Offshore Migratory Activity of Hawksbill Turtle (Eretmochelys imbricata) Hatchlings, I. Quantitative Analysis of Activity, with Comparisons to Green Turtles (Chelonia mydas)

2009 ◽  
Vol 8 (1) ◽  
pp. 28-34 ◽  
Author(s):  
F. C. Chung ◽  
N. J. Pilcher ◽  
M. Salmon ◽  
J. Wyneken
Keyword(s):  
Quantitative Analysis ◽  
Chelonia Mydas ◽  
Eretmochelys Imbricata ◽  
Migratory Activity ◽  
Green Turtles

Hawksbill turtle (Eretmochelys imbricata Linnaeus 1766) and green turtle (Chelonia mydas Linnaeus 1754) nesting activity (2002-2004) at El Cuyo beach, Mexico

2006 ◽  
Vol 27 (4) ◽  
pp. 539-547 ◽  
Author(s):  
Raquel Xavier ◽  
Andre Barata ◽  
Leopoldo Palomo Cortez ◽  
Nuno Queiroz ◽  
Eduardo Cuevas
Keyword(s):  
Green Turtle ◽  
Average Distance ◽  
Biosphere Reserve ◽  
Chelonia Mydas ◽  
Eretmochelys Imbricata ◽  
Nest Location ◽  
Hurricane Ivan ◽  
Green Turtles ◽  
Nest Site Fidelity ◽  
Nesting Activity

Abstract The Yucatan Peninsula nesting hawksbill turtles' population (Eretmochelys imbricata Linnaeus 1766) is the biggest in the Caribbean and fourth in the world; within the Ría Lagartos Biosphere Reserve, at El Cuyo beach both hawksbill and green turtle (Chelonia mydas Linnaeus 1754) nest. In the present study, the nesting trend and reproductive output of both species during three consecutive nesting seasons (2002-2004) was evaluated. Night patrols from mid April to September allowed the collection of data on number of nests, nest location and size of females. The number of hawksbill and green turtles' nests decreased along these seasons. No differences were found in mean length of female turtles of both species between nesting seasons. Both species showed high nest site fidelity with average distance between nests of 3 km for Hawksbill and 1.8 km for Green turtles. The regression analysis between size and fecundity was significant (p < 0.05) for both species. The spatial variation of laid nests was also analyzed revealing that both species nested mainly on the dune zone. Predation has risen on El Cuyo beach, affecting mostly hawksbills nests. Hurricane Ivan destroyed the majority of green turtles nests in 2004.

scholarly journals New foraging grounds for hawksbill (Eretmochelys imbricata) and green turtles (Chelonia mydas) along the northern Pacific coast of Costa Rica, Central America

2015 ◽  
Vol 62 (4) ◽  
pp. 109 ◽  
Author(s):  
Maike Heidemeyer ◽  
Randall Arauz-Vargas ◽  
Erick López-Agüero
Keyword(s):  
Costa Rica ◽  
Central America ◽  
Pacific Coast ◽  
Chelonia Mydas ◽  
Eretmochelys Imbricata ◽  
Green Turtles ◽  
Northern Pacific

<p>Existe poca información disponible sobre los sitios de forrajeo de las poblaciones de tortugas marinas del Pacífico Oriental, lo cual dificulta el diseño de estrategias de conservación tanto en el ámbito nacional como internacional.  Realizamos observaciones en cinco sitios a lo largo del Pacífico Norte de Costa Rica (Cabo Blanco, Punta Coyote, Punta Pargos, Punta Argentina y Bahía Matapalito) entre el 2010-2013, utilizando redes de enmalle tortugueras con luz de malla de 45 cm, con el objetivo de explorar y documentar nuevos sitios de forrajeo.  Estandarizamos la Captura Por Unidad de Esfuerzo (CPUE) como tortugas capturada por 100m de relinga superior por hora de inmersión, el cual varió de 0.06 en Punta Pargos hasta 0.58 en Bahía Matapalito para tortugas carey (Eretmochelys imbricata), y de 0.01 en Punta Coyota hasta 0.10 en Cabo Blanco para tortugas verde del Pacífico (Chelonia mydas).  Encontramos rangos de tamaño específicos por sitio para E.imbricata en Bahía Matapalito y Cabo Blanco, con promedio ± Desviación Estándar (SD) del Largo Curvo de Caparazón (CCL) de 42.46 ± 17.66cm y 61.25±13.08cm respectivamente.  Tan solo se encontró un individuo en los demás sitios con CCL de 49.6cm hasta 60.5 cm.  Se capturaron tortugas verde en tres de los sitios observados, con CCL de 67.67±19.44cm en Cabo Blanco, 69.40±9.40cm en Punta Coyote. y un único individuo en Bahía Matapalito con un CCL de 56.2cm. La ausencia de clases de tamaño de adultos para E.imbricata, así como de clases de tamaño de juveniles para la tortuga verde del Pacífico, enfatiza la complejidad de la distribución específica por especies durante las distintas fases de vida de las tortugas marinas en el Pacífico Oriental, y la necesidad emergente de implementar monitoreos a largo plazo en diferentes sitios a lo largo del Pacífico Norte del país para comprender la conectividad entre hábitats. El presente estudio revela la existencia de sitios de forrajeo frágiles desprotegidos para la tortuga carey y verde en el Pacífico norte de Costa Rica, y sirve de guía para futuras iniciativas de investigación para fortalecer estrategias de conservación en el ámbito nacional e internacional.</p>

Intake and excretion of arsenicals in green (Chelonia mydas) and hawksbill turtles (Eretmochelys imbricata)

2011 ◽  
Vol 8 (1) ◽  
pp. 19 ◽  
Author(s):  
Tetsuro Agusa ◽  
Kozue Takagi ◽  
Todd W. Miller ◽  
Reiji Kubota ◽  
Yasumi Anan ◽  
...  
Keyword(s):  
Feeding Behaviour ◽  
Chelonia Mydas ◽  
Water Soluble ◽  
Marine Animals ◽  
Eretmochelys Imbricata ◽  
Accumulation Pattern ◽  
Turtle Species ◽  
Green Turtles ◽  
Hawksbill Turtles ◽  
Prey Items

Environmental context Although among higher marine animals, relatively high concentration of arsenic and unique distribution of arsenic compounds are found in green (Chelonia mydas) and hawksbill turtles (Eretmochelys imbricata), the accumulation mechanism remains unknown. We examined the accumulation of arsenicals in two turtles from the standpoint of short- and long-term intake and excretion and found that prey items might be important for the arsenic accumulation. This study can provide useful information on the accumulation pattern of arsenic speciation in sea turtles. Abstract We analysed arsenic (As) compounds in the stomach and intestine contents, bile and urine of green (Chelonia mydas) and hawksbill turtles (Eretmochelys imbricata) to understand As accumulation through intake and excretion. Stable isotopes of δ15N and δ13C were also measured for understanding the feeding behaviour dependent accumulation of As. Major As species in gastrointestinal contents were unknown water-soluble As, followed by unextracted As. Concentrations of AB and DMA in the tissues were higher than those in the stomach contents (prey items), indicating high bioaccumulation of these arsenicals. In green turtles, AB concentration was high in bile and increased throughout the gastrointestinal tract, suggesting significant biliary excretion of AB. δ15N was positively correlated with AB level in green turtles, whereas a negative relationship between residual As and δ15N was observed in hawksbill turtles. This study indicates feeding behaviour-dependent accumulation of As compounds in both turtle species for the first time.

Green Sea Turtles Stranded by Cyclone Kathy on the South-Westeern Coast of the Culf of Carpentaria

1985 ◽  
Vol 12 (3) ◽  
pp. 523 ◽  
Author(s):  
CJ Limpus ◽  
PC Reed
Keyword(s):  
Breeding Season ◽  
Chelonia Mydas ◽  
Olive Ridley ◽  
Eretmochelys Imbricata ◽  
Lepidochelys Olivacea ◽  
Green Sea Turtles ◽  
Green Turtles ◽  
Previous Season ◽  
Hawksbill Turtles ◽  
Principal Species

Cyclone Kathy on 23 March 1984 stranded many green turtles, Chelonia mydas, on the coast adjacent to the Sir Edward Pellew Is. It is estimated that over 1000 were thrown up by the storm surge and that over 500 were left stranded by the receding waters, including migrants from the Raine I. rookery. These turtles, which were predominately large females, had been feeding close inshore on seagrass. Of the mature females sampled, 62% were preparing to breed in the next breeding season but none had bred in the previous season. The flatback turtle, Chelonia depressa, the principal species breeding on the Sir Edward Pellew Is, was not involved in the stranding. Hawksbill turtles, Eretmochelys imbricata, and olive ridley turtles, Lepidochelys olivacea, which occur in the deeper offshore waters were also not stranded. Some of the rescued turtles were subsequently recaptured nesting at Raine I.

Somatic Growth Rates of Green Turtles (Chelonia mydas) and Hawksbills (Eretmochelys imbricata) in the Galápagos Islands

2015 ◽  
Vol 49 (4) ◽  
pp. 641-648 ◽  
Author(s):  
Patricia M. Zárate ◽  
Karen A. Bjorndal ◽  
Jeffrey A. Seminoff ◽  
Peter H. Dutton ◽  
A. B. Bolten
Keyword(s):  
Growth Rates ◽  
Somatic Growth ◽  
Chelonia Mydas ◽  
Galapagos Islands ◽  
Galápagos Islands ◽  
Eretmochelys Imbricata ◽  
Green Turtles

Comparison of plasma androgen profiles in green and hawksbill sea turtles inhabiting Queensland waters

2004 ◽  
Vol 52 (3) ◽  
pp. 293 ◽  
Author(s):  
Tim S. Jessop ◽  
Colin J. Limpus ◽  
Joan M. Whittier
Keyword(s):  
Seasonal Variation ◽  
Phase Shift ◽  
Chelonia Mydas ◽  
Wild Populations ◽  
Ontogenetic Changes ◽  
Eretmochelys Imbricata ◽  
Green Turtles ◽  
Hawksbill Turtles ◽  
Delayed Phase ◽  
Androgen Levels

Investigations were made into profiles of plasma androgens (combined testosterone and 5α-dihydrotestosterone) in green (Chelonia mydas) and hawksbill (Eretmochelys imbricata) turtles inhabiting waters off Queensland, Australia. First, we documented the occurrence of sex-based and ontogenetic changes in plasma androgen of immature green and hawksbill turtles occurring in wild populations. Specifically, androgen levels are increased in pubescent individuals and adults of both species and sexes. Second, we measured seasonal variation in plasma androgen profiles of adult male green and hawksbill turtles. Third, we compared plasma androgens of post-nesting green and hawksbill turtles. As for previous studies on captive green turtles, our data indicate that wild populations of green turtles also show a prenuptial spermatogenic pattern, in which plasma androgen levels rise and peak prior to migration and courtship. However, our data from male hawksbill turtles are in contrast to this pattern and provide some evidence to suggest that a delayed phase shift may occur in this population. Unlike male green turtles, male hawksbill turtles in this study all showed signs of physiological preparation for breeding.

Sea-Turtle Rookeries in North-Western Torres Strait

1989 ◽  
Vol 16 (5) ◽  
pp. 517 ◽  
Author(s):  
CJ Limpus ◽  
D Zeller ◽  
D Kwan ◽  
W Macfarlane
Keyword(s):  
Papua New Guinea ◽  
Chelonia Mydas ◽  
Sea Turtle ◽  
Barrier Reef ◽  
Eretmochelys Imbricata ◽  
Green Turtles ◽  
North Eastern ◽  
Nesting Sites ◽  
Torres Strait ◽  
North Western

Deliverance Island, Kerr Islet and Turu Cay in north-western Torres Strait support a major nesting population and the most northerly recorded rookery of the flatback turtle, Natator depressa. Nesting occurs there year round, with a peak in the early months of the year. The islands are insignificant nesting sites for the green turtle, Chelonia mydas, and the hawksbill turtle, Eretmochelys imbricata. The N. depressa turtles that nest in western Torres Strait-north-eastern Gulf of Carpentaria are smaller and lay smaller eggs on average than the N. depressa turtles that breed in the southern Great Barrier Reef. On Deliverance Island, the inhabitants of nearby Queensland islands and Papua New Guinea coastal villages infrequently harvest N. depressa eggs as well as the green turtles that feed over the surrounding reef flats.

scholarly journals Plastic ingestion by sea turtles in Paraíba State, Northeast Brazil

2015 ◽  
Vol 105 (3) ◽  
pp. 265-270 ◽  
Author(s):  
Camila Poli ◽  
Daniel Oliveira Mesquita ◽  
Cinthia Saska ◽  
Rita Mascarenhas
Keyword(s):  
Gastrointestinal Tract ◽  
Carapace Length ◽  
Sea Turtles ◽  
Chelonia Mydas ◽  
Northeast Brazil ◽  
Plastic Pollution ◽  
Olive Ridley ◽  
Eretmochelys Imbricata ◽  
Lepidochelys Olivacea ◽  
Green Turtles

ABSTRACT Currently, plastics are recognized as a major pollutant of the marine environment, representing a serious threat to ocean wildlife. Here, we examined the occurrence and effects of plastic ingestion by sea turtles found stranded along the coast of Paraíba State, Brazil from August 2009 to July 2010. Ninety-eight digestive tracts were examined, with plastic found in 20 (20.4%). Sixty five percent (n = 13) of turtles with plastic in the digestive tract were green turtles (Chelonia mydas), 25% (n = 5) were hawksbills (Eretmochelys imbricata), and 10% (n = 2) were olive ridley (Lepidochelys olivacea). More plastic was found in the intestine (85%) than in other parts of the gastrointestinal tract. We observed complete blockage of the gastrointestinal tract due to the presence of plastic in 13 of the 20 turtles that had ingested plastic. No correlation was found between the curved carapace length (CCL) and the number or mass of the plastic ingested items. Significant differences were found between the intake of hard and soft plastic and the ingestion of white/transparent and colored plastic, with soft and white/transparent plastics being more commonly ingested. This study reveals the serious problem of plastic pollution to sea turtles at the area.

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