VERTICAL AND HORIZONTAL MOVEMENTS OF STRIPED MARLIN (TETRAPTURUS-AUDAX) NEAR THE HAWAIIAN-ISLANDS, DETERMINED BY ULTRASONIC TELEMETRY, WITHSIMULTANEOUS MEASUREMENT OF OCEANIC CURRENTS

We measured the vertical and horizontal movements of striped marlin (T etrapturus audax) off the leeward coast of the Island of Hawaii betwee n 20 November and 18 December 1992 while simultaneously gathering data on water temperature and oceanic currents. Fish movements were monito red by ultrasonic depth-sensitive transmitters, depth-temperature prof iles by an expendable bathythermograph system, and oceanic current pat terns by an acoustic Doppler current profiler. Like IndoPacific blue m arlin (Makaira mazara), striped marlin near Hawaii spend >85% of their time in the mixed layer (i.e., above 90 m depth). The maximum depth f or striped marlin appears to be limited by water temperatures 8C degre es colder than the mixed layer, rather than by an absolute lower tempe rature. We also found that the horizontal displacements of some stripe d marlin can be strongly influenced by currents.