Tiny, transparent, and threatened, krill are crucial to the Antarctic ecosystem. But the population of krill is crashing for reasons that continue to baffle the experts. A leading theory says that krill's life cycle is driven by an internal body clock that responds to the waxing and waning of the Antarctic ice pack, and as climate change alters the timing of the ice pack, their life cycle is disrupted. To test it, NOVA travels on the Polarstern, a state-of-the-art research vessel, to the frigid ice pack in the dead of winter. From camps established on the ice, scientists dive beneath the surface in search of the ice caves that shelter juvenile krill during the winter. There, they hope to discover what's causing the krill to vanish and, ultimately, how the shifting seasons caused by climate change could disrupt ecosystems around the world.

NOVA Season 43 Episodes...

• s43e01 - Dawn of Humanity
• s43e02 - Arctic Ghost Ship
• s43e03 - Secrets of Noah's Ark
• s43e04 - Cyberwar Threat
• s43e05 - Animal Mummies
• s43e06 - Making North America: Origins
• s43e07 - Making North America: Life
• s43e08 - Making North America: Human
• s43e09 - Inside Einstein's Mind
• s43e10 - Secret Tunnel Warfare
• s43e11 - Life's Rocky Start
• s43e12 - Mystery Beneath the Ice
• s43e13 - Himalayan Megaquake
• s43e14 - Creatures of Light
• s43e15 - Memory Hackers
• s43e16 - Iceman Reborn
• s43e17 - Rise of the Robots
• s43e18 - Vikings Unearthed
• s43e19 - Can Alzheimer's Be Stopped?
• s43e20 - Wild Ways
• s43e21 - Operation Lighthouse Rescue
• s43e22 - Bombing Hitler's Supergun

NOVA Show Summary

Seen in more than 100 countries, NOVA is the most watched science based television series in the world and the most watched documentary series on PBS. It is also one of television's most acclaimed series, having won many major television awards, most of them many times over.