Olive Ridley Turtles Lepidochelys Olivacea Research Articles

First Documented Record of Nesting by the Olive Ridley Turtle (Lepidochelys olivacea) in Ecuador

ABSTRACT We report on the first confirmed occurrence of Lepidochelys olivacea nesting in Ecuador based on the presence of eggshells and the identification of a late-stage embryo at a beach located in Manta (lat 0.94°S, long 80.7°W), Manabi Province, Ecuador, in October 2004. This is the second-most-southerly record of olive ridley nesting on the Pacific coast of South America.

Energetics during Hatchling Dispersal of the Olive Ridley TurtleLepidochelys olivaceaUsing Doubly Labeled Water

Studies of metabolism are central to the understanding of the ecology, behavior, and evolution of reptiles. This study focuses on one phase of the sea turtle life cycle, hatchling dispersal, and gives insight into energetic constraints that dispersal imposes on hatchlings. Hatchling dispersal is an energetically expensive phase in the life cycle of the olive ridley turtle Lepidochelys olivacea. Field metabolic rates (FMRs), determined using the doubly labeled water (DLW) method, for L. olivacea hatchlings digging out of their nest chamber, crawling at the sand surface, and swimming were five, four, and seven times, respectively, the resting metabolic rate (RMR). The cost of swimming was 1.5 and 1.8 times the cost of the digging and crawling phases, respectively, and we estimated that if L. olivacea hatchlings swim at frenzy levels, they can rely on yolk reserves to supply energy for only 3-6 d once they reach the ocean. We compared our RMR and FMR values by establishing an interspecific RMR mass-scaling relationship for a wide range of species in the order Testudines and found a scaling exponent of 1.06. This study demonstrates the feasibility of using the DLW method to estimate energetic costs of free-living sea turtle hatchlings and emphasizes the need for metabolic studies in various life-history stages.

The distribution and conservation status of marine turtles in The Gambia, West Africa: a first assessment

This paper reports the first systematic survey of the marine turtles of the 80 km of Gambian coastline, and brings together new data and all past records and reports of marine turtles in The Gambia. Green turtles Chelonia mydas are the most abundant turtles and this is the only species so far observed nesting in The Gambia, with peak nesting between August and October. Although 75% (60 km) of The Gambian coastline appears to be suitable for turtle nesting, most nesting activity is confined to the southern coastline. Offshore foraging habitat is apparently extensive. Strandings of green turtles, olive ridley turtles Lepidochelys olivacea, leatherback turtles Dermochelys coriacea and hawksbill turtles Eretmochelys imbricata have been recorded, but we were unable to find evidence for loggerhead turtles Caretta caretta. Threats are mainly of human origin, and include illegal harvesting of eggs, juveniles and adults, as well as mortality as fisheries bycatch, including trawling. One stranded green turtle apparently had fibropapilloma disease. The major threat to nesting habitats is erosion and unregulated development of the coast for tourism. Marine turtles are fully protected under Gambian law. Other national efforts to conserve turtles in The Gambia are described and assessed.

Pathology of Fibropapillomatosis in Olive Ridley TurtlesLepidochelys olivaceaNesting in Costa Rica

Fibropapillomatosis (FP) is a neoplastic disease that primarily affects green turtles Chelonia mydas in epidemic proportions worldwide. Although several infectious agents (herpesvirus, retrovirus, and papillomavirus) have been associated with the condition, the etiologic agent has not been isolated or characterized. Recently, FP has been reported in other sea turtle species including confirmed cases in loggerhead turtles Caretta caretta in Florida and field observations in olive ridley turtles Lepidochelys olivacea in the Pacific coasts of Mexico and Costa Rica. Skin and tumor specimens were collected from 72 olive ridley turtles nesting in Ostional Wildlife Refuge, Costa Rica, between July and September 1997. In all, 50 tumor biopsies were examined from 25 of the affected turtles. In addition, six biopsies were examined from five turtles that did not have visible masses and served as controls. Grossly, masses were 25 mm or less in diameter, white to gray, smooth to verruciform, raised tumors of the integument of the neck and flippers. Histologically, 42 of 50 were diagnosed as fibropapillomas and eight were classified as chronic active dermatitis and not tumors. Twenty of 42 fibropapillomas were in stages of regression and 9 of the remaining 22 tumors had histological changes that suggested early degeneration within the tumor. During field surveys based on gross lesions, prevalences of 1–10% have been reported in this nesting population. This is considered the first histopathologic confirmation of FP in olive ridley turtles.

Mortality of olive ridley turtles Lepidochelys olivacea due to incidental capture in fishing nets along the Orissa coast, India

The coastal state of Orissa, India, harbours three important mass-nesting beaches of the olive ridley sea turtle Lepidochelys olivacea. During a survey of sea turtle nesting beaches from December 1993 to May 1994, 5282 dead olive ridleys were counted along the 480 km coastline of Orissa. Almost all the deaths were due to incidental capture in offshore fishing nets. Increased fishing activities in the coastal waters near important sea-turtle nesting beaches pose a serious threat to the survival of this endangered sea turtle. It is therefore suggested that coastal waters adjacent to major sea-turtle nesting beaches be declared as closed areas for commercial fishing activities in order to ensure the sea turtle's long-term survival.

First record of the Olive Ridley Turtle, Lepidochelys olivacea, in Iranian coastal waters (Testudines, Cheloniidae)

Three specimens of the Olive Ridley Turtle (Lepidochelys olivacea) were collected in Guader (Gwatar) Bay in the Sea of Oman on 6 January, 1997. Two of them have been preserved for the Zoological Museum of Gorgan University. This is the first report of the Olive Ridley Turtle in Iranian coastal waters.