Marine Mammals pp 365-383 | Cite as

Marine Mammal Health: Holding the Balance in an Ever-changing Sea

  • Joseph R. Geraci
  • Valerie J. Lounsbury


Whales, dolphins, seals, and sea otters live in an environment that, for a mammal, may be the harshest on earth - too much salt, no oxygen to breathe, cold that drains body heat - and where food is hard to find, difficult to catch, and never guaranteed. Over millions of years, marine mammals have evolved adaptive mechanisms that allow them to survive - even thrive - under these conditions. Animals that come ashore weak or dying often reveal evidence of failed adaptations - such as electrolyte imbalance and emaciation - that can obscure or complicate other factors that may be at work. Here, we will review briefly a few of the physiological and anatomical specialisations essential for mammals in the marine environment. Then, using a young harbour seal and a sea otter as examples, we will show what happens to an animal as these adaptations gradually break down, and how disease often appears towards the end of that process. We conclude with a brief discussion of general concepts in marine mammal health, trends in the health of populations, and implications for the future.


Marine Mammal Killer Whale Bottlenose Dolphin Harbour Seal Grey Seal 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


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Copyright information

© Springer Science+Business Media New York 2002

Authors and Affiliations

  • Joseph R. Geraci
    • 1
    • 2
  • Valerie J. Lounsbury
    • 1
  1. 1.National Aquarium in BaltimoreBaltimoreUSA
  2. 2.Comparative Medicine ProgramUniversity of Maryland School of MedicineBaltimoreUSA

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