Offshore Dispersal and Predation of Sea Turtle Hatchlings I: A Study of Hawksbill Turtles at Chagar Hutang Turtle Sanctuary, Malaysia

2021 ◽  
Vol 109 (1) ◽  
Author(s):  
Javier Oñate-Casado ◽  
David T. Booth ◽  
Kevin Vandercamere ◽  
Sailee P. Sakhalkar ◽  
Mohd Uzair Rusli
Keyword(s):  
Sea Turtle ◽  
Hawksbill Turtles

scholarly journals Satellite tracking of rehabilitated sea turtles suggests a high rate of short-term survival following release

PLoS ONE ◽  
2021 ◽  
Vol 16 (2) ◽  
pp. e0246241
Author(s):  
David P. Robinson ◽  
Kevin Hyland ◽  
Gerhard Beukes ◽  
Abdulkareem Vettan ◽  
Aneeshkumar Mabadikate ◽  
...  
Keyword(s):  
Sea Turtles ◽  
Sea Turtle ◽  
Satellite Tracking ◽  
Anthropogenic Factors ◽  
Gulf Region ◽  
Term Survival ◽  
Turtle Species ◽  
Movement Characteristics ◽  
Loggerhead Turtles ◽  
Hawksbill Turtles

The rehabilitation of wildlife can contribute directly to the conservation of threatened species by helping to maintain wild populations. This study focused on determining the post-rehabilitation survival and spatial ecology of sea turtles and on comparing the movements of individuals with flipper amputations (amputees) to non-amputee animals. Our aims were to assess whether rehabilitated sea turtles survive after release, to compare and contrast the movement characteristics of the different species of sea turtles we tracked, and to examine whether amputees and non-amputees within species behaved similarly post-release. Twenty-six rehabilitated sea turtles from four species, including hawksbill Eretmochelys imbricata (n = 12), loggerhead Caretta caretta (n = 11), green Chelonia mydas (n = 2), and olive ridley Lepidochelys olivacea (n = 1) sea turtles from the United Arab Emirates were fitted with satellite tags before release. Rehabilitation times ranged from 89 to 817 days (mean 353 ± 237 days). Post-release movements and survival were monitored for 8 to 387 days (mean 155 ± 95 days) through satellite tracking. Tag data suggested that three tracked sea turtles died within four days of release, one after 27 days, and one after 192 days from what are thought to be anthropogenic factors unrelated to their pre-rehabilitation ailments. We then compared habitat use and movement characteristics among the different sea turtle species. Although half of all turtles crossed one or more international boundaries, dispersal varied among species. Loggerhead turtles had a high dispersal, with 80% crossing an international boundary, while hawksbill turtles displayed higher post-release residency, with 66% remaining within UAE territorial waters. Amputee turtles moved similarly to non-amputee animals of the same species. Loggerhead turtles travelled faster (mean ± sd = 15.3 ± 8 km/day) than hawksbill turtles (9 ± 7 km/day). Both amputee and non-amputee sea turtles within a species moved similarly. Our tracking results highlight that rehabilitated sea turtles, including amputees, can successfully survive in the wild following release for up to our ~one-year monitoring time therefore supporting the suitability for release of sea turtles that have recovered from major injuries such as amputations. However, more broadly, the high mortality from anthropogenic factors in the Arabian Gulf region is clearly a serious issue and conservation challenge.

scholarly journals Lipid profiling suggests species specificity and minimal seasonal variation in Pacific Green and Hawksbill Turtle plasma

PLoS ONE ◽  
2021 ◽  
Vol 16 (7) ◽  
pp. e0253916
Author(s):  
Chelsea E. Clyde-Brockway ◽  
Christina R. Ferreira ◽  
Elizabeth A. Flaherty ◽  
Frank V. Paladino
Keyword(s):  
Sea Turtles ◽  
Multiple Reaction Monitoring ◽  
Chelonia Mydas ◽  
Sea Turtle ◽  
Lipid Classes ◽  
Plasma Samples ◽  
Lipid Profiling ◽  
Eretmochelys Imbricata ◽  
Species Specific ◽  
Hawksbill Turtles

In this study, we applied multiple reaction monitoring (MRM)-profiling to explore the relative ion intensity of lipid classes in plasma samples from sea turtles in order to profile lipids relevant to sea turtle physiology and investigate how dynamic ocean environments affect these profiles. We collected plasma samples from foraging green (Chelonia mydas, n = 28) and hawksbill (Eretmochelys imbricata, n = 16) turtles live captured in North Pacific Costa Rica in 2017. From these samples, we identified 623 MRMs belonging to 10 lipid classes (sphingomyelin, phosphatidylcholine, free fatty acid, cholesteryl ester, phosphatidylserine, phosphatidylinositol, phosphatidylglycerol, phosphatidylethanolamine, ceramide, and triacylglyceride) and one metabolite group (acyl-carnitine) present in sea turtle plasma. The relative ion intensities of most lipids (80%) were consistent between species, across seasons, and were not correlated to body size or estimated sex. Of the differences we observed, the most pronounced was the differences in relative ion intensity between species. We identified 123 lipids that had species-specific relative ion intensities. While some of this variability is likely due to green and hawksbill turtles consuming different food items, we found indications of a phylogenetic component as well. Of these, we identified 47 lipids that varied by season, most belonging to the structural phospholipid classes. Overall, more lipids (n = 39) had higher relative ion intensity in the upwelling (colder) season compared to the non-upwelling season (n = 8). Further, we found more variability in hawksbill turtles than green turtles. Here, we provide the framework in which to apply future lipid profiling in the assessment of health, physiology, and behavior in endangered sea turtles.

Save the Turtles

2020 ◽  
pp. 116-142
Author(s):  
Sharika D. Crawford
Keyword(s):  
Costa Rica ◽  
Sea Turtles ◽  
Sea Turtle ◽  
Second World War ◽  
Postwar Period ◽  
World War ◽  
Economic Changes ◽  
Ocean Ecosystems ◽  
Hawksbill Turtles ◽  
Second World

This chapter traces the rise of an international movement to protect sea turtles during the postwar period. It explains how the economic changes brought on by the Second World War led the Caymanian government to envision and develop an alternative economy for its subjects when the turtle industry showed signs of distress. It also charts the development of oceanography and marine science in the years during and after the Second World War. This shift spurred awareness of ocean ecosystems and shaped the nascent marine environmentalism of the first wave of turtle scientists, including Archie Carr. It concludes with Carr's sea turtle research in Costa Rica and, more broadly, the greater Caribbean. The chapter argues that macrolevel changes coupled with the depletion of sea turtles forced turtlemen to end their generations' pursuit of green and hawksbill turtles in the 1970s.

Parasitic isopods associated with sea turtles nesting in Brazil

2014 ◽  
Vol 95 (5) ◽  
pp. 973-981 ◽  
Author(s):  
José C. Rocha Júnior ◽  
Joseph B. Pfaller ◽  
Ricardo Corbetta ◽  
Luciana Veríssimo
Keyword(s):  
Sea Turtles ◽  
Sea Turtle ◽  
Olive Ridley ◽  
Quantitative Survey ◽  
Recent Emergence ◽  
Parasitic Isopods ◽  
Biological Impacts ◽  
Basic Biology ◽  
Hawksbill Turtles ◽  
Nesting Season

Studies of sea turtle epibiosis have focused on the diversity and ecology of facultative commensalisms and less attention has been given to parasitic associations, in which the epibiont species derives nutrients from the tissue of the host turtle. We present the first description and quantitative survey of the parasitic isopods Excorallana costata, Excorallana bicornis and Excorallana oculata on loggerhead (N = 79) and hawksbill turtles (N = 23), and E. costata on olive ridley turtles (N = 9), nesting on Praia do Forte, Bahia, Brazil during the 2009–2010 season. Excorallana costata was the most common isopod species (N = 651), followed by E. bicornis (N = 77) and E. oculata (N = 20). Patterns include: (1) E. costata exhibited a higher frequency and intensity of parasitism than E. bicornis and E. oculata and (2) loggerheads hosted parasitic isopods at a higher frequency and intensity than hawksbills and olive ridleys. We also detected temporal shifts in the occurrence and intensity of parasitism across the nesting season, which strongly suggests that turtles were parasitized by all three isopod species during their internesting periods. Because parasitic isopods were observed only rarely prior to the 2009–2010 turtle-nesting season and have continued to be common in subsequent seasons, it is important to gain a better understanding of the basic biology of these interactions, the reasons for their recent emergence, and the potential biological impacts on turtle, as well as isopod, populations.

scholarly journals Uso de alimentos comerciales en el levante de tortugas carey (Eretmochelys imbricata, Cheloniidae)

2018 ◽  
Vol 47 (2) ◽  
Author(s):  
Ricardo Andrés Sarmiento-Devia ◽  
Guiomar Aminta Jaúregui-Romero ◽  
Adolfo Sanjuan-Muñoz
Keyword(s):  
Growth Rates ◽  
Low Cost ◽  
Sea Turtle ◽  
Eretmochelys Imbricata ◽  
Average Body Mass ◽  
Healthy Growth ◽  
Commercial Feeds ◽  
Nesting Beaches ◽  
Hawksbill Turtles ◽  
Average Body

Headstarting is a recovery strategy for sea turtle populations. It requires captive handling of hatchlings, which are transferred from nesting beaches with low percentages of hatching success. Providing adequate nutritional resources for hatchlings is costly but important, as it influences growth rates of young turtles. Assessing the potential of commercial diets as option for promoting healthy growth and reducing the costs of maintenance for captive Hawksbill Turtles, we evaluated the viability of two commercial feeds on the growth rates of the Hawksbill Turtle (Eretmochelys imbricata). We fed turtles to satiation twice a day between the sixth and tenth month of age. Individuals fed with fish flour meal (n=20) exhibited average body mass and straight carapace length (SCL) growth rates of 2.45±1.39 g.day-1 and 0.04±0.02cm.day-1, respectively. The turtles fed with squid flour meal (n =13) displayed growth rates of 3.35±1.11 g.day-1 and 0.04±0.01 cm.day-1. These differences, associated with the low avidity of the specimens for these pellets, may be due to the food characteristics, particularly the size, flotation capability and palatability of the food. However, the presence of amino acids and vitamins in these compounds, and their low cost, can make them viable as a supplementary item suggesting the use of commercial foods only as a dietary supplement.

scholarly journals Hematology, biochemistry, and toxicology of wild hawksbill turtles (Eretmochelys imbricata) nesting in mangrove estuaries in the eastern Pacific Ocean

2017 ◽  
Author(s):  
Aubrey M. Tauer ◽  
Michael J. Liles ◽  
Sofía Chavarría ◽  
Melissa Valle ◽  
Sada Amaya ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Pacific Ocean ◽  
Organic Pollutants ◽  
Persistent Organic Pollutants ◽  
Sea Turtle ◽  
Eastern Pacific ◽  
Eastern Pacific Ocean ◽  
Eretmochelys Imbricata ◽  
Mangrove Estuary ◽  
Hawksbill Turtles

AbstractSea turtles are a keystone species and are highly sensitive to changes in their environment, making them excellent environmental indicators. In light of environmental and climate changes, species are increasingly threatened by pollution, changes in ocean health, habitat alteration, and plastic ingestion. There may be additional health related threats and understanding these threats is key in directing future management and conservation efforts, particularly for severely reduced sea turtle populations. Hawksbill turtles (Eretmochelys imbricata) are critically endangered, with those in the eastern Pacific Ocean (Mexico–Peru) considered one of the most threatened sea turtle populations in the world. This study establishes baseline health parameters in hematology and blood biochemistry as well as tested for heavy metals and persitent organic pollutants in eastern Pacific hawksbills at a primary nesting colony located in a mangrove estuary. Whereas hematology and biochemistry results are consistent with healthy populations of other species of sea turtles, we identified differences in packed cell volume, heterophils and lympohcyte counts, and glucose when comparing our data to other adult hawksbill analysis (1), (2), (3). Our analysis of heavy metal contamination revealed a mean blood level of 0.245 ppm of arsenic, 0.045 ppm of lead, and 0.008 ppm of mercury. Blood levels of persistent organic pollutants were below the laboratory detection limit for all turtles. Our results suggest that differences in the feeding ecology of eastern Pacific hawksbills in mangrove estuaries may make them less likely to accumulate persistent organic pollutants and heavy metals in their blood. These baseline data on blood values in hawksbills nesting within a mangrove estuary in the eastern Pacific offer important guidance for health assessments of the species in the wild and in clinical rehabilitation facilities, and underscore the importance of preventing contamination from point and non-point sources in mangrove estuaries, which represent primary habitat to hawksbills and myriad other marine species in the eastern Pacific Ocean.

Sages of the Sea

2020 ◽  
pp. 15-38
Author(s):  
Sharika D. Crawford
Keyword(s):  
Twentieth Century ◽  
New World ◽  
Sea Turtle ◽  
Small Islands ◽  
Cayman Islands ◽  
Distinctive Features ◽  
The Caribbean ◽  
Migratory Patterns ◽  
Hawksbill Turtles ◽  
Insight Into

This chapter draws on an array of sources including twentieth century scientific studies to offer insight into the habits and migratory patterns of sea turtles. As a result, the chapter discusses basic sea turtle biology differentiating the distinctive features of green and hawksbill turtles. It then explains how the two turtle varieties became global commodities for niche luxury markets. The chapter explains how indigenous and early New World newcomers—both European and non-European—came to adapt and learn how to hunt turtles in the Caribbean. It also traces the development of turtle hunting in the Cayman Islands. The chapter argues that turtles played a pivotal role in shaping these small islands and coastal societies as much as sugar or banana commodities did in other parts of the Caribbean.

Pivotal temperature and predicted sex ratios for hatchling hawksbill turtles from Brazil

1999 ◽  
Vol 77 (9) ◽  
pp. 1465-1473 ◽  
Author(s):  
Matthew H Godfrey ◽  
Adriana F D'Amato ◽  
Maria  Marcovaldi ◽  
N Mrosovsky
Keyword(s):  
Low Temperatures ◽  
Sex Ratios ◽  
Sea Turtle ◽  
Temperature Dependent ◽  
Eretmochelys Imbricata ◽  
Conservation Implications ◽  
Incubation Duration ◽  
Incubation Temperatures ◽  
Hawksbill Turtles ◽  
Pivotal Temperature

Like all other species of sea turtle, the hawksbill turtle (Eretmochelys imbricata) exhibits temperature-dependent sexual differentiation, with high incubation temperatures producing females and low temperatures producing males. Relatively little is known about the sex ratios of hatchlings produced by nesting populations of hawksbill turtles. Here we estimate the overall seasonal sex ratios of hatchling hawksbill turtles produced in Bahia, Brazil, during 6 nesting seasons, based on incubation durations, pivotal temperature, and pivotal incubation duration. The overall sex ratio of hatchlings produced in Bahia from 1991-1992 through 1996-1997 was estimated to be >90% female, which is more female-biased than estimated sex ratios of hatchling loggerhead turtles from Bahia and Florida, U.S.A. The biological and conservation implications of skewed sex ratios are discussed.

scholarly journals Identification of Important Sea Turtle Areas (ITAs) for hawksbill turtles in the Arabian Region

2014 ◽  
Vol 460 ◽  
pp. 89-99 ◽  
Author(s):  
Nicolas J. Pilcher ◽  
Marina Antonopoulou ◽  
Lisa Perry ◽  
Mohamed A. Abdel-Moati ◽  
Thabit Zahran Al Abdessalaam ◽  
...  
Keyword(s):  
Sea Turtle ◽  
Hawksbill Turtles

scholarly journals Epibiont Assemblages on Nesting Hawksbill Turtles Show Site-Specificity in the Persian Gulf

2021 ◽  
Vol 9 ◽  
Author(s):  
Javad Loghmannia ◽  
Ali Nasrolahi ◽  
Mohsen Rezaie-Atagholipour ◽  
Bahram H. Kiabi
Keyword(s):  
Persian Gulf ◽  
National Park ◽  
Sea Turtle ◽  
Eretmochelys Imbricata ◽  
Lack Of Information ◽  
Harpacticoid Copepods ◽  
Study Sites ◽  
The Persian Gulf ◽  
Almost All ◽  
Hawksbill Turtles

Sea turtle epibionts can provide insights into the hosts' habitat use. However, at present, there is a lack of information on sea turtle epibiont communities in many locations worldwide. Here, we describe the epibiont communities of 46 hawksbill turtles (Eretmochelys imbricata) in the Persian Gulf. Specifically, we sampled 28 turtles from the Dayyer-Nakhiloo National Park (DNNP) in the northern Gulf and 18 turtles from Shibderaz beach in the Strait of Hormuz. A total of 54 macro, meio, and micro-epibiont taxa were identified, including 46 taxa from Shibderaz and 29 taxa from DNNP. The barnacles Chelonibia testudinaria and Platylepas hexastylos, as well as harpacticoid copepods and Rotaliid foraminifers, had the highest frequency of occurrence found on almost all turtle individuals. Harpacticoids were the most abundant epizoic taxa (19.55 ± 3.9 ind. per 9 cm2) followed by forams (Quinqueloculina spp.: 6.25 ± 1.5 ind. per 9 cm2 and Rotaliids: 6.02 ± 1.3 ind. per 9 cm2). Our results showed significant differences between the study sites in the composition of micro and macro-epibiont communities found on hawksbill turtles. We speculate that the differences in epibiont communities were largely influenced by local environmental conditions.

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