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- Title
- The physiological effects of Sargassum beach coverage on three species of sea turtle hatchlings.
- Creator
- Chaney, Abigail, Milton, Sarah L., Florida Atlantic University, Department of Biological Sciences, Charles E. Schmidt College of Science
- Abstract/Description
-
Sea turtle hatchlings face a variety of obstacles as they crawl down the beach to the ocean after emergence. One of these obstacles is Sargassum, a floating brown macroalgae, that washes up in large quantities on beaches from Florida to South America. This study examined the physiological response and physical performance of three species of sea turtle hatchlings (D. coriacea, C. caretta, and C. mydas) after crawling over various heights of Sargassum. In all three species, the addition of...
Show moreSea turtle hatchlings face a variety of obstacles as they crawl down the beach to the ocean after emergence. One of these obstacles is Sargassum, a floating brown macroalgae, that washes up in large quantities on beaches from Florida to South America. This study examined the physiological response and physical performance of three species of sea turtle hatchlings (D. coriacea, C. caretta, and C. mydas) after crawling over various heights of Sargassum. In all three species, the addition of Sargassum significantly increased the amount of time it took to crawl down the pathway. There was no significant difference in righting response, blood glucose levels, or plasma corticosterone concentrations between different crawling treatments. During periods of high Sargassum accumulation, hatchlings will spend more time on the beach trying to navigate through the algae, leaving them vulnerable to predation for longer periods of time.
Show less - Date Issued
- 2022
- PURL
- http://purl.flvc.org/fau/fd/FA00013939
- Subject Headings
- Sea turtles, Sargassum, Sea turtles--Ecology
- Format
- Document (PDF)
- Title
- Seafinding orientation of hatchlings exposed to filtered lighting: Effects of varying beach conditions.
- Creator
- Tuxbury, Susan Mary., Florida Atlantic University, Salmon, Michael
- Abstract/Description
-
Under normal conditions, hatchling sea turtles crawl toward the ocean but streetlights placed on coastal roadways can attract the turtles toward land. Two light filters were designed to exclude the shorter light wavelengths most attractive to turtles. I did laboratory tests to determine if green turtle and loggerhead hatchlings oriented normally ("seaward") in the presence of filtered lighting. Light passed through either filter (#2422 acrylic and NLW) attracted the turtles unless coastal...
Show moreUnder normal conditions, hatchling sea turtles crawl toward the ocean but streetlights placed on coastal roadways can attract the turtles toward land. Two light filters were designed to exclude the shorter light wavelengths most attractive to turtles. I did laboratory tests to determine if green turtle and loggerhead hatchlings oriented normally ("seaward") in the presence of filtered lighting. Light passed through either filter (#2422 acrylic and NLW) attracted the turtles unless coastal cues (an elevated horizon) were strong or background (full moon) illumination was present. Green turtles and loggerheads responded differently to the same filters, indicating that neither filter provided adequate protection for both species. I conclude that these filters fail to protect the turtles. Conventional forms of light control (shielding and/or lowering light fixtures, decreasing wattage, or turning off problem lights) remain the best way to shield turtles from the harmful effects of artificial lighting.
Show less - Date Issued
- 2001
- PURL
- http://purl.flvc.org/fcla/dt/12804
- Subject Headings
- Sea turtles, Light pollution
- Format
- Document (PDF)
- Title
- A comparative approach to understanding sea turtle hatchling metabolism during emergence.
- Creator
- Redfearn, Erin Cherish., Florida Atlantic University, Wyneken, Jeanette
- Abstract/Description
-
Sea turtle nests were compared to determine the effects of nest depth on hatchling anaerobic metabolism in Juno Beach, Florida, USA. In situ nests of 3 species (Caretta caretta, Chelonia mydas and Dermochelys coriacea) were compared. Relocated loggerhead nests were studied under an experimental regime. Nest temperatures and oxygen concentrations were monitored. On the night of first emergence, blood samples were taken from hatchlings resting at the nest chamber bottom and sand surface, and...
Show moreSea turtle nests were compared to determine the effects of nest depth on hatchling anaerobic metabolism in Juno Beach, Florida, USA. In situ nests of 3 species (Caretta caretta, Chelonia mydas and Dermochelys coriacea) were compared. Relocated loggerhead nests were studied under an experimental regime. Nest temperatures and oxygen concentrations were monitored. On the night of first emergence, blood samples were taken from hatchlings resting at the nest chamber bottom and sand surface, and digging to the sand surface. Samples were analyzed for lactate concentrations. Blood lactate levels were high in hatchlings actively digging and low for those resting. Lactate levels differed among species and nest depths. Within in situ nests, actively digging green turtle hatchlings had the highest lactate, followed by loggerhead hatchlings and leatherbacks (lowest). Loggerhead hatchlings digging from deeper relocated nests had higher lactate than those digging from shallower depths.
Show less - Date Issued
- 2000
- PURL
- http://purl.flvc.org/fcla/dt/15770
- Subject Headings
- Sea turtles--Metabolism, Loggerhead turtle, Green turtle, Leatherback turtle
- Format
- Document (PDF)
- Title
- A seasonal and latitudinal assessment of early growth rates in northern and southeastern loggerhead sea turtles (Caretta caretta L.).
- Creator
- Stokes, Lesley., Florida Atlantic University, Wyneken, Jeanette
- Abstract/Description
-
To improve our understanding of loggerhead life history, particularly factors affecting the duration of each age class and survivorship, detailed growth data must be interpreted. The purpose of this study was to investigate how temporal and spatial nest origin influence initial hatchling size and growth potential. Seasonal environmental fluctuations and maternal resource allocation could result in differential hatchling size and development. Hatchlings from ten sites from North Carolina to...
Show moreTo improve our understanding of loggerhead life history, particularly factors affecting the duration of each age class and survivorship, detailed growth data must be interpreted. The purpose of this study was to investigate how temporal and spatial nest origin influence initial hatchling size and growth potential. Seasonal environmental fluctuations and maternal resource allocation could result in differential hatchling size and development. Hatchlings from ten sites from North Carolina to Florida representing 2 subpopulations were sampled during 3 phases of the season. The largest (WT, SCL and SCW) hatchlings came from the northernmost site with initial size decreasing as latitude decreased. Turtles deposited during the earliest phase of the nesting season grew faster than those from later phases of the season. Differences in initial size and growth potential could influence early stage survivorship as a function of size-based predation, and may imply the need for separate consideration when constructing population models.
Show less - Date Issued
- 2003
- PURL
- http://purl.flvc.org/fcla/dt/13070
- Subject Headings
- Loggerhead turtle--Growth, Sea turtles
- Format
- Document (PDF)
- Title
- The effect of filtered roadway lighting on nesting by loggerhead sea turtles (Caretta caretta L.).
- Creator
- Pennell, Jeffrey P., Florida Atlantic University, Salmon, Michael, Department of Biological Sciences, Charles E. Schmidt College of Science
- Abstract/Description
-
The purpose of this study was to determine if filtered street lighting affected the nesting behavior of loggerhead sea turtles ( Caretta caretta L.). My study site was a nesting beach at Carlin Park, Jupiter, Florida. During the 1999 nesting season, portions of the beach were either kept dark or were illuminated by four 70 W high-pressure sodium (HPS) streetlights, each housed in a cut-off fixture covered by an acrylic (model #2422) filter. These filters excluded all light wavelengths below...
Show moreThe purpose of this study was to determine if filtered street lighting affected the nesting behavior of loggerhead sea turtles ( Caretta caretta L.). My study site was a nesting beach at Carlin Park, Jupiter, Florida. During the 1999 nesting season, portions of the beach were either kept dark or were illuminated by four 70 W high-pressure sodium (HPS) streetlights, each housed in a cut-off fixture covered by an acrylic (model #2422) filter. These filters excluded all light wavelengths below 540 nm. The excluded wavelengths repel nesting females. Daily counts of nesting and non-nesting crawls were made. Data from the 1999 nesting season were compared to historical records of nesting at the site between 1990 and 1998. I found no evidence that filtered lights affected nesting densities, or the ratio of successful to unsuccessful crawls. These results suggest that at Carlin Park, the nesting behavior of loggerhead females is unaffected by exposure of the beach to filtered street lighting.
Show less - Date Issued
- 2000
- PURL
- http://purl.flvc.org/fcla/dt/12720
- Subject Headings
- Loggerhead turtle, Sea turtles--Nests
- Format
- Document (PDF)
- Title
- Spatial and temporal distributions of sea turtles within the Florida Current and surrounding waters and their implications for oceanic energy development.
- Creator
- Bovery, Caitlin M., Wyneken, Jeanette, Graduate College
- Date Issued
- 2013-04-12
- PURL
- http://purl.flvc.org/fcla/dt/3361275
- Subject Headings
- Sea turtles, Florida Current, Sea turtles--Conservation
- Format
- Document (PDF)
- Title
- A comparison of stability in swimming loggerhead (Caretta caretta) and green (Chelonia mydas) sea turtle posthatchlings.
- Creator
- Dougherty, Erin., Charles E. Schmidt College of Science, Department of Biological Sciences
- Abstract/Description
-
Posthatchling green (Chelonia mydas) and loggerhead (Caretta caretta) turtles overlap ecologically but differ morphologically. This study compared hydrodynamic stability between the two species during swimming to test for functional differences in body shape. Flipper movement paths, four stability measures (yaw, pitch, heave, and sideslip), and the relative positions of the centers of buoyancy and gravity were compared between species. Both centers of buoyancy and gravity lie in the anterior...
Show morePosthatchling green (Chelonia mydas) and loggerhead (Caretta caretta) turtles overlap ecologically but differ morphologically. This study compared hydrodynamic stability between the two species during swimming to test for functional differences in body shape. Flipper movement paths, four stability measures (yaw, pitch, heave, and sideslip), and the relative positions of the centers of buoyancy and gravity were compared between species. Both centers of buoyancy and gravity lie in the anterior body; their positions relative to one another differed with species, but showed no functional consequences. Neither species demonstrated substantial yaw, sideslip, or pitch. Both experienced upward heave with the flippers' downstroke and downward heave with the upstroke; however phase relationships differed between these limb and body motions. No differences were found between the two species. Despite obvious morphological differences, loggerheads and green turtles were similarly stable during swimming, suggesting that the species use different mechanisms to achieve stability.
Show less - Date Issued
- 2009
- PURL
- http://purl.flvc.org/FAU/186689
- Subject Headings
- Sea turtles, Morphology, Sea turtles, Physiology, Animal locomotion, Marine ecology
- Format
- Document (PDF)
- Title
- Nest caging as a sea turtle management strategy: Do the benefits outweigh the costs on urban beaches?.
- Creator
- Adamany, Stephanie Lynne., Florida Atlantic University, Salmon, Michael
- Abstract/Description
-
Caging of sea turtle nests has used by City of Boca Raton's sea turtle conservation program to deter terrestrial predators and reduce human disturbance. The juxtaposition of nest cages and artificial lighting may pose serious threats to hatchlings. I addressed possible negative effects of cages on sea turtle hatchlings' seafinding abilities and potential "cage-trapping" under natural and artificially illuminated conditions. Cages did not effect hatchling orientation on artificially...
Show moreCaging of sea turtle nests has used by City of Boca Raton's sea turtle conservation program to deter terrestrial predators and reduce human disturbance. The juxtaposition of nest cages and artificial lighting may pose serious threats to hatchlings. I addressed possible negative effects of cages on sea turtle hatchlings' seafinding abilities and potential "cage-trapping" under natural and artificially illuminated conditions. Cages did not effect hatchling orientation on artificially illuminated or dark beaches. Hatchlings did not experience any delay in cage escape on dark beaches, but a significant number were trapped inside the cages on artificially illuminated beaches. The highest incidence of trapping occurred on nights surrounding a new moon. Disoriented hatchlings exited cages either after city lighting was reduced (past midnight) or as natural levels of illumination increased shortly before sunrise. When cages were darkened all turtles escaped but many still exhibited signs of disorientation.
Show less - Date Issued
- 1996
- PURL
- http://purl.flvc.org/fcla/dt/15312
- Subject Headings
- Sea turtles--Florida, Sea turtles--Nests
- Format
- Document (PDF)
- Title
- The use of wire cages to protect sea turtle nests: Are there better alternatives?.
- Creator
- Mroziak, Melissa Lynn, Florida Atlantic University, Salmon, Michael
- Abstract/Description
-
The beaches of Boca Raton, Florida serve as a rookery site for three species of sea turtles, all of whom are considered either federally threatened (loggerhead) or endangered (green turtle, leatherback). At this beach, nest security was though to be compromised by both human visitors and increasing mammalian predators populations. Since 1988, the City has employed the use of square wire cages to protect the nests from both factors. Cage effectiveness was questioned due to high predation rates...
Show moreThe beaches of Boca Raton, Florida serve as a rookery site for three species of sea turtles, all of whom are considered either federally threatened (loggerhead) or endangered (green turtle, leatherback). At this beach, nest security was though to be compromised by both human visitors and increasing mammalian predators populations. Since 1988, the City has employed the use of square wire cages to protect the nests from both factors. Cage effectiveness was questioned due to high predation rates, despite caging. Evaluations to determine the effectiveness of this method were conducted. Pairs of caged (control) and uncaged (experimental) nests were established in zones reflecting high/low traffic and high/low predator attacks and monitored on a daily basis. Following emergence, nest fate comparisons were made. Decoy cages were used to determine predator efficiency. Data suggest that cages are not needed in areas of low traffic or predator attacks. Additional data suggest that cages actually attract, rather than deter, mammalian predators.
Show less - Date Issued
- 1997
- PURL
- http://purl.flvc.org/fcla/dt/15441
- Subject Headings
- Sea turtles--Florida, Sea turtles--Nests--Florida
- Format
- Document (PDF)
- Title
- Fibropapillomatosis in stranded green turtles (Chelonia mydas) in Florida: 20 years of spatiotemporal trends and associations with environmental factors.
- Creator
- Niland, Hannah, Perrault, Justin, Salmon, Michael, Florida Atlantic University, Department of Biological Sciences, Charles E. Schmidt College of Science
- Abstract/Description
-
Fibropapillomatosis (FP) is a tumor disease that has reached panzootic proportions in green turtles (Chelonia mydas). FP is associated with chelonid alphaherpesvirus 5, although the etiology of FP is likely multifactorial, since high FP prevalence is often observed in degraded habitats. However, specific environmental cofactors for tumor development remain unknown. To explore this, I collated statewide green turtle stranding data from 2000–2020 to evaluate spatiotemporal trends of FP in...
Show moreFibropapillomatosis (FP) is a tumor disease that has reached panzootic proportions in green turtles (Chelonia mydas). FP is associated with chelonid alphaherpesvirus 5, although the etiology of FP is likely multifactorial, since high FP prevalence is often observed in degraded habitats. However, specific environmental cofactors for tumor development remain unknown. To explore this, I collated statewide green turtle stranding data from 2000–2020 to evaluate spatiotemporal trends of FP in Florida, and co-analyzed these data alongside patterns of river flow, chlorophyll-a (Chla), sea surface temperature (SST), El Niño (ENSO), and red tide (HAB). I found that FP was stable during 2000–2020. HAB (positively) and SST (negatively) correlated with statewide FP prevalence, as well as several interactions between various factors. These results suggest that SST and HABs may act as cofactors in the development of FP, and future work should be equally interdisciplinary in their investigation of this multifactorial disease
Show less - Date Issued
- 2023
- PURL
- http://purl.flvc.org/fau/fd/FA00014191
- Subject Headings
- Green sea turtles, Chelonia mydas, Sea turtles--Diseases
- Format
- Document (PDF)
- Title
- Using unmanned aerial vehicle (UAV) surveys and traditional methods to examine influences on loggerhead sea turtle (Caretta caretta) nest site selection.
- Creator
- Manestar, Summer, Briggs, Tiffany Roberts, Florida Atlantic University, Department of Geosciences, Charles E. Schmidt College of Science
- Abstract/Description
-
This study examined the environmental and anthropogenic factors that may influence loggerhead sea turtle nest site selection and how these factors vary between successful nesting attempts and false crawls on a high-density sea turtle nesting beach in Boca Raton, Florida. Beach morphology, sand texture, and nests’ proximity to artificial structures were measured using a combination of drone-based photogrammetry, traditional surveys with Real Time Kinematic Global Positioning System (RTK GPS),...
Show moreThis study examined the environmental and anthropogenic factors that may influence loggerhead sea turtle nest site selection and how these factors vary between successful nesting attempts and false crawls on a high-density sea turtle nesting beach in Boca Raton, Florida. Beach morphology, sand texture, and nests’ proximity to artificial structures were measured using a combination of drone-based photogrammetry, traditional surveys with Real Time Kinematic Global Positioning System (RTK GPS), and sediment granulometry. Proximity to dune crossover stairs was significantly different between nests and false crawls, and the probability of a false crawl occurring decreased as proximity to dune crossover stairs increased. The results of this study will provide researchers with a new tool for nest monitoring and a better understanding of the microhabitat cues that may influence loggerhead sea turtle nest site selection and aid in guiding beach and sea turtle management decisions.
Show less - Date Issued
- 2023
- PURL
- http://purl.flvc.org/fau/fd/FA00014184
- Subject Headings
- Loggerhead sea turtles, Drone aircraft, Sea turtles--Nests, Geomorphology
- Format
- Document (PDF)
- Title
- ANALYZING ULTRASONOGRAPHY AS A NON-INVASIVE TECHNIQUE FOR ESTIMATING BODY CONDITION IN GREEN (CHELONIA MYDAS) AND LOGGERHEAD (CARETTA CARETTA) SEA TURTLES.
- Creator
- Pico ,Marisa Nicole, Page-Karjian, Annie, Florida Atlantic University, Department of Biological Sciences, Charles E. Schmidt College of Science
- Abstract/Description
-
In sea turtles, body condition can be evaluated through subjective body condition scoring (BCS), calculating body condition index (BCI), and clinical blood parameters. The goal of this study was to analyze ultrasonography of subcutaneous fat depth as a method to estimate body condition in 10 green and 8 loggerhead sea turtle carcasses using two types of portable ultrasound technologies, the Ibex Evo® and the Renco Lean-Meater®. Despite the general lack of significant correlations between...
Show moreIn sea turtles, body condition can be evaluated through subjective body condition scoring (BCS), calculating body condition index (BCI), and clinical blood parameters. The goal of this study was to analyze ultrasonography of subcutaneous fat depth as a method to estimate body condition in 10 green and 8 loggerhead sea turtle carcasses using two types of portable ultrasound technologies, the Ibex Evo® and the Renco Lean-Meater®. Despite the general lack of significant correlations between ultrasound-assisted, gross, and histological measurements, the dorsal shoulder and lateral neck were determined to provide the most consistent images of subcutaneous fat. Florida live-captured green turtles were sampled and ultrasound-assisted fat depth measurements were taken at the dorsal shoulder region; however, there were no significant correlations found between fat depth and BCI or blood analytes (PCV, total protein). BCI reference quartiles were created using associations between BCI and BCS to help provide biological context to BCI data and allow for rapid categorization of sea turtle body condition.
Show less - Date Issued
- 2021
- PURL
- http://purl.flvc.org/fau/fd/FA00013747
- Subject Headings
- Ultrasonography, Sea turtles, Ultrasonic imaging
- Format
- Document (PDF)
- Title
- A comparison of body proportions in juvenile sea turtles: how shape may optimize survival in a vulnerable life stage.
- Creator
- Pate, Jessica Hope, Salmon, Michael, Florida Atlantic University, Charles E. Schmidt College of Science, Department of Biological Sciences
- Abstract/Description
-
Marine turtles produce many offspring which offsets the high mortality experienced by turtles during early development. Juvenile mortality might be reduced by evolving effective behavioral as well as morphological anti-predator defenses. Body proportions of three species (Caretta caretta, Chelonia mydas, Dermochelys coriacea) of turtles were measured in the first fourteen weeks of development to examine how growth may mitigate predation by gape-limited predators. Growth was categorized as...
Show moreMarine turtles produce many offspring which offsets the high mortality experienced by turtles during early development. Juvenile mortality might be reduced by evolving effective behavioral as well as morphological anti-predator defenses. Body proportions of three species (Caretta caretta, Chelonia mydas, Dermochelys coriacea) of turtles were measured in the first fourteen weeks of development to examine how growth may mitigate predation by gape-limited predators. Growth was categorized as isometric if shape did not change during development or allometric if body shape did change. All three species showed allometric growth in carapace width; however it was less pronounced in the larger D. coriacea turtles. Allometric growth in carapace width decreased as all three species grew in size. When high predation occurs in early development, many species will favor rapid growth into a size refuge. Juvenile sea turtles may optimize their survival by growing allometrically when predation risk is the greatest.
Show less - Date Issued
- 2014
- PURL
- http://purl.flvc.org/fau/fd/FA00004223, http://purl.flvc.org/fau/fd/FA00004223
- Subject Headings
- Predation (Biology), Sea turtles -- Growth, Sea turtles -- Mortality, Sea turtles -- Population viability analysis
- Format
- Document (PDF)
- Title
- Surveying Antibiotic Resistance of Gram-Negative Bacteria Isolated from Wild-Caught and Rehabilitated Green Sea Turtles (Chelonia mydas) and Loggerhead Sea Turtles (Caretta caretta) of Florida.
- Creator
- Cortes, Christina M., Milton, Sarah L., Florida Atlantic University, Department of Marine Science and Oceanography, Charles E. Schmidt College of Science
- Abstract/Description
-
Antibiotic resistance is a growing concern due to the improper use of antibiotics. Not only is antibiotic resistance increasingly occurring in human populations, but it appears to be spreading in wildlife populations too due to drug overuse and misuse in medicine, farming, and industrial settings, and the subsequent release into watersheds. This project examined the prevalence of antibiotic resistant bacteria in the hindgut microbiome of green (Chelonia mydas) (n=60) and loggerhead (Caretta...
Show moreAntibiotic resistance is a growing concern due to the improper use of antibiotics. Not only is antibiotic resistance increasingly occurring in human populations, but it appears to be spreading in wildlife populations too due to drug overuse and misuse in medicine, farming, and industrial settings, and the subsequent release into watersheds. This project examined the prevalence of antibiotic resistant bacteria in the hindgut microbiome of green (Chelonia mydas) (n=60) and loggerhead (Caretta caretta) (n=57) sea turtles. Hindgut swabs were cultured for gram negative bacteria and exposed to 6 antibiotics. 83.3% of samples were resistant or intermediately resistant to at least one antibiotic, and 27.7% of samples were resistant or intermediately resistant to three antibiotics. This study provides more information regarding the relationship between turtle characteristics and the presence of antibiotic resistance in the hindgut of Florida sea turtles, as well as examine the types of bacteria found in the hindgut.
Show less - Date Issued
- 2024
- PURL
- http://purl.flvc.org/fau/fd/FA00014489
- Subject Headings
- Green sea turtles, Loggerhead sea turtles, Sea turtles--Florida, Drug Resistance, Bacterial
- Format
- Document (PDF)
- Title
- Nest placement by three species of sea turtles in southeast Florida, USA.
- Creator
- Wood, Lawrence D., Florida Atlantic University, Koch, Marguerite
- Abstract/Description
-
Studies of loggerhead, leatherback and green turtle nest distribution across beaches (between water and dune) have revealed conflicting random versus non-random patterns of nest placement. I examined nest placement on a southeast Florida beach (Juno and Jupiter) with average beach widths of 30 (natural) and 90 m (nourished beach) and tested slope as a proximal cue for nesting using long-term data sets and GPS technology. All three species had similar species-specific crawl lengths and nest...
Show moreStudies of loggerhead, leatherback and green turtle nest distribution across beaches (between water and dune) have revealed conflicting random versus non-random patterns of nest placement. I examined nest placement on a southeast Florida beach (Juno and Jupiter) with average beach widths of 30 (natural) and 90 m (nourished beach) and tested slope as a proximal cue for nesting using long-term data sets and GPS technology. All three species had similar species-specific crawl lengths and nest sites relative to distance from water, regardless of beach width. Loggerheads and leatherbacks crawled and nested significantly shorter median distances (8--14 m) relative to the water compared to greens (15 m), corresponding to sites of maximum productivity measured as percent hatchling success. The observed consistencies of crawl distance across all beach profiles suggest a strong evolutionary selection for a non-random crawl length at this study site, regardless of beach width and slight shifts in slope.
Show less - Date Issued
- 2004
- PURL
- http://purl.flvc.org/fcla/dt/13185
- Subject Headings
- Sea turtles--Florida--Palm Beach County, Loggerhead turtle--Florida, Sea turtles--Nests--Florida
- Format
- Document (PDF)
- Title
- Measuring Nest-to-Surf Mortality of Florida’s East and West Coast Loggerhead Sea Turtle (Caretta caretta) Hatchlings.
- Creator
- Villegas Vindiola, Brianna, Wyneken, Jeanette, Florida Atlantic University, Charles E. Schmidt College of Science, Department of Biological Sciences
- Abstract/Description
-
Sea turtle hatchlings emerge from their nest and quickly crawl to the surf. During the crawl, hatchlings may encounter threats, biotic and abiotic, which can affect their ability to successfully reach the surf. The impact of these threats on hatchling survival during that crawl is largely undocumented. Current methods used to estimate cohort recruitment rely heavily on nest inventory data. This method, however, does not account for post-emergent hatchling mortality that occurs during the...
Show moreSea turtle hatchlings emerge from their nest and quickly crawl to the surf. During the crawl, hatchlings may encounter threats, biotic and abiotic, which can affect their ability to successfully reach the surf. The impact of these threats on hatchling survival during that crawl is largely undocumented. Current methods used to estimate cohort recruitment rely heavily on nest inventory data. This method, however, does not account for post-emergent hatchling mortality that occurs during the crawl. During the 2017-2018 nesting seasons, I quantified the fates of 1,379 loggerhead (Caretta caretta) hatchlings from 26 nest emergences during their crawl from the nest to the surf on the east and west coasts of Florida. I documented hatchling fates at 5 Florida nesting beaches: Wabasso, Boca Raton, Keewaydin Island, Naples, and Anna Maria Island. Overall, 6.5% of all emergent hatchlings died during the crawl from the nests to the surf. Ghost crabs, night herons, foxes, and coyotes killed hatchlings and photopollution and barriers on the beach (both abiotic threats) caused hatchling mortality. Anthropogenic (abiotic) threats accounted for more mortality than did predators. In order to assess how beach urbanization impacts hatchling mortality, I categorized each study site as urban (Wabasso and Naples), intermediate (Anna Maria Island and Boca Raton), or natural (Keewaydin Island) based on the relative levels of shoreline development and human activity at each beach. Sites with intermediate levels of urbanization accounted for greater levels of hatchling mortality than at other beaches due to the absolutely larger numbers of hatchlings lost to a disorientation event and to a beach barrier. Given the small numbers of emergences, at all sites, only a small proportion of the hatchlings mortalities (e.g., between 3 and 12 percent), site type could not be rigorously used as a discriminator. My results provide a better understanding of how specific environmental threats contribute to hatchling mortality. While nest-to-surf mortality is relatively low, its cumulative costs add up to several hundreds of thousands of hatchlings. Armed with this information, nesting beach managers can assess risks and focus their efforts to implement the most effective management practices to minimize losses of this imperiled species.
Show less - Date Issued
- 2019
- PURL
- http://purl.flvc.org/fau/fd/FA00013277
- Subject Headings
- Loggerhead turtle--Florida, Caretta caretta, Sea turtles--Nests, Sea turtles--Mortality
- Format
- Document (PDF)
- 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
-
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
- Calcium requirement and growth in the hatchling loggerhead sea turtle (Caretta caretta L.).
- Creator
- Alexander, Jeanne Louise., Florida Atlantic University, Wyneken, Jeanette
- Abstract/Description
-
The calcium requirement in captive-raised hatchling loggerhead sea turtles (Caretta caretta) was investigated. Comparisons were made among turtles on 6 experimental diets and between captive and wild turtles. Diets consisted of trout chow diets containing 1%, 2%, 3%, or 4% calcium and 1.65% phosphorous, AquaMax 500RTM (2% Ca), and shrimp. Feeding trials lasted 28 days and changes in body size and bone density were measured. The calcium and phosphorous content of foods eaten by post-hatchlings...
Show moreThe calcium requirement in captive-raised hatchling loggerhead sea turtles (Caretta caretta) was investigated. Comparisons were made among turtles on 6 experimental diets and between captive and wild turtles. Diets consisted of trout chow diets containing 1%, 2%, 3%, or 4% calcium and 1.65% phosphorous, AquaMax 500RTM (2% Ca), and shrimp. Feeding trials lasted 28 days and changes in body size and bone density were measured. The calcium and phosphorous content of foods eaten by post-hatchlings in the sargassum were compared with captive diets. Results showed that shrimp was high in protein and low in calcium, with nearly twice as much P as Ca. The growth trials showed that turtles fed shrimp versus all other diets grew larger. There was no difference in total bone density of any treatment over the study. No signs of hypocalcemia were present, therefore, no lower limit for calcium requirement was determined in this study.
Show less - Date Issued
- 2000
- PURL
- http://purl.flvc.org/fcla/dt/12708
- Subject Headings
- Loggerhead turtle, Sea turtles--Nutrition, Calcium in animal nutrition
- Format
- Document (PDF)
- Title
- Orientation of hatchling loggerhead sea turtles in response to the inclination of the magnetic field.
- Creator
- Light, Phillip Richard, Florida Atlantic University, Salmon, Michael, Charles E. Schmidt College of Science, Department of Biological Sciences
- Abstract/Description
-
Recent studies have shown that hatchling loggerhead sea turtles possess the ability to orient to the earth's magnetic field. These experiments did not identify the specific component of the field used by turtles to determine direction. One of the field's most important characteristics, inclination, has been implicated as the specific property used by birds to orient. This study investigated the possibility that sea turtles use the inclination of the earth's field in a similar manner. Results...
Show moreRecent studies have shown that hatchling loggerhead sea turtles possess the ability to orient to the earth's magnetic field. These experiments did not identify the specific component of the field used by turtles to determine direction. One of the field's most important characteristics, inclination, has been implicated as the specific property used by birds to orient. This study investigated the possibility that sea turtles use the inclination of the earth's field in a similar manner. Results show that turtles determine direction with the use of an inclination compass similar to the one used by birds to orient. This study has important implications regarding the mechanisms used by animals to orient and navigate.
Show less - Date Issued
- 1992
- PURL
- http://purl.flvc.org/fcla/dt/14787
- Subject Headings
- Loggerhead turtle, Animal orientation, Magnetic fields, Sea turtles--Migration
- Format
- Document (PDF)
- Title
- The magnetic compass of the loggerhead sea turtle (Caretta caretta L.): Can surface waves establish magnetic directional preference?.
- Creator
- Goff, Matthew Douglas, Florida Atlantic University, Salmon, Michael
- Abstract/Description
-
Hatchling loggerhead sea turtles emerge from their nests on oceanic beaches, crawl to the surf zone, and swim out to sea. How do turtles maintain oriented headings once they lose contact with land? I tested the hypothesis that by swimming into surface waves hatchlings establish an offshore heading (directional preference), and that once out to sea this heading is transferred to, and maintained by, a magnetic compass. This hypothesis was supported by laboratory and field experiments, described...
Show moreHatchling loggerhead sea turtles emerge from their nests on oceanic beaches, crawl to the surf zone, and swim out to sea. How do turtles maintain oriented headings once they lose contact with land? I tested the hypothesis that by swimming into surface waves hatchlings establish an offshore heading (directional preference), and that once out to sea this heading is transferred to, and maintained by, a magnetic compass. This hypothesis was supported by laboratory and field experiments, described herein. A directional preference can also be established by oriented crawling (from the nest to the surf zone). Thus hatchlings possess two mechanisms (crawling and swimming) for the establishment of an offshore heading. The use of these alternative mechanisms probably assures that turtles escape from shore under the broad range of conditions which they naturally encounter after emerging from their nests.
Show less - Date Issued
- 1996
- PURL
- http://purl.flvc.org/fcla/dt/15285
- Subject Headings
- Loggerhead turtle, Sea turtles--Orientation, Animal navigation
- Format
- Document (PDF)