Integrating video and acoustic non-invasive techniques to monitor coastal fish communities: A literature review with implications for MPA management

Abstract The ocean plays a crucial role in regulating climate, supporting biodiversity, and providing resources to coastal communities. However, human activities such as overfishing, pollution, and climate change are increasingly threatening marine ecosystems. Marine Protected Areas (MPAs) are essential for conservation, but their effectiveness depends on continuous, adaptive monitoring to track both ecological and behavioural changes in marine life. This review examines how different non-invasive monitoring techniques, and their combination, including Underwater Visual Census (UVC), Baited Remote Underwater Video Systems (BRUVS), and Passive Acoustic Monitoring (PAM) offer opportunities to survey fish community distribution and phenology. Sound is highlighted as a fundamental component of marine ecosystems, shaping species communication, habitat selection, and behavioural dynamics. Here, we discuss the comparison of ecological and ecoacoustic indices, such as acoustic complexity, richness, and evenness, to improve our understanding of acoustic behavioural patterns in fishes, with direct relevance for monitoring marine ecosystems. We further discuss how monitoring strategies can be refined to capture not only species presence and abundance, but also behaviour, ecosystem function, and the impacts of human activities, supporting more effective and adaptive MPA management.