Antarctica’s Strange Underwater World | NOVA | PBS

Beneath the Antarctic ice sheet lives a world of ancient sponges, giant jellyfish, sea spiders, and fish with natural antifreeze in their blood. Hosts Caitlin Saks and Arlo Pérez look at why creatures here evolved to survive water colder than freezing.

Why it's free: Free on NOVA PBS's own channel; GBH first ran it on PBS Terra and NOVA republished it here.