• Can tax policy change exploration levels? A case of Alaska oil legislation.

      Tappen, Samuel Weston; Baek, Jungho; Little, Joseph; Reynolds, Douglas (2014-08)
      This thesis applies modern Autoregressive Distributed Lag modeling techniques to estimate the effects of oil tax policy in the case of the 2007 ACES legislation on exploratory drilling within Alaska. This analysis uses recently released public data to examine the period of 1986 to 2013 in quarterly intervals which includes all periods in which ACES was in place. While this subject has become a popular subject of debate within the state and industry, no similar statistical analysis has been conducted to date. According to the results, ACES had a significantly negative and lasting effect on exploration levels while it was in effect. The oil price and interest rate are also found to be important variables in characterizing exploration activity.
    • Can We Remain Yup'ik In These Contemporary Times? A Conversation Of Three Yugtun-Speaking Mothers

      Michael, Veronica E.; Marlow, P. (2010)
      The Yup'ik people of southwestern Alaska are experiencing language shift from Yugtun to English. This study is a conversation between three Yugtun speaking mothers who are trying to understand this shift and wondering if they can maintain their identity, and that of their children, in this changing world. The study takes place in the village of Kuiggluk. Data collection included a research journal and focus group discussions. In this study, I have tried to paint a picture of who we are as Yup'ik mothers in our contemporary lives. Qayaruaq, Mikngayaq and I carry with us our own mothers' teachings, while at the same time we face different situations in school and schooling. Through our discussions we sought to understand the reasons for language loss/shift -- a shift that seems to be driving us away from our culture.
    • Canenermiut lifeways and worldview and western fish and wildlife management

      Jack, Carl T. (2002-12)
      The Canenermiut inter-generational worldview embodies the proper use and conservation of the resources necessary to sustain life from time immemorial. The classical Yupiaq conservation ethics in the utilization of subsistence resources are well established and practiced to this day by Canenermiut that is geared to the survival of their culture and community. When western fish and wildlife managers promulgate regulations from urban areas of Alaska on the taking of subsistence resources in rural Alaska they often find out that rural residents such as the Canenermiut ... are unwilling to follow the regulations. Caneneq is a coastal area between Kusquqvak (Kuskokwim) Bay up to Qaluyaaq (Nelson Island). Canenermiut is made up of two Yupiaq words, Caneneq as defined earlier and the suffix miut is a Yup'ik word defined as occupant of that geographic area or a place. The people from these villages see the imposition of the western precepts of fish and wildlife management systems as efforts by outsiders to control their way of life. They see this effort as inconsistent with their worldview of how a human should fit within the creation of a higher being. These people do not participate in the formulation of public policies or the promulgation of the regulations that affect their lives and as a consequence do not have a sense of ownership of them. The Canenermiut worldviews are fundamentally different from the worldview of the people of European origin who brought with them concepts of lifeways foreign to Alaska's indigenous people. The author of this thesis is one of Canenermiut from the Native Village of Kipnuk, who was raised by his parents the traditional Yupiaq way of life and taught by his uncle the art of hunting and fishing. He is also one who was also educated in schools of the dominant western society. As one of many other Alaska Native children who were subjected to the assimilation effort of the United States government in the image of the Other, the author is very cognizant of both the Other's lifeways and the classical Yupiaq lifeways ... The author having lived in both worlds, the world of Canenermiut in the Native Village of Kipnuk and in Anchorage will attempt to articulate the major components of Canenermiut worldview. This is a worldview that western fish and wildlife managers do not understand but ones that may help in enhancing the conservation and utilization of these subsistence resources. Secondly, the author will attempt to articulate the degree of the paradigm shift in the Canenermiut indigenous value system that has occurred among this generation. The desire of the Canenermiut to retain their cultural value system and to control their destiny is affirmed by the author. In addition, as the precepts of fish and wildlife management systems are accepted over time by Alaska Native people outside of the geographic area of Caneneq, the Canenermiut do not want to be left behind and have a strong desire to- participate in these management systems.
    • Capacitance measurements of bulk salinity and brine movement in first-year sea ice

      Backstrom, Lars G. E. (2007-05)
      Sea ice is an important component of the global climate system, as it changes the properties of the ocean-atmosphere interface. Understanding sea ice requires detailed knowledge of its temperature and bulk salinity. To measure these attributes using non-destructive in-situ techniques, instruments were frozen into first-year sea ice, and analysed jointly with ice-core, mass balance and climate data. The bulk salinity of the ice is calculated from measurements of temperature and complex dielectric permittivity at 50 MHz in landfast ice in McMurdo Sound, Antarctica, the Chukchi Sea, Alaska, and in an outdoor tank experiment in Fairbanks, Alaska. A simple relation for estimating brine volume fraction and bulk salinity in columnar, bubble-free ice from the real part of the complex dielectric permittivity was derived. For relative brine volumes below 50-70 % the error in the derived bulk salinity was below 15%. The observed brine movement events are analyzed. The data clearly indicate the extent and impact of brine movement on ice temperature and salinity. The analysis of a drainage event recorded by both the temperature and dielectric permittivity probe provided insight into gravity drainage of brine driven by a large brine reservoir in the freeboard layer.
    • CARBON AND NITROGEN ASSIMILATION IN THE CLAMS NUCULANA RADIATA AND MACOMA MOESTA FROM THE BERING SEA

      Weems, Jared; Iken, Katrin; Gradinger, Rolf; Wooller, Matthew (University of Alaska Fairbanks, 2011-08)
      The predicted climate-induced reduction in sea ice presence in the Bering Sea could impact benthic trophic interactions; however, species-specific consumer dependence on ice algal production is largely unknown. My objective was to track feeding in the benthic clams, Nuculana radiata and Macoma moesta, using stable carbon and nitrogen isotopes. Nuculana radiata had slow isotopic assimilation rates, with lipids taking up isotope markers fastest and muscle tissue the slowest. Lipids may thus be particularly suitable to track the immediate ingestion of sea ice algal export in benthic consumers. When isotopically enriched food was added to natural sediment cores, N. radiata assimilated 60% less of the isotope markers than when feeding on algal food in isolation. Possibly, this difference is related to the ingestion of other, naturally present food sources in the sediment. Macoma moesta showed 30% higher isotopic assimilation compared to N. radiata in sediment cores. I suggest that differing feeding behaviors between the species provide differential access to the sedimented algal food. Based on these results, N. radiata is likely better able to utilize food sources buried in the sediment and may be more competitive over M. moesta under conditions of reduced ice algal production in the northern Bering Sea.
    • Carbon And Nitrogen Flows In Zero -Water Exchange Shrimp Culture: Inferences Using Stable Isotope Tracers

      Epp, Michelle A.; Schell, Donald M. (2002)
      Nutrient and energy flow in cultures of Pacific White Shrimp, Litopenaeus vannamei, were examined in zero-water exchange, 1200--1300 L mesocosms at the Oceanic Institute (OI), Waimanalo, Hawaii. A technique was developed for monitoring shrimp use of formulated feeds through the addition of stable isotopically labeled nutrients to the feed ingredients. Crystalline amino acid compounds were ineffective as labels due to their rapid dissolution in the tank water with feed pellet break-up. Labels which were 'packaged' as algal cells prior to addition to the feed pellets were more effectively incorporated into shrimp tissues than crystalline label (approximately 27% versus 8% for crystalline label). The 'packaged' label technique was also used to test soluble proteins from pollock processing wastes (stickwater) as a feeding stimulant for Litopenaeus vannamei. Indoor controlled condition experiments and outdoor experiments with natural pond biota compared stickwater amended feed to squid liver powder amended feed for growth and assimilation by the shrimp. Initial results indicated that pollock processing by-products might function as a feeding stimulant in shrimp aquaculture. The addition of 15N-ammonium to outdoor shrimp tanks showed that natural tank production contributed significantly to shrimp growth requirements providing between 17 and 77% of the growth nitrogen. When labeled ammonium was added to black covered tanks, shrimp had slower growth rates (0.5 g/wk as compared to 0.7 g/wk for uncovered ammonium addition tanks) but significant uptake of this label, with a tank biota contributing 23%. This finding supported a bacterial role in shrimp nutrition that will require further study. Isotopic analysis of individual amino acids in shrimp muscle from outdoor tanks with and without added 15N-ammonium further established the role of tank natural populations to shrimp nutrition. Rapid increases in delta 15N for threonine one day after label addition suggested an increased requirement for this essential amino acid. Further identification of the contribution of tank biota to shrimp amino acid profiles will require profiles of the delta 15N of specific amino acids for suspended particulate organic matter.
    • Carbon And Nitrogen Isotope Ratios In Bowhead Whales (Balaena Mysticetus) And Their Zooplankton Prey As Indicators Of Feeding Strategy And Environmental Change.

      Vinette, Kimberly Ann; Schell, Don (1993)
      This study details regional, seasonal and inter-annual differences in $\delta\sp{13}$C and $\delta\sp{15}$N of zooplankton in the Bering and Chukchi Seas. These isotopic variations were correlated with inter-annual and long-term variations in $\delta\sp{13}$C and $\delta\sp{15}$N of bowhead whale baleen.<p> Statistical analyses indicate significant $\sp{13}$C-enrichment in Bering/Chukchi seas zooplankton relative to Beaufort Sea zooplankton, supporting the observed trends of $\sp{13}$C-depletion at higher latitudes and enrichment at lower latitudes. Bering/Chukchi seas zooplankton show a weak trend in $\sp{13}$C-depletion between 1987-1990, possibly due to inter-annual environmental changes affecting phytoplankton $\delta\sp{13}$C. The $\delta\sp{13}$C of baleen produced in fall/winter months is inversely correlated to sea surface temperature trends in the Bering Sea. Long-term changes in baleen $\delta\sp{13}$C may be helpful in assessing past climatic change.<p> The observed $\delta\sp{15}$N oscillations in baleen may be due to changes in trophic level of prey between seasonal feeding grounds or from physiological cycles in the bowhead whale. <p>
    • Carbon and nitrogen uptake dynamics during 1997 and 1998 anomalous conditions in the Bering Sea

      Rho, TaeKeun (2000-12)
      During 1997 and 1998, unusual physical conditions caused dramatic changes in the regional oceanic environment and function of the southeastern Bering Sea ecosystem. The changes in ecosystem function were examined using ¹³C and ¹⁵N tracer techniques. In 1997, unusually clear and calm conditions allowed an ice-related early bloom over the middle shelf of the southeastern Bering Sea and resulted in nitrate uptake below the pycnocline. In 1998, the duration of phytoplankton growth was extended by warm temperatures and frequent storms that resulted in slow growth of phytoplankton and prevented rapid utilization of nitrate over the shelf. In coccolithophorid bloom regions, ammonium concentrations were high (>3 uM), while nitrate concentrations had a larger range (O.1-10.8 uM). Nitrate utilization rates, which estimate 'new' production, were similar for both years and were somewhate greater (ca. 30%) than those observed during the 70's and 80's PROBES studies. The fate of primary production may have differed in 1997 and 1998.
    • Carbon biogeochemistry of the eastern Bering Sea shelf

      Cross, Jessica; Mathis, Jeremy; Feely, Richard; Stockwell, Dean; Weingartner, Thomas; Whitledge, Terry (2013-12)
      The uptake of anthropogenic carbon dioxide (CO₂) has caused perturbations to marine biogeochemistry in recent years, including decreasing ocean pH and carbonate mineral saturation states (Ω). Collectively termed ocean acidification (OA), these conditions hinder the growth of calcium carbonate shells and effectively reduce habitat for some marine calcifiers. Given that the Bering Sea is one of the world's most productive marine ecosystems and supports both commercial fishing industries and subsistence communities, it is integral to understand its susceptibility to OA. Here, new observations of the organic and inorganic carbon systems are used to identify mechanisms leading to CO₂ accumulation and sub-regional enhancement of vulnerability to OA processes. Chapter 1 describes the state of knowledge of OA in this area, highlighting two regions where low Ω conditions are consistently observed: near the coast, and over the northern shelf. Chapter 2 describes net heterotrophic processes near the coast, in conjunction with low bottom water Ω. Chapter 3 examines this heterotrophy in more detail, showing that focused deposition of organic matter and its subsequent respiration. Chapters 4 and 5 focus on very low Ω values observed over the northern shelf. In combination with natural respiration processes, anthropogenic CO₂ was shown to cause low Ω and seasonal dissolution of carbonate minerals in Chapter 4. Chapter 5 illustrates how sea ice cover inhibits the flux of CO₂ from the surface ocean to the atmosphere, which raises the inventory of CO₂ in the water column. These results are synthesized in Chapter 6. Low-Ω conditions and areas of carbonate mineral dissolution will continue to expand as anthropogenic CO₂ accumulates in shelf waters in the coming decades, further reducing viable habitat for key calcifiers. Model projections of future surface water conditions indicate that average Ω over the Bering Sea shelf will drop below the observed natural variability by 2100, with average conditions favoring carbonate mineral dissolution in surface waters by 2150. Presently, episodic events will cause regions of the Bering Sea to be undersaturated in Ω, which could have significant and cascading impacts throughout the Pacific-Arctic region.
    • Carbon Cycling In Three Mature Black Spruce ( Picea Mariana [Mill.] B.S.P.) Forests In Interior Alaska

      Vogel, Jason Gene; Valentine, David (2004)
      Climate warming in high latitudes is expected to alter the carbon cycle of the boreal forest. Warming will likely increase the rate of organic matter decomposition and microbial respiration. Faster organic matter decomposition should increase plant available nutrients and stimulate plant growth. I examined these predicted relationships between C cycle components in three similar black spruce forests (Picea mariana [Mill] B.S.P) near Fairbanks, Alaska, that differed in soil environment and in-situ decomposition. As predicted, greater in-situ decomposition rates corresponded to greater microbial respiration and black spruce aboveground growth. However root and soil respiration were both greater at the site where decomposition was slowest, indicating greater C allocation to root processes with slower decomposition. It is unclear what environmental factor controls spruce allocation. Low temperature or moisture could cause spruce to increase belowground allocation because slower decomposition leads to low N availability, but foliar N concentration was similar across sites and root N concentration greater at the slow decomposition site. The foliar isotopic composition of 13C indicated soil moisture was lower at the site with greater root and soil respiration. From a literature review of mature black spruce forests, it appears drier (e.g. Alaska) regions of the boreal forest have greater soil respiration because of greater black spruce C allocation belowground. Organic matter characteristics identified with pyrolysis gas chromatography-mass spectrometry correlated with microbial processes, but organic matter chemistry less influenced C and N mineralization than did temperature. Also, differences among sites in C and net N mineralization rates were few and difficult to explain from soil characteristics. Warming had a greater influence on C and N mineralization than the mediatory effect of soil organic matter chemistry. In this study, spruce root C allocation varied more among the three stands than other ecosystem components of C cycling. Spruce root growth most affected the annual C balance by controlling forest floor C accumulation, which was remarkably sensitive to root severing. Predicting the response of black spruce to climate change will require an understanding of how spruce C allocation responds to available moisture and soil temperature.
    • Carbon exchange and permafrost collapse: implications for a changing climate

      Myers-Smith, Isla Heather (2005-05)
      With a warmer climate, the wetlands of Interior Alaska may experience more frequent or extensive stand-replacing fires and permafrost degradation. This, in turn may change the primary factors controlling carbon emissions. I measured carbon exchange along a moisture transect from the center of a sphagnum-dominated bog into a burned forest (2001 Survey Line Fire) on the Tanana River Floodplain. Both the bog and the surrounding burn were sinks for CO₂, and the bog was a CH₄ source in the abnormally dry summer of 2004. Thermokarst and subsiding soils were observed on the margin of the bog in the three years since the fire, increasing the anaerobic portion of the soil landscape. I observed the greatest variation in carbon fluxes in this portion of the transect. I conclude that permafrost collapse is altering the pattern of emissions from this landscape. I tracked historical changes in vegetation, hydrology and fire at this site through macrofossil, charcoal and diatom analysis of peat cores. The paleoecological record suggests that fire mediates permafrost collapse in this system. This study indicates that future changes in temperature and precipitation will alter carbon cycling and vegetation patterns across this boreal landscape.
    • Carbon flux and particle-associated microbial remineralization rates in the northern Bering and southern Chukchi seas

      O'Daly, Stephanie Hicks; McDonnell, Andrew M. P.; Hardy, Sarah M.; Johnson, Mark A. (2019-12)
      It has been hypothesized that climate change will reduce the strength and episodic nature of vernal phytoplankton blooms, increase heterotrophy of microbes and zooplankton, and weaken the tight coupling between pelagic and benthic production that is characteristic of Arctic continental shelves. As a part of the Arctic Shelf Growth, Advection, Respiration, and Deposition rates measurement (ASGARD) project, I quantified sinking particle fluxes and incubated sinking particles to measure the rate of microbial respiration associated with those particles. These measurements were used to characterize the strength of the pelagic-benthic connection. After a record-breaking year of warm temperatures and low-ice conditions in the northern Bering and southern Chukchi Seas, we observed massive vernal fluxes of sinking particulate organic carbon, ranking amongst the highest observed in the global oceans. Moreover, low rates of particle-associated microbial respiration indicate negligible recycling of sinking organic matter within the water column. These results suggest that the strength of the biological carbon pump may be maintained or enhanced in a warming Arctic, supporting strong benthic and upper trophic level productivity and carbon export.
    • Carbon isotopic composition of polycyclic aromatic hydrocarbons and their weathering in Kachemak Bay sediment

      Borland, Tara Ann (2004-05)
      Identification of sources of polycyclic aromatic hydrocarbons (PAH) in sediments is an important step in reducing anthropogenic contamination. Identifications based solely on the composition of PAH can be confounded by compositional changes during weathering and biodegradation. Stable isotopic composition of individual PAH offer a source marker that may be less susceptible to alteration. The [alpha]¹³C values of PAH in major potential sources to the Kachemak Bay area were analyzed. To determine the stability of the [alpha]¹³C values of PAH in crude and diesel oil, microbial degradation experiments using sediment from the Kachemak Bay, Alaska, area were conducted over a one-year period. The impact of weathering on the isotopic composition of North Slope crude oil and diesel oil was also examined over a five-week period in aquaria with Macoma balthica, an intertidal bivalve. For both degradation experiments, PAH concentrations decreased and their composition changed, but the [alpha]¹³C values of individual PAHs remained stable. Hence, [alpha]¹³C values of individual PAHs have excellent potential as a relatively stable indicator of their sources. Based on isotopic and compositional data, the PAH in Kachemak Bay sediments appear to have several sources.
    • Carbon Sequestration In Alaska's Boreal Forest: Planning For Resilience In A Changing Landscape

      Fresco, Nancy; Chapin, Stuart (2006)
      Northern ecosystems and those who rely upon them are facing a time of unprecedented rapid change. Global boreal forests will play an important role in the feedback loop between climate, ecosystems, and society. In this thesis, I examine forest carbon dynamics and the potential for carbon management in Interior boreal Alaska in three distinct frameworks, then analyze my results in the context of social-ecological resilience. In Chapter 1, I analyze comparative historical trends and current regulatory frameworks governing the use and management of boreal forests in Russia, Sweden, Canada, and Alaska, and assess indicators of socio-ecological sustainability in these regions. I conclude that low population density, limited fire suppression, and restricted economic expansion in Interior Alaska have resulted in a 21st-century landscape with less compromised human-ecosystem interactions than other regions. Relative wealth and a strong regulatory framework put Alaska in a position to manage for long-term objectives such as carbon sequestration. In Chapter 2, I model the landscape-level ecological possibilities for sequestration under three different climate scenarios and associated changes in fire and forest growth. My results indicate that Interior Alaska could act as either a weak carbon source or as a weak sink in the next hundred years, and that management for carbon credits via fire suppression would be inadvisable, given the associated uncertainty and risks. In Chapter 3, I perform a social, ecological, and economic analysis of the feasibility of switching from fossil fuels to wood energy in Interior Alaska villages. I demonstrate that this is a viable option with the potential benefits of providing lower-cost power, creating local employment, reducing the risk of catastrophic wildfire near human habitation, and earning marketable carbon credits. Finally, in Chapter 4, I assess how each of the above factors may impact social-ecological resilience. My results show some system characteristics that tend to bolster resilience and others that tend to increase vulnerability. I argue that in order to reduce vulnerability, management goals for Alaska's boreal forest must be long-term, flexible, cooperative, and locally integrated.
    • Carbon sources and trophic connectivity in seafloor food webs in the Alaska Arctic and sub-Arctic

      Oxtoby, Laura Elizabeth; Wooller, Matthew; O'Brien, Diane; Iken, Katrin; Horstmann, Larissa; Budge, Suzanne (2016-05)
      Stable isotope analysis offers critical insight into organic matter pathways that sustain and link consumers in a food web. Indirect examination of organic matter sources and consumer diets using stable isotope analysis is especially valuable in the Alaska Arctic and sub-Arctic marine realm, where organisms of interest are difficult to observe given their remote habitat and elusive behavior. The research objective of this body of work was to use novel applications of stable isotope analysis to extend our understanding of organic matter sources, trophic pathways, and resource competition among benthic consumers. Microphytobenthos, a community of photosynthesizing unicellular microscopic algal cells on the seafloor sediment, has not been included in stable isotope food web models in the Alaska Arctic and sub-Arctic due to challenges associated with sample collection and analysis. I constrained the isotopic composition of this potential algal source by integrating field measurements, physiological relationships previously established by laboratory studies, and a range of algal growth rates specific to high latitude primary production. Relative to other sources of primary production in the Arctic, sub-Arctic, and lower latitude ecosystems, estimates for stable carbon isotope values of total organic carbon from microphytobenthos in the Beaufort and Chukchi seas were higher than those for Arctic riverine organic matter, but lower than ice algal sources and microphytobenthos measurements from lower latitudes. To further elucidate trophic pathways and resource partitioning among benthic invertebrate consumers, I combined compound-specific stable isotope analysis, a relatively new analytical tool, with fatty acid analysis to estimate proportional contributions of algal sources from ice, open ocean, and surface sediments to common polychaete and bivalve consumers in the Bering Sea. Benthic invertebrates were collected in 2009-2010 and represented a diverse range of feeding strategies, including the suspension/surface deposit-feeding bivalves Macoma calcarea and Ennucula tenuis, the subsurface deposit-feeding bivalve, Nuculana radiata, the head down deposit-feeding polychaete Leitoscoloplos pugettensis, and the predator/scavenger Nephtys spp. Differences in dominant algal sources to these invertebrate consumers corresponded, for the most part, to feeding strategy. Bivalves primarily obtained fatty acids from surface sediments, whereas L. pugettensis obtained fatty acids from a microbially altered phytodetrital fatty acid pool, and Nephtys spp. from ice algal fatty acids acquired indirectly through predation. This multi-proxy compound-specific stable isotope approach was then applied to examine dietary overlap between Pacific walruses (Odobenus rosmarus divergens) and bearded seals (Erignathus barbatus) in 2009-2011 who feed primarily on benthic invertebrate prey. Differences in the relative proportions of fatty acids produced exclusively by benthic prey (non-methylene interrupted fatty acids) indicated that walruses and bearded seals had divergent diets. Proportional contributions of algal sources from ice, open ocean, and surface sediments to the prey consumed by walruses and bearded seals also varied. Walruses consumed prey that relied primarily on benthic and pelagic carbon sources (i.e., suspension/surface and subsurface deposit-feeding bivalves). In contrast, bearded seals consumed prey that relied on benthic and ice algal carbon sources (i.e., omnivorous and predatory benthic invertebrates). In conclusion, this research revealed that, in the recent study years, benthic food webs in the Alaska Arctic and sub-Arctic contained several trophic pathways linking consumers to distinct organic matter sources. Consequently, projected changes in algal production with future climate warming may elicit species-specific responses among benthic organisms.
    • Carbonate facies and sequence stratigraphy of the carboniferous Lisburne group, Upper Nanushuk River Region, Central Brooks Range, Alaska

      White, Jesse Garnett (2007-12)
      This study documents the stratigraphy, facies, facies associations, depositional environment, sequence stratigraphy, and conodont biostratigraphy of the upper Nanushuk River section of the Lisburne Group. 1621 meters of Kayak Shale and Lisburne Group rocks were measured and studied for facies analysis. Sixteen lithofacies and eleven microfacies were identified composing six facies assemblages. Facies analysis, stacking patterns, and associations suggest that the Nansushuk River section represents a homoclinal carbonate ramp recording an intertidal (Kayak Shale) and open marine to basin transitional sequence. Facies associations, stacking patterns and marine flooding surfaces helped to delineate major sequence boundaries and maximum flooding surfaces. Six 3rd order stratigraphic sequences have been identified in the Nanushuk River section. The section ranges in age from Osagean to lower Morrowan based on conodont biostratigraphy. The reservoir rock potential of the Nanushuk River section resides primarily in the dolomite of the Wachsmuth Limestone. The remainder of the section is considered 'tight' from a microfacies standpoint. Regionally, this study is important for paleogeographic reconstruction of the Lisburne Group across northern Alaska and adds to the general geologic knowledge of the Lisburne Group by obtaining stratigraphic data from a relatively isolated area in the Brooks Range.
    • Carboniferous Lisburne Group Carbonates Of The Porcupine Lake Valley: Implications For Surface To Subsurface Sequence Stratigraphy, Paleogeography, And Paleoclimatology

      Mcgee, Michelle Marie; Whalen, Michael T. (2004)
      This study utilizes high-resolution stratigraphy and sequence stratigraphy to document the response of the Carboniferous Lisburne Group carbonate platform during a change from greenhouse to icehouse conditions. The Lisburne Group in northern Alaska represents a laterally extensive carbonate ramp deposited on a passive continental margin during a greenhouse to icehouse transition. The Lisburne Group is subdivided into the Mississippian Wachsmuth and Alapah Limestones and Mississippian to Pennsylvanian Wahoo Limestone. I have identified six depositional sequences and corresponding systems tracts within the Lisburne Group based on bounding surfaces, cycle stacking patterns, and lateral lithofacies relationships. The Wachsmuth Limestone (Sequences I and II) is comprised of relatively thick cycles that have a "layer cake" stacking pattern that records minor migration of facies. Cycles in the uppermost Wachsmuth Limestone and the Alapah Limestone (Sequences III and IV) are thick, less "layer cake"-like, have deep water tongues at the base, and record significant migration of facies. Cycles in the uppermost Alapah Limestone and the Wahoo Limestone (Sequences V and VI) are thin, juxtapose deep water over shallow water facies, and record significant migration of facies. An unconformity marked by paleosols and karst features has been documented near the Mississippian-Pennsylvanian boundary in the Wahoo Limestone. I interpret the distinct change in cycle stacking patterns between the Mississippian and Pennsylvanian Lisburne Group to be related to changes in Paleoclimate. I interpret Sequences I through IV to be deposited during a greenhouse and transitional climate; whereas, Sequences V and VI were deposited during an icehouse climate.
    • Caribou migration, subsistence hunting, and user group conflicts in northwest Alaska: a traditional knowledge perspective

      Halas, Gabriela; Kofinas, Gary; Fix, Peter; Joly, Kyle (2015-08)
      Alaska Natives of northwest Alaska are highly dependent on barren-ground caribou (Rangifer tarandus) for meeting their nutritional and cultural needs. The Alaska Native village of Noatak borders the Noatak National Preserve (NNP), an area historically and presently used by Iñupiaq for subsistence caribou hunting and other traditional activities. Interactions between local and non-local caribou hunters were analyzed through the lens of common pool resource theory, which I linked to traditional Iñupiaq management of access and use of resources. This study examined changes in caribou migration and its effect on local caribou hunting success, which have been perceived to be the result of the interaction with non-local hunters and commercial aircraft operators transporting non-locals. Past research, decades old at this point, was undertaken prior to some regulations in place today, such as zoned use areas. To understand the implications of these changes, I documented the perceptions of local hunters by drawing on their traditional ecological knowledge (TEK), using a mixed methods approach to capture information on caribou ecology and human-caribou interactions. Mixed methods included a survey of active hunters, semi-structured participatory mapping interviews with local caribou experts of Noatak, key informant interviews, and participatory observation. Local hunters reported that caribou migration has changed, and there has been a decrease in the population of the region's caribou herd, the Western Arctic Herd (WAH). Hunters also reported that caribou hunting has changed substantially in the last five years, with fewer caribou harvested and hunters adapting to accommodate caribou migration shifts. Local hunters ranked aircraft and non-locals hunters as having the greatest negative impact to caribou migration and local hunting, followed by predation, climate change and habitat change. Noatak hunters perceived that their harvest of caribou is most impacted by non-local activity in the Noatak region. As well, local hunters reported that aircraft are a greater disturbance than on-the-ground non-local hunters. Participatory mapping revealed that use-areas are shared by local and non-local users along the Noatak River corridor, including both inside and outside zoned use areas. Suggestions by respondents for improved caribou management and conflicts with non-locals ranged from reducing non-local activity, working together with non-locals and aircraft operators, improving economic development for Noatak, and teaching youth of the village traditional hunting practices. Findings of this research demonstrate that local hunters have a rich, localized knowledge of human-caribou systems, which can contribute further to understanding of caribou-human interactions and in turn help to inform wildlife management decision-making.