Whales are the largest
animals ever to have lived, larger even than the largest dinosaurs.
There are two reasons that they have managed to attain such
enormous size - well over a hundred tonnes for the largest blue
whales and nearing this amount for some other whale species.
1/ They live in
the oceans and so the buoyancy of the water can support their
great bulk without having to
be supported and moved on land by legs and muscles. Like most
other animals, the density of a whale is very close to that
The consequence of this is
that the higher up a food chain you get, the lower the biomass
of animals (that is number of animals multiplied by their weight).
As whales tap the food chain
low down - close to the producers, relatively little energy
is lost and so more is available to the whales, so they are
able to grow to enormous sizes.
Antarctic Ocean Food Web
Antarctic Food Web is relatively simple compared to ecosystems
in other parts of the world.
There are fewer different species, but greater numbers of them.
The second most numerous large mammal in the world (after man)
is the crab-eater seal, an archetypal Antarctic animal.
key part of the Antarctic food web are
krill small shrimp-like crustaceans
that the great majority of Antarctic animals, seal, whales,
penguins and other birds, fish etc. feed upon.