| Summary: | The sea is being continuously impacted by anthropogenic noise (anthropophony), largely harmful for marine biota. The field of soundscape is promising for long term environmental monitoring given its viability and low invasiveness. However, a robust methodology for the interpretation of soundscape data is still needed, especially for aquatic environments. Hence, the objective of the present work was to analyze how different acoustic indices and other descriptive acoustic metrics react to two levels of anthropophony in a marine environment. Data were collected in Abrolhos/BR in two areas: Control (low vessel traffic) and Treatment (high vessel traffic). For each area, we calculated PSD, nine acoustic (ACI, BGN, SNR, ACT, 1-H[t], 1-H[s], NDSI, EVN and SPD) indices and two visualization tools: Long-Duration FalseColours and ribbonplots. The two areas presented a different pattern in the PSD at frequencies below 600Hz, with Treatment presenting higher sound levels; such frequency range is characteristic of boat noise. Some indices were not able to differentiate the areas (SNR and ACT) while others were (p <.05), having more probable higher values in the Control (1-H [t], NDSI, 1-H [s]) or Treatment area (ACI, SPD, ACT, BGN). These results indicate that NDSI was able to distinguish anthropophony from zoophony, being useful as a measure of anthropic disturbance in a soundscape, whereas 1-H [t] and 1-H [s] acted as measures of acoustic dominance. ACI was influenced by the vocalization of a single species and should be used with caution as a measure of diversity. The result obtained in the LDFC and ribbonplots revealed complex sounds of diel patterns. Such patterns are derived from humpback whale singing activity, which uses the area as a breeding ground. The present work contributes to the methodological improvement of a soundscape approach in monitoring marine environments. O mar vem sendo continuamente impactado por ruídos antropogênicos (antropofonia), amplamente prejudiciais à biota marinha. O campo da paisagem ...
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