What does protection sound like? A modern approach to understanding New Zealand’s underwater soundscapes and acoustic anthropogenic pressures

Abstract

Global marine ecosystems have experienced degradation and loss of biodiversity as a result of human impacts and climate change. Monitoring of ecologically significant areas is vital in understanding these effects and their subsequent management. Soundscapes offer a unique opportunity for examining organisms and habitats in a way that eliminate many potential weaknesses of traditional monitoring techniques. This fundamental property of every environment is being increasingly influenced by the presence of human activities but is not yet recognized for the breadth of information it holds, and as a key indicator of change in an ecosystem. A nation-wide program, focusing on several high-priority protection sites, utilize passive acoustic monitoring (PAM) creating baseline datasets. With the emphasis on characterizing the ambient soundscapes and acoustic signatures of significant species, identifying key acoustic parameters that reflect ecosystem health and biodiversity, and in locations where human use will potentially contribute to negative acoustic exposures. Here, spatiotemporal trends in the underwater soundscapes at sites within Fiordland National Park are reported, illustrating diel, lunar, and seasonal patterns in sound pressure levels, identifying biotic, abiotic, and anthropogenetic sound sources where possible. PAM is an increasingly useful tool in understanding anthropogenic presence and ecosystem status, and offers an effective, minimally invasive, and less labor-intensive way of monitoring marine ecosystems.