Though the majority of the Antarctic continent is covered by ice, portions of Antarctica, mainly in the McMurdo Dry Valleys and the Transantarctic Mountains (TAM), are currently ice-free. The soils which have developed on these surfaces have been re-worked by the advance and ret…
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American Eel is an economically, ecologically, and culturally valuable fish. Increased fishing pressure and other stressors have earned international threatened and endangered designations in an effort to protect the species. U.S. Fish and Wildlife Service (USFW) species status …
Broad Whitefish (Coregonus nasus) is a critically important subsistence species for Alaska's Indigenous communities, yet little is known about the basic ecology of this species at the individual level. Understanding habitat use by Broad Whitefish is challenging due to their mobi…
Carbon Monoxide (CO) is an important atmospheric trace gas that affects the oxidative capacity of the atmosphere by being a major sink of the hydroxyl radical. Ice cores may preserve a record of past atmospheric CO for analysis and interpretation; therefore, a new analytical sys…
Anthropogenic nutrient loading has long been identified as potentially harmful to coastal waters surrounding the Hawaiian Islands, with excess nutrients being delivered by stream runoff as well as by inputs to groundwaters that exit the coast as submarine groundwater discharge (…
Species reintroductions are an important aspect of conservation biology to prevent biodiversity loss, and post-release monitoring can help in understanding and improving restoration success. Generally, population sizes are monitored to determine if reintroductions are successful…
Contemporary species are undergoing population declines and extinction at rates unprecedented in recorded history. These ongoing global biodiversity losses are largely caused by human overpopulation and other anthropogenic impacts on the environment such as natural habitat destr…
The Grand Staircase-Escalante National Monument contains sedimentary rocks that have recorded the fluid flow history from Jurassic to Cenozoic time. Despite the importance of understanding these processes and dynamics, our knowledge of past fluid flow in many regions is limited.…
Bigheaded carp (bighead carp and silver carp) are invasive species in the US and have spread throughout most of the Mississippi River Basin. Population abundance upstream of Lock and Dam 19 (LD19) on the Upper Mississippi River has been limited by the high head dam at this locat…
Estuaries are important habitats to many coastal fishes. Some species of fish can use the low salinity and freshwater environments that estuaries provide, though the exact patterns of usage for these habitats for some species is not well understood. Stable isotope and microchemi…
Once abundant in the Arctic, bison (Bison bison) declined almost to extinction in the North but have subsequently been reintroduced into Alaska. The predecessors of these modern bison were the ancient steppe bison (Bison priscus), which were abundant throughout the Northern Hemi…
Understanding the degree of connectivity among populations, forming migratory links and evaluating factors that influence reproductive fitness is fundamental for the successful management of migratory species of conservation concern. In this thesis I focus on a regionally import…
In this dissertation, the origins of Fe-carbonates in the Paleoproterozoic Gunflint Formation of Ontario, Canada are investigated through petrographic and isotopic analysis of carbonate-rich Gunflint samples as well as experiments designed to elucidate the chemical conditions th…
This study focuses on the history of natural and human-induced environmental change as recorded in the sediments of two lakes: Mountain Lake in the Presidio National Park, San Francisco, California and Big Soda Lake, near Fallon, Churchill County, Nevada. The records of these la…
Black carbon (BC) is the highly graphitized byproduct of incomplete combustion that could be a sink for fixed carbon. Little data is currently available for BC concentrations and fluxes to remote marine environments and there are often great discrepancies between model simulatio…
Trade and exchange exerted a powerful force in the historic and protohistoric past of Island Southeast Asian communities. Exchange and interaction are also hypothesized to have played an important role in the spread of new technologies and lifestyles throughout the region during…
Herbivorous mammals in modern tropical ecosystems are characterized by a high degree of specialization, resulting in the systematic division of food resources among them. In order to test whether this also occurred within ancient tropical ecosystems, stable carbon and oxygen iso…
Western Pacific leatherback turtles migrate to geographically distinct foraging regions. Turtles that nest between April and September in Bird's Head nesting beaches in Papua Barat, Indonesia migrate to the South China Sea (SCS), North Pacific Transition Zone (NPTZ), and Northea…
Despite the importance of tropical rivers to the global carbon cycle, the nature of carbon cycling within these watersheds has been dealt with by only a handful of studies. The current work attempts to address this lack of information, using stable isotope and concentration meas…