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- Title
- The risk of hatchling loss to nearshore predators at a high-density loggerhead nesting beach in southeast Florida.
- Creator
- Stewart, Kelly Rhoda., Florida Atlantic University, Wyneken, Jeanette
- Abstract/Description
-
It has been recognized that mortality is high for juvenile stages of long-lived vertebrates such as sea turtles, however few studies have quantified mortality rates. The objective of this study was to assess the relative risk that hatchlings face in their first few minutes in the water, at the commencement of their offshore migration from a natural high-density nesting beach (Juno/Jupiter, FL). I followed 217 hatchlings at night by kayak, as they left the beach and documented the proportion...
Show moreIt has been recognized that mortality is high for juvenile stages of long-lived vertebrates such as sea turtles, however few studies have quantified mortality rates. The objective of this study was to assess the relative risk that hatchlings face in their first few minutes in the water, at the commencement of their offshore migration from a natural high-density nesting beach (Juno/Jupiter, FL). I followed 217 hatchlings at night by kayak, as they left the beach and documented the proportion surviving the initial 15 minutes in the water. Of these, 206 survived for an empirical survival rate of 95%. Tarpon were the most common predator observed. This survival rate is much higher than that previously observed at a hatchery (72%); this may be due to temporal and spatial variation in nest location at the natural beach. Juno and Jupiter beaches are therefore highly productive sea turtle rookeries.
Show less - Date Issued
- 2001
- PURL
- http://purl.flvc.org/fcla/dt/12822
- Subject Headings
- Loggerhead turtle--Florida, Sea turtles--Mortality
- Format
- Document (PDF)
- Title
- Relocation and Flood Impacts on Loggerhead Sea Turtle (Caretta caretta) Nest Success.
- Creator
- Esposito, Lisa Anne, Milton, Sarah L., Florida Atlantic University, Department of Biological Sciences, Charles E. Schmidt College of Science
- Abstract/Description
-
Sea level rise threatens loggerhead sea turtle (Caretta caretta) nests laid close to the high tide line (HTL) with inundation from washover. Boca Raton, Florida is a relatively steep, dynamic beach with changes in beach morphology even during nonactive hurricane seasons. One potential solution to conserve sea turtle nests is to relocate nests laid at or below the HTL closer to the dune. In this study, I examined reproductive success for in situ vs relocated nests. Relocation did not decrease...
Show moreSea level rise threatens loggerhead sea turtle (Caretta caretta) nests laid close to the high tide line (HTL) with inundation from washover. Boca Raton, Florida is a relatively steep, dynamic beach with changes in beach morphology even during nonactive hurricane seasons. One potential solution to conserve sea turtle nests is to relocate nests laid at or below the HTL closer to the dune. In this study, I examined reproductive success for in situ vs relocated nests. Relocation did not decrease reproductive success, while nests left near the HTL were at risk of washout. During a dry season, nests that experienced one to three days of washover had significantly higher reproductive success than nests that experienced no washover. Relocation can be a useful method to preserve nests against sea level rise, but nonrelocated nests near the HTL may sometimes benefit from washover to cool the nests during hot and dry years.
Show less - Date Issued
- 2023
- PURL
- http://purl.flvc.org/fau/fd/FA00014177
- Subject Headings
- Loggerhead turtle, Caretta caretta, Sea turtles--Nests
- 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
- Incubation temperature, morphology, and loggerhead (Caretta caretta) sea turtle hatchling hydrodynamics.
- Creator
- Moyle, Alexis K., Milton, Sarah L., Florida Atlantic University, Department of Biological Sciences, Charles E. Schmidt College of Science
- Abstract/Description
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High nest incubation temperatures can result in numerous physiological and behavioral outcomes in sea turtle hatchlings, including body characteristics for efficient swimming. This project examined the effects of incubation temperature on yolk metabolization, body morphology, buoyancy, swimming kinematics, and blood chemistry to better understand variations in locomotor performance in loggerhead (Caretta caretta) sea turtle hatchlings of South Florida. Nest temperatures, body measurements,...
Show moreHigh nest incubation temperatures can result in numerous physiological and behavioral outcomes in sea turtle hatchlings, including body characteristics for efficient swimming. This project examined the effects of incubation temperature on yolk metabolization, body morphology, buoyancy, swimming kinematics, and blood chemistry to better understand variations in locomotor performance in loggerhead (Caretta caretta) sea turtle hatchlings of South Florida. Nest temperatures, body measurements, and blood samples were collected in conjunction with swim-trial force measurements and video recordings. Data suggest hatchlings from nests with higher incubation temperatures tend to be significantly smaller in size, less buoyant, and display lower power stroke frequencies. These variations between hatchling morphology and performance indicate hatchlings from high temperature nests (i.e., >33°C) may exhibit weaker swimming abilities. The results of this study provide a further understanding of the effect of incubation temperatures on hatchling physiology and early survival in their important frenzy period.
Show less - Date Issued
- 2023
- PURL
- http://purl.flvc.org/fau/fd/FA00014268
- Subject Headings
- Loggerhead turtle, Eggs--Incubation, Sea turtles--Ecology
- Format
- Document (PDF)
- Title
- Effects of various sand types on nest temperature and hatching success in the loggerhead (Caretta caretta) sea turtle.
- Creator
- Cheeks, Rebecca Joan., Florida Atlantic University, Lutz, Peter L.
- Abstract/Description
-
Because of the logistics involved with field experiments, most of what is known about effects of temperature on the nest environment of loggerhead (Caretta caretta) sea turtles has been learned in the laboratory. Until now, scientists have been forced to speculate on what effects different sands might have on temperature within the nest. Results of the present study indicate that the upper lethal temperature limit of loggerheads is between 33-35C; this temperature is more likely to be reached...
Show moreBecause of the logistics involved with field experiments, most of what is known about effects of temperature on the nest environment of loggerhead (Caretta caretta) sea turtles has been learned in the laboratory. Until now, scientists have been forced to speculate on what effects different sands might have on temperature within the nest. Results of the present study indicate that the upper lethal temperature limit of loggerheads is between 33-35C; this temperature is more likely to be reached in larger clutches, causing high mortality and low emergence success. Furthermore, the metabolic heat of a larger clutch will be exacerbated by warmer sand types. Ranges of temperatures experienced during the middle period of incubation, not only within the clutch, but over the course of the nesting season, are both above and below the pivotal temperature for sex determination in loggerheads. Perhaps it is inappropriate to use mean beach temperatures to predict outcomes of sex ratios on various coasts. It would be more prudent to concern ourselves with predicting survivorship of a clutch using results from this field study along with beach temperatures, rather than using laboratory temperatures to predict sex ratios.
Show less - Date Issued
- 1997
- PURL
- http://purl.flvc.org/fcla/dt/15459
- Subject Headings
- Loggerhead turtle--Nests, Loggerhead turtle--Effect of temperature on
- Format
- Document (PDF)
- Title
- Polychlorinated biphenyls and p,p’-DDE in loggerhead and green postyearling Atlantic sea turtles.
- Creator
- McKim, James M., Jr., Johnson, Kenneth L., Harbor Branch Oceanographic Institute
- Date Issued
- 1983
- PURL
- http://purl.flvc.org/FCLA/DT/3176716
- Subject Headings
- Sea turtles, Polychlorinated biphenyls, Green turtle, Loggerhead turtle, Chelonia mydas, Caretta caretta, Pesticides
- 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
- 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
- IMPACT OF DEVELOPED COASTLINE ON NESTING AND HATCHLING SEA TURTLES IN SOUTHEASTERN FLORIDA.
- Creator
- MANN, THOMAS MASON, Florida Atlantic University
- Abstract/Description
-
The impact of coastline development on nesting sea turtles, nest contents, and hatchlings was investigated in southeastern Florida. There were 95-128 loggerhead (Caretta caretta) nests per mile on six miles of beach. Seventeen green turtle (Chelonia mydas) nests were found. Nesting females did not avoid lighted, developed beaches in favor of undeveloped beaches. Hatchling emergence bearings were measured at 397 nests, and ambient light intensities were correlated with the incidence of...
Show moreThe impact of coastline development on nesting sea turtles, nest contents, and hatchlings was investigated in southeastern Florida. There were 95-128 loggerhead (Caretta caretta) nests per mile on six miles of beach. Seventeen green turtle (Chelonia mydas) nests were found. Nesting females did not avoid lighted, developed beaches in favor of undeveloped beaches. Hatchling emergence bearings were measured at 397 nests, and ambient light intensities were correlated with the incidence of misorientation. Most hatchlings emerging where artificial light sources were visible were misoriented inland. From 0-96% of misoriented hatchlings were killed by automobiles, ghost crabs, or dessication. Mortality was greatest where hatchlings were able to enter roadways, and lowest where barriers prevented this. Analysis of post-emergence contents of 422 nests revealed that mortality within nests was greater on soft beaches with large-grained sand than on fine-grained, firmer beaches, and was increased by human footfalls and beach-cleaning machinery.
Show less - Date Issued
- 1977
- PURL
- http://purl.flvc.org/fcla/dt/13839
- Subject Headings
- Sea turtles--Florida--Palm Beach County, Sea turtles--Florida--Broward County, Green turtle, Loggerhead turtle
- Format
- Document (PDF)
- Title
- Hatchling sex ratios and nest temperature-sex ratio response of three South Florida marine turtle species (Caretta caretta L., Chelona mydas L., and Dermochelys coriacea V.).
- Creator
- Rogers, Micah Marie., Charles E. Schmidt College of Science, Department of Biological Sciences
- Abstract/Description
-
South Florida's loggerhead (Caretta caretta), green (Chelonia mydas) and leatherback (Dermochelys coriacea) sea turtles hatchling have environmentally determined sex. The in situ nest mean hatchling sex ratios (SR) were highly female-biased : loggerhead F=0.89) and green turtle F=0.81; leatherback's SR was nearly balanced (0.55F). Nest temperatures and SRs differed between leatherbacks and loggerhead and green turtles. The latter two did not differ. The loggerhead response parameters were...
Show moreSouth Florida's loggerhead (Caretta caretta), green (Chelonia mydas) and leatherback (Dermochelys coriacea) sea turtles hatchling have environmentally determined sex. The in situ nest mean hatchling sex ratios (SR) were highly female-biased : loggerhead F=0.89) and green turtle F=0.81; leatherback's SR was nearly balanced (0.55F). Nest temperatures and SRs differed between leatherbacks and loggerhead and green turtles. The latter two did not differ. The loggerhead response parameters were estimated within biological limitations by both 50-65% of incubation and mean middle 1/3 temperature. The maximum middle 1/3 temperature was the best-fit predictor for green turtles. No best-fit sex ratio-temperature response could be identified for leatherbacks. Clutches incubating under natural conditions can vary greatly in SR ; TRT differences may account for differences among species' sex ratios.
Show less - Date Issued
- 2013
- PURL
- http://purl.flvc.org/fcla/dt/3361062
- Subject Headings
- Sex ratio, Sex determination, Genetic, Sea turtles, Nests, Sea turtles, Embryology, Loggerhead turtle, Nests, Loggerhead turtle, Effect of temperature on
- Format
- Document (PDF)
- Title
- Determination of sex ratios and their relationship to nest temperature of loggerhead sea turtle (Caretta caretta, L.) hatchlings produced along the southeastern Atlantic coast of the United States.
- Creator
- Blair, Kimberly., Florida Atlantic University, Wyneken, Jeanette
- Abstract/Description
-
The sex ratios of hatchling loggerheads (Caretta caretta) were determined to provide robust assessments of regional and seasonal contributions of males and females to the population. Hatchlings from nests along the Atlantic coastline were raised to 120 g, sexed laparoscopically and verified histologically. Sex ratios differed at the beach, subseason, and subpopulation levels. There was no difference in overall sex ratios between the two study years. Average nest temperature and incubation...
Show moreThe sex ratios of hatchling loggerheads (Caretta caretta) were determined to provide robust assessments of regional and seasonal contributions of males and females to the population. Hatchlings from nests along the Atlantic coastline were raised to 120 g, sexed laparoscopically and verified histologically. Sex ratios differed at the beach, subseason, and subpopulation levels. There was no difference in overall sex ratios between the two study years. Average nest temperature and incubation durations were not accurate sex ratio correlates. Temperatures that produced female biased or male biased sex ratios overlapped in ranges with those producing a single sex. I found that the Transitional Range of Temperatures for loggerhead sea turtles is approximately 26.5°C--32°C, and the best correlation between average temperature and sex ratio occurred at 50--65% of incubation. Further studies are needed to define the roles of other environmental factors or the responses of tissues in loggerhead sex determination.
Show less - Date Issued
- 2005
- PURL
- http://purl.flvc.org/fcla/dt/13197
- Subject Headings
- Sea turtles--Nests--United States, Sex (Biology), Sea turtles--Atlantic Coast (U S ), Loggerhead turtle--Nests, Loggerhead turtle--Breeding
- 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
-
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
- Incubation Temperature Effects on Loggerhead (Caretta caretta) and Green (Chelonia mydas) Sea Turtle Hatchling Vigor.
- Creator
- Henaghan, Christopher, Milton, Sarah, Florida Atlantic University, Charles E. Schmidt College of Science, Department of Biological Sciences
- Abstract/Description
-
Climate change has the potential to expose sea turtle nests to higher temperatures, which may negatively impact sea turtle hatchling vigor. In this study, loggerhead and green hatchlings were sampled from the Boca Raton, Florida beach and via lab incubation, and hatchling vigor was determined. Elevated nest temperatures decreased loggerhead and green turtle hatchling performance and corticosterone levels, with the most significant effects found in hatchlings exposed to maximum incubation...
Show moreClimate change has the potential to expose sea turtle nests to higher temperatures, which may negatively impact sea turtle hatchling vigor. In this study, loggerhead and green hatchlings were sampled from the Boca Raton, Florida beach and via lab incubation, and hatchling vigor was determined. Elevated nest temperatures decreased loggerhead and green turtle hatchling performance and corticosterone levels, with the most significant effects found in hatchlings exposed to maximum incubation temperatures above 35°C during late development. Lab-incubated loggerhead post-hatchling corticosterone levels and growth rates were also determined. The differences seen in corticosterone levels with overall nest incubation temperatures, mean temperatures during early, middle or late stages of development, and its negative correlation with hatchling performance improves our understanding of the underlying physiological mechanisms linking elevated incubation temperatures and sub-lethal physiological effects that may significantly impact hatchling survival, a critical step for sea turtle conservation in south Florida and elsewhere.
Show less - Date Issued
- 2018
- PURL
- http://purl.flvc.org/fau/fd/FA00013157
- Subject Headings
- Loggerhead turtle--Florida, Caretta caretta, Chelonia mydas, Green turtle, Temperature, Eggs--Incubation
- Format
- Document (PDF)
- Title
- Magnetic orientation of loggerhead sea turtle hatchlings: migratory strategies in the Gulf of Mexico.
- Creator
- Merrill, Maria W., Charles E. Schmidt College of Science, Department of Biological Sciences
- Abstract/Description
-
Loggerhead sea turtles nest on either the Atlantic or Gulf coast of Florida. The hatchlings from these nests migrate offshore in opposite directions. The purpose of my study was to determine if Gulf coast hatchlings use magnetic maps, as Atlantic coast hatchlings do, both to locate areas favorable for survival in the Gulf of Mexico and to orient appropriately within surface currents that could transport them into the Atlantic Ocean. To find out, I presented Gulf coast hatchlings with magnetic...
Show moreLoggerhead sea turtles nest on either the Atlantic or Gulf coast of Florida. The hatchlings from these nests migrate offshore in opposite directions. The purpose of my study was to determine if Gulf coast hatchlings use magnetic maps, as Atlantic coast hatchlings do, both to locate areas favorable for survival in the Gulf of Mexico and to orient appropriately within surface currents that could transport them into the Atlantic Ocean. To find out, I presented Gulf coast hatchlings with magnetic fields corresponding to different locations inside the Gulf, and within currents leading into (Florida Straits) and within (Gulf Stream) the western portion of the Atlantic Ocean. I conclude that Gulf coast hatchlings (i) use a high resolution magnetic map for navigation within the Gulf of Mexico, (ii) initially remain within the eastern Gulf, but later may (iii) gain entry into currents that transport them into Atlantic waters.
Show less - Date Issued
- 2010
- PURL
- http://purl.flvc.org/FAU/2138106
- Subject Headings
- Animal orientation, Magnetic fields, Sea turtles, Migration, Loggerhead turtle, Migration
- Format
- Document (PDF)
- Title
- Long-term analyses (1986-2018) of the Loggerhead Sea Turtle (Caretta caretta) nesting data from Keewaydin Island, Florida.
- Creator
- Hoover, Shelby R., Salmon, Michael, Florida Atlantic University, Department of Biological Sciences, Charles E. Schmidt College of Science
- Abstract/Description
-
Few studies on marine turtles focus on the variation in reproductive performance of individual females. I use a long-term nesting data set (1986 – 2018) of individual loggerheads including information on 1,854 individuals, of which 853 were seen nesting multiple times. During this time, emergence success has declined while the number of females nesting, and the number of nests deposited has increased. Declining emergence success can be linked to an increase in predation in most recent years;...
Show moreFew studies on marine turtles focus on the variation in reproductive performance of individual females. I use a long-term nesting data set (1986 – 2018) of individual loggerheads including information on 1,854 individuals, of which 853 were seen nesting multiple times. During this time, emergence success has declined while the number of females nesting, and the number of nests deposited has increased. Declining emergence success can be linked to an increase in predation in most recent years; however, this does not fully explain the decline in emergence success over all years. Females were found to vary in productivity. Successful females were larger and deposited more eggs in nests. This study shows that an increasing in nesting numbers does not mean that productivity is increasing proportionally and that recovery efforts are uniformly successful. This study is also a powerful tool for understanding the reproductive strategies of individual female loggerheads.
Show less - Date Issued
- 2019
- PURL
- http://purl.flvc.org/fau/fd/FA00013381
- Subject Headings
- Loggerhead turtle--Florida, Reproduction, Sea turtles--Nests, Predation (Biology)
- Format
- Document (PDF)
- Title
- THE IMPACT OF ENVIRONMENTAL FACTORS ON LOGGERHEAD SEA TURTLE (CARETTA CARETTA) HATCHLING BIOLOGY.
- Creator
- Lolavar, Alexandra A., Wyneken, Jeanette, Florida Atlantic University, Department of Biological Sciences, Charles E. Schmidt College of Science
- Abstract/Description
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The eggs of all sea turtle species develop in underground nests on oceanic nesting beaches. Eggs are unattended and their incubation conditions are subject to effects of the environment. Nest temperature influences various aspects of hatchling biology, including sex determination. Past studies identified that sea turtle embryos have a warm female cool male response pattern and rainfall has been thought to cool nest temperature. The effects of rainfall or periods of drought were often inferred...
Show moreThe eggs of all sea turtle species develop in underground nests on oceanic nesting beaches. Eggs are unattended and their incubation conditions are subject to effects of the environment. Nest temperature influences various aspects of hatchling biology, including sex determination. Past studies identified that sea turtle embryos have a warm female cool male response pattern and rainfall has been thought to cool nest temperature. The effects of rainfall or periods of drought were often inferred but not verified. Using laboratory and field studies, I examined how changes in environmental factors during incubation, particularly sand moisture, can affect nest conditions and hatchling biology. I derived temperature-sex ratio response curves for eggs incubated at different moisture levels to determine the effect of moisture on how embryos respond to temperature. I also studied how increasing moisture levels in relocated nests through daily watering influence nest conditions and discuss if this method is an effective mitigation strategy for the detrimental effects of increasing temperatures on embryo survival and sex ratios. I investigated how environmental factors, nest conditions, and hatchling biology can differ among sites on a nesting beach. Extreme moisture conditions, both low and high, result in a narrower transition between one sex ratio bias to another. I demonstrated that watering nests decreases nest temperatures and increases hatching success but watering has a minimal impact on sex ratios. Ambient beach conditions vary slightly in air temperature, rainfall, solar radiation, and humidity, depending on beach location. Nest conditions such as nest temperature and moisture also differ, but hatching success and sex ratios do not vary among different sites on the same nesting beach in Boca Raton, Florida. Ultimately, these studies together help identify and demonstrate how these environmental factors and drivers can affect the nest environment during incubation. Further developing our understanding of environmental factors, particularly nest moisture, and their variability will provide better predictions of future climate change effects and perhaps create more effective mitigation strategies.
Show less - Date Issued
- 2019
- PURL
- http://purl.flvc.org/fau/fd/FA00013390
- Subject Headings
- Loggerhead turtle, Sea turtles--Nests, Environment, Eggs--Hatchability, Eggs--Incubation, Moisture
- Format
- Document (PDF)
- Title
- Sex determination of loggerhead sea turtles (Caretta caretta) via hormonal analysis by high performance liquid chromatography.
- Creator
- Botterill, Brooke L., Florida Atlantic University, Milton, Sarah L.
- Abstract/Description
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Sea turtles have temperature-dependent sex determination, with males being produced at cooler temperatures and females at warmer ones. Thus, sex ratios are often estimated on average nest temperatures, but this is unreliable. Therefore, many studies have begun to look to alternative methods to identify sex ratios. Other methods used to determine sex require hatchling sacrifice or are labor intensive. This study utilized high performance liquid chromatography (HPLC) to investigate correlations...
Show moreSea turtles have temperature-dependent sex determination, with males being produced at cooler temperatures and females at warmer ones. Thus, sex ratios are often estimated on average nest temperatures, but this is unreliable. Therefore, many studies have begun to look to alternative methods to identify sex ratios. Other methods used to determine sex require hatchling sacrifice or are labor intensive. This study utilized high performance liquid chromatography (HPLC) to investigate correlations between steroid hormone levels in hatchling plasma and allantoic fluid, nest temperature and sex. Hatchling sex was determined laparoscopically to ground-truth hormone profiles. No correlation was found between hormones, nest temperature and sex. However, as hormones were readily detectable by HPLC, the technique may be applicable to juvenile or adult turtles with mature profiles.
Show less - Date Issued
- 2005
- PURL
- http://purl.flvc.org/fcla/dt/13284
- Subject Headings
- Sea turtles--Nests--United States, Loggerhead turtle--Breeding, Sex (Biology), High performance liquid chromatography
- Format
- Document (PDF)
- Title
- A long-term dietary analysis of loggerhead sea turtles ( Caretta caretta) based on strandings from Cumberland Island, Georgia.
- Creator
- Youngkin, Dale Allan, Florida Atlantic University, Wyneken, Jeanette
- Abstract/Description
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Information is lacking regarding the foraging ecology of many sea turtle species. This represents the first long-term study to partition gut content samples to look for differences in diets among seasons, across size classes, or between health or sex categories. In this study complete gut contents from loggerhead sea turtles (Caretta caretta) that stranded on Cumberland Island, Georgia USA from 1979--99 are analyzed (n = 369). The long-term nature of this study and large sample size allows...
Show moreInformation is lacking regarding the foraging ecology of many sea turtle species. This represents the first long-term study to partition gut content samples to look for differences in diets among seasons, across size classes, or between health or sex categories. In this study complete gut contents from loggerhead sea turtles (Caretta caretta) that stranded on Cumberland Island, Georgia USA from 1979--99 are analyzed (n = 369). The long-term nature of this study and large sample size allows for comparisons of diets across years as well as the categories mentioned above. Diets were shown to shift significantly over the years of the study as well as among seasons. Ontogenetic shifts in diets were also observed, while diets did not seem to differ with sex and apparent health of the turtles. The findings from this study point to potential biases from shorter-term studies that lack a robust distribution of turtle size.
Show less - Date Issued
- 2001
- PURL
- http://purl.flvc.org/fcla/dt/12823
- Subject Headings
- Loggerhead turtle--Food--Georgia--Cumberland Island, Sea turtles--Food
- Format
- Document (PDF)