Current Search: Sea turtles -- Habitat -- Conservation (x)
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- Title
- MULTIPLE ENVIRONMENTAL FACTORS PRODUCE HIGH HATCHING AND EMERGENCE SUCCESS IN NORTHWEST ATLANTIC LOGGERHEADS (CARETTA CARETTA).
- Creator
- Gravelle, Jessica, Wyneken, Jeanette, Florida Atlantic University, Department of Biological Sciences, Charles E. Schmidt College of Science
- Abstract/Description
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Sea turtle nest success, defined as the number of eggs in a nest that successfully hatch and emerge, is closely linked to environmental conditions. Interacting biotic and abiotic factors influence hatching and hatchling emergence success. To date, combinations of multiple factors interacting together, which result in highly successful sea turtle nests are not well understood. Using 25-years of historic nest data and local expert experience, I identified five historically successful loggerhead...
Show moreSea turtle nest success, defined as the number of eggs in a nest that successfully hatch and emerge, is closely linked to environmental conditions. Interacting biotic and abiotic factors influence hatching and hatchling emergence success. To date, combinations of multiple factors interacting together, which result in highly successful sea turtle nests are not well understood. Using 25-years of historic nest data and local expert experience, I identified five historically successful loggerhead (Caretta caretta) nesting beaches (hotspots) along the Florida (USA) Atlantic coast and measured nest environments along with nest success. Principal component analysis was used to reduce 12 environmental variables so that the relative contributions of sand characteristics, nest temperature, sand moisture, and nest location were considered. The nest environments differed among nesting beaches and were broadly segregated into two distinct climates: subtropical (hot and humid) and warm-temperate (warm and dry). I found that nests at subtropical sites, compared with the warm-temperate sites, were characterized by environmental gradients in contrasting ways. Nest locations were predominantly mid-beach in subtropical sites but clustered at higher elevations and closer to the base of the dune at warm-temperate climate sites. Collectively, highly successful nest hotspots represent a mosaic of abiotic factors providing conditions that promote successful hatching and emergence. This new perspective on consistently successful loggerhead nesting beach traits demonstrate that the key traits of sea turtle nesting habitat vary with prevailing climate type and should be managed accordingly.
Show less - Date Issued
- 2022
- PURL
- http://purl.flvc.org/fau/fd/FA00013900
- Subject Headings
- Loggerhead turtle--Florida, Sea turtles--Nests, Caretta caretta, Sea turtles--Habitat--Conservation
- Format
- Document (PDF)
- Title
- Ecosystem health and environmental influences on innate immune function in the loggerhead (Caretta caretta) and green (Chelonia mydas) sea turtle.
- Creator
- Sposato, Patricia L., Milton, Sarah L., Florida Atlantic University, Charles E. Schmidt College of Science, Department of Biological Sciences
- Abstract/Description
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Loggerhead (Caretta caretta) and green (Chelonia mydas) turtles recruit to nearshore environments as juveniles. These often degraded habitats are associated with emerging diseases such as green turtle fibropapillomatosis (GTFP), however there are few studies on immune function in sea turtles. The objective of this research was to quantify phagocytosis of the innate immune system by flow cytometry and compare levels between animals from a degraded habitat (the Indian River Lagoon, FL) to a...
Show moreLoggerhead (Caretta caretta) and green (Chelonia mydas) turtles recruit to nearshore environments as juveniles. These often degraded habitats are associated with emerging diseases such as green turtle fibropapillomatosis (GTFP), however there are few studies on immune function in sea turtles. The objective of this research was to quantify phagocytosis of the innate immune system by flow cytometry and compare levels between animals from a degraded habitat (the Indian River Lagoon, FL) to a more pristine environment (the Trident Basin, Port Canaveral, FL), and across a range of temperatures. While in vitro temperatures did not alter rates of phagocytosis, it was higher in samples obtained in the summer than winter. Rates of phagocytosis in sea turtles with GTFP and from degraded environments with increased prevalence of GTFP were low compared to animals from the more pristine environment, suggesting that the environment can alter innate immunological function and thus contribute to the development of disease.
Show less - Date Issued
- 2014
- PURL
- http://purl.flvc.org/fau/fd/FA00004333, http://purl.flvc.org/fau/fd/FA00004333
- Subject Headings
- Developmental biology, Ecosystem management -- Florida, Loggerhead turtle -- Habitat -- Environmental aspects, Marine biodiversity conservation, Sea turtles -- Immunology
- Format
- Document (PDF)
- Title
- Origins, movements, and foraging behavior of Hawksbill Sea Turtles (Eretmochelys imbricata) in Palm Beach County waters, Florida, USA.
- Creator
- Wood, Lawrence D., Milton, Sarah L., Florida Atlantic University, Charles E. Schmidt College of Science, Department of Biological Sciences
- Abstract/Description
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This dissertation examined the natal origins, home-range, and in-situ foraging behavior of an aggregation of sub-adult hawksbill turtles (Eretmochelys imbricata) found off the coast of Palm Beach County, Florida. Surveys were conducted on approximately 30 linear km of reef between 15 and 30 m in depth. Tissue samples were retrieved from 112 turtles for mtDNA haplotype determination. GPS-linked satellite transmitters were deployed on six resident sub-adults, resulting in both minimum convex...
Show moreThis dissertation examined the natal origins, home-range, and in-situ foraging behavior of an aggregation of sub-adult hawksbill turtles (Eretmochelys imbricata) found off the coast of Palm Beach County, Florida. Surveys were conducted on approximately 30 linear km of reef between 15 and 30 m in depth. Tissue samples were retrieved from 112 turtles for mtDNA haplotype determination. GPS-linked satellite transmitters were deployed on six resident sub-adults, resulting in both minimum convex polygon (MCP) and 95%, 50%, and 25% kernel density estimates (KDE) of home-range size. A foraging ethogram was developed, and sequential analysis performed on thirty videos (141 total minutes) of in-situ foraging behavior. Seventeen total haplotypes were identified in this aggregation, the majority (75%) of which represented rookeries on Mexico’s Yucatan Peninsula. Other sources, from most to least important, include Barbados, Costa Rica, Puerto Rico, Antigua, and the U.S. Virgin Islands.
Show less - Date Issued
- 2014
- PURL
- http://purl.flvc.org/fau/fd/FA00004339
- Subject Headings
- Animal behavior, Animal orientation, Hawksbill turtle -- Ecology, Predation (Biology), Sea turtles -- Habitat, Wildlife conservation, Wildlife management
- Format
- Document (PDF)
- Title
- Feeding behavior of loggerhead and leatherback sea turtles:a study to better understand longline bycatch.
- Creator
- Warraich, Natasha, Wyneken, Jeanette, Florida Atlantic University, Charles E. Schmidt College of Science, Department of Biological Sciences
- Abstract/Description
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Two species of sea turtle, loggerheads (Caretta caretta) and leatherbacks (Dermochelys coriacea) are caught frequently as bycatch in longline fisheries. These fisheries use hooks baited with fish or squid. Yet, leatherbacks feed on gelatinous prey while loggerheads are carnivores. I investigated the responses of these two species to bait odors in controlled laboratory experiments to better understand their feeding behavior and why they interact with longlines. Both species initiated feeding...
Show moreTwo species of sea turtle, loggerheads (Caretta caretta) and leatherbacks (Dermochelys coriacea) are caught frequently as bycatch in longline fisheries. These fisheries use hooks baited with fish or squid. Yet, leatherbacks feed on gelatinous prey while loggerheads are carnivores. I investigated the responses of these two species to bait odors in controlled laboratory experiments to better understand their feeding behavior and why they interact with longlines. Both species initiated feeding behavior in the presence of squid bait odors and just C. caretta showed feeding behavior with sardine odors; neither responded to mackerel odors. The turtles are hooked differently on longlines. Loggerheads are usually hooked in the mouth while leatherbacks are usually hooked in the shoulder or flippers. Comparisons of prey attack behavior and accuracy in apprehending a stimulus in the presence of waterborne food odors identified speciesspecific differences that may predispose the turtles to particular kinds of hooking.
Show less - Date Issued
- 2014
- PURL
- http://purl.flvc.org/fau/fd/FA00004171, http://purl.flvc.org/fau/fd/FA00004171
- Subject Headings
- Bycatches (Fisheries) -- Prevention, Longlining (Fisheries) -- Bycatches -- Prevention, Longlining (Fisheries) -- Environmental aspects, Sea turtles -- Effect of fishing on, Sea turtles -- Habitat -- Conservation, Sea turtles -- Mortality, Wildlife conservation
- Format
- Document (PDF)
- Title
- The role of air and waterborne odors in orientation and food detection in three species of marine turtles.
- Creator
- Kedzuf, Stephanie C., Salmon, Michael, Florida Atlantic University, Charles E. Schmidt College of Science, Department of Biological Sciences
- Abstract/Description
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The cues used by marine turtles to locate foraging areas in the open ocean are largely unknown though some species (especially the green turtle [Chelonia mydas], the loggerhead [Caretta caretta], and the leatherback [Dermochelys coriacea]) somehow locate areas of high productivity. Loggerheads can detect airborne odors, but a capacity to orient has not yet been investigated. In this comparative study, tethered loggerheads and leatherbacks were exposed to dimethyl sulfide (DMS) or food odors...
Show moreThe cues used by marine turtles to locate foraging areas in the open ocean are largely unknown though some species (especially the green turtle [Chelonia mydas], the loggerhead [Caretta caretta], and the leatherback [Dermochelys coriacea]) somehow locate areas of high productivity. Loggerheads can detect airborne odors, but a capacity to orient has not yet been investigated. In this comparative study, tethered loggerheads and leatherbacks were exposed to dimethyl sulfide (DMS) or food odors in a laminar flow of air. Turtles did not orient into the air current. Free-swimming loggerheads and green turtles were also exposed to air- or waterborne food (squid) odor plus a neutral visual stimulus. Both species showed increases in swimming activity and biting behavior to both stimuli. These results suggest that airborne odors are likely not used to locate distant areas, but that they are used in localized food searching efforts.
Show less - Date Issued
- 2014
- PURL
- http://purl.flvc.org/fau/fd/FA00004296
- Subject Headings
- Animal behavior, Animal orientation, Population genetics, Predation (Biology), Sea turtles -- Habitat, Sea turtles -- Life cycles, Wildlife conservation
- Format
- Document (PDF)
- Title
- Activity and Habitat Selection by Loggerhead (Caretta caretta L.) and Green Turtle (Chelonia mydas. L.) Hatchlings: A Laboratory and Field Study.
- Creator
- Smith, Morgan M., Salmon, Michael, Florida Atlantic University, Department of Biological Sciences, Charles E. Schmidt College of Science
- Abstract/Description
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Loggerhead and green turtle neonates migrate from Florida's coast during a 24-36 h frenzy. Post-frenzy loggerheads are often found in flotsam (Sargassum), while postfrenzy green turtles "disappear." This study compared the frenzy and post-frenzy activity of each species, their response to flotsam (in the laboratory and field), and the role of experience in habitat selection. Both species were most active during day I; activity thereafter declined (especially in loggerheads). Inactive...
Show moreLoggerhead and green turtle neonates migrate from Florida's coast during a 24-36 h frenzy. Post-frenzy loggerheads are often found in flotsam (Sargassum), while postfrenzy green turtles "disappear." This study compared the frenzy and post-frenzy activity of each species, their response to flotsam (in the laboratory and field), and the role of experience in habitat selection. Both species were most active during day I; activity thereafter declined (especially in loggerheads). Inactive loggerheads occupied Sargassum and open water (day or night) whereas inactive green turtles occupied Sargassum by day and both habitats at night. Exposure to Sargassum had no effect on the later habitat choices ofloggerheads, while exposed green turtles preferred Sargassum over plastic plants. In the field, both species preferred flotsam to open water, but occupied distinct microhabitats. Loggerheads preferred the mat surface while green turtles hid within the mat. Differences in activity and habitat selection likely reflect species-specific migratory and anti-predator strategies.
Show less - Date Issued
- 2007
- PURL
- http://purl.flvc.org/fau/fd/FA00000832
- Subject Headings
- Sea turtles--Ecology--Case studies, Wildlife conservation--Case studies, Habitat partitioning (Ecology), Adaptation (Biology)
- Format
- Document (PDF)
- Title
- Plasma Steroid Hormones in Loggerhead and Green Sea Turtle Hatchlings.
- Creator
- Reis, Andrea, Milton, Sarah L., Florida Atlantic University, Charles E. Schmidt College of Science, Department of Biological Sciences
- Abstract/Description
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Florida’s sea turtle populations are increasing due to conservation efforts; however, sea turtle species are vulnerable to climate change. Turtles exhibit temperaturedependent sex determination, in which nest environment influences sex. Environmental changes may produce altered sex ratios that limit reproduction potential; therefore hatchling sex ratios should be monitored. Hatchlings are not externally sexually dimorphic, making sex identification difficult. This study established baseline...
Show moreFlorida’s sea turtle populations are increasing due to conservation efforts; however, sea turtle species are vulnerable to climate change. Turtles exhibit temperaturedependent sex determination, in which nest environment influences sex. Environmental changes may produce altered sex ratios that limit reproduction potential; therefore hatchling sex ratios should be monitored. Hatchlings are not externally sexually dimorphic, making sex identification difficult. This study established baseline plasma hormone concentrations in hatchling and post-hatchling green (Chelonia mydas) and loggerhead (Caretta caretta) sea turtles using High Performance Liquid Chromatography. Five hormones were assayed and were present in the majority of samples (testosterone: N.D.-10.12, progesterone: N.D.-0.43, estradiol: N.D.-4.78, estriol: N.D.-5.55 and estrone: N.D.-1.67 μg/mL). Plasma hormones did not distinguish hatchling sex because male and female ranges overlapped. Hormone concentrations varied with sex but also with incubation temperature, indicating that climate change could impact hatchling and posthatchling hormone profiles and thus could impact future fitness.
Show less - Date Issued
- 2016
- PURL
- http://purl.flvc.org/fau/fd/FA00004626
- Subject Headings
- Sea turtles--Embryology., Sea turtles--Habitat--Conservation., Sex determination, Genetic., Loggerhead turtle--Effect of temperature on., Developmental genetics.
- Format
- Document (PDF)