Marine Seismic Surveys and the Environment: An updated critical review of the potential impacts of marine seismic surveys on fish and invertebrates

Marine seismic surveys are a fundamental tool for geological mapping, including the exploration for offshore oil and gas resources, but the sound generated during these surveys is an acute source of noise in the marine environment. Growing concern and increasing scientific evidence about the potential impacts of underwater noise associated with marine seismic surveys presents an interdisciplinary challenge to multiple sectors including government, industries, scientists and environmental managers. To inform this issue, Geoscience Australia, in collaboration with Curtin University and CSIRO, published a literature review (Carroll et al. 2017) that summarised 70 peer-reviewed scientific studies that investigated the impacts of impulsive low-frequency sound on marine fish and invertebrates. Here we provide an updated, critical synthesis of recently published data to ensure that the Australian governments’ understanding of the potential impacts of seismic surveys on fisheries and the broader marine environment remains current. A significant body of scientific research into the effects of marine seismic sounds on the marine environment has been undertaken over the past four years and scientific knowledge in this area is continuing to improve. This is partly due to increased sophistication of experimental designs that integrate the controlled aspects of laboratory studies, with field-based (before-after-control-impact) studies. However, there remain several research issues and challenges associated with progressing our understanding of the full impact of marine seismic surveys on fisheries and the marine environment. These include the need to broaden the research to cover a wider range of marine species, and to expand our understanding to impacts at the population and ecosystem scale, rather than the individual organism. There is also a continued need for improved standardisation in terminology and measurement of sound exposure. To address the research gaps and issues, Geoscience Australia recommends measures including: 1) undertaking additional multidisciplinary co-designed scientific research to examine short and long term impacts on important life stages of key species (including protected and commercially important species); 2) gathering robust environmental baselines and time-series data to account for spatiotemporal variability in the marine environment and to help inform management and monitoring; 3) continuing to develop and refine standards for quantifying sound exposure; 4) modelling population and ecosystem consequences, and; 5) further studying the interaction of seismic signals with other stressors to better assess cumulative impacts. If applied these recommendations may advance the scientific evidence-base to better inform stakeholder engagement, environmental impact assessment and management of the potential impacts of seismic surveys on fisheries and the marine environment.