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 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.

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.

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 Evolutionary Comparisons of Chelonid Alphaherpesvirus 5 (ChHV5) Genomes from Fibropapillomatosis-Afflicted Green (Chelonia mydas), Olive Ridley (Lepidochelys olivacea) and Kemp’s Ridley (Lepidochelys kempii) Sea Turtles

Animals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 2489
Author(s):  
Liam Whitmore ◽  
Kelsey Yetsko ◽  
Jessica A. Farrell ◽  
Annie Page-Karjian ◽  
Whitney Daniel ◽  
...  
Keyword(s):  
Gene Evolution ◽  
Disease Incidence ◽  
Keystone Species ◽  
Chelonia Mydas ◽  
Sea Turtle ◽  
Neoplastic Disease ◽  
Nucleotide Polymorphisms ◽  
Oncogenic Virus ◽  
Olive Ridley ◽  
Turtle Species

The spreading global sea turtle fibropapillomatosis (FP) epizootic is threatening some of Earth’s ancient reptiles, adding to the plethora of threats faced by these keystone species. Understanding this neoplastic disease and its likely aetiological pathogen, chelonid alphaherpesvirus 5 (ChHV5), is crucial to understand how the disease impacts sea turtle populations and species and the future trajectory of disease incidence. We generated 20 ChHV5 genomes, from three sea turtle species, to better understand the viral variant diversity and gene evolution of this oncogenic virus. We revealed previously underappreciated genetic diversity within this virus (with an average of 2035 single nucleotide polymorphisms (SNPs), 1.54% of the ChHV5 genome) and identified genes under the strongest evolutionary pressure. Furthermore, we investigated the phylogeny of ChHV5 at both genome and gene level, confirming the propensity of the virus to be interspecific, with related variants able to infect multiple sea turtle species. Finally, we revealed unexpected intra-host diversity, with up to 0.15% of the viral genome varying between ChHV5 genomes isolated from different tumours concurrently arising within the same individual. These findings offer important insights into ChHV5 biology and provide genomic resources for this oncogenic virus.

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 Molecular Assessment of Chelonid Alphaherpesvirus 5 Infection in Tumor-Free Green (Chelonia mydas) and Loggerhead (Caretta caretta) Sea Turtles in North Carolina, USA, 2015–2019

Animals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1964 ◽  
Author(s):  
Annie Page-Karjian ◽  
Maria E. Serrano ◽  
Jeffrey Cartzendafner ◽  
Ashley Morgan ◽  
Branson W. Ritchie ◽  
...  
Keyword(s):  
Immune Response ◽  
North Carolina ◽  
Sea Turtles ◽  
Chelonia Mydas ◽  
Caretta Caretta ◽  
Enzyme Linked Immunosorbent Assay ◽  
Western Atlantic ◽  
Blood Samples ◽  
Turtle Species ◽  
Green Turtles

Fibropapillomatosis is associated with chelonid alphaherpesvirus 5 (ChHV5) and tumor formation in sea turtles. We collected blood samples from 113 green (Chelonia mydas) and 112 loggerhead (Caretta caretta) turtles without fibropapillomatosis, including 46 free-ranging turtles (20 green turtles, 26 loggerheads), captured in Core Sound, North Carolina, and 179 turtles (93 green turtles, 86 loggerheads) in rehabilitative care in North Carolina. Blood samples were analyzed for ChHV5 DNA using quantitative polymerase chain reaction (qPCR), and for antibodies to ChHV5 peptides using an enzyme-linked immunosorbent assay (ELISA). None of the samples from foraging turtles tested positive for ChHV5 by qPCR; ELISA was not used for foraging turtles. Samples from 18/179 (10.1%) rehabilitating turtles tested positive for ChHV5 using qPCR, and 32/56 (57.1%) rehabilitating turtles tested positive for antibodies to ChHV5 using ELISA. Five turtles that tested positive by qPCR or ELISA at admission converted to being undetectable during rehabilitation, and five that initially tested negative converted to being positive. Both sea turtle species were significantly more likely to test positive for ChHV5 using ELISA than with qPCR (p < 0.001). There was no difference in the proportions of green turtles versus loggerheads that tested positive for ChHV5 using qPCR, but loggerheads were significantly more likely than green turtles to test positive for ChHV5 using ELISA. This finding suggests that loggerheads infected with ChHV5 at some point in their life may be more able than green turtles to mount an effective immune response against recrudescent infection, pointing to species-specific genetic differences in the two species’ immune response to ChHV5 infection. This is the first study to analyze antibodies to ChHV5 in loggerhead turtles and represents the most complete dataset on ChHV5 DNA detection in sea turtles encountered in the more northern latitudes of their western Atlantic habitat.

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 Evolutionary Genomic Comparisons of Chelonid Herpesvirus 5 (chhv5) From Fibropapillomatosis-Afflicted Green (Chelonia Mydas), Olive Ridley (Lepidochelys Olivacea), And Kemp’s Ridley (Lepidochelys Kempii) Sea Turtles.

2021 ◽  
Author(s):  
Liam Whitmore ◽  
Kelsey Yetsko ◽  
Jessica A. Farrell ◽  
Annie Page-Karjian ◽  
Whitney Daniel ◽  
...  
Keyword(s):  
Gene Evolution ◽  
Disease Incidence ◽  
Keystone Species ◽  
Chelonia Mydas ◽  
Sea Turtle ◽  
Neoplastic Disease ◽  
Nucleotide Polymorphisms ◽  
Oncogenic Virus ◽  
Olive Ridley ◽  
Turtle Species

The spreading global sea turtle fibropapillomatosis (FP) epizootic is threatening some of Earth&rsquo;s ancient reptiles, adding to the plethora of threats faced by these keystone species. Understanding this neoplastic disease, and its likely aetiological pathogen, chelonid alphaherpesvirus 5 (ChHV5), is crucial to understand how the disease impacts sea turtle populations and species and the future trajectory of disease incidence. We generated 20 ChHV5 genomes, from three sea turtle species, to better understand the viral variant diversity and gene evolution of this oncogenic virus. We revealed previously underappreciated genetic diversity within this virus (with an average of 2,035 single nucleotide polymorphisms [SNPs], 1.54% of the ChHV5 genome) and identified genes under the strongest evolutionary pressure. Furthermore, we investigated the phylogeny of ChHV5 at both genome and gene level, confirming the propensity of the virus to be interspecific with related variants able to infect multiple sea turtle species. Finally, we revealed unexpected intra-host diversity, with up to 0.15% of the viral genome varying between ChHV5 genomes isolated from different tumours concurrently arising within the same individual. These findings offer important insights into ChHV5 biology and provide genomic resources for this oncogenic virus.

scholarly journals Comparative Study of Plasma Parameters in Olive Ridley (Lepidochelys Olivacea) and Hawksbill (Eretmochelys Imbricata) During Nesting

2002 ◽  
Vol 7 (2) ◽  
pp. 231
Author(s):  
A.Y.A. Alkindi ◽  
I.Y. Mahmoud ◽  
J.L. Plude
Keyword(s):  
Plasma Parameter ◽  
Sea Turtles ◽  
Stress Hormones ◽  
Sea Turtle ◽  
Olive Ridley ◽  
Plasma Parameters ◽  
Eretmochelys Imbricata ◽  
Turtle Species ◽  
Lepidochelys Olivacea ◽  
Significant Difference

The aim of this study is to investigate the role of plasma level parameters during nesting activity and provide data potentially useful to future studies on the dynamics of reproductive and stress hormones in the most endangered sea turtle species in the world. Plasma parameters in the sea turtles, olive ridley (Lipodochelys oliveacea) and hawksbill (Eretmochelys imbricata) from Masirah Island, Oman, were analyzed relative to nesting stress. To date, no study has been conducted on plasma parameter levels in sea turtles during nesting. Field observations were conducted under ideal temperature conditions. At the time of sampling, there was no significant difference for cloacal, sand, air or water temperature for the two species. Electrolytes (Cl¯, Ca++, K+, Na+ and Mg++), cholesterol, urea, uric acid and osmolarity were measured during nesting. Both species were observed to spend between 1.5 and 2.00 hours on the nesting grounds. Some had successful oviposition and completed all nesting phases, while others with incomplete nesting phases failed to oviposit their  eggs. Under both conditions, the turtles of both species had an exhaustive and stressful nesting exercise. Plasma parameter values, both intra-specifically and inter-specifically, were not significantly different for oviposited and non-oviposited turtles. This may indicate that both species have the same physiological adjustment relative to plasma parameters whether or not the turtles oviposited their eggs.  

scholarly journals Occurrence and diet analysis of sea turtles in Korean shore

2021 ◽  
Vol 45 (1) ◽  
Author(s):  
Jihee Kim ◽  
Il-Hun Kim ◽  
Min-Seop Kim ◽  
Hae Rim Lee ◽  
Young Jun Kim ◽  
...  
Keyword(s):  
Dna Analysis ◽  
Sea Turtles ◽  
Sea Turtle ◽  
Diet Analysis ◽  
Portunus Trituberculatus ◽  
Olive Ridley ◽  
Leatherback Turtle ◽  
Turtle Species ◽  
Green Turtles ◽  
Loggerhead Turtles

Abstract Background Sea turtles, which are globally endangered species, have been stranded and found as bycatch on the Korean shore recently. More studies on sea turtles in Korea are necessary to aid their conservation. To investigate the spatio-temporal occurrence patterns of sea turtles on the Korean shore, we recorded sampling locations and dates, identified species and sexes and measured sizes (maximum curved carapace length; CCL) of collected sea turtles from the year 2014 to 2020. For an analysis of diets through stomach contents, we identified the morphology of the remaining food and extracted DNA, followed by amplification, cloning, and sequencing. Results A total of 62 stranded or bycaught sea turtle samples were collected from the Korean shores during the study period. There were 36 loggerhead turtles, which were the dominant species, followed by 19 green turtles, three hawksbill turtles, two olive ridley turtles, and two leatherback turtles. The highest numbers were collected in the year 2017 and during summer among the seasons. In terms of locations, most sea turtles were collected from the East Sea, especially from Pohang. Comparing the sizes of collected sea turtles according to species, the average CCL of loggerhead turtles was 79.8 cm, of green turtles was 73.5 cm, and of the relatively large leatherback turtle species was 126.2 cm. In most species, the proportion of females was higher than that of males and juveniles, and was more than 70% across all the species. Food remains were morphologically identified from 19 stomachs, mainly at class level. Seaweeds were abundant in stomachs of green turtles, and Bivalvia was the most detected food item in loggerhead turtles. Based on DNA analysis, food items from a total of 26 stomachs were identified to the species or genus level. The gulfweed, Sargassum thunbergii, and the kelp species, Saccharina japonica, were frequently detected from the stomachs of green turtles and the jellyfish, Cyanea nozakii, the swimming crab, Portunus trituberculatus, and kelps had high frequencies of occurrences in loggerhead turtles. Conclusions Our findings support those of previous studies suggesting that sea turtles are steadily appearing in the Korean sea. In addition, we verified that fish and seaweed, which inhabit the Korean sea, are frequently detected in the stomach of sea turtles. Accordingly, there is a possibility that sea turtles use the Korean sea as feeding grounds and habitats. These results can serve as basic data for the conservation of globally endangered sea turtles.

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