DIVING BEHAVIOR OF PORPOISES USING MICRO DATA LOGGER

1993-1997年，在北海道丰贺湾，将带有释放装置的微型数据记录器安装在港湾豚（Phocoena PHOCOENA）的背鳍上，以监测自由活动的鲸目动物的潜水行为。1994年对11头江豚进行了微数据记录，记录了时间-深度信息，但后来增加了游泳速度，1994年成功回收了2头江豚，记录了141小时的潜水数据，其中包括4小时的深度和水温，871次潜水。海豚几乎连续潜水，很少在水面长时间休息。最大潜水深度98.6米，70%以上在20米或更低的深度下，海豚的下潜时间为20米或更低。大多数的浅潜是V形的，没有底部时间。下降速率与最后下潜深度并不恒定。分析表明，海豚在开始下潜之前已经预测了它们将下潜的深度。氧气的代谢促使海豚通常在有氧潜水极限下下潜。

IN ORDER TO MONITOR THE DIVING BEHAVIOR OF FREE-RANGING CETACEANS.MICRO DATA LOGGERS, WITH RELEASE MECHANISMS, WERE ATTACHED TO THE DOR-SAL FINS OF HARBOR PORPOISES, PHOCOENA PHOCOENA, IN FUNKA BAY, HOKKAI-DO DURING 1993-1997. A TOTAL OF ELEVEN HARBOR PORPOISES WERE TAGGEDWITH MICRO DATA LOGGER WHICH RECORDS TIME-DEPTH INFORMATION, BUT SWIM-KING SPEED WAS ADDED IN LATER YEARS.TWO SUCCESSFULLY RECOVERED LOG-GERS IN 1994, REVEALED 141 HOURS DIVE DATA WHICH INCLUDE DEPTH ANDWATER TEMPERATURE IN 4,871 DIVES.PORPOISES DIVED ALMOST CONTIONUOUSLYRARELY EXHIBITING LONG-TERM REST AT THE SURFACE.MAXIMUM DIVE DEPTHSWERE 98.6 METERS WITH MORE THAN 70% OF DIVING TIME AT 20 METERS ORLESS.MOST SHALLOW DIVES WERE V-SHAPED WITH NO BOTTOM TIME.THE DESCE-NT RATE WAS NOT CONSTANT RELATED TO A FINAL DIVE DEPTHRANGE.ANALYSISSUGGESTED THAT THE PORPOISES HAVE ANTICIPATED THE DEPTH TO WHICH THEYWILL DIVE BEFORE INITIATING THE DIVE ITSELF.MATABOLISM OF OXYGEN SUG-GESTED THE PORPOISES USUALLY DIVE UNDER THE AEROBIC DIVE LIMITS.