Long-term characterization of the marine soundscape in Kona, Hawaii

Abstract

Soundscape analysis of marine environments is still a new field of inquiry, with the majority of studies focusing on individual species or acoustic functional groups. Additionally, the challenges of making long term acoustic recordings in marine habitats, particularly in deep water, have limited the duration of many analyses. The Pacific Islands Fishery Science Center has been collecting passive acoustic data at a depth of 630 m off the Kona coast of the Island of Hawaii since 2007, and has recently begun a soundscape analysis effort to characterize the contributors to the local acoustic environment. This project seeks to examine not only low frequency noise patterns, below 1 kHz, but also higher frequency sounds that may overlap in frequency with the signals of many cetacean species. We have begun by identifying the relative contribution of odontocete echolocation, and also close approaches of boats and the presence of echosounders. The temporal patterns in these signals reveal daily and seasonal cycles in biological and anthropogenic sounds, which provide both detailed insight into the interactions between humans, animals and their environment, and long term trends in activity of those sound sources.Soundscape analysis of marine environments is still a new field of inquiry, with the majority of studies focusing on individual species or acoustic functional groups. Additionally, the challenges of making long term acoustic recordings in marine habitats, particularly in deep water, have limited the duration of many analyses. The Pacific Islands Fishery Science Center has been collecting passive acoustic data at a depth of 630 m off the Kona coast of the Island of Hawaii since 2007, and has recently begun a soundscape analysis effort to characterize the contributors to the local acoustic environment. This project seeks to examine not only low frequency noise patterns, below 1 kHz, but also higher frequency sounds that may overlap in frequency with the signals of many cetacean species. We have begun by identifying the relative contribution of odontocete echolocation, and also close approaches of boats and the presence of echosounders. The temporal patterns in these signals reveal daily and seasonal cycles ...