Predation on turtle nests in the southwestern coast of the Baja California Peninsula

Threats and Vulnerabilities for the Globally Distributed Olive Ridley (Lepidochelys olivacea) Sea Turtle: A Historical and Current Status Evaluation

The olive ridley (Lepidochelys olivacea) is the most abundant of all seven sea turtles, found across the tropical regions of the Atlantic, Pacific, and Indian Oceans in over 80 different countries all around the globe. Despite being the most common and widely distributed sea turtle, olive ridley populations have been declining substantially for decades. Worldwide, olive ridleys have experienced a 30–50% decline, putting their populations at risk and being considered an Endangered Species by the IUCN. Natural habitat degradation, pollution, bycatch, climate change, predation by humans and animals, infectious diseases and illegal trade are the most notorious threats to explain olive ridley populations rapidly decline. The present review assesses the numerous dangers that the olive ridley turtle has historically faced and currently faces. To preserve olive ridleys, stronger conservation initiatives and strategies must continue to be undertaken. Policies and law enforcement for the protection of natural environments and reduction in the effects of climate change should be implemented worldwide to protect this turtle species.

Evaluation of nest management phases for Lepidochelys olivacea at two beaches in Northwest Mexico

The olive ridley turtle, Lepidochelys olivacea, is a vulnerable and endangered species according to the IUCN and Mexican Official Standard NOM-059, respectively. On most solitary nesting beaches of olive ridley turtles, the eggs are removed from the in situ nest to hatcheries due to the high incidence of predation, human poaching, and beach erosion; therefore, it is necessary to collect and analyze information on the protection activities conducted for this species from egg laying to hatchling release. In general, protection activities during nest management can be divided into 5 phases: nest logging (F1), egg collection (F2), egg transfer (F3), egg incubation and hatching (F4), and hatchling release (F5). This work was carried out on two Pacific beaches in northwestern Mexico, Ceuta Beach Sanctuary (CBS) during 2013-2019 and Caimanero Beach (CB) during the 2013-2018 nesting seasons, with the objective of quantitatively evaluating the management phases of the protection program for olive ridley turtles by assessing the nest, egg, and hatchling losses in each of the phases using the model of Godínez-Domínguez et al. (1991). The results of the statistical analyses indicate that the greatest losses occurred during the incubation phase (F4) at both beaches, with a 41.99% loss at CBS and a 33.09% loss at CB, followed by the F2 (with 15.56 and 27.27% losses, respectively) and F1 (21.28 and 25.56% losses, respectively) phases. Significant differences between the beaches were observed in F4, F5 and F3, with greater losses at CBS than at CB, indicating that the success of the management phases may vary among beaches. The results obtained show that it is necessary to focus on strategies for improving the success of mainly phase F4 and phases F1 and F2 at both beaches.