In the Pacific, a tiny island 300 miles away from the shore hides a giant mountain beneath the waves that forms a home for thousands of planton feeding fish. These fish attract tuna, and the tuna attract thousands of sharks. Watch this video to learn more about this fascinating food chain, and hear some weird but true facts about the visiting Hamerhead sharks. Brilliant short from BBC wildlife show Blue Planet. Narrated by Sir David Attenborough. Visit http://www.bbcearth.com for all the latest animal news and wildlife videos and watch more high quality videos on the new BBC Earth YouTube channel here: http://www.youtube.com/bbcearth