NOVA: Mystery Beneath the Ice

(Photo courtesy of Heather Walsh, courtesy of WGBH Boston)
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 waxin