O uso de índices ecoacústicos para o monitoramento de ecossistemas marinhos

Abstract

Monitoring of coastal marine ecosystems faces significant challenges due to their environmental, biological, and ecological complexity. Despite being an emerging field, acoustic ecology offers promising solutions to improve the effectiveness of these environmental monitoring efforts. The study of the underwater soundscape, combined with the application of ecoacoustic indices, stands out as a tool capable of monitoring vast stretches for long periods, even under adverse conditions and at relatively lower costs. Acoustic indices, which are quantitative metrics used to characterize and analyze sound patterns in a specific soundscape, have a variety of applications. They can be used to assess acoustic complexity and species diversity in a soundscape, allowing inferences about the biological diversity and environmental quality of a particular ecosystem. This study aims to investigate relevant experiences related to the application of acoustic indices in marine ecosystems, identifying challenges and limitations, and proposing advances. A need highlighted by the literature review is to test the application of these indices in a wide range of environmental conditions. Thus, four acoustic indices were evaluated under different conditions of light, water temperature, wind intensity and direction, as well as the number of vessels in the acoustic landscape near the island of Cabo Frio, in Arraial do Cabo (RJ). It is important to emphasize that a deep understanding of how environmental variables impact the interpretation of acoustic indices is a prerequisite for the development of an efficient monitoring system, capable of distinguishing common events from atypical situations. In addition, to overcome another limitation pointed out in the literature review on the difficulty of comparing index values between different studies, this study begins the discussion on the creation of a new index based on the relationship between biophony, geophony, and technophony. Finally, an interactive dashboard is proposed, integrating acoustic indices and environmental variables, generating a marine biotechnological product with great potential as a tool for monitoring marine ecosystems.