Bioacoustic Absorption Spectroscopy: Bio-alpha Measurements off the West Coast

Abstract

The long-term goal is to demonstrate the significance of bio-alpha, attenuation due to large numbers of fish, on attenuation, transmission loss, scintillation index and reverberation in the ocean through at sea measurements and theoretical models. The objectives are to: Determine the effects of fish with swim bladders on attenuation (bio-alpha), transmission loss (TL), scintillation index (SI) and reverberation through an experiment off the west coast of the USA, and theoretical modeling. Demonstrate the effectiveness of range dependent (moving source) TL measurements for inferring bio-alpha - all previous bio-alpha measurements were conducted with fixed sources and receivers. Determine the effects of hake, a physoclists (volumes of their swim bladders are independent of depth) on bio-alpha, TL and SI - all previous bio-alpha experiments were conducted on physostomes (volumes of their swim bladders decrease with depth). Infer number densities of fish from bio-alpha measurements for comparison with number densities derived from echo sounder and trawl surveys. Determine effects of bio-alpha on reverberation.

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Document Details

Document Type
Technical Report
Publication Date
Sep 30, 2013
Accession Number
ADA598898

Entities

People

  • Orest Diachok

Organizations

  • Johns Hopkins University

Tags

DTIC Thesaurus Topics

  • Absorption
  • Acoustic Measurement
  • Aquatic Organisms
  • Attenuation
  • Fish
  • Fisheries
  • Frequency
  • Hot Spots
  • Losses
  • Measurement
  • Oceans
  • Physics Laboratories
  • Reverberation
  • Sonar
  • Spectroscopy
  • Swim Bladders
  • Transmission Loss

Fields of Study

  • Physics

Readers

  • Acoustical Oceanography.

Technology Areas

  • AI & ML
  • AI & ML - Bayesian Inference