Harbor sound level estimation for assessment of underwater ship noise

It is well known that rising anthropogenic underwater noise has chronic impacts on marine fauna. Since the contribution of navigation is particularly important to this kind of noise, areas near big harbors can be critically affected. One case of great environmental concern is the Port of Santos, the largest harbor in Latin America that, additionally, is expected to be expanded. The port is located on the brazilian southeast coast, a region with rich marine biodiversity including marine mammals, close to two marine conservation areas. Although evaluating impacts of ship noise in the area is a true concern, there is little information available on the topic nowadays. In this context, the present work aims to assess the magnitude of ship noise in a delimited geographical area around Santos harbor. For this purpose, Sound Pressure Level (SPL), Sound Exposure Level (SEL), and Power Spectral Density (PSD) were calculated. The SPL and SEL were similar to levels reported from other studied regions, reaching values that could interfere with some marine species. Results show that vessels noise is a major contributor to the ambient noise in the area assessed.