Underwater soundscapes investigation in industrial-port areas using passive acoustic monitoring and modelling: a case study in Canada

Abstract

Port areas regroup a number of activities that contribute to the increase of anthropic noise in the general underwater soundscape of an environment. In a context of global climate change and increased shipping activities, ports need to better understand their soundscape to ensure mitigation of impacts from anthropic sound emission in their jurisdiction. As underwater noise can pose multiple threats to marine mammals, fish and invertebrates in an ecosystem, such as behavioural changes and injuries, a series of studies have been initiated to understand in-situ underwater noise and its effects in the Sept-Îles and Saguenay River port zones, two major industrial port areas in Canada. An underwater noise data collection campaign and a marine mammal inventory were conducted between 2020 and 2023. Overall, a higher species diversity was found in the Sept-Îles Bay area, where eleven marine mammal species were detected in contrast to four in the Saguenay River. Sound levels were found to be higher in winter in all studied areas, with the noisiest station being in Baie Sainte-Catherine. Exposure was modeled for the two regions in summer and winter for the current vessel navigation and various scenarios such as a projected increase in vessel navigation or the removal of bulker navigation. These results are critical to increase the understanding of the effects of underwater noise in port areas, and they support the production of reliable management plans to promote sustainable anthropogenic development and adaptation of maritime operations in regards to climate change.