Igor Vraux

Investigating connectivity between coral reefs of Aruba, Bonaire and Curacao

This thesis focuses on understanding the connectivity patterns of coral larvae in the area around Aruba, Bonaire and Curacao and their implications for population dynamics and conservation efforts. The study aims to analyze the spatio-temporal variability of larval dispersal and identify key factors influencing larval connectivity among different reef systems. Connectivity is studied by simulating currents with the 2D version of the Second generation Louvain-la-Neuve Ice-Ocean Model SLIM coupled with a Lagrangian Particle Tracker (LPT). Using a combination of field observations, numerical modeling, and graph theory analysis, we investigated the larval dispersal patterns of four coral species during their respective spawning seasons, the behavior of another species during 6 different months and the connectivity of a fictional species with low mortality rate and no competency loss. The results revealed distinct species-specific differences in larval connectivity, with some species exhibiting higher levels of connectivity within a short distance from their spawning sites, while others displayed broader dispersal capabilities. We also highlighted a strong seasonal variability in the area. Inter-island connectivity have been found for the fictional species and intra-island pattern have been focused on. Furthermore, using other tools from graph theory, the analysis of connectivity matrices and computation of connectivity indicators helped identifying zones of high interest for protection and restoration measures. The research outcomes contribute to the understanding of larval connectivity dynamics in the South-Eastern Caribbean Sea and provide insights for coral reef management and conservation. The results highlight the need for targeted conservation efforts to protect critical larval dispersal pathways and promote genetic exchange among reef systems.



Data type
Research report
Research and monitoring
Geographic location