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ANALYSIS OF SWIM VELOCITIES DURING DEEP AND SHALLOW DIVES OF TWO NORTHERN FUR SEALS, CALLORHINUS URSINUS |
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| Authors: | Paul J Ponganis Roger L Gentry Edward P Ponganis Katherine V Ponganis |
| Institution: | Physiological Research Laboratory, Scholander Hall, Scripps Institution of Oceanography, University of California, San Diego, La Jolla, California 92903;NMFS, National Marine Mammal Laboratory, 7600 Sand Point Way, N.E., Building 4, Seattle, Washington 98115;Micromonitors, 1348 Shasta Avenue, San Jose, California 95126;Physiological Research Laboratory, Scholander Hall, Scripps Institution of Oceanography, University of California, San Diego, La Jolla, California 92903 |
| Abstract: | Swim velocities at 15-sec intervals and maximum depth per dive were recorded by microprocessor units on two "mixed diver" adult female northern fur seals during summer foraging trips. These records allowed comparison of swim velocities of deep (>75 m) and shallow (<75 m) dives. Deep dives averaged 120 m depth and 3 min duration; shallow dives averaged 30 m and 1.2 min. Mean swim velocities on deep dives were 1.8 and 1.5 m/sec for the two animals; mean swim velocities on shallow dives were 1.5 and 1.2 m/sec. The number of minutes per hour spent diving during the deep and shallow dive patterns were 11 and 27 min, respectively. Swim velocity, and hence, relative metabolic rate, did not account for the differences in dive durations between deep and shallow dives. The long surface durations associated with deep dives, and estimates of metabolic rates for the observed swim velocities, suggest that deep dives involve significant anaerobic metabolism. |
| Keywords: | Callorhinus ursinus fur seal swim velocities metabolic rates |