These are just some of the highlights in tonight’s episode of the BBC One show.
Up to 17 million people have been tuning in on television and online.
The series has already been bought by broadcasters around the world.
Paul Dempsey, president of global markets at BBC Worldwide, said: “We are seeing phenomenal demand for Blue Planet II and we expect it to sell to well over 200 territories. Where it has already been shown internationally it has been a huge hit with audiences of all ages.”
In tonight’s episode a Pacific leaping blenny, a fish that lives on land, is captured performing a routine that could rival Strictly Come Dancing.
In the Galapagos Islands, sea lions have learned to form gangs in order to herd yellow fi n tuna into shallow water.
Once trapped, the fish are easy pickings, pictured left.
In Norway, Atlantic puffin are filmed being mugged in mid-air by arctic skua on a three-hour round trip to catch fish for their young.