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Pacuare Reserve investigates the role of microorganisms in leatherback turtle embryonic development

Updated: May 17, 2023

A new research has started at Pacuare Reserve, entitled "Pathogens affecting embryonic development in leatherback turtle (Dermochelys coriacea) nests in the Pacuare Reserve, Limón, Costa Rica".


The study is part of the doctoral thesis of the Reserve's Research and Conservation Coordinator, Claudio Quesada, in Natural Sciences for Development (DOCINADE).


The research focuses on obtaining information about the microbiota in various environments, to find a relationship between cloacal microbiota, in the sand where the nest will be placed and in the eggs after exhumation with hatching success in leatherback turtles, in addition to performing metagenomic and virological analyses.

Blood sampling of a leatherback turtle. May 2023


Claudio’s research objective is to determine if there are viruses, bacteria, or fungi that could positively or negatively affect embryo development and, therefore, sea turtle hatching success.


These analyses seek to understand why the hatching success of leatherback sea turtles is lower than other sea turtle species, to take measures to mitigate the factors that affect hatching success and increase it through appropriate conservation strategies.


Another goal is to analyze whether the "mucus" produced during turtle nesting has antiseptic properties that can counteract the presence of other pathogens in the sand. To do this, samples will be collected from the turtles' cloaca and from the beach soil for laboratory analysis.

In the laboratory, we’ll work on a metagenomic analysis. This will help us understand which microbiota that are in these environments and see which of them could be negatively or positively affecting the sea turtle hatchlings. It could be that we find one type that could be helping attack some harmful fungus and that we need it in this microbiota. - that will be the first part of the project", explains Quesada.

In the second stage of the research, a blood test will be conducted on sea turtles at different times during the nesting season, from the first nest to their last, to describe the blood chemistry and look for possible changes that may influence embryonic development and hatching success.

First samples sent to the laboratory for analysis. April 2023


The research process will last 3 to 4 years. As the stages are completed, scientific publications will be made as part of the requirements of the PhD program, where the results obtained during this research will be shared.


All analyses will be carried out at the Veterinary Laboratory of the National University (Universidad Nacional).


The DOCINADE PhD program is offered by three public universities in Costa Rica: the Instituto Tecnológico de Costa Rica (Technological Institute of Costa Rica), the Universidad Nacional, and the Universidad Estatal a Distancia (State Distance University).



Another ongoing research


In addition to this study, other projects are underway at Pacuare Reserve to address different aspects related to wildlife conservation.


One of the ongoing investigations focuses on the impact of microplastics on sea turtles and their hatching success. Given the growing problem of plastic pollution in the oceans, research is being conducted on how microplastics may be affecting the reproduction and survival of sea turtles at Pacuare Reserve. This study seeks to understand the magnitude of the problem and will propose conservation measures to reduce the impact of microplastics on these vulnerable species.


Another ongoing study is the use of camera traps to study the big feline species present in the Reserve and analyze their potential prey. This information is crucial to understand the dynamics of top predators in the ecosystem and how they relate to their environment. The data collected will allow the implementation of conservation strategies focused on protecting both the felines and their prey and maintaining a healthy ecological balance at the Reserve.

Jaguar spotted by camera trap. March 2023


In addition, a research program has been established to monitor and study the primates present at the Reserve. Through primate ethology, we seek to understand the behavior, social interactions, and mobility patterns of these species.


Also, since 2004, the Pacuare Reserve has been collecting data on the nesting population and reproduction of a colony of Agami Heron (Agamia agami). Monitoring and conservation of this population is essential because it is the only known nesting site between southern Mexico and Colombia. The research seeks to understand the threats faced by the colony in order to propose measures to reduce their impacts.


Combined, all of this research not only contributes to scientific knowledge, but also provides valuable information to guide conservation actions in the field and ensure the preservation of the rich wildlife of the Pacuare Reserve.


For more information about our research and conservation programs click here.

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