Changes in reef fish assemblage and coral reef community in a newly established Marine Protected Area

Coral reef ecosystems are vital to sustaining marine biodiversity and provide invaluable resources to coastal communities. However, coral reefs across the globe are exposed to harmful local and global anthropogenic pressures that can lead to the mortality of key reef-building corals, consequently disrupting ecosystem functioning. Preserving biodiversity of coral reef systems continues to be a challenging topic in conservation. Marine Protected Areas (MPAs) are a globally recognised spatial management tool, designed to protect marine species and habitats from anthropogenic induced stressors. Here, using a long-term dataset collected over the last ten years from the unique coral reef system of Banco Capiro in the Mesoamerican Reef region of Honduras, the changes of reef fish assemblage and coral reef community in a newly established MPA were investigated. Spatiotemporal data on fish populations and reef health were collected using Stereo-Video System surveys and Line-Point-Intercept transect benthic surveys. While the MPA designation led to an increase in reef fish abundance, no other significant positive effects on fish assemblage and coral reef community were detected. In addition, there were rapid and detectable changes in functional groups attributed to the immediate impacts of the 2023-2024 El Niño event. The findings from this research highlights how MPAs may not protect against some anthropogenic impacts, such as marine heatwaves, but they are vital tools to encourage recovery and resilience after ecological disturbance.