scholarly journals Population dynamic between vulnerable coastal jaguars (Panthera onca) and endangered green sea turtles (Chelonia mydas) in Tortuguero National Park, Costa Rica.

2018 ◽  
Author(s):  
Stephanie Butera ◽  
Jaime Restrepo
Keyword(s):  
National Park ◽  
Sea Turtles ◽  
Chelonia Mydas ◽  
Sea Turtle ◽  
Predator Prey ◽  
Green Sea Turtles ◽  
Turtle Population ◽  
Nest Depredation ◽  
The Impact ◽  
Nest Predators

New-born sea turtles face a number of predators between the time the mothers lay eggs on the beach to when the hatchlings grow into larger juveniles. Nest depredation impacts reproductive success of nesting sea turtles, reducing the number of new turtles that make it to the sea. On Tortuguero beach nest predators include; dogs, coati, and raccoons. Nest depredation within Tortuguero National Park (TNP) has decreased dramatically since 1979. This decrease in nest depredation is linked to the increased jaguar population within TNP as the aforementioned species are considered the jaguars natural prey. Although jaguars prey on nesting turtles, they also control the populations of nest predators. Even more, jaguars have been demonstrated to change their behaviour to suit their preference in prey species therefore the nest predator distribution in TNP was examined to investigate whether changes in jaguar prey preference had an effect. Nest predation and the number of adult turtles lost to jaguar depredation were examined to determine the significance of the threat jaguars pose to the sea turtle population. This study investigates the predator prey relationship between jaguars, nest predators, and nesting female sea turtles; aiming to assessing the impact that jaguars have on the turtle's population.

scholarly journals Population dynamic between vulnerable coastal jaguars (Panthera onca) and endangered green sea turtles (Chelonia mydas) in Tortuguero National Park, Costa Rica.

2018 ◽  
Author(s):  
Stephanie Butera ◽  
Jaime Restrepo
Keyword(s):  
National Park ◽  
Sea Turtles ◽  
Chelonia Mydas ◽  
Sea Turtle ◽  
Predator Prey ◽  
Green Sea Turtles ◽  
Turtle Population ◽  
Nest Depredation ◽  
The Impact ◽  
Nest Predators

New-born sea turtles face a number of predators between the time the mothers lay eggs on the beach to when the hatchlings grow into larger juveniles. Nest depredation impacts reproductive success of nesting sea turtles, reducing the number of new turtles that make it to the sea. On Tortuguero beach nest predators include; dogs, coati, and raccoons. Nest depredation within Tortuguero National Park (TNP) has decreased dramatically since 1979. This decrease in nest depredation is linked to the increased jaguar population within TNP as the aforementioned species are considered the jaguars natural prey. Although jaguars prey on nesting turtles, they also control the populations of nest predators. Even more, jaguars have been demonstrated to change their behaviour to suit their preference in prey species therefore the nest predator distribution in TNP was examined to investigate whether changes in jaguar prey preference had an effect. Nest predation and the number of adult turtles lost to jaguar depredation were examined to determine the significance of the threat jaguars pose to the sea turtle population. This study investigates the predator prey relationship between jaguars, nest predators, and nesting female sea turtles; aiming to assessing the impact that jaguars have on the turtle's population.

scholarly journals The Impact of Temperature-Dependent Sex Determination on the Population Dynamics of Green Sea Turtles (Chelonia mydas)

Bionatura ◽  
2020 ◽  
Vol 5 (1) ◽  
pp. 1029-1038
Author(s):  
Candy Herrera ◽  
Evelyn Guerra ◽  
Andrea Rosas ◽  
Yingying Wei ◽  
Jack Pringle ◽  
...  
Keyword(s):  
Incubation Temperature ◽  
Sea Turtles ◽  
Sex Ratios ◽  
Chelonia Mydas ◽  
Continuous Model ◽  
Sea Turtle ◽  
Green Sea Turtle ◽  
Green Sea Turtles ◽  
Turtle Population ◽  
The Impact

The sex of the turtles is determined by the incubation temperature of the eggs during the mid-trimester of development. In green sea turtles (Chelonia mydas), recent studies show that sex ratios are changing, producing a female-biased sex ratio within the population. We developed a novel continuous model to analyze the dynamics of the green sea turtle population long-term. We determine the safe operating space for the proportion of eggs that become male at which the population of green sea turtle can exist without going to extinction. When the proportion of male eggs leaves this range the overall turtles’ population collapses. Additionally, we examined how temperature changes affect the sex ratios of the green sea turtle population.

scholarly journals Association of ocean macroplastic debris with stranded sea turtles in the Central Gulf of Thailand

2021 ◽  
Author(s):  
Jindarha Prampramote ◽  
Worakan Boonhoh ◽  
Sutsiree Intongead ◽  
Watchara Sakornwimol ◽  
Pimchanok Prachamkhai ◽  
...  
Keyword(s):  
Sea Turtles ◽  
Chelonia Mydas ◽  
Sea Turtle ◽  
Gulf Of Thailand ◽  
Marine Life ◽  
Green Sea Turtles ◽  
Global Concern ◽  
Ftir Spectrometer ◽  
The Impact ◽  
The Relationship

The impact of macroplastic debris (> 5 mm in size) on marine life is a global concern but is rarely investigated in Thailand. Our objective was to investigate the relationship between stranded sea turtles and macroplastics found in the Central Gulf of Thailand. The turtle (n = 388) stranding record between 2017-2020 was analysed retrospectively to determine their size, species, and interaction with macroplastics. Thereafter, between 2019-2020, macroplastics were collected, from the gastrointestinal (GI) tract of dead turtles and from the beaches where stranded turtles were found. A stereomicroscope was used to visually categorise the macroplastics, and the plastic composition was analysed using a Fourier-transform infrared (FTIR) spectrometer. Green sea turtles (Chelonia mydas) were found to account for the majority of stranded turtles (74%, n = 251), and macroplastics were discovered in 74% of cases of entanglement and ingestion. At the juvenile stage, the stranded turtle was strongly related to macroplastics. Immature turtles were more likely to become entangled than adult turtles. Entangled turtles had a greater survival rate than turtles that had consumed plastic. The plastic fibres were the majority of macroplastics found in the GI tracts (62%, n = 152/244) and on the beach (64%, n = 74/115). Most fibres from GI tracts (83%, n = 126/152) and the beaches (93%, n = 68/74) were identified as the fishing net comprised of polyethylene or polypropylene. We concluded that fishing nets made of polyethylene or polypropylene might be one of the significant causes of sea turtle stranding in the Central Gulf of Thailand, and this issue requires immediate resolution.

scholarly journals JUMLAH TEMPAT PENELURAN PENYU HIJAU (Chelonia mydas) BERDASARKAN VEGETASI PANTAI DI TAMAN WISATA ALAM (TWA) TANJUNG BELIMBING KECAMATAN PALOH KABUPATEN SAMBAS

2020 ◽  
Vol 8 (3) ◽  
Author(s):  
Wawan Kurniawan ◽  
Erianto Erianto ◽  
Iswan Dewantara
Keyword(s):  
Sea Turtles ◽  
Chelonia Mydas ◽  
Sea Turtle ◽  
Coastal Vegetation ◽  
Survey Method ◽  
Green Sea Turtle ◽  
Nature Tourism ◽  
Green Sea Turtles ◽  
Nesting Sites ◽  
Turtle Population

The decline in the population of green sea turtles (Chelonia mydas) occurs continuously due to the destruction of the nesting beach habitat, therefore efforts are needed to increase the green sea turtle population by rearranging nesting sites. One thing that is considered important from the green sea turtle nesting habitat is the coastal vegetation. This research was conducted in Tanjung Belimbing Nature Tourism Park, Sambas Regency, West Kalimantan Province. This study aims to obtain information on vegetation conditions that are preferred by green sea turtles to lay eggs through the number of nesting sites approach. The method used is a survey method. Data collection was carried out by direct observation in the field. In this study, 12 nesting sites were found spread over four observation sites, with the highest number of nesting site found at observation location 1 as many as 8 nesting sites. At observation location 1, besides cemara laut (Casuarina equisetifolia) and pandan laut (Pandanus tectorius) also found waru (Hibiscus tiliaceus) and api-api (Avicennia sp) as well as shrub plants such as kamboja laut (Scaevola taccada), serunai laut (Melanthera biflora) ) and herbal plants such as tapak kuda (Ipomoea pes-caprae), alaban tanah (Vitex rotundifolia), rumput tembaga (Ischaemum muticum), bayam berduri (Amaranthus sp) and bakung laut (Crynum asiaticum L).Keywords: Nesting Sites, Vegetation, Green sea turtle, Tanjung Belimbing Nature Tourism Park

scholarly journals Red blood cell osmotic fragility in healthy loggerhead and green sea turtles

2020 ◽  
Vol 32 (6) ◽  
pp. 908-911
Author(s):  
Rebecca Radisic ◽  
Sean D. Owens ◽  
Charles A. Manire ◽  
Nicole Montgomery ◽  
Doug Mader ◽  
...  
Keyword(s):  
Blood Cell ◽  
Red Blood Cell ◽  
Sea Turtles ◽  
Osmotic Fragility ◽  
Chelonia Mydas ◽  
Sea Turtle ◽  
Green Sea Turtles ◽  
Nacl Concentration ◽  
Life Threatening ◽  
Rehabilitation Facilities

Loggerhead ( Caretta caretta; Cc) and green sea ( Chelonia mydas; Cm) turtles admitted to rehabilitation facilities may require blood transfusions for supportive treatment of disorders resulting in life-threatening anemia, but, considering the unique erythrocyte chemistry of sea turtles, standardized donor red blood cell (RBC) storage protocols have not been established. Prolonged cold storage and the effects of various anticoagulant-preservative solutions have been associated with increased RBC osmotic fragility across a broad range of species. Increased RBC fragility in stored RBC products has been associated with acute transfusion reactions. The osmotic fragility test is used to measure erythrocyte resistance to hemolysis while being exposed to a series of dilutions of a saline solution. We obtained baseline measurements for osmotic fragility in healthy Cc and Cm. Osmotic fragility testing was performed on samples from 10 Cc to 10 Cm. Fifty percent (50%) RBC hemolysis was identified at a mean NaCl concentration of 0.38% in both species. Results of our study will help guide future studies evaluating optimal storage solutions for sea turtle blood products.

Predation on green sea turtle, Chelonia mydas, hatchlings by invasive rats

2019 ◽  
Vol 25 (4) ◽  
pp. 423 ◽  
Author(s):  
Markus Gronwald ◽  
Quentin Genet ◽  
Margaux Touron
Keyword(s):  
Food Source ◽  
Sea Turtles ◽  
Rattus Rattus ◽  
Chelonia Mydas ◽  
Sea Turtle ◽  
French Polynesia ◽  
Camera Traps ◽  
Green Sea Turtle ◽  
Green Sea Turtles ◽  
Invasive Rats

We used camera traps to identify invasive Rattus rattus as predators at a green sea turtle, Chelonia mydas, nest in French Polynesia. The footage shows that the hatchlings are a familiar food source for rats and that the control of invasive rats has to be considered for the protection of endangered green sea turtles.

scholarly journals Climate change and green sea turtle sex ratio – Preventing possible extinction

2020 ◽  
Author(s):  
Jana Blechschmidt ◽  
Meike J. Wittmann ◽  
Chantal Blüml
Keyword(s):  
Climate Change ◽  
Sex Ratio ◽  
Nest Site ◽  
Sea Turtles ◽  
Chelonia Mydas ◽  
Sea Turtle ◽  
Change Scenario ◽  
Green Sea Turtles ◽  
The Face ◽  
Nest Depth

AbstractClimate change poses a threat to species with temperature-dependent sex determination. A recent study on green sea turtles (Chelonia mydas) at the northern Great Barrier Reef (GBR) showed a highly female-skewed sex ratio with almost all juvenile turtles being female. This shortage of males might eventually cause population extinction, unless rapid evolutionary rescue, migration or conservation efforts ensure a sufficient number of males. We built a stochastic individual-based model inspired by C. mydas, but potentially transferrable to other species with TSD. Nest depth, level of shade, and pivotal temperature were evolvable traits. Additionally, we considered the effect of crossbreeding between the northern and southern GBR, nest-site philopatry, and conservation efforts. Among the evolvable traits, nest depth was the most likely to rescue the population in the face of climate change, but even here the more extreme climate-change scenario led to extinction. Surprisingly, nest-site philopatry elevated extinction rates. Conservation efforts to artificially increase nest depth promoted population survival and did not preclude trait evolution. Although extra information is needed to make reliable predictions for the fate of green sea turtles, our results illustrate how evolution can shape the fate of long lived, vulnerable species in the face of climate change.Graphical Abstract

scholarly journals Quantifying Illegal Extraction of Sea Turtles in Costa Rica

2021 ◽  
Vol 2 ◽  
Author(s):  
Helen Pheasey ◽  
George Glen ◽  
Nicole L. Allison ◽  
Luis G. Fonseca ◽  
Didiher Chacón ◽  
...  
Keyword(s):  
Costa Rica ◽  
Sea Turtles ◽  
Chelonia Mydas ◽  
Sea Turtle ◽  
Wildlife Trade ◽  
Caribbean Coast ◽  
Turtle Species ◽  
Illegal Wildlife Trade ◽  
The Caribbean ◽  
The Impact

Estimates of illegal wildlife trade vary significantly and are often based on incomplete datasets, inferences from CITES permits or customs seizures. As a result, annual global estimates of illegal wildlife trade can vary by several billions of US dollars. Translating these figures into species extraction rates is equally challenging, and estimating illegal take accurately is not achievable for many species. Due to their nesting strategies that allow for census data collection, sea turtles offer an exception. On the Caribbean coast of Costa Rica, three sea turtle species (leatherback, Dermochelys coriacea; green, Chelonia mydas; and hawksbill, Eretmochelys imbricata) are exploited by poachers. Despite the consumption of turtle eggs and meat being illegal, they are consumed as a cultural food source and seasonal treat. Conservation programmes monitor nesting beaches, collect abundance data and record poaching events. Despite the availability of robust long-term datasets, quantifying the rate of poaching has yet to be undertaken. Using data from the globally important nesting beach, Tortuguero, as well as beaches Playa Norte and Pacuare on the Caribbean coast of Costa Rica, we modelled the spatial and temporal distribution of poaching of the three sea turtle species. Here, we present data from 2006 to 2019 on a stretch of coastline covering c.37 km. We identified poaching hotspots that correlated with populated areas. While the poaching hotspots persisted over time, we found poaching is declining at each of our sites. However, we urge caution when interpreting this result as the impact of poaching varies between species. Given their low abundance on these beaches, the poaching pressure on leatherback and hawksbill turtles is far greater than the impact on the abundant green turtles. We attribute the decline in poaching to supply-side conservation interventions in place at these beaches. Finally, we highlight the value of data sharing and collaborations between conservation NGOs.

DIGENETIC TREMATODE COMMUNITY IN NESTING GREEN SEA TURTLES (CHELONIA MYDAS) FROM TORTUGUERO NATIONAL PARK, COSTA RICA

2006 ◽  
Vol 92 (6) ◽  
pp. 1202-1206 ◽  
Author(s):  
Mario Santoro ◽  
Ellis C. Greiner ◽  
Juan Alberto Morales ◽  
Beatriz Rodríguez-Ortíz
Keyword(s):  
Costa Rica ◽  
National Park ◽  
Sea Turtles ◽  
Chelonia Mydas ◽  
Digenetic Trematode ◽  
Green Sea Turtles

scholarly journals Chelonid Alphaherpesvirus 5 Prevalence and First Confirmed Case of Sea Turtle Fibropapillomatosis in Grenada, West Indies

Animals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1490
Author(s):  
Amanda James ◽  
Annie Page-Karjian ◽  
Kate E. Charles ◽  
Jonnel Edwards ◽  
Christopher R. Gregory ◽  
...  
Keyword(s):  
West Indies ◽  
Sea Turtles ◽  
Chelonia Mydas ◽  
Sea Turtle ◽  
Dermochelys Coriacea ◽  
Neoplastic Disease ◽  
Extrinsic Factors ◽  
Eretmochelys Imbricata ◽  
Specific Pcr ◽  
The Impact

Chelonid alphaherpesvirus 5 (ChHV5) is strongly associated with fibropapillomatosis, a neoplastic disease of sea turtles that can result in debilitation and mortality. The objectives of this study were to examine green (Chelonia mydas), hawksbill (Eretmochelys imbricata), and leatherback (Dermochelys coriacea) sea turtles in Grenada, West Indies, for fibropapillomatosis and to utilize ChHV5-specific PCR, degenerate herpesvirus PCR, and serology to non-invasively evaluate the prevalence of ChHV5 infection and exposure. One-hundred and sixty-seven turtles examined from 2017 to 2019 demonstrated no external fibropapilloma-like lesions and no amplification of ChHV5 DNA from whole blood or skin biopsies. An ELISA performed on serum detected ChHV5-specific IgY in 18/52 (34.6%) of green turtles tested. In 2020, an adult, female green turtle presented for necropsy from the inshore waters of Grenada with severe emaciation and cutaneous fibropapillomas. Multiple tumors tested positive for ChHV5 by qPCR, providing the first confirmed case of ChHV5-associated fibropapillomatosis in Grenada. These results indicate that active ChHV5 infection is rare, although viral exposure in green sea turtles is relatively high. The impact of fibropapillomatosis in Grenada is suggested to be low at the present time and further studies comparing host genetics and immunologic factors, as well as examination into extrinsic factors that may influence disease, are warranted.

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