Blue Planet 3 returns with David Attenborough and a land-hunting octopus

Blue Planet 3 is returning to BBC One and iPlayer next Sunday at 8pm, 25 years after the original series first appeared. Sir David Attenborough is back to present the third series. The BBC says it ventures deeper beneath the waves and uncovers new stories from icy polar waters to the tropics. The rest of the world can watch from November.

The breakout star is a small female octopus living off the coast of a remote Japanese island. She leaves the safety of her rock pool to hunt on land, and at one point she strays dangerously far inland, a potentially fatal error. The rock pools she relies on begin to evaporate. Oxygen levels fall, her skin pales and she appears to be suffocating. The programme makers say she was in genuine danger and that they did not intervene, documenting events naturally until she reaches safety.

Filming the series took four and a half years and more than 2,000 filming days. The team set out to find stories that were new not only to the audience but to Attenborough himself. At 100, he remains fascinated by what he sees. The programme makers said that if a story was good enough to intrigue him, it would be good enough for viewers.

The series also features humpback whales off the coast of Manhattan. A four-week filming window was set aside, but the crew captured the sequence in the first hour. The reporter said he became very attached to the octopus and cried when the team left on the boat.