Browsing by Autor "Alberto Acosta"

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Conservation at the edge: connectivity and opportunities from non-protected coral reefs close to a national park in the Colombian Caribbean
(Research Square (United States), 2022) Laura Rodríguez; Alberto Acosta; Fanny L. González-Zapata; Matías Gómez‐Corrales; Milena Marrugo; Elvira Alvarado-Chacon; Luisa F. Dueñas; Julio Andrade; Lina Gutierrez-Cala; Juan A. Sánchez
Abstract Confronting a sustained coral reef conservation crisis, we need new opportunities to rethink how to protect areas successfully and efficiently in the face of a changing world. We studied the benthic community, including foraminifera, fish community, and genetic connectivity (SSRs and SNPs) of main reef-building coral, Orbicella faveolata and Agaricia undata coral, along a Non-Protected Area (NPA) reef tract in Barú peninsula, including some isolated banks, near Cartagena and the National Natural Park Corales del Rosario y San Bernando (NNP CRySB), Colombia. The fringing reef track studied is homogeneous in benthic components, including algae, corals, sponges, and foraminifera between all the sites studied. Many reef sites sustain between 42.8% and 53% coral cover, which are among the highest recorded in this region, even higher than values in the nearby NNP. A total of 82 fish species were found, and the Foram Index-FI varies between 2 and 2.5, showing environmental conditions marginal for reef growth. The Barú NPA reef system can be considered spatial refugia under climate change and Anthropocene conditions, including resilient reefs at the mouth of Cartagena Bay (Magdalena River), a place of increased stressing factors. The admixture between NPA and NNP populations, the high coral cover in the NPA, the fish density and composition, the uniqueness of the diapiric banks, and the disturbance resistance are major arguments to protect this reef tract. We suggest designing a co-management scheme to ensure species connectivity, avoid further degradation, and involve different stakeholders.
The footprint of endolithic algae in shaping the skeletal structure of massive coral skeletons: insights into micro and macro-porosity
(2024) Edwin S. Uribe; Amalia Murgueitio; Carlos E. Gómez; Alberto Acosta; Juan A. Sánchez
<title>Abstract</title> Coral skeletons provide habitat for a euendolithic community, forming a green band within the skeleton, where <italic>Ostreobium</italic> spp. is the dominant group. Euendoliths, actively penetrate live coral skeletons, but how they use and modify skeletal structure is not properly understood. This study explores the microstructural characteristics of skeletal microenvironments through a micro-CT technique that analyzes the "footprint" of the euendolithic community on the porosity of coral skeleton. We compared three <italic>Porites</italic> species based on the percentage of the relative volume of microporosity, macroporosity, total porosity, and solid volume fraction of CaCO<sub>3</sub> among three distinct zones within the coral colony: coral tissue, the green band (characterized by eundolithic community) and the bare skeletal region. We found a significant increase in microporosity within the green band, while the opposite occurs for macroporosity that decreased within this zone, for all analyzed species. We describe a model to explain the porosity gradient along the vertical axis for <italic>Porites</italic> coral colonies, and suggests that within the “green band” microenvironment, the metabolic activity of the community is the responsible for this pattern. Our findings provide insights on the ecological relationship with the coral holobiont: macroerosion mitigation and microporosity filling.