V9 Antarctic Peninsula_Voyage_Log

Whales: Friendly Giants of the Sea
Amanda Dalsgaard – Lecturer (Marine Biology) and Expedition Guide
13
When one talks about whales, we must acknowledge
the vast diversity of whales on earth and the
uniqueness of each species. All whales fall into an
order of marine mammals known as Cetaceans. The
scientists who first discovered and named this order of
marine mammals, used the word cetacean or
‘ceatacea’ from the Greek word ‘ketos,’ meaning
monster.
Long ago, when whales were first scientifically
observed and recorded, people believed they were
monsters, due to their incredible size compared to
humans. Today, we know much more about the gentle
giants that roam our planet’s seas. Thanks to a number
scientific and technological advances, our knowledge
of these creatures will only continue to grow.
The order Cetacea is divided into two sub-orders,
Odontocete and Mysticeti. Odontocete, meaning
‘toothed-whale’, includes all of the whales and
dolphins with teeth. Mysticeti comes from the Latin
root meaning “mustache”, and includes all of the
whales that have baleen plates in their mouth instead
of teeth..
Since whales are marine mammals, they must breath
air to survive. They do so by breathing at the water’s
surface through their blow holes.
Interestingly enough, however, toothed whales have
only one blow hole or spout, while baleen whales have
two. Plus, many whales can be identified from afar
using the size and shape of their spout blow as well.
For example, grey whales tend to have spouts shaped
like hearts, while orcas have low bushy spouts. It’s
important to keep these differences in mind when
trying to observe whales from a ship as this
information can help identify cetaceans from far away
Another distinguishing characteristic that sets these
two sub-orders apart is the way that they
communicate. Odontocetes use a method of
communication called echolocation. This is best
described as a series or clicks and precise sounds that
are then reflected back to the animal and allows the
whale to ‘see’ their environment through noise. It is
the same communication style used by bats in
terrestrial ecosystems. Mysticetes on the other hand,
communicate through a variety of low-frequency
songs. These songs have been described by scientists
as being beautiful, mysterious and sometimes gloomy,
with the males being the most active singers of the
Mysticeti clan.
Regardless of the kind of whale you see however, any
encounter with one of these graceful marine giants,
however brief, is sure to be a memorable experience
for years to come.
5 JAN 2020 – 14 JAN 2020
Volume 2, Issue 9