A influência da antropofonia no coro bioacústico marinho da ilha do Cabo Frio

Abstract

Fish choir is an important contribution to the biophony of the marine environment. The soundscape of some habitats is dominated by biophony, which is particularly intense at certain times of the day due to the presence of this chorus. However, changes in the acoustic landscape, referring to anthropogenic activities, such as those arising from vessels, have been a matter of great concern. One of the main consequences of the change in the acoustic landscape is the masking of important communication signals between living beings, due to the overlapping of sounds. This work aims to understand the influence of anthropogenic offspring obtained by nautical tourism on the bioacoustic choir of the Cabo Frio Island region in Arraial do Cabo, RJ. The characterization of nautical traffic was carried out through the registration of vessels provided by the IEAPM and the acoustic data of the BIOCOM project. The central bands of 1/3 octave of 63 Hz, 125 Hz, 250 Hz, 500 Hz, 1000 Hz and 2000 Hz were used to characterize the acoustic landscape of the region, according to European Marine Strategy Framework (MSFD) for marine noise monitoring. The categories of analysis of Sound Pressure Level (SPL) for the assessment of anthropophony related to traffic were raised as categories: days with and without tours, months of high and low season, weekdays, weekends and holidays. Greater variability was observed in the frequencies of 250 Hz and 500 Hz in all categories of analysis and less variability in 2000 Hz. The times of greatest intensity of vessels were defined in the bands of 63Hz, 125 Hz, 250 Hz and 500Hz, showing times of highest peaks from 9 am to 3 pm. Greater SPL intensity was observed on weekends and holidays. The bioacoustic choir was recorded from zero to five o'clock in the day and in the evening, from 17 to 20 hours. Anthropogenic noise influences the onset time and duration of the choir at dusk, best observed at the frequency of 250 Hz and 500 Hz. The SPL of intense days of nautical traffic approached the limits recommended in MSFD. The acoustic monitoring presented in this work is a non-invasive method to study and contribute to the conservation of coastal marine biodiversity. The results of this study can be useful to raise awareness about the importance of sound in the marine environment and contribute to a management plan that considers passive acoustic monitoring as an important tool for assessing noise risks.