Thesis (Ph. D.)--University of Florida, 2000. / Title from PDF title page (viewed on July 4, 2005). Vita. Includes bibliographical references (p. 144-163).

Thesis (Ph. D.)--University of Alabama at Birmingham, 2009. / Title from PDF title page (viewed Feb. 1, 2010). Additional advisors: Ken Marion, David C. Rostal, Robert W. Thacker, Jeanette Wyneken. Electronic data (1 file : 10.93 mb). Includes bibliographical references (p. 13-18).

Thesis (M. Sc.)--College of William and Mary. / Vita. Includes bibliographical references (leaves 115-122).

The critically endangered Kemp's ridley sea turtle experienced a dramatic decline in population size (demographic bottleneck) between 1947 and 1987 from 160,000 mature individuals to less than 5000. Demographic bottlenecks can cause genetic bottlenecks where significant losses of genetic diversity occur through genetic drift. The loss of genetic diversity can lower fitness through the random loss of adaptive alleles and through an increase in the expression of deleterious alleles. Molecular genetic studies on endangered species require collecting tissue using non-invasive or minimally invasive techniques. Such sampling techniques are well developed for birds and mammals, but not for sea turtles. The first objective was to explore the relative success of several minimally invasive tissue-sampling methods as source of DNA from Kemp's ridley sea turtles. Tissue sampling techniques included; blood, cheek swabs, cloacal swabs, carapace scrapings, and a minimally invasive tissue biopsy of the hind flipper. Single copy nuclear DNA loci were PCR amplified with turtle-specific primers. Blood tissue provided the best DNA extractions. Additionally, archival plasma samples are shown to be good sources of DNA. However, when dealing with hatchlings or very small individuals in field situations, the tissue biopsy of the hind flipper is the preferred method. This study's main focus was to evaluate whether the Kemp's ridley sea turtle sustained a measurable loss of genetic variation resulting from the demographic bottleneck. To achieve this goal, three alternative approaches were used to detect a reduction in Kemp's ridley's effective population size (Ne) from microsatellite data. These approaches were 1) Temporal change in allele frequencies, 2)An excess of heterozygotes in progeny, and 3)A mean ratio (M) of the number of alleles (k) to the range of allele size (r). DNA samples were obtained from Kemp's ridleys caught in the wild. PCR was used to amplify eight microsatellite loci and allele frequencies were determined. Data from only four microsatellites could be used. Although the reduced number of loci was a limiting factor in this study, the results of all three approaches suggest that Kemp's ridley sustained a measurable loss of genetic variation due to the demographic bottleneck.

<p dir="ltr">The Northwest Atlantic Ocean, which surrounds the US eastern coastline, is an area rich in marine life. The US eastern coastline is also highly urbanized, resulting in a lot of pollutants (like heavy metals) entering the marine environment. This is of concern for long-lived marine species like sea turtles. Since sea turtles are long-lived and highly migratory, their tissues can often incorporate these pollutants through environmental and dietary exposure. I collected tissue samples from 5 different sea turtle populations in the Northwest Atlantic and analyzed them for concentrations of silver (Ag), aluminum (Al), arsenic (As), cadmium (Cd), cobalt (Co), chromium (Cr), iron (Fe), manganese (Mn), nickel (Ni), lead (Pb), selenium (Se) and zinc (Zn) using an Inductively Coupled Plasma Mass Spectrometry (ICP-MS). The first chapter looks at skin (reflects exposure ~1 year ago) and scute (reflects exposure from 4-6 years ago) samples collected during necropsies of juvenile green (<i>Chelonia mydas</i>) (n=8), Kemp’s ridley (<i>Lepidochelys kempii</i>) (n=30) and loggerhead (<i>Caretta caretta</i>) (n=17) turtles that were found cold-stunned in Cape Cod Bay, Massachusetts. In scute samples, the heavy metal with the highest concentration for green turtles was iron, zinc for loggerhead turtles, and arsenic for Kemp’s ridley turtles. In skin samples, the heavy metal with the highest concentration for green turtles was iron, arsenic for loggerhead turtles, and aluminum for Kemp’s ridley turtles. Overall, I found scute samples to have higher heavy metal concentrations than skin samples. The second chapter looks at scute samples collected from loggerhead turtles of different life stages. These samples were collected during necropsies of cold-stunned loggerhead turtles from Cape Cod Bay, Massachusetts (CCB; n=17), as well as from live loggerhead turtles in the Mid-Atlantic Bight (MAB; n=37) and off the coast of North Carolina (NC; n=9). We also collected commonly known loggerhead turtle prey items including whelk (<i>Buccinum undatum</i>) (n=12), Atlantic scallop (<i>Placopecten magellanicus)</i> (n=10) and Jonah crab (<i>Cancer borealis</i>) (n=5) from the Mid-Atlantic Bight region to study the occurrence of biomagnification through trophic pathways. NC loggerhead turtles had higher heavy metal concentrations than other locations except for cadmium and zinc, where CCB loggerhead turtles were higher. I found that all heavy metals except silver, cadmium, and lead appear to be biomagnified (TTF>1) in loggerhead turtles. These two chapters provided baseline information on heavy metal concentrations in sea turtles in east coast US.</p>