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Potential Applications of Passive Acoustics to Fisheries.


  1. Applications
    1. Location of calling fishes allows identification of essential fish habitat (EFH)
    2. Continuous monitoring allows determination of daily and seasonal activity patterns
    3. Together with underwater video allows more detailed studies of fish behaviors
    4. Can be used to passively monitor anthropogenic impacts on EFH, and fish reaction to fishing activities
    5. With data on the sound characteristics of specific behaviors, can allow researchers to examine all of the above in regards to a specific behavior (e.g., spawning)
    6. Can be used as a new tool to Census Marine Life
    7. "Backyard science" even low-tech systems can be used to make a valuable contribution to our understanding of the spatial and temporal distribution patterns and behavioral ecology of fishes in both freshwater and marine environments
  2. Advantages
    1. Non-destruction, non-invasive
    2. Inexpensive relative to other technologies
    3. Long-term data acquisition capabilities
    4. Capability of remote monitoring
    5. High profile educational tool, increased public interest, especially when coupled with the internet
    6. Works at night without bias (versus video)
    7. Low tech systems can be used in widespread studies of estuarine, reef and freshwater habitats to allow biological census activities similar to bird watches
  3. What can you do with the data?
    1. Web access to time-lapse or real time fish sounds - education and public interest
    2. Supplement long term monitoring of species diversity, particularly of cryptic soniferous species
    3. Local, regional, national and international networks of "listening posts" can be used to provide synoptic data for the Census of Marine Life
    4. Seasonal temporal patterns of occurrence at a locality (i.e., when species first occur/or first become vocally active)
    5. Daily cycle in vocal activity
    6. Infer temporal patterns of local spawning for species with tight correlations between specific calls and spawning behavior
    7. Monitor temporal patterns in noise pollution at each locality
    8. Monitor sources of noise pollution (passing ships, small boats, trawling, scalloping, other activities can be distinguished)
    9. Examine potential impact of noise pollution on soniferous behaviors such as spawning activity
    10. With a single simple omni-directional hydrophone can get crude indicator of species abundance/spawning intensity (much more information can be derived from more sophisticated array systems)
  4. Limitations
    1. The primary limitation is the detection range - fish can be detected on scales of a few meters to 1 km depending on species and conditions, boats can be detected for up to several km.
    2. Limited availability of reference data for identification of fish species/behaviors based on sound.
  5. Technology/development needs
    1. Sound identification
      1. Establish National Reference Library of fish/animal sounds (underway)
      2. Rescue historical data archives (e.g. Fish and Mowbray 1970) (in progress)
      3. Research to provide field data to validate sound source identity and associated behaviors
      4. Establishment of voucher specimens and their calls in National Ichthyological Collections
    2. Research to quantify sound detection ranges of fishes and other marine animals
    3. Research on light effects on fish behavior by wavelength and intensity (a critical problem for in situ studies of nocturnal behaviors)
    4. Development of local, regional, national and international networks of "listening posts" designed to provide a census of marine life
    5. Software
      1. Automatic species/behavior recognition
      2. Automatic event detection/analysis software to quantify temporal patterns of sounds over long time periods (critical to success of continuous monitoring over intermediate (days to weeks) and long term (months to years) time periods
      3. Real-time detection and processing (e.i.-ii)
      4. Localization/tracking software allowing any size acoustic array and 3-d localization, incorporate (e.i-iii)
      5. For simultaneous analysis of video and audio data on fish behavior, i.e., click on the sound wave of a fish call and go to the corresponding video frame. Needed to allow rapid correlation of individual sounds and sound components with behavior.
    6. Technology
      1. Archival acoustic recorders - remote, independent, highly portable for use on ships of opportunity
      2. Sonobuoys with mobile phone, VHS-radio, or satellite data telemetry
      3. Homing devices to locate sound sources for identification and study (major initiative now underway)
      4. Portable, modular hydrophone array systems to allow detailed tracking studies at specific locations/habitats, automatic determination of hydrophone locations and array configuration. Associated GPS/tracking software to allow overlay of environmental data and sound source locations
      5. Recorder allowing simultaneous audio and video data collection - archival or data transfer via tether or telemetry
      6. Hand-held video/audio recorder, GPS, environmental data interface for shore based and small boat applications (recorder is the most difficult component)
      7. Multifrequency, variable intensity light source for various recorders
      8. Miniature ROV designed to obtain video and acoustic data of fish behavior, light-weight, portable and suitable for deployment from shore and small boat


This page was last modified on March 18, 2005

Copyright © 2001, 2005 by Rodney Rountree. All rights reserved

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