Green turtle population recovery at Aldabra Atoll continues after 50 years of protection

Fibropapillomatosis is a neoplastic disease that affects sea turtles. It is characterized by multiple papillomas, fibropapillomas and cutaneous and/or visceral fibromas. Although its etiology has not been fully elucidated, it is known that there is a strong involvement of an alpha - herpesvirus, but the influence of other factors such as parasites, genetics, chemical carcinogens, contaminants, immunosuppression and ultraviolet radiation may be important in the disease, being pointed out as one of the main causes of a reduction in the green turtle population. Thus, the objective of this article was to describe the morphology of cutaneous fibropapillomas found in specimens of the green turtle (Chelonia mydas), using light and scanning electron microscopy in order to contribute to the mechanism of tumor formation. Microscopically, it presented hyperplastic stromal proliferation and epidermal proliferation with hyperkeratosis. The bulky mass was coated with keratin, with some keratinocyte invaginations, that allowed the keratin to infiltrate from the epidermis into the dermis, forming large keratinized circular spirals. Another fact that we observed was the influence of the inflammation of the tumors caused by ectoparasites.

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The Recent Nesting Record of Female Green Turtle, Chelonia mydas, at Pamban, Gulf of Mannar

Notulae Scientia Biologicae ◽

10.15835/nsb649374 ◽

2014 ◽

Vol 6 (4) ◽

pp. 414-416

Author(s):

Vellathi VENKATESAN ◽

Chellapa KALIDAS

Keyword(s):

Green Turtle ◽

Monsoon Season ◽

High Tide ◽

Chelonia Mydas ◽

Gulf Of Mannar ◽

Important Place ◽

Continuous Mixing ◽

Nesting Site ◽

Turtle Population ◽

Egg Diameter

A female green turtle was sighted at Pamban along the Gulf of Mannar just after the nesting on the beach on 15th January 2011. Morphometric measurements of the turtle were taken and data suggests that this individual is adult. A total number of laid eggs were 109. The distance between the nesting site and the high tide line was found to be 7 m. The depth and diameter of the nesting pit was 52 and 16 cm, whereas the mean egg diameter and weight were found to be 44.3 mm and 40.5 g respectively. Pamban coast may also be considered an important place for nesting, because of the continuous mixing of waters of GOM and Palk Bay areas, which in turn create current patterns continuously throughout the year in addition to the monsoon season. Conservation of nesting habitat along Gulf of Mannar will be important to maintain the green turtle population.

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Stochastic simulation modelling of southern Great Barrier Reef green turtle population dynamics

Ecological Modelling ◽

10.1016/s0304-3800(01)00433-1 ◽

2002 ◽

Vol 148 (1) ◽

pp. 79-109 ◽

Cited By ~ 83

Author(s):

Milani Chaloupka

Keyword(s):

Population Dynamics ◽

Great Barrier Reef ◽

Stochastic Simulation ◽

Green Turtle ◽

Simulation Modelling ◽

Barrier Reef ◽

Turtle Population

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Using Animal-Borne Imaging to Assess Green Turtle (Chelonia mydas) Foraging Ecology in Moreton Bay, Australia

Marine Technology Society Journal ◽

10.4031/002533207787441953 ◽

2007 ◽

Vol 41 (4) ◽

pp. 9-13 ◽

Cited By ~ 28

Author(s):

Karen E. Arthur ◽

Judith M. O'Neil ◽

Colin J. Limpus ◽

Kyler Abernathy ◽

Greg Marshall

Keyword(s):

Feeding Ecology ◽

Green Turtle ◽

Foraging Ecology ◽

Chelonia Mydas ◽

Lyngbya Majuscula ◽

Imaging Device ◽

Green Turtles ◽

Moreton Bay ◽

Turtle Population ◽

Insight Into

Traditional techniques for studying green turtle foraging ecology, such as the analysis of food availability and ingested dietary material, have concluded that green turtles are primarily herbivorous but selective foragers. However, green turtles that forage during Lyngbya majuscula blooms are exposed to toxins produced by the cyanobacterium overgrowing the seagrass. We used the Crittercam, an animal-borne imaging device, to observe green turtle foraging behavior in Moreton Bay, Australia, and to evaluate the system for assessing the impacts of Lyngbya blooms on green turtles. Eight large green turtles were captured while foraging on seagrass flats and each was fitted with a Crittercam. The deployments yielded over 28 hours of video and associated time-depth records. Turtles swam almost continuously and rarely stopped to feed on seagrass. Six turtles were observed feeding and all six consumed gelatinous animals from the water column. This prey source was previously undocumented in the Moreton Bay green turtle population but described in other green turtle populations using the Crittercam. Only one turtle was observed foraging on seagrass. The results of this study indicate that Crittercam technology can provide insight into turtle diet selection and that it will be a useful tool in identifying the impacts of Lyngbya blooms on green turtle feeding ecology. This study has also demonstrated that turtles in Moreton Bay may have a more flexible diet than previously described, indicating they could potentially supplement their diet with alternate prey items when seagrass quality or quantity is compromised. Longer deployment times, with an initial acclimation phase, are required to more fully understand questions pertaining to feeding ecology.

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The effect of on-shore light pollution on sea-turtle hatchlings commencing their off-shore swim

Wildlife Research ◽

10.1071/wr16143 ◽

2017 ◽

Vol 44 (2) ◽

pp. 127 ◽

Cited By ~ 7

Author(s):

Zoe Truscott ◽

David T. Booth ◽

Colin J. Limpus

Keyword(s):

Environmental Conditions ◽

Green Turtle ◽

Sea Turtle ◽

Swimming Behaviour ◽

Light Pollution ◽

The World ◽

Near Shore ◽

Turtle Population ◽

Nesting Beaches ◽

Nesting Season

Context Off-shore recruitment impairment of sea-turtle hatchlings because of light pollution is a growing concern to conservation of sea-turtle population throughout the world. Studies have focussed on sea-turtle hatchling sea-finding behaviour, and ignored the possible effect that on-shore lighting might have on hatchlings after they have entered the sea. Aims We experimentally evaluated the effect that on-shore light pollution has on the swimming behaviour of green turtle hatchlings once they have entered the sea and begun swimming off-shore. We also estimated the decrease in off-shore recruitment of hatchlings as a result of light pollution disruption of the off-shore swim. Methods Hatchling misorientation rates were quantified by releasing marked hatchlings to the sea from different land-based locations adjacent to light-polluted beach areas under a variety of environmental conditions. The beach in light-polluted regions was then searched for marked hatchlings returning to shore from the sea. Key results Misorientation rates were highest in trials conducted during moonless nights (66.7% of trials had some hatchlings return to shore) and lowest during trials conducted during moonlit nights (no trials had hatchlings return to shore). Green turtle hatchling off-shore recruitment for the entire 2014–15 nesting season at Heron Island was estimated to decrease 1.0 –2.4% as a result of on-shore lights disrupting hatchling off-shore swimming behaviour. Conclusions On moonless nights, sea-turtle hatchlings after having successfully completed their journey from nest to sea and entered the sea can be lured back to shore again by shore-based light pollution and, this will decrease their off-shore recruitment success. Implications To ensure maximum off-shore recruitment of sea-turtle hatchlings, on-shore light pollution adjacent to nesting beaches needs to be minimised so as to minimise misorientation and disorientation of hatchlings while on the beach and in near-shore waters.

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Climate change implications for the nest site selection process and subsequent hatching success of a green turtle population

Mitigation and Adaptation Strategies for Global Change ◽

10.1007/s11027-015-9668-6 ◽

2015 ◽

Vol 22 (1) ◽

pp. 121-135 ◽

Cited By ~ 4

Author(s):

Katherine Comer Santos ◽

Marielle Livesey ◽

Marianne Fish ◽

Armando Camargo Lorences

Keyword(s):

Climate Change ◽

Site Selection ◽

Green Turtle ◽

Nest Site ◽

Hatching Success ◽

Selection Process ◽

Nest Site Selection ◽

Turtle Population

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Genetic diversity of the Green Turtle (Testudines: Cheloniidae: Chelonia mydas (Linnaeus, 1758)) population nesting at Kosgoda Rookery, Sri Lanka

Journal of Threatened Taxa ◽

10.11609/jott.2797.9.6.10261-10268 ◽

2017 ◽

Vol 9 (6) ◽

pp. 10261

Author(s):

E. M.L. Ekanayake ◽

T. Kapurusinghe ◽

M. M. Saman ◽

D. S. Rathnakumara ◽

P. Samaraweera ◽

...

Keyword(s):

Genetic Diversity ◽

Sri Lanka ◽

Green Turtle ◽

Chelonia Mydas ◽

Sea Turtle ◽

High Genetic Diversity ◽

Tissue Samples ◽

Hardy Weinberg Equilibrium ◽

Turtle Population ◽

The Mean

We determined the genetic diversity of the Green Turtle Chelonia mydas (Linneaus, 1758) nesting at Kosgoda rookery, the second largest sea turtle aggregation on the southwestern coast of Sri Lanka. Skin tissue samples were collected from 68 nesting females and genetic diversity was estimated using six microsatellite loci. High genetic diversity was observed within the population as all loci analyzed were highly polymorphic with a total of 149 alleles observed. The mean number of alleles per locus was 24.7 and the mean observed and expected heterozygosity across all loci were 0.75 and 0.93, respectively. It appears that five out of six loci were not in Hardy-Weinberg equilibrium, while micro-checker analysis suggested that the Kosgoda Green Turtle population was possibly in equilibrium. The viability of a population is unlikely to be reduced if high genetic diversity is maintained within it. Although the Green Turtle population nesting at Kosgoda is small compared to other nesting rookeries in the world, the high genetic diversity observed suggests that the population may not be undergoing a bottleneck.

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