Dead sharks for sale at Tanjung Luar Fish Market, Lombok

Sharks are the Apex Predator of an ecosystem spanning 2/3s of the surface area of Earth. Their role as Apex Predator serves to keep this system in balance. And I'm not talking Chi. I'm talking critical to balancing an ecosystem that provides 3 billion humans with their livelihood - http://www.un.org/sustainabledevelopment/oceans/ - An ecosystem that produces more of the oxygen we breath than all of the rainforests put together. An ecosystem that removes half of all our CO2 emmissions, providing the best defence we currently have against Global Warming - http://news.nationalgeographic.com/news/2004/07/0715_040715_oceancarbon.html - An ecosystem that helps regulate the temperature and weather of our planet, stopping it from getting so extreme it kills us.

Sound unlikely? Terrifyingly, that's all true. Sharks are crucial to life for the human race as we know it. But how can they possibly play such a huge role?