Radford Craig A.

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Craig A.

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  • Article
    Auditory sensitivity in aquatic animals
    (Acoustical Society of America, 2016-06-08) Lucke, Klaus ; Popper, Arthur N. ; Hawkins, Anthony D. ; Akamatsu, Tomonari ; Andre, Michel ; Branstetter, Brian K. ; Lammers, Marc O. ; Radford, Craig A. ; Stansbury, Amanda L. ; Mooney, T. Aran
    A critical concern with respect to marine animal acoustics is the issue of hearing “sensitivity,” as it is widely used as a criterion for the onset of noise-induced effects. Important aspects of research on sensitivity to sound by marine animals include: uncertainties regarding how well these species detect and respond to different sounds; the masking effects of man-made sounds on the detection of biologically important sounds; the question how internal state, motivation, context, and previous experience affect their behavioral responses; and the long-term and cumulative effects of sound exposure. If we are to better understand the sensitivity of marine animals to sound we must concentrate research on these questions. In order to assess population level and ecological community impacts new approaches can possibly be adopted from other disciplines and applied to marine fauna.
  • Article
    Listening forward: approaching marine biodiversity assessments using acoustic methods
    (The Royal Society, 2020-08-26) Mooney, T. Aran ; Di Iorio, Lucia ; Lammers, Marc O. ; Lin, Tzu-Hao ; Nedelec, Sophie L. ; Parsons, Miles J. G. ; Radford, Craig A. ; Urban, Edward ; Stanley, Jenni A.
    Ecosystems and the communities they support are changing at alarmingly rapid rates. Tracking species diversity is vital to managing these stressed habitats. Yet, quantifying and monitoring biodiversity is often challenging, especially in ocean habitats. Given that many animals make sounds, these cues travel efficiently under water, and emerging technologies are increasingly cost-effective, passive acoustics (a long-standing ocean observation method) is now a potential means of quantifying and monitoring marine biodiversity. Properly applying acoustics for biodiversity assessments is vital. Our goal here is to provide a timely consideration of emerging methods using passive acoustics to measure marine biodiversity. We provide a summary of the brief history of using passive acoustics to assess marine biodiversity and community structure, a critical assessment of the challenges faced, and outline recommended practices and considerations for acoustic biodiversity measurements. We focused on temperate and tropical seas, where much of the acoustic biodiversity work has been conducted. Overall, we suggest a cautious approach to applying current acoustic indices to assess marine biodiversity. Key needs are preliminary data and sampling sufficiently to capture the patterns and variability of a habitat. Yet with new analytical tools including source separation and supervised machine learning, there is substantial promise in marine acoustic diversity assessment methods.
  • Article
    Potential role of the anterior lateral line in sound localization in toadfish (Opsanus tau)
    (Company of Biologists, 2018-11-26) Cardinal, Emily A. ; Radford, Craig A. ; Mensinger, Allen F.
    Male oyster toadfish (Opsanus tau) acoustically attract females to nesting sites using a boatwhistle call. The rapid speed of sound underwater combined with the close proximity of the otolithic organs makes inner ear interaural time differences an unlikely mechanism to localize sound. To determine the role that the mechanosensory lateral line may play in sound localization, microwire electrodes were bilaterally implanted into the anterior lateral line nerve to record neural responses to vibrational stimuli. Highest spike rates and strongest phase-locking occurred at distances close to the fish and decreased as the stimulus was moved further from the fish. Bilateral anterior lateral line neuromasts displayed differential directional sensitivity to incoming vibrational stimuli, which suggests the potential for the lateral line to be used for sound localization in the near field. The present study also demonstrates that the spatially separated neuromasts of the toadfish may provide sufficient time delays between sensory organs for determining sound localization cues. Multimodal sensory input processing through both the inner ear (far field) and lateral line (near field) may allow for effective sound localization in fish.
  • Article
    Sounding the call for a global library of underwater biological sounds
    (Frontiers Media, 2022-02-08) Parsons, Miles J. G. ; Lin, Tzu-Hao ; Mooney, T. Aran ; Erbe, Christine ; Juanes, Francis ; Lammers, Marc O. ; Li, Songhai ; Linke, Simon ; Looby, Audrey ; Nedelec, Sophie L. ; Van Opzeeland, Ilse ; Radford, Craig A. ; Rice, Aaron N. ; Sayigh, Laela S. ; Stanley, Jenni A. ; Urban, Edward ; Di Iorio, Lucia
    Aquatic environments encompass the world’s most extensive habitats, rich with sounds produced by a diversity of animals. Passive acoustic monitoring (PAM) is an increasingly accessible remote sensing technology that uses hydrophones to listen to the underwater world and represents an unprecedented, non-invasive method to monitor underwater environments. This information can assist in the delineation of biologically important areas via detection of sound-producing species or characterization of ecosystem type and condition, inferred from the acoustic properties of the local soundscape. At a time when worldwide biodiversity is in significant decline and underwater soundscapes are being altered as a result of anthropogenic impacts, there is a need to document, quantify, and understand biotic sound sources–potentially before they disappear. A significant step toward these goals is the development of a web-based, open-access platform that provides: (1) a reference library of known and unknown biological sound sources (by integrating and expanding existing libraries around the world); (2) a data repository portal for annotated and unannotated audio recordings of single sources and of soundscapes; (3) a training platform for artificial intelligence algorithms for signal detection and classification; and (4) a citizen science-based application for public users. Although individually, these resources are often met on regional and taxa-specific scales, many are not sustained and, collectively, an enduring global database with an integrated platform has not been realized. We discuss the benefits such a program can provide, previous calls for global data-sharing and reference libraries, and the challenges that need to be overcome to bring together bio- and ecoacousticians, bioinformaticians, propagation experts, web engineers, and signal processing specialists (e.g., artificial intelligence) with the necessary support and funding to build a sustainable and scalable platform that could address the needs of all contributors and stakeholders into the future.