Vertical and Horizontal Migrations Affect Local and Integrated Water-Column Scattering Strengths

Abstract

The primary objectives of our current research are to develop a predictive understanding of emergence by coastal macrofauna in one region. By emergence we mean leaving the seabed to become part of the plankton or nekton, which typically occurs at night. In high-frequency acoustic records, this emergence appears as a shallow scattering layer that typically leaves the seabed after dusk and returns before dawn. Emergence and re-entry (return to the seabed) in shallow water appear to represent an evolutionary solution that avoids visual predation analogously with oceanic deep scattering layers. In the coastal zone, the water is simply too shallow to provide a holoplanktonic solution.

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Document Details

Document Type
Technical Report
Publication Date
Sep 30, 2007
Accession Number
ADA572673

Entities

People

  • Peter A. Jumars

Organizations

  • University of Maine

Tags

DTIC Thesaurus Topics

  • Acoustic Propagation
  • Acoustic Properties
  • Acoustics
  • Aquatic Organisms
  • Continental Shelves
  • Crack Propagation
  • Cracks
  • Elastic Properties
  • Materials
  • Mechanical Properties
  • Mechanics
  • Migration
  • Modulus Of Elasticity
  • Observation
  • Physical Properties
  • Scattering
  • Water

Readers

  • Aquatic Ecology
  • Coastal Oceanography
  • Educational Psychology