Use of Underwater Acoustics in Marine Conservation and Policy: Previous Advances, Current Status, and Future Needs

Abstract

The interdisciplinary field of assessing the impacts of sound on marine life has benefited largely from the advancement of underwater acoustics that occurred after World War II. Acoustic parameters widely used in underwater acoustics were redefined to quantify sound levels relevant to animal audiometric variables, both at the source and receiver. The fundamental approach for assessing the impacts of sound uses a source-pathway-receiver model based on the one-way sonar equation, and most numerical sound propagation models can be used to predict received levels at marine animals that are potentially exposed. However, significant information gaps still exist in terms of sound source characterization and propagation that are strongly coupled with the type and layering of the underlying substrate(s). Additional challenges include the lack of easy-to-use propagation models and animal-specific statistical detection models, as well as a lack of adequate training of regulatory entities in underwater acoustics.

Development of Sound-Fish Aggregating Devices (S-FAD) Applied at Lift Net

“…Guan et al [8] stated that there was three group types of animals that produced sound with different characteristics, including (1) crustacea, especially shrimp, (2) teleost with swimming bubbles, and (3) aquatic mammals such as whales and dolphins. Fish (a) group of vertebrates can produce sound through their swimming bubbles.…”

The Use of Psychoacoustics in Marine Mammal Conservation in the United States: From Science to Management and Policy

“…However, such a simple approach for estimating injury zones may not always be accurate. First, the simplified spreadsheet approach only uses geometrical spreading for sound propagation [7], and under certain circumstances (e.g., a moving source), only spherical spreading is incorporated [103]. Second, the estimation of SEL cum for transient sounds does not consider potential recovery between exposuresbut neither does sophisticated modeling.…”

“…Despite the availability of tools to assess the impacts of sound on marine mammals, the regulatory community has yet to incorporate the latest scientific information or use the tools (e.g., animats) and models (e.g., sound propagation models) in-house for its impact assessments [7]. This has prevented regulatory agencies from determining more realistic estimates when calculating harassment takes.…”

“…The former two aspects lie within the field of underwater acoustics, while the latter is addressed in animal bioand psychoacoustics. An overview of the application of underwater acoustics in marine conservation, which focuses on knowledge gained regarding anthropogenic sound sources and sound propagation relevant to impact assessments is discussed in a companion review paper [7]. Here, we provide a review of the application of psychoacoustics in marine mammal impact assessments that support management and policy in the United States.…”

“…The Navy used many of the same criteria in its EISs for previous shock trials and for training and testing activities analyzed under the Tactical Training Theater Assessment and Planning (TAP I) documents 6. Along with Type I weighting functions 7. For more than two decades, the Navy also has used a metric it has termed "single ping equivalent" (SPE) to estimate behavioral responses of marine mammals to Surveillance Towed Array Sensor System Low Frequency Active (SURTASS LFA) sonar.…”