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- Title
- Use Of Molecular Techniques To Understand The Spatial And Temporal Features Of The Oceanic Stage In Hawksbill Sea Turtles, Eretmochelys Imbricata; A Thesis Proposal.
- Creator
- Coppenrath, Christina, Salmon, Michael, Graduate College
- Abstract/Description
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For highly migratory species, it is important to understand what habitats are used and what requirements are essential for growth and development. These migrations often span different political and regulatory boundaries, complicating conservation strategies. The hatchlings and post-hatchlings of most sea turtle species migrate to oceanic habitats where they remain for several years before returning to shallow developmental habitats. For critically endangered hawksbill turtle, Eretmochelys...
Show moreFor highly migratory species, it is important to understand what habitats are used and what requirements are essential for growth and development. These migrations often span different political and regulatory boundaries, complicating conservation strategies. The hatchlings and post-hatchlings of most sea turtle species migrate to oceanic habitats where they remain for several years before returning to shallow developmental habitats. For critically endangered hawksbill turtle, Eretmochelys imbricata, most research has concentrated on nesting ecology and very little is known about the posthatchling migration. Many sea turtles then spend years in different foraging habitats before reaching sexual maturity, and such foraging grounds typically represent a mixed stock of turtles from different nesting beaches. Mitochondrial DNA analysis can be used to estimate genetic stock structure of mixedstock foraging populations for sea turtles, and the duration of the post-hatchling oceanic stage can be estimated using stable isotope analysis and satellite telemetry. Our objectives are to determine the duration of the post-hatchling oceanic stage of development, to determine if the turtles sampled in a particular foraging habitat represent a biased or unbiased assortment of matrilineages, and to infer potential migratory pathways by investigating ocean currents between nesting beaches and the foraging site. Here we discuss our methods, to determine the duration of the post-hatchling oceanic stage and stock structure for immature hawksbills at a developmental foraging ground.
Show less - Date Issued
- 2015
- PURL
- http://purl.flvc.org/fau/fd/FA00005873
- Format
- Document (PDF)
- Title
- What Controls The Nocturnal Emergence Rhythm Of Hatchling Marine Turtles?.
- Creator
- Prio, Joseph D., Salmon, Michael, Graduate College
- Abstract/Description
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Most marine organisms partition particular activities, such as growth, migration, reproduction, and hatching, to particular seasons, times of the day or night, or phases of the lunar cycle. The result is characterized as a “rhythm”. Scientists who study these rhythms generally ask two kinds of questions: why do they occur when they do that is, what is their survival value, and how are they controlled, physiologically? Hatchling marine turtles almost always emerge from their nests at night,...
Show moreMost marine organisms partition particular activities, such as growth, migration, reproduction, and hatching, to particular seasons, times of the day or night, or phases of the lunar cycle. The result is characterized as a “rhythm”. Scientists who study these rhythms generally ask two kinds of questions: why do they occur when they do that is, what is their survival value, and how are they controlled, physiologically? Hatchling marine turtles almost always emerge from their nests at night, then crawl down the beach to the sea and migrate offshore. By doing so at night they avoid lethally warm beach sands and diurnally active predators in the shallows. But these “survival value” explanations do not account for how the turtles, digging their way upward inside the nest toward the beach surface, know that it’s dark and time to emerge. The classic explanation for how they “know” is based upon surface sand temperatures. During the day, these sands can be very warm 50° C. When hatchlings digging upward encounter these heated sands, they stop digging until the sand cools, after sunset. But these observations fail to explain why in most studies, hatchlings rarely emerge from their nests at dawn or in the early morning, when the sand is still cool. To account for those observations, we hypothesize that the turtles must also possess a time sense that inhibits emergence during inappropriate times, such as shortly before or after sunrise.
Show less - Date Issued
- 2015
- PURL
- http://purl.flvc.org/fau/fd/FA00005909
- Format
- Document (PDF)