scholarly journals Complexity and variation in loggerhead sea turtle life history

2007 ◽  
Vol 3 (6) ◽  
pp. 592-594 ◽  
Author(s):  
Catherine M McClellan ◽  
Andrew J Read
Keyword(s):  
North Carolina ◽  
Life History ◽  
Coastal Waters ◽  
Sea Turtle ◽  
Open Ocean ◽  
Niche Shift ◽  
Loggerhead Sea Turtles ◽  
Loggerhead Sea Turtle ◽  
Marine Reptiles ◽  
Ontogenetic Niche Shift

Juvenile loggerhead sea turtles spend more than a decade in the open ocean before returning to neritic waters to mature and reproduce. It has been assumed that this transition from an oceanic to neritic existence is a discrete ontogenetic niche shift. We tested this hypothesis by tracking the movements of large juveniles collected in a neritic foraging ground in North Carolina, USA. Our work shows that the shift from the oceanic to neritic waters is both complex and reversible; some individuals move back into coastal waters and then return to the open ocean for reasons that are still unclear, sometimes for multiple years. These findings have important consequences for efforts to protect these threatened marine reptiles from mortality in both coastal and open-ocean fisheries.

scholarly journals Nesting Patterns of Loggerhead Sea Turtles (Caretta caretta): Development of a Multiple Regression Model Tested in North Carolina, USA

2018 ◽  
Vol 7 (9) ◽  
pp. 348 ◽  
Author(s):  
Joanne Halls ◽  
Alyssa Randall
Keyword(s):  
North Carolina ◽  
Negative Binomial ◽  
Management Strategies ◽  
Temporal Trends ◽  
Caretta Caretta ◽  
Sea Turtle ◽  
Multiple Regression Model ◽  
Loggerhead Sea Turtles ◽  
Loggerhead Sea Turtle ◽  
Nesting Patterns

Numerous environmental conditions may influence when a female Loggerhead sea turtle (Caretta caretta) selects a nesting site. Limited research has used Geographic Information Systems (GIS) and statistical analysis to study sea turtle spatial patterns and temporal trends. Therefore, the goals of this research were to identify areas that were most prevalent for nesting and to test social and environmental variables to create a nesting suitability predictive model. Data were analyzed at all barrier island beaches in North Carolina, USA (515 km) and several variables were statistically significant: distance to hardened structures, beach nourishment, house density, distance to inlets, and beach elevation, slope, and width. Interestingly, variables that were not significant were population density, proximity to the Gulf Stream, and beach aspect. Several statistical techniques were tested and Negative Binomial Distribution produced good regional results while Geographically Weighted Regression models successfully predicted the number of nests with an average of 75% of the variance explained. Therefore, the combination of traditional and spatial statistics provided insightful predictive modeling results that may be incorporated into management strategies and may have important implications for the designation of critical Loggerhead nesting habitats.

Assessing the Impacts of Human Activities on Nesting of Loggerhead Sea-turtles (Caretta caretta L.) on Zákynthos Island, Western Greece

1988 ◽  
Vol 15 (4) ◽  
pp. 327-334 ◽  
Author(s):  
Margarita Arianoutsou
Keyword(s):  
Human Activities ◽  
Caretta Caretta ◽  
Sea Turtle ◽  
Loggerhead Sea Turtles ◽  
Loggerhead Sea Turtle ◽  
Marine Park ◽  
Sound Management ◽  
Unique Species ◽  
Western Greece ◽  
Beach Use

The island of Zákynthos, in western Greece, supports the most important nesting biotope of the endangered Loggerhead Sea-turtle (Caretta caretta) within Europe. The evaluation of the impacts of human activities, such as beach-use by people, lights, noise, and traffic, on its nesting habitats revealed that they are running out of time under the pressure of rapid and massive tourist development. It is therefore essential for the protection of this unique species to conserve its nesting biotope. This implies adequate, ecologically sound management, which might well be ensured through the establishment of a Marine Park.

Intraerythrocytic inclusion bodies in the loggerhead sea turtle Caretta caretta from Madeira

2000 ◽  
Vol 80 (5) ◽  
pp. 957-958 ◽  
Author(s):  
J.C. Eiras ◽  
T. Dellinger ◽  
A.J. Davies ◽  
G. Costa ◽  
A.P. Alves de Matos
Keyword(s):  
Red Blood Cells ◽  
Blood Cells ◽  
Inclusion Bodies ◽  
Sea Turtles ◽  
Caretta Caretta ◽  
Sea Turtle ◽  
Loggerhead Sea Turtles ◽  
Loggerhead Sea Turtle ◽  
Intracytoplasmic Inclusion ◽  
Intracytoplasmic Inclusion Bodies

Intracytoplasmic inclusion bodies were detected in the mature red blood cells of twenty juvenile loggerhead sea turtles, Caretta caretta, captured in Madeira. The bodies were mostly single, round to oval, frequently irregular in outline, and their diameter varied from 0.5 to 2.0 μm. Most bodies were associated with small granular areas, often in the form of a tail or projection. In some cells, only granular areas were apparent. The nuclei of most erythrocytes were irregular in outline but degeneration of red blood cells was not observed. The identity of these intraerythrocytic structures is not clear but they may be viral or rickettsial in nature.

scholarly journals First record of loggerhead sea turtles Caretta caretta in Sebastián Vizcaíno Bay, Baja California Peninsula, Mexico

2020 ◽  
Vol 48 (1) ◽  
pp. 146-149
Author(s):  
Helena Fernández-Sanz ◽  
Fabián Castillo Romero ◽  
Joaquín Rivera Rodríguez ◽  
Noé López Paz ◽  
Gabriel Arturo Zaragoza Aguilar ◽  
...  
Keyword(s):  
Baja California ◽  
Sea Turtles ◽  
Chelonia Mydas ◽  
Caretta Caretta ◽  
First Record ◽  
Sea Turtle ◽  
Baja California Peninsula ◽  
Loggerhead Sea Turtles ◽  
Biometric Data ◽  
Loggerhead Sea Turtle

The loggerhead sea turtle (Caretta caretta) is an endangered species which distributes around the west coast of the Baja California Peninsula. In Baja California Sur, the conservation efforts for this species were focused in the Gulf of Ulloa; however, within the Pacific coast of the Baja California Peninsula, Sebastián Vizcaíno Bay (SVB) biological active center suit the optimal conditions for the presence of loggerheads. This study aimed to investigate SVB as a potential foraging area for loggerheads. Between July and August 2018, three prospective surveys were conducted, in search of marine turtles in SVB. A total of three loggerhead turtles and one eastern Pacific green turtle (Chelonia mydas) were captured; biometric data were recorded, and organisms were classified as juveniles. This is the first report of the loggerhead sea turtles in the SVB and given the oceanographic characteristics of the bay, it is a potential foraging and development area for the species.

scholarly journals Maternally derived sex steroid hormones impact sex ratios of loggerhead sea turtles

2020 ◽  
Author(s):  
Emma C. Lockley ◽  
Thomas Reischig ◽  
Christophe Eizaguirre
Keyword(s):  
Sex Determination ◽  
Steroid Hormones ◽  
Sex Ratios ◽  
Physiological Mechanism ◽  
Sea Turtle ◽  
Sex Steroid Hormones ◽  
Sex Steroid ◽  
Loggerhead Sea Turtles ◽  
Loggerhead Sea Turtle ◽  
Egg Yolks

AbstractGlobal warming could drive species with temperature-dependent sex determination to extinction by persistently skewing offspring sex ratios. Evolved mechanisms that buffer these biases are therefore paramount for their persistence. Here, we tested whether maternally-derived sex steroid hormones affect the sex-determination cascade and provide a physiological mechanism to buffer sex ratio bias in the endangered loggerhead sea turtle (Caretta caretta). We quantified estradiol and testosterone in nesting females and their egg yolks at oviposition, before incubating nests in situ at standardised temperatures. Upon hatchling emergence, we developed a new, non-lethal method to establish the sex of individuals. Despite standardised incubation temperatures, sex ratios varied widely among nests, correlating non-linearly with the estradiol:testosterone ratio in egg yolks. Males were produced at an equal ratio, with females produced either side of this optimum. This result provides evidence that maternal hormone transfer forms a physiological mechanism that impacts sex determination in this endangered species.

scholarly journals Helminth Infection of the Loggerhead Sea Turtle Caretta caretta along the Coasts of Sicily and the North West Adriatic Sea

Animals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1408
Author(s):  
Antonino Gentile ◽  
Tullia Amato ◽  
Andrea Gustinelli ◽  
Maria Letizia Fioravanti ◽  
Delia Gambino ◽  
...  
Keyword(s):  
Adriatic Sea ◽  
Sea Turtles ◽  
Single Species ◽  
Caretta Caretta ◽  
Sea Turtle ◽  
Helminth Parasites ◽  
Loggerhead Sea Turtles ◽  
Loggerhead Sea Turtle ◽  
North West ◽  
The North

We provide new data on the presence of helminth parasites in 64 individual loggerhead sea turtles Caretta caretta stranded along the coasts of Sicily and the northwest Adriatic Sea between June 2014 and August 2016. The necropsy examination revealed 31 individuals (48.4%) positive for endoparasites, showing a greater prevalence of trematodes than nematodes. In particular, seven species and a single genus of Trematoda (Hapalotrema) and a single species and genus of Nematoda (Kathlania) were identified. Among the Digenea flukes the species with the highest prevalence of infection were Rhytidodes gelatinosus (34.6%) and Hapalotrema sp. (33.3%), while among the Nematoda they were Kathlania sp. (33.3%) and Sulcascaris sulcata (33.3%). Analysis of variance (ANOVA) was applied among the recovery sites of the stranded loggerhead sea turtles and prevalence of endoparasites was used to highlight any relationship between the parasites and the origin of the hosts. ANOVA showed significant differences (p < 0.001) among the data used.

The widely occurring brittlestar Ophiactis savignyi (Amphilepidida: Ophiactidae) as an epibiont on loggerhead sea turtle, Caretta caretta

Zootaxa ◽  
2019 ◽  
Vol 4695 (5) ◽  
pp. 497-500
Author(s):  
RYOTA HAYASHI ◽  
MASANORI OKANISHI
Keyword(s):  
New Species ◽  
Sea Turtles ◽  
Caretta Caretta ◽  
Sea Turtle ◽  
The Novel ◽  
Loggerhead Sea Turtles ◽  
Loggerhead Sea Turtle ◽  
First Occurrence

We describe the first occurrence of the widely occurring brittlestar Ophiactis savignyi (Müller & Troschel, 1842) as epibionts on Caretta caretta (Linnaeus, 1758), the loggerhead sea turtles. On the sea turtle epibionts, the coronulid barnacles were well studied as listed in Hayashi (2013), and recently some crustaceans were collected from loggerhead sea turtles and described as new species (Tanabe et al. 2017; Tanaka and Hayashi 2019). In contrast, echinoderm epibionts listed from sea turtles are poorly understood (Table 1) and this study represents the novel discovery of an ophiuroid, which was not previously known to occur on the surface of this species. 

scholarly journals Dynamic Thermal Corridor May Connect Endangered Loggerhead Sea Turtles Across the Pacific Ocean

2021 ◽  
Vol 8 ◽  
Author(s):  
Dana K. Briscoe ◽  
Calandra N. Turner Tomaszewicz ◽  
Jeffrey A. Seminoff ◽  
Denise M. Parker ◽  
George H. Balazs ◽  
...  
Keyword(s):  
North Pacific ◽  
Bone Growth ◽  
Sea Turtles ◽  
Sea Turtle ◽  
Loggerhead Sea Turtles ◽  
Data Set ◽  
Loggerhead Sea Turtle ◽  
The North ◽  
Ocean Conditions ◽  
Formed Part

The North Pacific Loggerhead sea turtle (Caretta caretta) undergoes one of the greatest of all animal migrations, nesting exclusively in Japan and re-emerging several years later along important foraging grounds in the eastern North Pacific. Yet the mechanisms that connect these disparate habitats during what is known as the “lost years” have remained poorly understood. Here, we develop a new hypothesis regarding a possible physical mechanism for habitat connectivity – an intermittent “thermal corridor” – using remotely sensed oceanography and 6 juvenile loggerhead sea turtles that formed part of a 15 year tracking dataset of 231 individuals (1997–2013). While 97% of individuals remained in the Central North Pacific, these 6 turtles (about 3%), continued an eastward trajectory during periods associated with anomalously warm ocean conditions. These few individuals provided a unique opportunity to examine previously unknown recruitment pathways. To support this hypothesis, we employed an independently derived data set using novel stable isotope analyses of bone growth layers and assessed annual recruitment over the same time period (n = 33, 1997–2012). We suggest evidence of a thermal corridor that may allow for pulsed recruitment of loggerheads to the North American coast as a function of ocean conditions. Our findings offer, for the first time, the opportunity to explore the development of a dynamic ocean corridor for this protected species, illuminating a longstanding mystery in sea turtle ecology.

scholarly journals Record of the Loggerhead Sea Turtle, Caretta caretta (Testudines, Cheloniidae), in the Black Sea with the Review of the Species Occurrence in the Region

Zoodiversity ◽  
2021 ◽  
Vol 55 (2) ◽  
pp. 127-132
Author(s):  
O. Zinenko ◽  
K. A. Vishnyakova ◽  
L. Stoyanov ◽  
P. E. Gol’din
Keyword(s):  
Black Sea ◽  
Sea Turtles ◽  
Caretta Caretta ◽  
First Record ◽  
Sea Turtle ◽  
The Black Sea ◽  
Loggerhead Sea Turtles ◽  
Loggerhead Sea Turtle ◽  
The North ◽  
North Western

A rare live record of the loggerhead sea turtle Caretta caretta (Linnaeus, 1758) is reported from the Dzharylgach Gulf in the north-western Black Sea. This is the first record from Ukrainian waters since 1962 and the northernmost record of the species in the Black Sea. The loggerhead sea turtles of the east Mediterranean origin are increasingly often seen in the Marmara and the Black Sea during the latest decade, which is an evidence for potential expansion of this species range, at least partly due to climate changes. Key words: sea turtles, Caretta caretta, Black Sea, Ukraine, range expansion.

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