Advertisement

Marine Biology

, Volume 138, Issue 2, pp 429–446 | Cite as

Radio-acoustic positioning as a tool for studying site-specific behavior of the white shark and other large marine species

  • A. Peter Klimley
  • Burney J. Le Boeuf
  • Kelly M. Cantara
  • John E. Richert
  • Scott F. Davis
  • S. Van Sommeran

Abstract

We describe a method, radio-acoustic-positioning (RAP), for continuously monitoring the movements and behavior of large marine animals. An ultrasonic transmitter on the animal can be localized with high spatial accuracy (2 to 10 m) within an area of 1 km2, based on when the same pulse arrives at three hydrophones on sonobuoys aligned in a triangular array. Radio transceivers communicate with the base station, where the x and y coordinates of the subject are calculated using hyperbolic equations. The base station plots the individual's position and displays information from the tag's sensors in real time on a computer monitor before saving the data on a disk. The base station must be situated either on land or on a vessel within the reception range of the three buoys. We used a RAP system to monitor the movements and behavior of white sharks (Carcharodon carcharias) near the elephant seal rookery at Año Nuevo Island in central California. This type of system is an ideal tool to study the predatory behavior of the white shark because individuals patrol for seal prey within a zone <1300 m from shore. We describe the operation of the system, including acoustic triangulation, range of detection and positioning, data acquisition and analysis, and positional accuracy. We illustrate the implementation of the method and its advantages and disadvantages by describing an ongoing study of white shark hunting-behavior. Sample data from this study are presented to illustrate specific points. We describe the movements of five sharks within the receiving range and their behavior relative to each other. The RAP system is compared to other complementary tracking methods. We conclude that this system has great potential for monitoring the movements and behavior of large marine animals within a relatively small zone, where feeding or reproduction takes place.

Keywords

Hyperbolic Equation Hydrophone Tracking Method Spatial Accuracy Predatory Behavior 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

Copyright information

© Springer-Verlag Berlin Heidelberg 2001

Authors and Affiliations

  • A. Peter Klimley
    • 1
  • Burney J. Le Boeuf
    • 2
  • Kelly M. Cantara
    • 1
  • John E. Richert
    • 1
  • Scott F. Davis
    • 2
  • S. Van Sommeran
    • 2
  1. 1.Bodega Marine Laboratory, University of California, Davis, P.O. Box 247, Bodega Bay, California 94923, USAUS
  2. 2.Department of Biology and Institute of Marine Sciences, University of California, Santa Cruz, 1156 High Street, Santa Cruz, California 95064, USAUS

Personalised recommendations