Use of an Automated Acoustic Telemetry System to Passively Track Juvenile Blacktip Shark Movements

Abstract

An array of 14 automated acoustic receivers were deployed within a coastal shark nursery on the central Gulf Coast of Florida during the summer of 1999. These units were used to monitor the long-term movements and behavior patterns of neonate Carcharhinus limbatus within the study site. Eighteen sharks were fitted with coded acoustic transmitters and passively tracked for periods of 3–159 days. The methods of equipment deployment and data collection and analysis are described. The extensive data collected from the hydrophone array were sorted and condensed using a FORTRAN program with user defined variables. Examination of the data revealed that sharks remained within a confined portion of the study site during the first three months of the study (May-July). During the months of August-November sharks began to utilize the remainder of the nursery area habitat. Active tracking of three additional sharks was used to validate results collected via the automated system and allowed comparisons between the two methods.