Studying Fish Behavior Using High Resolution Imaging Sonar

The study of fish behavior has typically relied on the use of video or direct observations.  These observation techniques are dependent on ambient light levels which can be inhibited by turbidity, night and depth.  High resolution imaging sonar systems operate by emitting acoustic pulses and converting the returning echoes into digital images.  This allows users the ability to "see" in zero visibility environments.  These "acoustic cameras" have given new insight into the study of fish behavior, migration and population assessments.  This presentation will focus on three recent field trials studying the behavior of river herring (Alosa aestivalis and Alosa pseudoharengus), steelhead trout (Oncorhynchus mykiss) and bull sharks (Carcharhinus leucas) using the ARIS high resolution imaging sonar.  Data from these studies will be used in this presentation to serve as case studies to highlight the advantages and disadvantages of these systems as well as their potential for studying fish behavior and other aspects of fisheries research.