Assinatura bioacústica de costões rochosos: caracterização, modelagem e aplicações biotecnológicas

Abstract

The marine soundscape has been studied by several research institutions around the world. This soundscape is divided in three parts: biophony (sounds of biological origin, e.g. dolphins, fishes, shrimps, etc.), geophony (sounds of environmental origin, e.g. waves, wind, rain, etc.), and anthropophony (sounds of human origin, e.g., ships, platforms, etc.). Biophony is a part that includes complex sounds that take a very wide frequency range. In coastal areas, the sounds produced by benthic invertebrates might be quite representative. Thus, when many organisms are active in a given marine environment, the sounds merge into a timed signal, forming a bioacoustic chorus. However, each marine environment has its own acoustic signature, also important for local ecological processes. This signature might suffer a strong influence from abiotic factors throughout a day. In this sense, the modeling of this signature provides a more detailed view of the effects caused by the environment, making it possible to make a more detailed assessment of it. Thus, this study investigates the influence of abiotic factors on the bioacoustic signature of rocky shores off the Cabo Frio Island, Arraial do Cabo - RJ. This investigation starts from abiotic factors more representative in the study area, such as the upwelling phenomenon, to factors that drive marine life, as light, tide, and circadian cycles. Using the acoustic datasets and relating them to the available abiotic factors, a model was developed relating acoustics data to main abiotic factors, and it explained approximately 62% of the local bioacoustic signature variance. This model might have several applications, such as developing of environmental biotechnological techniques using bioacoustic approach to estimate benthic organisms population density as well as provide efficient monitoring of marine ecosystems. Key-words: Marine soundscape, passive acoustic monitoring, acoustic ecology, acoustic modelling, environmental biotechnology.