Underwater Noise Emissions from Ships During 2014-2020

Abstract

This paper reports the input of underwater noise energy trend in global shipping, based on bottom-up modeling of individual ships. In terms of energy, we predict the doubling of global shipping noise emissions every six years, on average, but there are large regional differences. Shipping noise emissions increase rapidly in Arctic areas, the Norwegian Sea and Pacific Ocean. The largest contributors are the Containerships, Bulk Cargo and Tankers vessels which emit almost 80% of the underwater shipping noise energy. The COVID-19 pandemic changed vessel traffic patterns and our modeling indicates a reduction of 24% in shipping noise energy in the 63 Hz ⅓ octave band. This reduction was largest in the Arctic, Greenland Sea, and the Gulf of California, temporarily disrupting the increasing pre-pandemic noise trend. However, in some sea areas, such as the Yellow Sea and Eastern China Sea the emitted noise energy was only slightly reduced. In global scale, COVID-19 pandemic reduced the underwater shipping noise emissions close to 2017 levels, but it is expected that the increasing trend of underwater noise will continue when the global economy recovers.