Food webs are structured by intricate nodes of species interactions which govern the flow of organic matter in natural systems. Despite being long recognized as a key component in ecology, estimation of food web functioning is still challenging due to the difficulty in accurately measuring species interactions within a food web. Novel tracing methods that estimate species diet uptake and trophic position are therefore needed for assessing food web dynamics. The focus of this thesis is the use of compound specific nitrogen and carbon stable isotopes and molecular techniques for assessing predator-prey interactions and energy flow in natural aquatic ecosystems, with a particular focus on the species links between phytoplankton and zooplankton. The use of δ15N amino acid values to predict organism trophic position are evaluated through a meta-analysis of available literature which included measurements from 359 marine species (article I). Through a controlled feeding study isotope incorporation in aquatic organisms, across both plant-animal and animal-animal species linkages is further assessed (article II). These studies showed that δ15N amino acid values are useful tools for categorizing animal trophic position. Organism feeding ecology influenced nitrogen trophic discrimination (difference in isotope ratio between consumer and diet), with higher discrimination in herbivores compared to omnivores and carnivores (article I). Nitrogen isotope trophic discrimination also varied among feeding treatments in the laboratory study (article II). The combined findings from articles I &amp; II suggest that researchers should consider using group specific nitrogen trophic discrimination values to improve accuracy in species trophic position predictions.  Another key finding in the controlled laboratory study (article II) was consistently low carbon isotope discrimination in essential amino acids across all species linkages, confirming that these compounds are reliable dietary tracers. The δ13C ratios of essential amino acids were applied to study seasonal dynamics in zooplankton resource use in the Baltic Sea (article III). Data from this study indicated that zooplankton assimilate variable resources throughout the growing season. Molecular diet analysis (article IV) showed that marine copepod and cladoceran species ingested both autotrophic and heterotrophic resources. Evidence from both articles III &amp; IV also revealed that zooplankton feed on a relatively broad range of diet items but not opportunistically on all available food sources. Mesozooplankton feeding patterns suggested that energy and nutritional flows were channelled through an omnivorous zooplankton food web including microzooplankton prey items. Overall the results of this thesis highlight that stable isotope ratios in specific compounds and molecular techniques are useful tracing approaches that improve our understanding of food web functioning. / <p>At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 2: Manuscript. Paper 4: Manuscript.</p><p> </p>

East Africa is central to many aspects of human evolution and diversification. At the same time, diet is a key aspect of the ecology of any population. Therefore, one is often interested in the diets of past populations. To assess human diet in the past, stable isotope ratio and dental microwear analyses are often perceived as the only semi-quantitative and objective techniques. However, there are still many unknowns on how isotopic and microwear signals change in response to dietary variation, because few controlled studies have been carried out in modern populations. To investigate this issue, this study targeted living humans from African ethnic groups (El Molo, Turkana, Luhya, and Luo, from Kenya, and Baka, from Cameroon) that practise a wide range of traditional subsistence strategies (pastoralism, fishing, and agriculture), with the objective of building a framework in which to consider past diet in an East African context. This study analysed human hair (n = 143), nail (n = 83), and breath (n = 186) for δ$^{13}$C and δ$^{15}$N from the six different communities, and dental moulds (n = 150) from five of those communities (no moulds were collected from the Baka), and related the findings to dietary information. Dental microwear analyses had a low success rate because microwear features were obscured by the biofilm produced by mouth bacteria. Nevertheless, a visual analysis of the results suggested that the El Molo have the hardest and the toughest diet among all the groups studied, possibly through the inclusion of abrasives in the diet during food processing. In turn, the isotopic analyses revealed the ways in which agriculturalists and hunter gatherers differ from pastoralists and fishers in their isotopic values, although the variation in δ$^{13}$C and δ$^{15}$N did not distinguish between pastoralists and fishers. The results emphasise recent changes in the diet of these groups, the importance of local factors in isotope values, and the variable sensitivity of isotopes to dietary practices. In conclusion, although each technique could provide complementary data that would contribute to a more inclusive view of diet, dental microwear analyses are not easily applied to modern human groups, due to the difficulty in acquiring comparative in vivo data, and in distinguishing between patterns caused by food items, or food processing techniques.

abstract: This dissertation focuses on the diversity inherent to the process of social community construction. Building upon previous archaeological and bioarchaeological studies of community identities, the current project emphasizes the need for consideration of the impact of diversity on community identity formation in the past and illustrates the utility of a bioarchaeological approach for undertaking this task. Three specific aspects of community formation are addressed: (1) the relationship between symbolic community boundaries and geographic space, (2) the influence of diverse discourses of intra-community sub-groups on community formation, and (3) the negotiation of community boundaries by outsiders. To investigate these aspects of community construction in the past, dietary practices and mortuary rituals of the Late Intermediate Period (c. AD 900-1470) Ychsma society of the central Peruvian coast are examined as a case study. Previous anthropological and sociological studies demonstrate that diet and burial customs are common mechanisms used in processes of group identification around the world, including the Andes. In the current study, analyses of materials from Armatambo and Rinconada Alta in the Rimac Valley are used to examine the ways in which isotopic and dental indicators of diet and archaeological contextual indicators of mortuary rituals correspond with or crosscut spatial burial patterns and additional groups based on sex, age at death, and biogeochemically reconstructed residential origins. Observed patterns are interpreted using a theoretical framework that incorporates sociocultural theory of identity with pre-Columbian Andean ideology of the body, self, and social environment. Results reveal differences in large-scale trends in diet and mortuary practices associated with burial at each site that are interpreted as evidence of symbolic community boundaries between sites. Complexities within larger trends reveal evidence of internal diversity as well as fluidity across community boundaries. Specifically, evidence is presented for intra-community dietary differences, intra-community differences associated with age and sex, and finally evidence of external relationships. This consideration of diversity in community identity construction is concluded to profoundly refine current understandings of Ychsma social interactions. Consequently, this study demonstrates empirical investigation of social diversity is necessary for understanding the complex nature of the social construction of communities in the past. / Dissertation/Thesis / Doctoral Dissertation Anthropology 2015

Fish can have complex life histories and use multiple habitats and resources throughout their life span. Consequently, their life histories are often poorly understood. The Atlantic Tarpon, Megalops atlanticus, is a large, typically migratory, elopomorph fish that is both ecologically and economically important. Atlantic Tarpon are under threat due to regional exploitation, loss of natal and juvenile habitat, poor water management, and offshore impacts. In addition, little is known about its lifelong habitat and resource use. In Chapter 1, I used stable isotope analysis of eye lens δ13C and δ15N values to explore patterns in trophic history and habitat use of 16 Atlantic Tarpon from West-Central Florida and Louisiana. The stable isotope chronologies showed 100% use of backcountry habitats during the early life history and an ontogenetic habitat shift to coastal waters at approximately 10 years of age and 140 cm total length. During the coastal phase Atlantic Tarpon displayed among-individual variability and within-individual consistency in basal resource use. In Chapter 2, mark-recapture data from a multi-year genetic tagging program were used to investigate survival and growth rates, ontogenetic habitat use, and migration of juvenile Atlantic Tarpon in Florida. The study found that juvenile Atlantic Tarpon take approximately 10 years to reach the length associated with maturity, and appear to have a high survival rate (~80%), possibly due to effective use of habitats with reduced competition and predation. Atlantic Tarpon underwent several ontogenetic habitat shifts throughout the juvenile phase. In addition, juvenile Atlantic Tarpon did not migrate long distances but instead showed fidelity to systems wherein only short movements were needed to shift habitat types. This work serves to fill critical gaps in our knowledge of Atlantic Tarpon life history and may aid in better management and conservation of the species.

Southeast Florida’s continual urban expansion will potentially increase anthropogenic pollution in adjacent coastal marine systems. Furthermore, increased nutrient loads could have detrimental effects on the already threatened Florida Reef Tract. The present study uses a stable isotopic approach to determine the sources and the impact of nutrients on the Florida Reef Tract. δ13C and δ15N analysis of macroalgae, sponges, and sediment were analyzed in order to determine nutrient inputs in this region. While δ13C data did not display any significant trends spatially, δ15N values of the majority of biota exhibited a strong East to West gradient with more enriched values close to shore. Relative enrichment in δ15N values were measured for sediments sampled along the Florida Reef Tract in comparison to a pristine Marquesas Keys sediment core. The δ15N data also implies that shoreline anthropogenic nutrients have more nutrient loading implications on reefs than major point sources.

Strontium isotope (87Sr/86Sr) analyses have been used effectively to reconstruct the origin of osteological remains that have not been exposed to increasing temperatures (Bentley, 2006; Juarez, 2008; Knudson et al., 2005). However, previous research has shown that no thermally induced changes occur to original strontium isotope values (87Sr/86Sr) of bone and teeth specimens that have been subjected to temperatures between 212 and 1832 degrees Fahrenheit (Beard and Johnson, 2000; Grupe and Hummel, 1991; Harbeck et al., 2011), though the published literature regarding strontium isotope ratio stability and survivorship in thermally altered bone and teeth is limited. This is surprising given the potential implications for geolocation inquiries of cremains (or severely burnt remains) in both forensic and archaeological contexts. This research will focus on the latter context by using strontium isotope analyses, via thermal ionization mass spectrometry, to reconstruct the origins of human remains from a unique late Woodland period (A.D. 600-850) archaeological burial site known as the Perrins Ledge crematory, located in the lower Illinois River valley. Strontium isotope signatures derived from the Perrins Ledge cremains will be compared with values obtained from osteological faunal remains from three contemporary neighboring sites (Carlin, Apple Creek, and Newbridge). It is expected that the Perrins Ledge values will mirror those derived from the neighboring contemporary habitation sites suggesting local groups used the crematorium.

No description available.

Bats are important components of biodiversity within forested ecosystems. This research addressed habitat characteristics that influence species occupancy and stable isotopes and wing morphology to assess community structure within the Sam D. Hamilton Noxubee National Wildlife Refuge. To meet these objectives, I deployed echolocation recorders, mist-nets and conducted roost checks to capture bat acoustics; fur samples were also collected to measure ratios of carbon (C13/12) and nitrogen (N15/14). Relationships between occupancy, habitat class and features were not apparent for most species. However, Lasiurus and Mytois spp. showed positive relationships with proximity to roads, Lasiurus, positive with stem density and Perimyotis subflavus, negative with basal area. Stable isotope analysis revealed some distinction of trophic niches while wing morphometrics indicated bats of similar wing shape and size show greater trophic overlap. Collectively, these results suggest that habitat management, as current within the study area, will have limited influence on local bat distributions.

This bachelor’s essay aims to discuss breastfeeding and complications related to breastfeeding within archaeological contexts. Why complications have arisen when such a natural act is per- formed and how individuals have tried to manage them. By looking at different methods of recording breastfeeding patterns I aim to broaden the interpretations of breastfeeding in differ- ent time periods and locations. Isotope analysis will be an important part as well as paleopatho- logical analysis of human remains. Information from three completed studies from Öland and Västerhus in Sweden and Quarto Cappello del Prete in Rome will be presented and discussed. In conclusion I suggest that breastfeeding is a complex act surrounded by difficulties such as diseases and cultural norms. There is variation within populations regarding breastfeeding and weaning. People have been struggling as well as fighting for the survival of their children.

This dissertation seeks to establish the possible provenance of copper and copper alloys used at Great Zimbabwe (1000-1700CE) to infer local and regional circulation circuits. It employs archaeological, archival, and geochemical methods to characterize samples of 26 wound wire bracelets, bangles, anklets, necklaces, and other forms of expressive and decorative wear excavated from the southern terrace, (Hill Complex) at Great Zimbabwe. The samples were macroscopically, microscopically, chemically and isotopically characterized to understand the technique of manufacture, chemical composition, lead isotopic ratios and the starting composition of uranium and thorium in relation the model ages. The Pb isotopic data calculated 238U/204Pb (μ), 232Th/ 238U(κ) ratios and estimated model ages (T) were compared with published lead isotopic ratios from various ore samples from central and southern Africa. Within opportunities afforded by the historical record and limitations imposed by small sample sizes especially of the comparative geology, indications are that the studied objects were produced using ores matching the Cu-Ni mineralization at Empress Mine (in Zimbabwe), Cu Ag and Cu Pb Zn Ag mineralization associated with the Kundelungu Plateau (bordering Zambia and Democratic Republic of Congo). This suggests that Great Zimbabwe participated directly and indirectly in the vibrant micro, regional and interregional circulation of copper and other resources. Future work, must however, add more trace element data from the objects and increase the number of samples from ancient mines and other sites to develop a fuller picture of the movement of copper in Iron Age southern Africa through space and time.