were an effective tool for isolating the specific period of inertial oscillation and examining how it changed over time.
    • Assessment and application of DNA metabarcoding for characterizing Arctic shorebird chick diets

      Gerik, Danielle Elizabeth; López, J. Andrés; Lanctot, Richard; Gurney, Kirsty; Wipfli, Mark (2018-12)
      Climate change in the Arctic is affecting the emergence timing of arthropods used as food by nesting shorebirds and their young. Characterizing the diets of shorebird young is a prerequisite to evaluate the potential for asynchrony to occur between the timing of arthropod emergence and when shorebird young hatch, an example of trophic mismatch. In this study, DNA metabarcoding was used to identify arthropod remains in feces collected from wild-caught Red Phalarope (Phalaropus fulicarius), Pectoral Sandpiper (Calidris melanotos), and Dunlin (Calidris alpina), young in Utqiaġvik, Alaska between 2014 and 2016. Arthropod specimens were collected at the field site to generate DNA reference sequences from potential prey items. The newly generated sequences in combination with publicly available sequences served as a reference set for species determinations. I assessed the ability of two mitochondrial markers (CO1 and 16s) to detect arthropods in the feces of captive pre-fledged young in controlled feeding experiments. After combining information from both markers, experimental prey taxa were detected in chick feces 82-100% of the time, except for Trichoptera which was never detected. I used the same strategy to characterize the diets of wild-caught shorebird young. The technique detected nearly all prey families documented in historical gut content analyses, as well as 17 novel families. Some of the novel prey diversity may be the result of detecting the prey of prey, known as secondary consumption. We observed that the diets of shorebird young shifted over the course of a summer. Changes in diet generally reflected arthropod composition in the environment estimated from collection of arthropods in pitfall traps. Evidence of diet flexibility by shorebird young suggests that chicks can shift their diets to take advantage of intra-seasonal changes in prey availability. Here, I provide an evaluation and application of DNA metabarcoding to characterize prey resource use by shorebird young for assessing the presence and impacts of trophic mismatch.
    • Assessment and prediction of electroshocked-induced injury in North American fishes

      Holliman, Farland Michael (2003-05)
      Electrofishing has served as an efficient method for scientific sampling of freshwater fishes since the mid-1900s, but it has become apparent since the 1990's that electroshock can cause fish injury. Electroshock-induced fish injury (damage to hard or soft tissues), which is primarily manifested as vertebral fracture or hemorrhage (broken blood vessels) along the backbone, can be a critical determinant of fish survival. The ability to predict factors influencing fish injury rate (the proportion of. injured fish in a sample) would be very useful to biologists. To test the null hypothesis of no effect of electrical waveform (W), voltage gradient (E), and fish size (S) on injury rate, I conducted controlled electroshock experiments on chinook salmon Oncorhynchus tshawytscha, rainbow trout O. mykiss, channel catfish Ictalurus punctatus, largemouth bass Micropterus salmoides, bluegill Lepomis macrochirus, and hybrid striped bass Morone saxatalis x M. chrysops. Data collected included electrical stimulus, fish behavioral response (R), length (L) and weight (W), and injury status (present/absent). Vertebral injury was determined using radiography, and hemorrhage by bilateral filleting. My model selection criteria, which was based on Akaike's Information Criterion (AIC), indicated that risks for both types of injury in chinook salmon and channel catfish were best represented by the (W, E, S) model, the (W, S) model for both types of injury in rainbow trout, the (W, E) model for hemorrhage and the (W, E, S) model for vertebral injury in largemouth bass, the (W) model for both injury types in hybrid striped bass, and, that risk for injury in bluegill injury was best described by the null model (no effect of W, E, S). A mechanistic model relating electrical stimulus, the force of contraction, and the resistance to contraction to electroshock-induced injury, using (R) as a surrogate for electrical stimulus, (L) as a surrogate for force of contraction, and vertebral count (V) as a surrogate of resistance to injury, was explored. Application of the mechanistic model (R, L, V) to the pooled data set demonstrated a strong predictive relationship. This model offers guidance for the reduction and prevention of electroshock-induced injury for all species in all situations.
    • Assessment And Prediction Of Potentially Mineralizable Organic Nitrogen For Subarctic Alaska Soils

      Zhao, Aiqin; Zhang, Mingchu (2011)
      The objective of this study was to identify a rapid laboratory technique to predict potentially mineralizable organic N for subarctic Alaska soils. Soil samples were taken from major agricultural area of subarctic Alaska. Laboratory incubation followed by kinetic model fit was first used to select a best model to estimate potential soil N mineralization. By correlating the model estimated organic N pool sizes and different chemical extracted organic N, I then found the best chemical method to estimate soil potentially mineralizable N. Spectroscopic properties of water extractable organic matter were also determined and correlated with model estimated organic N pool sizes in order to improve the estimation of soil mineralizable N pool. Finally, the best chemical method and spectroscopic property were used in the selected best kinetic model for the prediction of soil N mineralization in field incubation. Model comparisons showed that models with fixed rate constants were better than that the ones with rate constants estimated from simulation. Among models with fixed rate constants, fixed double exponential model was best. This model differentiated active mineralizable organic N pool with a fixed rate constant of 0.693 week-1 and slow mineralizable organic N pool with a fixed rate constant of 0.051 week-1. By correlating model estimated organic N pool size and chemical extracted organic N amount, I found that the potentially mineralizable organic N size was closely correlated with hot (80 �C) water extractable organic N or 1 M NaOH hydrolysable organic N. By correlating model estimated organic N size and spectroscopic characteristics of water extractable organic matter, I found that the active mineralizable organic N pool was correlated with humification index in cold (22 �C) water extraction (R 2=0.89, p<0.05), which indicates that characterizing extracted organic matter was a useful tool to improve the estimation of soil organic N pools. In summary, potential mineralizable organic N in soils from subarctic Alaska can be estimated by hot water extractable organic matter or 1 M NaOH hydrolysable organic N, which accounted for 70% and 63% of the variation in potentially mineralizable organic N, respectively. This approach will provide fundamental insight for farmers to manage N fertilizer application in agricultural land and also provide some basic information for ecologists on predicting N release from Alaska soil that can be used for assessing the N impact on ecosystem.
    • Assessment of contaminant concentrations and transport pathways in rural Alaska communities' solid waste and wastewater sites

      Mutter, Edda Andrea; Schnabel, William; Barnes, David; Duddleston, Khrys; Duffy, Lawrence; Hagedorn, Birgit (2014-05)
      Waste management practices currently employed in many rural Alaska communities are potentially contributing to human and environmental health impacts, and this problem may be exacerbated with the anticipated warming climate. For rural communities, factors that contribute to insufficient waste management practices include climate and environmental conditions, limitation of federal and state capital funding for construction, and the continuing financial burden associated with providing adequate operations and maintenance. As a response, federal regulatory exemptions are granted for construction and design of solid waste sites and limited state regulations are in place for wastewater discharge criteria. Due to the absence of proper site assessment and monitoring, very little is known about the fate and transport of point source pollutants arising from these wastewater and solid waste sites. Moreover, these fate and transport processes may be susceptible to changes resulting from human activity or a warming climate. Thus, this knowledge gap associated with waste-related pollutants in rural Alaska could obscure potential threats to human and environmental health by concealing impacts to freshwater systems. This research was intended to achieve a better understanding of rural Alaska waste leachate compositions by evaluating contaminant prevalence and diversity, quantifying contaminant concentration levels, and evaluating their potential migration into nearby freshwater systems. Over the course of three years, waste sites at five rural Alaska communities were sampled and tested for heavy metals, organic constituents, and microbial indicator organisms. The purpose of the analysis was to evaluate the impact of waste sites on soil, surface, and subsurface waters in the vicinity of the sites. The resulting findings are assembled into three chapters describing 1) the assessment of heavy metal leachate in rural Alaska solid waste sites, 2) the identification of new emerging organic pollutants in rural Alaska waste sites, and 3) the partitioning and transport behavior of pathogen indicator organisms in cold regions. The research outcome of E.coli and Enterococcus sp. were observed in waste impacted water and soil samples, heavy metal migration into nearby freshwaters, and pharmaceuticals, phthalates, and benzotriazole in waste impacted water samples. The research findings highlight the need to apply state regulations to remove potentially hazardous components from rural Alaska wastewater and municipal solid waste streams. Additionally, there is a need to establish effective solid waste and wastewater leachate monitoring and assessment strategies for active and closed rural Alaska waste sites.
    • Assessment of formation damage from drilling fluids dynamic filtration in gas hydrate reservoirs of the North Slope of Alaska

      Kerkar, Prasad B.; Patil, Shirish L.; Chukwu, Godwin A.; Dandekar, Abhijit Y.; Khataniar, Santanu (2005-08)
      Gas hydrates in the Alaska North Slope, with a potential of 590 TCF gas-in-place near existing infrastructures of Prudhoe Bay, Kuparuk River and Milne Point Units, have sparked interest among unconventional energy experts. Drilling through gas hydrates has always been critical as a source of heat into the formation, leading to dissociation of hydrates. Moreover, the recent drive toward open hole completions and highly deviated or horizontal wells have emphasized the need for evaluation of drilling or completion fluids suitability from a perspective of formation damage. A significant decrease in well productivity near the well-bore can occur due to the invasion of fine solids from drilling fluids, forming external and internal filter cake under dynamic conditions. An experimental setup for the evaluation of formation damage at in-situ conditions was designed. The dynamic filtration experiments were conducted with Berea sandstone cores. The absolute permeability was measured both before and after the drilling fluid circulation. The drilling fluid type, its flow rate, and shear rate, effective particle size, additive concentration, and amount of overbalance were found to influence drilling mud leak-off volume and the post mud circulation permeability.
    • Assessment of high latitude variability and extreme events in the Bering Sea as simulated by a global climate model

      Walston, Joshua M.; Walsh, John E.; Gibson, Georgina A.; Bhatt, Uma S. (2014-08)
      Atmospheric and Oceanic observations of the Arctic and Subarctic are relatively sparse and hinder our ability to analyze short term variability and long-duration anomalies of physical and biological variables over decadal time scales. Earth System Models (ESM's), such as the Community Earth System Model (CESM1), represent a useful tool to advance the understanding and the predictive potential of large-scale shifts in the climate and climate related impacts. This thesis initially focuses on assessing the skill of the Community Climate System Model (CCSM4), to capture natural variability of the climate system. Subsequently, I examine the impacts of variability and seasonal-scale extremes of the physical environment on the marine ecosystem of the eastern Bering Sea as simulated by an earth system model, the CESM1, which includes the CCSM4 and earth system elements. A performance assessment of key atmospheric components (air temperature, sea level pressure, wind speed and direction) simulated by the CCSM4 over the Bering Sea and Arctic domains suggests a general improvement in model predictions at high latitudes relative to the model's predecessor, the CCSM3. However, several shortcomings, with possible implications for marine ecosystem modeling, still remain in this version of the CCSM. The most important of which includes an under-simulated Siberian High and a large northwest displacement of the Aleutian Low resulting in a negative bias of up to 8 hPa over the Bering Sea. The simulated inter-annual variability of surface air temperature and sea level pressure over the Bering Sea was found to exceed observed variability by ~1.5 to 2 times. The displaced pressure systems and increased variability could have important ramifications for modeling efforts that use CCSM atmospheric output as drivers for marine ecosystem studies.
    • Assessment of LiDAR and spectral techniques for high-resolution mapping of permafrost on the Yukon-Kuskokwim Delta, Alaska

      Whitley, Matthew Allen; Maio, Christopher V.; Frost, Gerald V.; Jorgenson, M. Torre (2017-05)
      The Yukon-Kuskokwim Delta (YKD) is one of the largest and most ecologically productive coastal wetland regions in the pan-Arctic. Formed by the Yukon and Kuskokwim Rivers flowing into the Bering Sea, nearly 130,000 square kilometers of delta support 23,000 Alaskan Natives living subsistence lifestyles. Permafrost on the outer delta commonly occurs on the abandoned floodplain deposits. Ground ice in the soil raises surface elevations on the order of 1-2 meters, creating plateaus on the landscape. Better drainage on the plateaus supports distinct Sphagnum-rich vegetation, which in turn protects the permafrost from rising air temperatures with low thermal conductivity during the summer. This ecosystem-protected permafrost is thus vulnerable to disturbances from rising air temperatures, vegetation mortality, and inland storm surges, which have been known to flood up to 37 km inland. This thesis assesses several novel techniques to map permafrost distribution at high-resolution on the YKD. Accurate baseline maps of permafrost extent are critical for a variety of applications, including long-term monitoring. As air and ground temperatures rise across the Arctic, monitoring landscape change is important for understanding permafrost degradation processes (e.g. thermokarst) and greenhouse gas dynamics from the local to global scales. This thesis separately explored the value of Light Detection And Ranging (LiDAR) and spectral datasets as tools to map permafrost at a high spatial resolution. Furthermore, this thesis sought to automate these processes, with the vision of high-resolution mapping over large spatial extents. Fieldwork was conducted in July 2016 to both parameterize and then validate the mapping efforts. The LiDAR mapping extent assessed a 135 km² area (~15% permafrost cover), and the spectral mapping extent assessed an 8 km² area (~20% permafrost cover). For the LiDAR dataset, the use of a simple elevation threshold informed by field ground truth values provided a permafrost map with 94.9% accuracy. This simple approach was possible because of the extremely flat terrain. For the spectral datasets, an ad-hoc masking technique was developed using a combination of texture analysis, principal component analysis, and morphological filtering. Two contrasting workflows were evaluated with fully-automated and semi-automated methods with mixed results. The highest mapping accuracy was 89.4% and the lowest was 79.1%, though the error of omission in mapping the permafrost remained high (7.02 - 59.7%) for most analyses. The spectral mapping algorithms did not replicate well across different high-resolution images, raising questions about the viability of using spectral methods alone to track thermokarst and landscape change over time. However, incorporating the spectral methods explored in this analysis with other datasets (e.g. LiDAR) has the potential to increase mapping accuracies. Both the methods and the results of this thesis enhance permafrost mapping efforts on the YKD, and provide a good first step to monitoring landscape change in the region.
    • Assessment of particulate accumulation climatology under inversions in Glacier Bay for the 2008 tourist season using WRF/Chem data

      Pirhalla, Michael A.; Mölders, Nicole; Bhatt, Uma; Polyakov, Igor; Gende, Scott (2014-05)
      Each summer, roughly one million tourists come to Southeast Alaska aboard cruise ships to see the pristine landscape and wildlife. Tourism is an integral component in the economy for most of the towns and villages on the Alaska Panhandle. With ship emissions only modestly regulated, there have been some concerns regarding the potential environmental impacts that cruise ships have on air quality, wildlife, and visitor experience. Cruise ships travel to remote regions, and are frequently the only anthropogenic emissions source in federally protected parks, such as Glacier Bay National Park and Preserve. In the absence of winds and synoptic scale storm systems common in the Gulf of Alaska, temperature inversions frequently develop inside Glacier Bay due to radiative cooling influenced by the complex topography inside the park. Inversions act as a lid, and may trap pollutants from cruise-ship emissions depending on the meteorological conditions present. Since meteorological observations are sparse and frequently skewed to easily accessible locations, data from the Weather Research and Forecasting Model, coupled with a chemistry package (WRF/Chem), were used to examine the physical and chemical processes that are impossible to determine through direct observations. Model simulation data for 124 days during the 2008 tourist season (May 15 to September 15), including a cruise-ship emission inventory for all 225 cruise ship entries in Glacier Bay, was analyzed. Evaluation of WRF/Chem through meteorological observations reveals that the model accurately captures the synoptic conditions for most of the summer, despite problems with complex topography. WRF/Chem simulated quasi-multi-day inversion events, with strengths as high as 6.7 K (100 m)⁻¹. Inversions were present in all grid-cell locations in Glacier Bay, with inversions occurring on average of 42% of the days during the tourist season. WRF/Chem was able to model PM₁₀ (particulate matter with diameter less than 10 μm) concentrations from cruise ships, but the absence of aerosol monitoring sites does not allow us to confirm the results. However, no simulated particulates ever exceed the daily average National Ambient Air Quality Standard (NAAQS) of 150 μg m⁻³. The high variability of particle concentrations in Glacier Bay suggests the need for an air quality observational network to further assess local air quality issues.
    • An assessment of suspended sediment transport in Arctic Alaskan rivers

      Lamb, Erica K.; Toniolo, Horacio; Schnabel, William; Kane, Douglas (2013-05)
      Provided here is an initial assessment of suspended sediment transport in several rivers on the North Slope of Alaska. This study was divided into two parts: the Umiat project, which involved the Chandler, Anaktuvuk and Itkillik Rivers, and the NPR-A study, which considered Prince, Seabee and Fish Creeks, as well as a brief look at the lkpikpuk River, Otuk Creek, Judy Creek and the Ublutuoch River. Methods used included depth-integrated suspended sediment samples, grab samples, automatic pump-style samplers, discharge measurements, bed sediment grain size analysis and the inclusion of a variety of meteorological measurements from other projects. With slightly less than two years of data collection from May 2011 to September 2012, an initial analysis was completed. Suspended sediment rating curves developed for the Anaktuvuk and Chandler Rivers over the two-year study period revealed a strong correlation between suspended sediment concentration (SSC) and discharge. The most data was collected for the Anaktuvuk and Chandler Rivers; on these rivers, suspended sediment discharge was also analyzed, showing that over 90% of suspended sediment transport occurred during the spring melt period in 2011. Spring melt was not measured in 2012, so analysis was only completed for 2011.
    • Assessment of the benthic environment following offshore placer gold mining in Norton Sound, northeastern Bering Sea

      Jewett, Stephen Carl; Smith, Ronald L. (1997)
      The effects of placer gold mining on the benthic environment of Norton Sound in the northeastern Bering Sea were assessed. Research focused on red king crab Paralithodes camtschaticus, a species with commercial and subsistence importance in the Sound and seasonal occurrence in the mining area. The study addressed mining effects on: (1) benthic macroinvertebrates, many serving as food for this crab, (2) crab relative abundance, distribution, and food, and (3) heavy metal concentrations in crabs. Mining on variable substrates in $<$20 m water depths occurred between 1986-90 during ice-free months when crabs were further offshore. Sampling nearly a year subsequent to mining revealed moderate substrate alteration. Benthic community parameters and abundance of numerically predominant families (e.g., owenid, spionid, and capitellid polychaetes and echinarachniid sand dollars) were reduced in mined areas. Many reduced taxa are known crab prey. Although young individuals of opportunistic taxa predominated, taxa were generally smaller at mined areas. Multi-year surveys of a once-mined area showed continued smoothing of bottom relief. Ordination of taxon abundance from mined (1 yr after mining), recolonizing (2-7 yrs after mining), and unmined stations reflected decreasing station disturbance. At least four years were required for benthos to recover from mining. Mining had a negligible effect on crabs. Crab catches, size, sex, and most prey groups in stomachs were similar between mined and unmined areas. Concentrations of eight heavy metals in muscle and hepatopancreas tissues were generally not different in mined areas. Furthermore, these metals were not different in sediments upcurrent and downcurrent of mining. Concentrations of most metals in tissues showed no temporal trend. Elemental concentrations in muscle tissues were below or within the range of concentrations in red king crabs from other North Pacific locations. Most metals from Norton Sound crabs were well below federal guidance levels for human consumption. Effects from mining were apparent for benthic macrofauna with virtually no effects observed for king crabs. Absence of any demonstrable effects of mining on this crab is primarily a result of the high natural dynamics of the Sound and opportunistic feeding behavior and high mobility of the crab.
    • Assessment of the oyster market distribution chain and its implications for cooperative formation in the Alaska mariculture industry

      Harrington, Erin D. (2005-05)
      Market preference for attributes of Alaska-produced Pacific oysters (Crassostreas gigas) is studied using survey techniques. Oyster buyers in the continental United States are surveyed to determine the relative importance of intrinsic and extrinsic product attributes, ranging from oyster size to seasonal availability patterns. Implications of market preferences for the development of mariculture cooperatives are then considered. Extrinsic product characteristics such as a good business reputation, frequency and seasonality of product availability, and product price were relatively important to respondents when compared to intrinsic product characteristics such as size, shape, or presence of grit in the oyster.
    • Assessment of the reproductive ecology of harbor seals (Phoca vitulina) and northern sea otters (Enhydra lutris kenyoni) in Alaska using subsistence biosampling programs

      Hutchinson, Emily A.; Atkinson, Shannon; Hoover-Miller, Anne; Kruse, Gordon; Wynne, Kate (2014-08)
      Harbor seals (Phoca vitulina) and northern sea otters (Enhydra lutris kenyoni) in Alaska have experienced extreme fluctuations in abundance in recent decades. The purpose of this study was to examine growth and determine the age and size at sexual maturity in populations of these two species, as spatial and temporal variations in environmental conditions and changes in ecological constraints as a result of population fluctuations can influence growth and reproductive characteristics of individuals. All samples for this research were collected via biosampling, the collection of measurements and biological tissue samples, as a component of subsistence harvesting by Alaska Natives. In Chapter 1, morphometric measurements and reproductive tracts were collected by the Alaska Native Harbor Seal Commission's Biosampling Program from female harbor seals harvested throughout the Gulf of Alaska from 1998 through 2005. Seals attained an asymptotic standard length (SE) of 147.7 ± 2.6 cm and body mass of 82.2 ± 4.8 kg. Female harbor seals did not mature until a minimum age of 3 yr, a standard length of 122 cm, and a weight of 48 kg. The average age of sexual maturity was 4.2 ± 0.7 yr (95% CI). Fetal growth was measured by standard length, curvilinear length, axillary girth, the cube root of fetal mass, skull length, condylobasal length, zygomatic width, and skull width against the day of the year the mother was harvested. The x-intercept of the linear regression of each fetal growth measurement against the day of the year produced estimates of the implantation date that ranged from September 22nd to October 17th, with a mean date of September 30th ± 8 d (SD). Harbor seals from this study are smaller in length, have a later implantation date, and are larger at sexual maturity compared to harbor seals in the Gulf of Alaska from the 1960s. In Chapter 2, morphometric measurements and reproductive tracts were collected by a Native Alaskan subsistence hunter from 40 male sea otters near Gustavus, in Southeast Alaska. The maximum recorded standard length and axillary girth were 160 cm and 78.7 cm, respectively. Sexual maturity was assessed by the histological examination of the testes and epididymides and the subsequent measurement and characterization of the seminiferous tubules. Male sea otters in the region reached sexual maturity at 3 to 4 yr of age, after attaining a standard body length of 130 cm., a mean seminiferous tubule diameter of 140 µm, and a baculum length of 14 cm. Sea otters outside Gustavus, Alaska exhibit increased body size and lower ages of sexual maturity compared to sea otters in other regions of Alaska, suggesting that resources are abundant and are not limiting maturation rates of male sea otters near Glacier Bay. In the future, as anthropogenic influences continue to increase and environmental conditions fluctuate, biosampling programs will be an invaluable tool for continued monitoring of marine mammals in Alaska.
    • Assessment of tight gas sands in Cook Inlet Basin

      Patel, Kanhaiyalal U.; Ogbe, David O.; Zhu, Tao; Patil, Shirish L. (2005-05)
      The Cook Inlet Basin is the source for all of the natural gas used in south-central Alaska. The estimated ultimate recovery from existing Cook Inlet gas fields is approximately 8.5 trillion cubic feet (tcf) and the proven reserves remaining on January 1, 2004 were 1.8 tcf. It will be difficult to meet the peak demand for gas in south-central Alaska after 2009. Cook Inlet Basin contains vast quantities of unconventional gas resources in tight sands. Resources-in-place and producible gas reserves from the tight sands are unknown. It is likely that these tight sands will be developed as additional gas reserves and will be produced along with the high permeability conventional gas reserves in order to meet both local and export demands. The objectives of this study are to quantify the distribution of tight gas sands; to estimate the resources in place and producible gas reserves in the Cook Inlet Basin; and to predict the post-stimulation gas production. Rate transient analysis, well log analysis and reservoir stimulation analysis were therefore conducted on selected key tight sand wells. Results indicate that the tight gas can play an important role in meeting south-central Alaska's gas demand beyond 2009.
    • Assessment of total mercury and methyl mercury in selected subsistence fish in Western Alaska

      Zhang, Xiaoming; Duffy, Lawrence K.; Kelly, John J.; Naidu, Satyanarayan (2001-08)
      Total Hg (THg) and methylmercury (MeHg) were examined in muscle and liver samples of salmon species (Chinook: Oncorhynchus tshawytscha; Chum: O. keta; Sockeye: O. nerka; Coho: O. kisutch) and freshwater fish species (Pike: Esox lucius; Grayling: Thymallus arcticus; Whitefish: Caregonus nelsoni) collected in 1999 and 2000 from the Western Alaska rivers (Yukon, Kuskokwim, Nushagak and Kvichak). The THg in salmon muscles has a mean value of 62 ng/g (ww). In Pike muscles, THg has a mean value of 879 ng/g. The mean concentrations of THg in Grayling and Whitefish muscle are 153 ng/g and 32 ng/g respectively. In salmon muscle and liver the MeHg levels constitute 77% and 62% of the THg levels, respectively. In Pike muscle the MeHg levels constitute 100% of the THg levels. A significant correlation between Hg levels and fish length was found. Calculated consumption limits indicate that children may consume 0.05-1.5 kg of fish per month, depending on the species consumed. The study suggests that, from 1979 to 1998, nearly 21 kg of MeHg was transported by Sockeye salmon to the Alaskan rivers of the Bering Sea east coast.
    • An assessment of trap efficiency to estimate coho salmon smolt abundance in a small Alaskan stream

      Eskelin, Anthony Alexander (2004-08)
      Smolt abundance is commonly estimated using trap efficiency-based methods; however, few studies have investigated the accuracy of trap efficiency estimates. The objectives of this study were to: (1) test the hypotheses that (i) trap efficiency is not affected by release timing nor release distance, (ii) trap efficiency-based estimates of smolt abundance are concordant with smolt-adult mark-recapture estimates, and (2) evaluate if water level and turbidity influence trap efficiency. In Deep Creek, Alaska, during 2001 and 2002, coho salmon Oncorhynchus kisutch smolt abundance was estimated using trap efficiency-based methods and compared to independent smolt-adult mark-recapture estimates. Marked smolts were released at two times of day (1200 hours and 0000 hours) and two release distances upstream of the trap (400 m and 1500 m) every 2 to 4 d throughout each year. Trap efficiency estimates were highly variable (range 0%-55%) and trap efficiency-based estimates of abundance were not concordant with smolt-adult mark-recapture estimates. Release timing and turbidity significantly influenced trap efficiency, whereas release distance did not. Several assumptions of the trap efficiency approach were not met, which produced biased estimates and conflicting results among years when comparing estimation techniques. These results suggest that assumptions of the trap efficiency-based methods be fully assessed to accurately estimate smolt abundance.
    • Assisting adolesecents transitioning from residential treatment to public school

      Church, Sylvia; Cook, Christine; Morotti, Allan; Simpson, Joni (2017-05)
      This research project aims to aid residential treatment facilities and school personnel in recognizing the importance of transition planning, developing strategies to assist a successful transition from inpatient residential treatment centers to the students next school, while also taking into account adolescent perspectives on their needs during this transition. This paper introduces the importance of addressing education while in treatment and explores barriers to aftercare and current aftercare models using an ecological model to recognize how multiple systems interact in shaping the experiences of students. Included in this paper is a small pilot study of three students that attended a residential treatment program at the Boys and Girls Home of Alaska. It is important to note that since interviews were conducted, the Boys and Girls Home of Alaska no longer operates in the State of Alaska and is now under new ownership. The application resulting from this project is a presentation for both treatment and school staff.
    • Assisting school personnel with youth transitioning from residential treatment to a school environment

      Smith, Kristi; Cook, Christine; McMorrow, Samantha; Gifford, Valerie (2015-12)
      The following research project examines the data and literature regarding youth who reside in residential treatment centers for behavior and mental health purposes. The paper introduces common risk factors that youth are experiencing which contribute to their placement in the facilities, as well as the difficulties they face upon exiting the treatment program. This project explores how schools can assist students in the transition from residential treatment to a school setting using a bio-ecological model that supports the students on an individual level up to a systemic level. School counselors serve as a key point of contact for transitioning students and can help teachers to understand this population and introduce supports both in the classroom and schoolwide. Teachers will also learn how to identify and modify potential negative stigmas, frustrations, and thought processes by practicing cognitive behavior techniques. The application resulting from the project is a counselor lead in-service for elementary through high school teachers, administrators, and student support services personnel.