Underwater noise pollution has become a major concern in marine habitats. Guanabara Bay, southeastern
Brazil, is an impacted area of economic importance with constant vessel traffic. One hundred acoustic
recording sessions took place over ten locations. Sound sources operating within 1 km radius of each
location were quantified during recordings. The highest mean sound pressure level near the surface
was 111.56 ± 9.0 dB re 1 lPa at the frequency band of 187 Hz. Above 15 kHz, the highest mean sound
pressure level was 76.21 ± 8.3 dB re 1 lPa at the frequency 15.89 kHz. Noise levels correlated with num
ber of operating vessels and vessel traffic composition influenced noise profiles. Shipping locations had
the highest noise levels, while small vessels locations had the lowest noise levels. Guanabara Bay showed
noise pollution similar to that of other impacted coastal regions, which is related to shipping and vessel
traffic