Underwater noise levels in Indian waters off the coast of Mormugao Port

摘要

Among various factors influencing the ocean noise levels, shipping traffic radiated underwater noise levels were identified as the major contributors. The increase in ambient noise levels due to natural and anthropogenic sources threatens the marine species communication. India has a coastline of 7,516.6 Km with 12 major and similar to 187 minor ports. The hydrophone system measured for 39 days helped in investigating the distant shipping traffic lane noise levels and its influence on ambient noise levels of the region. The ocean noise levels measurement were similar to 115 dB re 1 mu Pa for the prevailing environmental conditions. The noise exposure levels were similar to 10 dB higher at 1 kHz. The maximum and minimum range of shipping noise spectra for both the month's data indicated peak sound pressure level in the lower frequency. Thus, the outcome of the measurements helped in understanding ocean noise levels off the coast of Mormugao Port and the influence of shipping traffic. A similar study for longer duration shall be useful to develop specific traffic lanes in the port entrance which is free from the mammal movements.