How do animals adapt to the ocean enviroment???

Question

How do animals adapt to the ocean enviroment???

Answer 1

They don't.  They drown, or they swim to shore, and are thus no longer in the ocean.

Answer 2

Mammals have evolved to ocean environments.  They  all have some characteristics in common, to more or lesser degrees.

Kidneys change to handle the high salinity.

Body shapes tend toward fish-like bodies, losing individual fingers and gaining fins/flippers.

Nostrils drift to the top of the head or develop ways to seal shut completely.

Body fat increases proportionally.

Importance of vision decreases, replaced by increased hearing.

Stronger slower hearts, greater lung capacity and other changes (not well understood) that let animals stay underwater for longer times without breathing.

Herding.  Most sea mammals are herd animals, this may be a carry over from when they where land dwellers in some cases.  There are exceptions.

Answer 3

by evolving.