ABSTRACT: This paper presents evidence of deep diving performances by fin whales Balaenoptera physalus in the Mediterranean Sea, never directly recorded for any other species of baleen whales. By means of velocity-time-depth-recorders applied to the whales with suction cups, depths of at least 470 m were registered twice, over 7 dives below 150 m recorded during a total of 12 h 38 min of remote tracking. The deep bouts occurred in late afternoon, in coincidence with the diel vertical upward migration of krill Meganyctiphanes norvegica, the principal prey species for Mediterranean fin whales. The data presented indicate that fin whale diving capabilities are opportunistically adapted to deep prey availability in the area.

KEY WORDS: Deep diving · Fin whale · Mediterranean Sea · Feeding ecology · Telemetry · Krill migration

Published in MEPS Vol. 187 (1999) on October 14
ISSN: 0171-8630. Copyright © Inter-Research, Oldendorf/Luhe, 1999