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.

scholarly journals Incidental capture of sea turtles by industrial bottom trawl fishery in the Tropical South-western Atlantic

2017 ◽  
Vol 98 (6) ◽  
pp. 1525-1531 ◽  
Author(s):  
Suzana Machado Guimarães ◽  
Davi Castro Tavares ◽  
Cassiano Monteiro-Neto
Keyword(s):  
Sea Turtles ◽  
Action Plan ◽  
Chelonia Mydas ◽  
Sea Turtle ◽  
Bottom Trawl ◽  
Conservation Strategies ◽  
Future Research ◽  
Olive Ridley ◽  
Western Atlantic ◽  
Turtle Species

The five sea turtle species occurring in Brazilian waters are susceptible to threats, including incidental catches by fisheries. Studies on incidental captures in fishing gears are the main focus of several conservation actions due to high sea turtle fishery mortality worldwide. This study provides the first evaluation of incidental sea turtle catches by industrial bottom trawl fisheries operating in Brazilian waters. Four twin-trawler vessels were monitored between July 2010 and December 2011 by captains who voluntarily completed logbooks. Forty-four turtles were captured during the 1996 tows (8313 fishing hours), resulting in a catch of 5.3 ± 0.8 turtles per 1000 h per unit effort. Captured species included the loggerhead turtle (Caretta caretta, 22 individuals), olive ridley turtles (Lepidochelys olivacea, 21 individuals) and one green turtle (Chelonia mydas). Water depth was the only variable that significantly affected sea turtle captures according to Generalized Linear Models. The capture rates reported in this study ranked sixth in relation to other published studies of similar fisheries occurring worldwide. Considering the importance of this region for sea turtles, the increasing evidence of sea turtle mortality and the goals of the National Action Plan for Conservation of Sea Turtles in Brazil, it is essential to identify the main threats towards these animals and propose mitigating solutions to reduce sea turtle mortality induced by fishing activities. This study provides results that may guide future research and goals in meeting sea turtle conservation strategies.

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 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.

Comparative Cytogenetics of Four Sea Turtle Species (Cheloniidae): G-Banding Pattern and in situ Localization of Repetitive DNA Units

2020 ◽  
Vol 160 (9) ◽  
pp. 531-538
Author(s):  
Caroline R.D. Machado ◽  
Larissa Glugoski ◽  
Camila Domit ◽  
Marcela B. Pucci ◽  
Daphne W. Goldberg ◽  
...  
Keyword(s):  
Ribosomal Dna ◽  
Sea Turtles ◽  
Chelonia Mydas ◽  
Sea Turtle ◽  
Marine Biodiversity ◽  
Comparative Cytogenetics ◽  
Turtle Species ◽  
Lepidochelys Olivacea ◽  
Karyotypic Formula

Sea turtles are considered flagship species for marine biodiversity conservation and are considered to be at varying risk of extinction globally. Cases of hybridism have been reported in sea turtles, but chromosomal analyses are limited to classical karyotype descriptions and a few molecular cytogenetic studies. In order to compare karyotypes and understand evolutive mechanisms related to chromosome dif­ferentiation in this group, <i>Chelonia mydas</i>, <i>Caretta caretta</i>, <i>Eretmochelys imbricata</i>, and <i>Lepidochelys olivacea</i> were cytogenetically characterized in the present study. When the obtained cytogenetic data were compared with the putative ancestral Cryptodira karyotype, the studied species showed the same diploid number (2n) of 56 chromosomes, with some variations in chromosomal morphology (karyotypic formula) and minor changes in longitudinal band locations. In situ localization using a 18S ribosomal DNA probe indicated a homeologous microchromosome pair bearing a 45S ribosomal DNA locus and size heteromorphism in all 4 species. Interstitial telomeric sites were identified in a microchromosome pair in <i>C. mydas</i> and <i>C. caretta</i>. The data showed that interspecific variations occurred in chromosomal sets among the Cheloniidae species, in addition to other Cryptodira karyotypes. These variations generated lineage-specific karyotypic diversification in sea turtles, which will have considerable implications for hybrid recognition and for the study, the biology, ecology, and evolutionary history of regional and global populations. Furthermore, we demonstrated that some chromosome rearrangements occurred in sea turtle species, which is in conflict with the hypothesis of conserved karyotypes in this group.

scholarly journals DISTRIBUCIÓN DE PLAYAS DE ANIDACIÓN Y ÁREAS DE ALIMENTACIÓN DE TO RTUGAS MARINAS Y SUS AMENAZAS EN EL CARIBE COLOMBIANO

2016 ◽  
Vol 33 ◽  
Author(s):  
Claudia Ceballos Fonseca
Keyword(s):  
Chelonia Mydas ◽  
Sea Turtle ◽  
Local Communities ◽  
Regional Level ◽  
Turtle Species ◽  
Green Turtles ◽  
Direct Observations ◽  
Counting Data ◽  
The Caribbean ◽  
San Andres

Between June and October 2002, six field assistants covered the Colombian Caribbean seashore gathering morphological, biotic and socio-cultural information, by direct observations and interviews with the local communities and authorities. From 1,650 km of Caribbean seashore, 181 beaches (730 km), are visited by one or all sea turtle species to nest or feed in surrounding grounds. Species distribution varied along the different regions of the Colombian Caribbean; however, there was a tendency of some species for specific ecosystems. Green turtles (Chelonia mydas) were most often found in the central Guajira, where sea grasses are most abundant, and hawksbills (E retmochelys imbricata) were most abundant on the coral reefs areas around San Bernardo, Rosario, Fuerte and Tortuguilla islands and the San Andrés cays. Though there was no sea turtle marking or individual counting, data was good enough to establish relative abundance categories as rare, common, and abundant. These categories, along with the also categorized identified threats, allowed me to make regional level recommendations for the conservation of sea turtles in the Caribbean coast of Colombia.

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 Ocular ultrasonography of sea turtles

2020 ◽  
Vol 62 (1) ◽  
Author(s):  
Caterina Muramoto ◽  
Vinícius Cardoso-Brito ◽  
Ana Cláudia Raposo ◽  
Thais Torres Pires ◽  
Arianne Pontes Oriá
Keyword(s):  
Anterior Chamber ◽  
Environmental Changes ◽  
Sea Turtles ◽  
Corneal Thickness ◽  
Anterior Chamber Depth ◽  
Chelonia Mydas ◽  
Caretta Caretta ◽  
Sea Turtle ◽  
Olive Ridley ◽  
Turtle Species

Abstract Background Environmental changes contribute to the development of ophthalmic diseases in sea turtles, but information on their eye biometrics is scarce. The aim of this study was to describe ophthalmic ultrasonographic features of four different sea turtle species; Caretta caretta (Loggerhead turtle; n = 10), Chelonia mydas (Green turtle; n = 8), Eretmochelys imbricata (Hawksbill turtle; n = 8) and Lepidochelys olivacea (Olive ridley; n = 6) under human care. Corneal thickness, scleral ossicle width and thickness, anterior chamber depth, axial length of the lens, vitreous chamber depth and axial globe length were measured by B-mode sonography with a linear transducer. Carapace size and animal weight were recorded. A sonographic description of the eye structures was established. Results The four species presented an ovate eyeball, a relatively thin cornea, and a small-sized lens positioned rostrally in the eye bulb, near the cornea, resulting in a shallow anterior chamber. The scleral ossicles did not prevent the evaluation of intraocular structures, even with a rotated eye or closed eyelids; image formation beyond the ossicles and measurements of all proposed structures were possible. B-mode sonography was easily performed in all animals studied. The sonographic characteristics of the eye were similar among the four species. Since there was a correlation between the size of the eye structures and the size of the individual, especially its carapace size, the differences found between E. imbricata and Caretta caretta are believed to be due to their overall difference in size. Conclusions Sonography is a valuable tool in ophthalmic evaluation of these species. Only minor differences were found between the species in this study, reinforcing their phylogenetic proximity and their similar functions and habitats.

Trace metal concentrations in livers and kidneys of sea turtles from south-eastern Queensland, Australia

1998 ◽  
Vol 49 (5) ◽  
pp. 409 ◽  
Author(s):  
A. R. Pople ◽  
A. N. Gordon ◽  
J. Ng
Keyword(s):  
Sea Turtles ◽  
Chelonia Mydas ◽  
Sea Turtle ◽  
Metal Concentrations ◽  
Eretmochelys Imbricata ◽  
Turtle Species ◽  
Lepidochelys Olivacea ◽  
South Eastern ◽  
Obvious Association ◽  
High Concentrations

The concentrations of some or all of arsenic (As), cadmium (Cd), mercury (Hg), selenium (Se) and zinc (Zn) were determined in the livers and kidneys of 50 stranded sea turtles (38 Chelonia mydas, eight Caretta caretta, three Eretmochelys imbricata, one Lepidochelys olivacea) from the Moreton Bay region of south-eastern Queensland, Australia. Concentrations of Cd, Se and Zn in the kidney tended to decrease with age, whereas concentrations of Zn in the liver tended to increase. Concentrations of Cd in all sea turtle species (1.7–75.9 µg g-1 wet weight) were amongst the highest recorded for marine vertebrates globally. Although there was no obvious association between metal concentrations and particular diseases in C. mydas, the high concentrations of Cd found in edible turtle tissues may pose a threat to the health of indigenous people whose diet includes C. mydas.

scholarly journals First field observation of the predation by Jaguar (Panthera onca) on Olive Ridley sea turtle (Lepidochelys olivacea) at Nancite Beach, Santa Rosa National Park, Costa Rica

2016 ◽  
Vol 3 (1) ◽  
pp. 20-23
Author(s):  
Sergio Escobar-Lasso ◽  
Luis Fonseca ◽  
Wilbert N. Villachica ◽  
Hansel Herrera ◽  
Roldán A. Valverde ◽  
...  
Keyword(s):  
Costa Rica ◽  
Sea Turtles ◽  
Chelonia Mydas ◽  
Sea Turtle ◽  
Dermochelys Coriacea ◽  
Olive Ridley ◽  
Eretmochelys Imbricata ◽  
Lepidochelys Olivacea ◽  
Santa Rosa National Park ◽  
Key Resources

Jaguars have been recorded preying on adult female sea turtles on their nesting beaches in Costa Rica, Guyana, Mexico and Suriname (Fretey 1977, Autar 1994, Cuevas et al. 2014, Guildera et al. 2015). Jaguars prey on Green (Chelonia mydas), Olive Ridley (Lepidochelys olivacea), Hawksbill (Eretmochelys imbricata), and Leatherback (Dermochelys coriacea) sea turtles (see Fretey 1977, Autar 1994, Carrillo et al. 1994, Chinchilla 1997, Tröeng 2000, Heithaus et al. 2008, Veríssimo et al. 2012, Arroyo-Arce et al. 2014, Cuevas et al. 2014, Arroyo-Arce & Salom-Pérez 2015, Guildera et al. 2015). The capture effort and risk of injury associated with the predation of nesting sea turtles is expected to be lower relative to other prey species in the jaguar’s diet (Cavalcanti & Gese 2010). Additionally, they can be key resources when other pr ey availability is low (Veríssimo et al. 2012).

scholarly journals Using Random Forest Algorithm to Model Cold Stunning Events in Sea Turtles in North Carolina

2020 ◽  
pp. 0000-0000
Author(s):  
Jennifer N Niemuth ◽  
Casey C Ransom ◽  
Sarah A Finn ◽  
Matthew H Godfrey ◽  
Stacy A.C. Nelson ◽  
...  
Keyword(s):  
North Carolina ◽  
Random Forest ◽  
Air Temperature ◽  
Sea Turtles ◽  
Meteorological Data ◽  
Warning System ◽  
Chelonia Mydas ◽  
Sea Turtle ◽  
Turtle Species ◽  
Change In Mean

Sea turtle strandings due to cold stunning are seen when turtles are exposed to ocean temperatures that acutely and persistently drop below approximately 12 °C. In North Carolina, this syndrome affects imperiled loggerhead Caretta caretta, green Chelonia mydas, and Kemp's ridley Lepidochelys kempii sea turtle species. Based on oceanic and meteorological patterns of cold stunning in sea turtles, we hypothesized that we could predict the daily size of cold stunning events in North Carolina using random forest models. We used cold stunning data from the North Carolina Sea Turtle Stranding and Salvage Network from 2010-2015 and oceanic and meteorological data from the National Data Buoy Center from 2009-2015 to create a random forest model that explained 99% of the variance. We explored additional models using the 10 and 20 most important variables or only oceanic and meteorological variables. These models explained similar percentages of variance. The variables most frequently found to be important were related to air temperature, atmospheric pressure, wind direction, and wind speed. Surprisingly, variables associated with water temperature, which is critical from a biological perspective, were not among the most important variables identified. We also included variables for the mean change in these metrics daily from 4 days prior to the day of stranding. These variables were among the most important in several of our models, especially the change in mean air temperature from 4 days prior to stranding to the day of stranding. The importance of specific variables from our RF models can be used to guide the selection of future model predictors to estimate daily size of cold stunning events. We plan to apply the results of this study to a predictive model that can serve as a warning system and to a downscaled climate projection to determine the potential impact of climate change on cold stunning event size in the future.

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