The weather is much calmer now and we’re back to mapping and doing lots
of CTDs. It’s hard to believe it’s been just under a month out here
already! Pretty soon we’re going to be wrapping up the last of the
science and starting the long trip back to port. I had hoped to see more
whales while we were out here, but it is late in the season and the ice
is filling in. We got to see a few minke whales, but they tend to
surface, breathe a few times, then seemingly disappear. I wasn’t even
fast enough to get a photo of them!
A minke whale in Antarctica on the previous NBP cruise. Photo by Kathleen Gavahan.
Tristen, 1st grade, Jacquelyn, 3rd grade and Yadhira, 3rd grade, would like to take a closer look at dolphins and whales.
Cetaceans are whales, dolphins, and porpoises. There are a lot of whales
that either live in Antarctica or migrate here to feed. They can be
broken down into two different groups: mysticetes (baleen whales) and
odontocetes (tooth cetaceans). Baleen cetaceans are animals like fin
whales, blue whales, humpback whales, and minke whales, which have
keratin plates in their mouth that they use to filter feed plankton and
small fish. Toothed cetaceans are dolphins, porpoises, and whales with
teeth. All cetaceans are mammals and breathe air like we do, however
they use a blowhole, which is like nostrils on the top of their head.
Mysticetes have two blowholes or nostrils, while odontocetes have a
single blowhole or nostril. We have many of the same species of
cetaceans in our local waters as can be found here in
Antarctica, like blue whales and dolphins. However, these groups are
separate populations and tend not to make the huge journey across the
oceans and mix.
Diego, 2nd grade, Zak, 1st grade, Jose, 1st grade, Finn, 1st grade and Kimberly, 2nd grade, would like to learn more about orcas in Antarctica.
The most well-known of these toothed cetaceans in Antarctica (and the
animal I received the most questions about right behind penguins) is the
orca or killer whale. Orcas, which are the largest member of the dolphin
family, can be found in oceans all over the world. However, there are
different groups with different behaviors, hunting styles and ways of
communicating, in different areas of the world. While some of these
groups stay in home areas, others migrate over far distances to find
In Antarctica, scientists have found three “ecotypes” or types of
groups of orcas which they call: Type A, Type B, and Type C. Type A
orcas like ice free waters and hunt minke whales in packs, like wolves.
Type B orcas, live closer to shore around the ice and prefer to prey on
seals (though they will also hunt minke whales too). These are the orcas
we normally see on TV, working as a team to tip ice bergs or create
waves to push seals into the water. Type C orcas are found in ice and
open water and mainly eat just fish. All of these orcas are fast
(swimming up to 35 mph at a sprint) and have huge ranges—traveling all
around the waters surrounding the continent.
A Northern Pacific orca, although from the same species this animals is from a different population than the Antarctica orcas.