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- Title
- Factors affecting the hatching success of loggerhead sea turtle eggs: (Caretta caretta caretta).
- Creator
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McGehee, M. Angela, Elmhart, L.M., Natural Sciences
- Abstract / Description
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University of Central Florida College of Natural Sciences Thesis; Clutches of eggs wore collected from nesting loggerhead sea turtles (Caretta caretta caretta) on Merritt Island, Florida, during June - August 1977. Of these, 46 clutches were selected for experimentation to determine the extent to which certain factors affect hatching success. Twelve clutches were divided into subsamples which were incubated in sand maintained at 0, 25, 50, 75, and 100% moisture. Another twelve clutches were...
Show moreUniversity of Central Florida College of Natural Sciences Thesis; Clutches of eggs wore collected from nesting loggerhead sea turtles (Caretta caretta caretta) on Merritt Island, Florida, during June - August 1977. Of these, 46 clutches were selected for experimentation to determine the extent to which certain factors affect hatching success. Twelve clutches were divided into subsamples which were incubated in sand maintained at 0, 25, 50, 75, and 100% moisture. Another twelve clutches were divided into subsamples and incubated in sand kept moist with the following percentages of seawater: 0 (distilled water), 25, 50, 75, and 100%; subsamples from four other clutches were subjected to the effects of one tidal inundation. Eggs from four of the clutches used in the moisture and salinity experiments were monitored for changes in size. Fifteen clutches were divided into subsamples which were kept in incubators maintained at 20, 24, 27, 30, 32, 35, and 38[degrees]C; subsamples from seven of these clutches were moved from unfavorable to optimal temperatures to study their ability to recover from stress. Three clutches were selected for an experiment to determine the effects of handling on hatching success; the following year, another five clutches were used for similar studies. Some of the hatchling turtles produced in this project were abnormal, and these were discussed in depth. From the experiments, it was determined that 25% moisture, 0-25% seawater, and 27[degrees]C produced the maximum percent hatch. The effects of handling on hatching success depended variably on the time and manner of handling. The optimum values indicated in the experiments closely approximated values for moisture, salinity, and temperature obtained from natural turtle nests on the beach.
Show less - Date Issued
- 1979
- Identifier
- CFR0004341, ucf:52974
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFR0004341
- Title
- EFFECTS OF A SHORE PROTECTION PROJECT ON LOGGERHEAD AND GREEN TURTLE NESTING ACTIVITY AND REPRODUCTION IN BREVARD COUNTY, FLORIDA.
- Creator
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Brock, Kelly, Ehrhart, Llewellyn, University of Central Florida
- Abstract / Description
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Marine turtle reproductive success is strongly correlated with the stability and quality of the nesting environment. Because females show fidelity to key nesting beaches, the management and physical characteristics of these beaches directly affect future generations of marine turtles and may be essential for the recovery of these threatened and endangered species. The impacts of beach restoration on loggerhead turtles (Caretta caretta) and on green turtles (Chelonia mydas) were investigated....
Show moreMarine turtle reproductive success is strongly correlated with the stability and quality of the nesting environment. Because females show fidelity to key nesting beaches, the management and physical characteristics of these beaches directly affect future generations of marine turtles and may be essential for the recovery of these threatened and endangered species. The impacts of beach restoration on loggerhead turtles (Caretta caretta) and on green turtles (Chelonia mydas) were investigated. Previous studies concerning beach nourishment projects have focused on loggerhead turtles. I compared data between nourished and non-nourished areas and between loggerhead and green turtles. I found, at one season post-nourishment, negative effects on nesting success and no significant effect on reproductive success for both loggerheads and established the same relationships with green turtles. Physical attributes of the fill sand, which did not facilitate acute scarp formation or severe compaction, did not physically impede turtles in their attempts to nest. Instead, the decrease in nesting success was attributed to an absence of abiotic and or biotic factors that cue nesting behavior. The increase in loggerhead nesting success rates during the second season post-nourishment was attributed to the equilibration process of the seaward crest of the berm. After the beach was restored, both species of turtles placed nests significantly farther from the water in the nourished area than in the non-nourished area. Green turtles nested on or near the dune and loggerheads nested on the seaward crest of the berm. The tendency of loggerheads to nest closer to the water resulted in more loggerhead than green turtle nests being "washed out" by erosion during the equilibration process. There was a significant increase in hatching success only for loggerheads when wash outs were excluded, thus illustrating the importance of nest placement and the detrimental effects of the equilibration process to the reproductive success of loggerheads. A decrease in reproductive output occurred during the first season post-nourishment. The reduction in the estimated total number of hatchlings produced (reproductive output) was a consequence of decreased nesting success lowering nest numbers. This reduction demonstrates that, regardless of similar reproductive success rates, marine turtles incurred net losses during the first season following nourishment. These results further reveal the impacts of decreased nesting success and the importance of minimizing excessive non-nesting emergences associated with beach nourishment.
Show less - Date Issued
- 2005
- Identifier
- CFE0000493, ucf:46365
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0000493
- Title
- CASCADING EFFECTS OF PREDATOR REMOVAL ON THE ECOLOGY OF SEA TURTLE NESTING BEACHES.
- Creator
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Barton, Brandon, Roth, James, University of Central Florida
- Abstract / Description
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Traditional views of food web dynamics have characterized species interactions as linear and direct. However, modern food web theory suggests that interactions can also be nonlinear and indirect, so that disturbance at one trophic level is transmitted throughout the community. Many previous studies have demonstrated that the removal of top predators from terrestrial ecosystems can have broad-scale impacts on community ecology. I examined the direct and indirect effects of raccoon removal from...
Show moreTraditional views of food web dynamics have characterized species interactions as linear and direct. However, modern food web theory suggests that interactions can also be nonlinear and indirect, so that disturbance at one trophic level is transmitted throughout the community. Many previous studies have demonstrated that the removal of top predators from terrestrial ecosystems can have broad-scale impacts on community ecology. I examined the direct and indirect effects of raccoon removal from sea turtle nesting beaches in east-central Florida during the summers of 2003 and 2004. Raccoon and ghost crab predation are among the highest causes of egg mortality for sea turtles in Florida and raccoons are intraguild predators of ghost crabs. Because of the damage done to sea turtle nests, raccoons have been removed from some beaches during the sea turtle nesting season. I compared the diet and demography of a raccoon population that had experienced two decades of raccoon removal to a population that had previously been unmanipulated. I found that long-term raccoon removal had created a significantly male-biased sex ratio in that population. I also examined the indirect effects of raccoon removal by comparing the abundances of raccoons and ghost crabs at four study sites using passive tracking plots. My data suggest intraguild predation by raccoons limits ghost crab abundance and that reduced raccoon abundance allowed ghost crab abundance to increase, resulting in a net increase in sea turtle egg predation. These results support my hypothesis that intraguild predation of ghost crabs by raccoons is an influential interaction on sea turtle nesting beach community dynamics.
Show less - Date Issued
- 2005
- Identifier
- CFE0000521, ucf:46466
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0000521
- Title
- Relating climate change to the nesting phenology and nest environment of marine turtles.
- Creator
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Schwoerer, Monette, VonHolle, Mary, Weishampel, John, Mansfield, Katherine, University of Central Florida
- Abstract / Description
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Ectotherms (including marine turtles) being especially sensitive to climate, are at risk to the accelerated rate of human-driven climate change. This study addresses two concerns associated with marine turtles and climate change (-) the relationship between the timing of marine turtle nesting and sea surface temperature; and the concern over the feminization of marine turtle populations due to rising sand temperatures. Previous studies of loggerhead sea turtles (Caretta caretta) and green sea...
Show moreEctotherms (including marine turtles) being especially sensitive to climate, are at risk to the accelerated rate of human-driven climate change. This study addresses two concerns associated with marine turtles and climate change (-) the relationship between the timing of marine turtle nesting and sea surface temperature; and the concern over the feminization of marine turtle populations due to rising sand temperatures. Previous studies of loggerhead sea turtles (Caretta caretta) and green sea turtles (Chelonia mydas) have documented the relationship between sea surface temperatures and nesting phenology. Earlier nesting behaviors in both species have been associated with warmer sea surface temperatures. Also, sex determination for marine turtles is temperature-dependent. Due to current sand temperatures, it is estimated that loggerhead (Caretta caretta) nests along the Atlantic coast of Florida already produce over 89% female hatchlings. Using shade to reduce nest temperature and increase the proportion of male hatchlings is one option for mitigating the impacts of climate change on marine turtle sex ratios. In this study, a 21-year (1988-2008) dataset of hawksbill sea turtle (Eretmochelys imbricata) nesting at Buck Island Reef National Monument, St. Croix, USVI was analyzed in a similar manner to previous studies. It was found that warmer sea surface temperatures were associated with longer nesting seasons and later median nesting dates. Additionally, a preliminary sand shading study was conducted in the first field season (2011) with a subsequent loggerhead nest shading study in the following field season (2012). Although hatching success was not significantly impacted, temperatures were significantly reduced in the majority of shaded nests. This practice may not be immediately applicable as a means of managing sex ratios, but it could be used to reverse the temperature effects of nest relocation.
Show less - Date Issued
- 2013
- Identifier
- CFE0005057, ucf:49973
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0005057
- Title
- Economic Valuation of Florida Sea Turtles in Face of Sea Level Rise.
- Creator
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Hamed, Ahmed, Madani Larijani, Kaveh, VonHolle, Mary, Wright, James, Milon, Joseph, University of Central Florida
- Abstract / Description
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Sea level rise (SLR) is posing a great risk of flooding and inundation to coastal areas in Florida. Some coastal nesting species, including sea turtle species, have experienced diminished habitat from SLR. In an effort to assess the economic and ecosystem service loss to coastal areas with respect to sea turtles Contingent Valuation Method (CVM) and Habitat Equivalency Analysis (HEA) were used. The CVM was used to measure the economic impacts of SLR on sea turtles. Open-ended and dichotomous...
Show moreSea level rise (SLR) is posing a great risk of flooding and inundation to coastal areas in Florida. Some coastal nesting species, including sea turtle species, have experienced diminished habitat from SLR. In an effort to assess the economic and ecosystem service loss to coastal areas with respect to sea turtles Contingent Valuation Method (CVM) and Habitat Equivalency Analysis (HEA) were used. The CVM was used to measure the economic impacts of SLR on sea turtles. Open-ended and dichotomous choice CVM was used to obtain the willingness to pay (WTP) values of Florida residents to implement certain mitigation strategies which would protect Florida's east coast sea turtle nesting areas. The problem of sample selection bias was reduced by surveying residents of two cities that would potentially have varying interest in coastal conservation due to their relative distance from the coast. The hypothetical WTP of Florida households to implement policies designed to protect sea turtle habitat from development encroachment was estimated to be between $21 and $29 per year for a maximum of five years. Characteristics of respondents were found to have statistically significant impacts on their WTP. Findings include a negative correlation between the age of a respondent and the probability of an individual willing to pay the hypothetical WTP amount. Counter intuitively, it was found that WTP of an individual was not dependent on prior knowledge of the effects of SLR on sea turtle habitat. As the level of this awareness increased, the probability to pay the hypothetical WTP value decreased. The greatest indicators of whether or not an individual was willing to pay to protect sea turtle habitat were the respondents' perception regarding the importance of sea turtle population health to the ecosystem, and their confidence in the conservation methods used. Concepts of Habitat Equivalency Analysis were used in order to determine the ecosystem service lost due to SLR. The study area of Archie Carr National Wildlife Refuge (ACNWR) has a continually increasing sea turtle population due to various conservation efforts. However, how the inundation of the coastal area will injure this habitat was assessed, and if mitigation strategies to compensate for the loss are necessary. The carrying capacity (CC) of the refuge was chosen as the metric of the ecosystem service. Using the estimated area of ACNWR and the approximate area needed by a sea turtle to nest, the theoretical number of sea turtle nests possible on the refuge was calculated. This value was then projected to the year 2100 using the sea level rise scenarios provided by IPCC (2007) and NRC (2010). In order to quantify the injury caused by the decrease in the refuge's CC, the number of sea turtle nests on the refuge was projected to the year 2100 using the data obtained over the past 30 years. The analysis concludes a potential loss of service to be experienced as early as 2060's due to the carrying capacity of the refuge diminishing with the loss of the habitat due to the increase in the mean sea level.
Show less - Date Issued
- 2013
- Identifier
- CFE0005002, ucf:50021
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0005002
- Title
- AN ASSESSMENT OF SEA TURTLE NESTING BEHAVIOR IN RELATION TO HURRICANE- AND RESTORATION-INDUCED BEACH MORPHODYNAMICS.
- Creator
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Long, Tonya, Weishampel, John, University of Central Florida
- Abstract / Description
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Coastal habitats are highly dynamic and vulnerable to landscape-level disturbances such as storms and restoration projects. Along the east coast of Florida these areas are particularly valuable as they provide significant nesting habitat for two sea turtle species, the threatened loggerhead (Caretta caretta) and the endangered green turtle (Chelonia mydas). This coast was heavily impacted by three major hurricanes in 2004 and in some areas by large restoration projects in 2005. Recent remote...
Show moreCoastal habitats are highly dynamic and vulnerable to landscape-level disturbances such as storms and restoration projects. Along the east coast of Florida these areas are particularly valuable as they provide significant nesting habitat for two sea turtle species, the threatened loggerhead (Caretta caretta) and the endangered green turtle (Chelonia mydas). This coast was heavily impacted by three major hurricanes in 2004 and in some areas by large restoration projects in 2005. Recent remote sensing methods allow for broad evaluation of the shoreline and thus the ability to assess sea turtle nesting habitat at a landscape scale. I collected nesting data for southern Brevard County, Florida from 1989 – 2005 and for Canaveral National Seashore, Florida from 1995 – 2005. I used LiDAR (Light Detection and Ranging) and IfSAR (Interferometric Synthetic Aperture Radar) remote sensing to map sea turtle nesting habitat in both areas following the 2004 hurricanes and any subsequent restoration. Canaveral National Seashore underwent no restoration while southern Brevard County received extensive restoration. Topographic variables (e.g., total sand volume, width, and slope) derived from the remote sensing data were compared across three time periods (pre-hurricane, post-hurricane, and recovery period) and I compared nesting success data from 2004 to 2005. I built regression models for 2004 and 2005 to determine which topographic features influenced loggerhead and green turtle nesting the most. Green turtle nesting success declined from 2004 to 2005 only in highly restored areas while loggerhead nesting sucess declined throughout. Hurricanes caused a reduction in most of the topographic variables and restoration predominantly impacted aspects of the beach profile (e.g. slope and width). Loggerheads responded to profile characteristics (e.g. upper and lower beach slopes) though green turtles showed no consistent response to topography. The results indicate that both loggerheads and green turtles are sensitive to beach restoration, although loggerhead nesting is more influenced by beach morphology and green turtle nesting may be influenced more by other dune features such as vegetation cover.
Show less - Date Issued
- 2010
- Identifier
- CFE0003051, ucf:48344
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0003051
- Title
- FACTORS AFFECTING PREDATION OF MARINE TURTLE EGGS BY RACCOONS AND GHOST CRABS ON CANAVERAL NATIONAL SEASHORE, FL.
- Creator
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Brown, Justin, Roth, James, University of Central Florida
- Abstract / Description
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Changes in abundance of interactive species can have cascading, community-wide effects (Soulé et al. 2003). Raccoons (Procyon lotor) prey on a competitor for marine turtle eggs, the Atlantic ghost crab (Ocypode quadrata). Conservation of marine turtles often includes managing raccoons--the most obvious egg predator--which may have broader ecological effects, and unknown effects on egg predation. Neither the relationship between raccoons and ghost crab density nor the effects of ghost...
Show moreChanges in abundance of interactive species can have cascading, community-wide effects (Soulé et al. 2003). Raccoons (Procyon lotor) prey on a competitor for marine turtle eggs, the Atlantic ghost crab (Ocypode quadrata). Conservation of marine turtles often includes managing raccoons--the most obvious egg predator--which may have broader ecological effects, and unknown effects on egg predation. Neither the relationship between raccoons and ghost crab density nor the effects of ghost crab density on egg predation are well understood. I studied raccoon-ghost crab interactions and the effects of environmental variation on their activity during the 2007 marine turtle nesting season on Canaveral National Seashore, FL. My goal was to model predator activity and identify efficient management strategies to reduce egg predation. Raccoon activity increased with increasing habitat diversity and edge of the dominant cover type, coastal strand. Raccoon activity increased locally and became less variable near segments of beach accessed for human recreation, but activity was greater on undeveloped beach, where habitat diversity and edge were greater. Ghost crab density and size were primarily affected by sand characteristics and recreation but decreased with increasing raccoon activity in June, which may have contributed to sustained declines in ghost crab density. Hatching success of marine turtles decreased with increasing ghost crab egg predation, suggesting ghost crabs are an important cause of egg mortality and not merely scavengers on unhatched eggs. Egg predation by ghost crabs was unrelated to ghost crab density or size, likely a result of monitoring limitations, but raccoon activity increased with increasing egg predation by ghost crabs, supporting previous research and experimental evidence suggesting ghost crabs can facilitate secondary nest predation by raccoons. This indirect interaction has strong implications for marine turtle conservation, because its strength may increase with increasing ghost crab density, potentially negating the effects of raccoon removal.
Show less - Date Issued
- 2009
- Identifier
- CFE0002667, ucf:48235
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0002667
- Title
- Using Biomarkers to Assess the Migratory Ecology and Reproduction of the Florida Green Turtle (Chelonia mydas).
- Creator
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Chabot, Ryan, Mansfield, Kate, Worthy, Graham, Seminoff, Jeffrey, University of Central Florida
- Abstract / Description
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Migratory connectivity between breeding and foraging areas is a vital component of the ecology of a diverse collection of marine vertebrates. Habitat quality, composition, and resource availability at these locations have direct ramifications for individual fitness. The green turtle (Chelonia mydas) is a long-lived, highly migratory species of conservation concern. Important green turtle nesting habitat in Florida is protected, but more information is needed to identify foraging habitats and...
Show moreMigratory connectivity between breeding and foraging areas is a vital component of the ecology of a diverse collection of marine vertebrates. Habitat quality, composition, and resource availability at these locations have direct ramifications for individual fitness. The green turtle (Chelonia mydas) is a long-lived, highly migratory species of conservation concern. Important green turtle nesting habitat in Florida is protected, but more information is needed to identify foraging habitats and the influence these habitats have on reproduction. Here, I used stable isotope analysis of ?13C, ?15N, and ?34S and satellite telemetry validation to determine the number of putative foraging areas used by the breeding aggregation at the Archie Carr National Wildlife Refuge (ACNWR), and the relative contribution of each foraging area. I evaluated the influence of foraging area and other variables on egg size, clutch size, hatching success, and emerging success using model selection frameworks. Isotopic values of skin and eggs were used to build conversion equations between the two tissue types. Results suggest strong migratory connectivity between the ACNWR and the Florida Keys/Florida Bay complex. I found that the influences of foraging area are likely to be more detectable when evaluating female-centric fitness metrics like clutch size and egg size; these influences are more muted in hatching and emerging success, which are strongly influenced by nest incubation conditions. These are the first green turtle-specific tissue conversion equations for ?13C and ?15N, and the first ?34S equation for any marine turtle species. These will allow researchers to have a (")common currency(") between frequently collected samples to better compare results.
Show less - Date Issued
- 2017
- Identifier
- CFE0006574, ucf:51314
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0006574
- Title
- Turtle Cam: Live Multimedia Interaction For Engaging Potential Visitor Population To Canaveral National Seashore.
- Creator
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Tortorelli, Brian, Cabrera, Cheryl, Lindgren, Robb, Reedy, Robert, University of Central Florida
- Abstract / Description
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This project expands the outreach of the Canaveral National Seashore to its visitors, potential visitors, and virtual visitors through its goals in conservancy and preservation of its natural resources. This paper is involved with the current iteration of a series of digital media projects, the Sea Turtle Nest Camera, also known as, Turtle Cam. It details how and why this project was designed to be an ongoing initiative to assist in those goals.
- Date Issued
- 2012
- Identifier
- CFE0004330, ucf:49446
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0004330
