TUTORIAL 1 INTRO: Underwater Noise Maps – a demonstration of the HARMONI-SN webtool and tutorial of practical acoustic measurements
Over the past decades, Underwater radiated noise (URN) from vessels has been identified as a significant threat to the health of marine ecosystems due to the adverse behavioural and physical effects it entails on marine fauna, especially marine mammals. In this regard, the ability to assess and present the spatiotemporal distribution of URN to stakeholders and decision makers acts as a crucial enabler for the promotion of environmental protection-driven policy initiatives, regulation, and long-term scientific assessment. The Hydro-Acoustic Real-time Monitoring Initiative of Shipping Noise (HARMONI-SN) is a freely accessible interactive web tool that displays the distribution of vessels and estimated URN emissions on a Geographic Information System (GIS). For the display of vessel data, HARMONI-SN integrates static and dynamic vessel data from the Automatic Identification System (AIS). For the estimation of underwater noise emission source levels for each vessel, a supervised machine learning Support Vector Machines (SVM) algorithm is used. To describe the spatial distribution of URN emissions as they propagate through the water column, a Gaussian beam ray-tracing propagation model is used. The propagation model accounts for the environmental conditions (i.e., sound speed profile and bathymetry) at each geographical location. HARMONI-SN has the potential to act as a powerful tool for stakeholders and decision makers to assess where and when URN emissions may adversely affect marine ecosystems and act as a basis for policy initiatives and regulation.