Understanding Gulf of Mexico soundscapes

Abstract

The contributors, defining baseline soundscapes in the Gulf of Mexico, are analyzed exploring the subtle changes in ambient noise due to the pandemic impact on the maritime and energy industry. The acoustic data were collected by five Environmental Acoustic Recording System buoys in the Mississippi Valley/Canyon region between May 2018 and June 2020, as a part of the long-term observational efforts. In April 2020, the 63-Hz and 125-Hz decidecade band levels were among the lowest in two years. On the contrary, noise levels in the 250-Hz and 500-Hz bands stayed high, probably indicating the presence of the fleet, transporting essential goods, and fishing industry. Marine mammal’s acoustic presence exhibits strong seasonal patterns (with the maximum band levels during the winter months) and was not impacted by the COVID-19 closures. To interpret the trends, shipping traffic density, vessel category metadata, marine mammal detections, and weather data are correlated with noise dynamics. April 2020, the first COVID-19 closure month, provided a rare opportunity to measure baseline levels in bands usually dominated by the energy industry activities. These levels are important for future monitoring efforts and understanding overall GoM noise environment on the Wenz curve scale. [Research funded by BOEM via HDR.]