Where do gentoo penguins live in antarctica?

The Gentoo penguin is a sea bird and lives at sea.

However, according to Wikipedia, its breeding ground does include the Antarctic Peninsula. Otherwise, they breed on the sub-Antarctic islands.
No animal lives on the Antarctic continent; it's too cold and there is no food chain there.

Gentoo penguins breed on the northern-most beaches of the Antarctic Peninsula. Their food chain is in the sea and that's where they 'live'.