EPOW - Ecology Picture of the Week

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Sperm Whale Sounding

Credit & Copyright: Dr. Bruce G. Marcot

Explanation:  After lifting its head out of the water for that final breath, this Sperm Whale off the Kaikoura coast of South Island, New Zealand, begins its diving or sounding actions.  It lunges forward, arches its back, and the tail flukes and rear third of its body come completely out of water.  Nearly vertical now, the whale drops vertically down the water column at 1-3 meters (3-10 feet) per second (2-7 mph).  Sperm Whales usually dive to 300-600 meters (985-1,965 feet) but may be able to reach at least 3,000 meters (9,845 feet).  At that depth, water pressure is nearly unimaginable, and their lungs temporarily collapse and they then rely on the oxygen stored in their blood and muscles, which fuels mainly their heart and brain.   Sperm Whales dive to feed on squid and other foods and to maintain contact with other Sperm Whales.   Taking photos of their flukes is a useful way to keep track of individual Sperm Whales, as each whale seems to have a unique pattern.  Whales are also tracked by using a multi-beam scanning sonar.