I am a marine ecologist from Venezuela with expertise in tropical coastal ecology and biology.
My main interest lies in understanding how different environmental settings influence marine communities. Through extensive fieldwork, I have mapped benthic community structures of corals in Venezuela and Curaçao using orthomosaics and 3D models, and I have explored how the physiological traits of gobies relate to marginal ecosystems such as marine lakes. Currently, in my PhD project, I combine visual and molecular survey techniques to assess trajectories of marine communities in Raja Ampat, Indonesia, under high temperature and nutrients levels.
Keywords
Tropical reefs, marine ecology, photogrammetry, community structure, metabarcoding, bioindicators
Projectdescription
Tropical coral reefs are going through fundamental changes due to increase seawater temperature and nutrient load. Most studies have focused on the coral-to-algae dominated shift. However, in the Pacific region the shift towards other groups such as sponges, soft corals and cyanobacteria can also dominate the system. The mechanisms and conditions under which these groups will dominate are poorly understood. The overall aim of my project is to understand how community dominance shifts through a temperature and nutrient gradient and identify indicators that can signal early shifts in the benthic community and toward which dominated state will transition. Using the unique environments of marine lakes -islands of seawater- and reefs of Indonesia, we will look into different indicators of transitioning communities such as: microbes in water and sediment, benthic cyanobacterial mats, and foraminifera assemblages. This will be done using a multifaceted approach: orthomosaics, 3D models, sediment and water metabarcoding.
Reefs and marine lakes in Raja Ampat, Indonesia, are the main settings for our environmental gradients. Marine lakes are discrete marine communities replicated over space, under similar degrees of eutrophication while each lake differs in temperature. In contrast, coral reefs in Raja Ampat offer a natural nutrient gradient of healthy and high coral cover reefs, but with locations that are increasingly influenced by different levels of human activities (e.g., resorts, villages).
Keypublications
- Kornder N.A., Cappelletto J., Mueller B., Zalm M.J.L., Martinez S.J., Vermeij M.J.A., Huisman J., de Goeij J.M. 2021. Implications of 2D versus 3D surveys to measure the abundance and composition of benthic coral reef communities. Coral Reefs 40, 1137-1153. https://doi.org/10.1007/s00338-021-02118-6
- Martinez S.J., Cavada-Blanco F., Cappelletto J., Agudo-Adriani E., Croquer A. 2021. Distribution, abundance, and health indicators of the critically endangered coral species Acropora cervicornis in Los Roques National Park, 2014. Advances in Oceanography and Limmnology 12(2). https://doi.org/10.4081/aiol.2021.10005
- Cavada-Blanco F., Cappelletto J., Agudo-Adriani E., Martinez S.J., Rodriguez J.P., Croquer A. 2020. Status of the pillar coral Dendrogyra cylindrus in Los Roques National Part, Southern Caribbean. bioRvix. https://doi.org/10.1101/2020.09.15.297770
- Becking L., Martinez S.J., Aji L.P., Ahmad A., Alzate A., Folkers M., Lestari D.F., Subhan B., Hoeksema B.W. 2024. Stony corals and their associated fauna residing in marine lakes under extreme environmental conditions. Diversity 16(5), 295. https://doi.org/10.3390/d16050295
- All publications