Journal of Comparative Physiology B

, Volume 169, Issue 2, pp 93–99

Thermoregulation during swimming and diving in bottlenose dolphins, Tursiops truncatus

  • D. P. Noren
  • T. M. Williams
  • P. Berry
  • E. Butler
ORIGINAL PAPER

DOI: 10.1007/s003600050198

Cite this article as:
Noren, D., Williams, T., Berry, P. et al. J Comp Physiol B (1999) 169: 93. doi:10.1007/s003600050198

Abstract

Heat transfer from the periphery is an important thermoregulatory response in exercising mammals. However, when marine mammals submerge, peripheral vasoconstriction associated with the dive response may preclude heat dissipation at depth. To determine the effects of exercise and diving on thermoregulation in cetaceans, we measured heat flow and skin temperatures of bottlenose dolphins (Tursiops truncatus) trained to follow a boat and to dive to 15 m. The results demonstrated that skin temperatures usually remained within 1 °C of the water after all exercise levels. Heat flow from peripheral sites (dorsal fin and flukes) increased over resting values immediately after exercise at the water surface and remained elevated for up to 20 min. However, post-exercise values for heat flow from the flukes and dorsal fin decreased by 30–67% when dolphins stationed at 15 m below the surface. The pattern in heat flow was reversed during ascent. For example, mean heat flow from the flukes measured at 5 m depth, 40.10 ± 2.47 W · m−2, increased by 103.2% upon ascent. There is some flexibility in the balance between thermal and diving responses of dolphins. During high heat loads, heat transfer may momentarily increase during submergence. However, the majority of excess heat in dolphins appears to be dissipated upon resurfacing, thereby preserving the oxygen-conserving benefits of the dive response.

Key words ThermoregulationDivingExerciseDolphinHeat flow

Copyright information

© Springer-Verlag Berlin Heidelberg 1999

Authors and Affiliations

  • D. P. Noren
    • 1
  • T. M. Williams
    • 2
  • P. Berry
    • 3
  • E. Butler
    • 3
  1. 1.Departments of Marine Sciences and Biology, Earth and Marine Sciences Building, Room A316, University of California, Santa Cruz, California 95064, USA e-mail: dnoren@biology.ucsc.edu, Tel.: +1 831-459-4133, Fax: +1 831-459-5353US
  2. 2.Department of Biology, University of California, Santa Cruz, California, USAUS
  3. 3.The Dolphin Experience, Port Lucaya, Grand Bahama Island, The BahamasBS