Wadmilton Manuel da Trindade Fernandes
Elasmobranchs (sharks and rays) are among the most endangered vertebrate groups, with over 33% of species threatened with extinction due to overexploitation and habitat degradation (Dulvy et al., 2021). Their biological traits, such as slow growth and late maturity, make them particularly vulnerable to population declines (Bräutigam et al., 2015). However, monitoring these elusive species remains challenging, often expensive, and may involve methods that are invasive or harmful, ultimately hindering conservation efforts.
DNA extraction conducted at the CIBIO Research Center for Biodiversity and Genetic Resources © Sofia Manuel
Environmental DNA (eDNA) metabarcoding is emerging as a powerful solution, allowing the detection of species through traces of genetic material left in the environment (Bakker et al., 2017). This method is non-invasive, cost-effective, and increases detection of rare, cryptic, or mobile species while reducing identification errors (West et al., 2024). Studies have demonstrated its value in tropical environments, especially for elasmobranch detection (Boussarie et al., 2018; Mariani et al., 2021; de la Hoz Schilling et al., 2024). Still, effective management of these species requires regionally grounded data on their distribution and diversity.
São Tomé and Príncipe (STP), located in the Gulf of Guinea, is part of a recognized marine biodiversity hotspot and a global conservation priority (Roberts, 2002). Due to its long isolation from mainland Africa, the archipelago hosts high levels of endemism across many taxonomic groups. While terrestrial ecosystems have received increasing attention and nearly 30% of land area is under protection, marine ecosystems remain poorly studied. Local ecological knowledge and the scarcity of BRUVS observations suggest population declines (Pissarra et al., 2024; Porriños et al., 2024). Amidst declining fisheries and growing conservation concern, the country is preparing to implement its first network of marine protected areas (MPAs).
This project aims to use eDNA-based methods to: (1) establish a baseline of elasmobranch diversity in STP; (2) identify potential elasmobranch hotspots; and (3) compare these zones with the proposed MPA network to support evidence-based marine conservation. Additionally, we will explore the use of teleo primers to generate complementary data on teleost fish diversity. To strengthen community involvement, we will conduct educational sessions in coastal schools to raise awareness about the ecological importance of sharks and rays and promote their conservation.