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Automated Monitoring of Yellowfin Tuna at Hawaiian FADs and Relationship to Water Mass Dynamics Based Upon Satellite Imagery

Progress Reports (PDF): FY 1995, FY 1994

Project Overview
The long-term occurrence and movements of yellowfin tuna among FADs off Hawaii will be monitored and correlated with oceanographic parameters and processes. This will be accomplished through ultrasonic transmitter tags on the fish and automated monitors on the FADs. The resultant information on seasonal migratory patterns and environmental preferences of the tuna will aid management planning.

Project findings published in Marine Biology (1999). PDF file available.
See Journal Publications page for other journal articles by PFRP investigators.


Principal Investigators:

Dr. Peter Klimley
Bodega Marine Laboratory
University of California-Davis
P.O. Box 247
Bodega Bay, California 94933
Phone (707) 875-2055
FAX (707) 875-2089
email: szklimle@peseta.ucdavis.edu
Mr. Charles Holloway
University of Hawaii at Manoa
School of Ocean and Earth Science and Technology (SOEST)
Hawaii Underwater Research Laboratory (HURL)
1000 Pope Road, MSB 303
Honolulu, Hawaii 96832 USA
Ph. (808) 259-9991
FAX (808) 259-9646
email: holloway@soest.hawaii.edu


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Progress Report

Funding was received at the University in December 1993.

Tunas and other pelagic fishes are attracted to almost any floating object. The aggregations thus formed may be quite extensive, and the aggregation phenomenon is exploited throughout the world in a variety of different fisheries. In Hawaii, a network of moored bouys or fish aggregation devices (FADs) has been established, and the fishing community depends on these FADs both to improve fishing productivity and to reduce costs of fishing. The benefits of these devices to the fish are less clear and how the fish actually exploit FADs is almost totally unknown. Yellowfin tunas will be tagged at selected FADs with ultrasonic pingers that broadcast a unique identification signal. Monitoring devices will be deployed on FADs to record the presence of tagged fish over periods of many months. The results will indicate the frequency at which individual fish utilize particular FADs and the oceanographic factors that moderate their near-shore distribution.

Authorization has been obtained from State of Hawaii authorities to attach monitoring devices to FADs. Poor fishing for yellowfin during field periods in 1994 combined with battery failures to restrict the number of functional transmitters that could be deployed to eleven. Two of three monitors also failed. The remaining monitor produced usable data but no record of yellowfin proximity. Temperature and light recorders functioned perfectly.

Field plans for 1995 were revised in response to previous experience. A local full-time research assistant has been employed. The scope of field activity has been enlarged to increase the likelihood of successful field deployment of both transmitters and monitors.

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This page updated August 14, 2006