PBS - Nova: Mystery Beneath the Ice (2016) 720p HDTV x264-W4F

They're so tiny you might not notice them if you weren't looking for them. But these delicate, transparent, shrimp-like creatures are crucial to the Antarctic ecosystem and, maybe, to the future of all our oceans. The population of krill has crashed since the 1970s 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. As climate change alters the timing of the ice pack, their life cycle is disrupted–or so the theory goes.