Loggerhead turtle (Caretta caretta) nest predation at Cape Range National Park

Most of the existing sea turtle populations worldwide are in decline. In particular, loggerhead turtles (Caretta caretta) are listed as endangered and loggerhead nesting populations in Eastern Australia have declined by 86% since the 1970s. However, whilst Eastern Australian loggerhead populations have been extensively studied and monitored, not much is known about the Western Australian nesting population

Immature Sea Turtles in Gullivan Bay, Ten Thousand Islands, Southwest Florida

An in-water survey for immature endangered and threatened sea turtles in the coastal waters of southwest Florida during 1997-2003 yielded 191 Kemp\u27s ridley (Lepidochelys kempi), 15 loggerhead (Caretta caretta), 13 green (Chelonia mydas), and one hybrid hawksbill (Eretmochelys imbricata)-loggerhead turtle. Mean carapace lengths were 40.3 cm minimum straightline carapace length (MSCL) for Kemp\u27s ridley, 65.5 cm MSCL for loggerhead, and 51.6 cm MSCL for green turtles. Fibropapilloma tumors were found on seven of the green turtles and one loggerhead turtle. The mean growth rate of recaptured Kemp\u27s ridleys was 6.3 cm/yr. The nearshore waters of Gullivan Bay in the Ten Thousand Islands are an important developmental habitat for the highly endangered Kemp\u27s ridley turtle, and to a lesser degree, immature loggerhead and green turtles

Caretta caretta

Number of Pages: 7Integrative BiologyGeological Science

Diet of oceanic loggerhead sea turtles (Caretta caretta) in the central North Pacific

Diet analysis of 52 loggerhead sea turtles (Caretta caretta) collected as bycatch from 1990 to 1992 in the high-seas driftnet fishery operating between lat. 29.5°N and 43°N and between long. 150°E and 154°W demonstrated that these turtles fed predominately at the surface; few deeper water prey items were present in their stomachs. The turtles ranged in size from 13.5 to 74.0 cm curved carapace length. Whole turtles (n =10) and excised stomachs (n= 42) were frozen and transported to a laboratory for analysis of major faunal components. Neustonic species accounted for four of the five most common prey taxa. The most common prey items were Janthina spp. (Gastropoda); Carinaria cithara Benson 1835 (Heteropoda); a chondrophore, Velella velella (Hydrodia); Lepas spp. (Cirripedia), Planes spp. (Decapoda: Grapsidae), and pyrosomas (Pyrosoma spp.)

Social values of biodiversity conservation for the endangered loggerhead turtle and monk seal

The Mediterranean monk seal (Monachus monachus) and the loggerhead turtle (Caretta caretta) are two species on the priority list for conservation in Greece due to their dwindling populations worldwide. Hence the issue of estimating willingness to pay for their conservation is germane to any protection initiative. Zakynthos Island in Greece has created a marine park for the conservation of such species. We report the results of a survey of visitors and residents of this island who were asked about making one-time donations in the form of either a tax for residents or a plane landing fee for tourists. We find that all people were willing to pay to protect these species; however, residents were willing to pay more than tourists. We then tested whether there was a sequence or ordering effect if the seal questions came before the turtles as well as if the turtle questions came before the seals. Such effect was found when turtle questions were presented first, but not when seal questions were presented first. Due to the extensive interest, it is recommended that an increase in the airplane landing fee to Zakynthos could be used to contribute towards funds for loggerhead turtle and monk seal protection

Now Hear This! Orientation and Behavioral Responses of Hatchling Loggerhead Sea Turtles, Caretta caretta, to Environmental Acoustic Cues

Although the visual and geologic orientation cues utilized by sea turtle hatchlings during seafinding, when they move from the nest to the sea after hatching, have been well studied, the potential for auditory stimuli to act as an orientation cue has not been well explored. Over the past several decades our knowledge of the auditory capacity of sea turtles has increased greatly, yet little is known about the biological significance of this sensory ability. To investigate whether hatchlings can use ocean sounds during seafinding, we measured the behavioral responses of hatchling loggerhead sea turtles (Caretta caretta) collected from nesting beaches in North Carolina to the presence of beach wave sound recorded on a nesting beach during the summer of 2015. The highest sound energy of beach waves occursHz, which overlaps with the most sensitive hearing range of loggerhead hatchlings (range of frequency detection: 50-1600 Hz, maximum sensitivity: 50-400 Hz). In our experiment, we placed turtles in a V-maze that isolated them from visual, vibratory, and chemical cues. One end of the V held a speaker producing beach wave sounds recorded from nesting beaches, while the other end held sound-reducing foam. We examined the phonotaxic behaviors of the hatchlings at two sound pressure levels (68 dB re: 20μPa and 64 dB re: 20μPa measured directly in front of the speaker). In the presence of the higher sound pressure level (68 dB re: 20μPa), hatchlings exhibited no phonotaxic response (p=1.0); yet, at the reduced sound pressure level (64 dB re: 20μPa), hatchlings exhibited a negative phonotaxic response (p=0.005). In control trials, hatchlings oriented to the two sides of the V-maze equally (p=0.701), suggesting the hatchlings in the lower volume treatment group were responding negatively to the sound. These results indicate the need for further auditory orientation experiments to better understand hatchling behavioral responses to environmental acoustic cues and to address possible impacts of anthropogenic beach sounds that have the potential to disorient hatchlings during seafinding

Sea turtle nesting activity along Eglin Air Force Base on Cape San Blas and Santa Rosa Island, Florida from 1994 to 1997.

Along EAFB on Cape San BIas, the only sea turtle species nest observed has been the loggerhead turtle. The first green turtle nest documented along the Florida panhandle coast was observed on EAFB property, however (D. Atencio, EAFB, pers. comm). Santa Rosa Island, located approximately 150 miles west of Cape San BIas supports a small but consistent, group of nesting green turtles (Fig. 2). Although erosion is not as severe along Santa Rosa Island as it is on Cape San BIas, and vehicular traffic is not permitted, sea turtles nesting on this barrier island must survive severe tropical storms, predation, and artificial lighting to be successful. Because this area supports a rare group of nesting green turtles and is disturbed by intense artificial lighting from Air Force missions and adjacent resort towns, continued monitoring is necessary. The sea turtle species that nest along this barrier island, and the human activities that disturb those sea turtles present unique circumstances for management ofthis area. Protection ofthe significant nesting populations of sea turtles on EAFB properties on Cape San BIas and Santa Rosa Island requires yearly monitoring of the nesting activity and the natural and human disturbances influencing the nesting females. The objectives ofthis study were to monitor sea turtle nesting along EAFB on Cape San BIas to determine number of nests and hatching success, assess disturbances, and determine proper management to ensure successful nesting and hatching.(56 page document

First data on microflora of loggerhead sea turtle (Caretta caretta) nests from the coastlines of Sicily

Caretta caretta is threatened by many dangers in the Mediterranean basin, but most are human-related. The purposes of this research were: (i) to investigate microflora in samples from six loggerhead sea turtle nests located on the Sicilian coast and (ii) to understand microbial diversity associated with nests, with particular attention to bacteria and fungi involved in failed hatchings. During the 2016 and 2018 summers, 456 eggs and seven dead hatchling from six nests were collected. We performed bacteriological and mycological analyses on 88 egg samples and seven dead hatchlings, allowing us to isolate: Fusarium spp. (80.6%), Aeromonas hydrophila (55.6%), Aspergillus spp. (27.2%) and Citrobacter freundii (9%). Two Fusarium species were identified by microscopy and were confirmed by PCR and internal transcribed spacer sequencing. Statistical analyses showed significant differences between nests and the presence/absence of microflora, whereas no significant differences were observed between eggs and nests. This is the first report that catalogues microflora from C. caretta nests/eggs in the Mediterranean Sea and provides key information on potential pathogens that may affect hatching success. Moreover, our results suggest the need for wider investigations over extensive areas to identify other microflora, and to better understand hatching failures and mortality related to microbial contamination in this important turtle species

Sea turtle nesting in the Ten Thousand Islands of Florida

Loggerhead sea turtles (Caretta caretta) nest in numerous substrate and beach types within the Ten Thousand Islands (TTl) of southwest Florida. Nesting beach selection was analyzed on 12 islands within this archipelago. Numerous physical characteristics were recorded to identify the relatedness of these variables and determine their importance for nesting beach selection in C. caretta. These variables were chosen after evaluating the islands, conducting literature searches and soliciting personal communications. Along transects, data were collected, on the following: height of canopy, beach width, overall slope (beach slope and slope of offshore approach) and sand samples analyzed for pH, percentage of water, percentage of organic content, percentage of carbonate and particle size (8 size classes). Data on ordinal aspect of beaches and beach length were also recorded and included in the analysis. All of the variables were analyzed by tree regression, incorporating the nesting data into the analysis. In the TTl, loggerheads appear to prefer wider beaches (p< 0.001; R2 = 0.56) that inherently have less slope, and secondarily, wider beaches that have low amounts of carbonate (p< O.00 1). In addition, C. caretta favors nest sites within or in close proximity to the supra-littoral vegetation zone of beaches in the TTl (p< 0.001). (86 page document

Biology of pelagic sea turtles: effects of marine debris

Objectives: 1. Quantify the sub-lethal effect of debris ingestion (nutrient dilution) on nutrient gain 2. Model sub-lethal effects of debris ingestion on nutrient intake and growth 3. Evaluation of stress from entanglement on the loggerhead sea turtle 4. Movement patterns and behavior of pelagic-stage loggerheads in the eastern Atlantic 5. Document the genetic relationships of pelagic-stage loggerheads in the eastern Atlantic with rookeries in the southeast US (Document has 14 pages; lists publications resulting from research