California Sea Lion

Verified Timeline

Lore & Background

The series took almost five years to make, involving nearly 200 filming locations. The fact that most of the ocean environment remains a mystery presented the production team with many challenges. Besides witnessing some animal behaviours for the first time, the crew also observed some that were new to science. The producers were helped by marine scientists all over the world with state-of-the-art equipment. Blue whales – whose migration routes were previously unknown – were located by air, after some of the animals had been given temporary radio tags. The camera team spent three years on standby, using a microlight to land on the water nearby when they finally caught up with the creatures in the Gulf of California. The open ocean proved more difficult and over 400 days were spent in often unsuccessful filming trips. After six weeks, the crew chanced upon a school of spinner dolphins, which in turn led them to a shoal of tuna. Off Mexico, the behaviour of a flock of frigatebirds guided the cameramen to a group of sailfish and marlin: the fastest inhabitants of the sea. Near the coast of Natal in South Africa, the team spent two seasons attempting to film the annual sardine run, a huge congregation of predators such as sharks and dolphins, that assembles to feast on the migrating fish by corralling them into "bait balls". Meanwhile, in Monterey Bay, orca were documented attacking gray whales and killing a calf. Filming in the deep ocean required the use of special submersibles. One of them enabled the crew to dive over a mile into the San Diego trench, where the carcass of a 40-ton gray whale had been placed to attract a large variety of scavengers. When first transmitted on BBC One, over 12 million people watched the series and it regularly achieved an audience share of over 30%. In 2018 a newly-discovered species of phytoplankton (Syracosphaera azureaplaneta) was named by scientists in honour of the programme, and in recognition of David Attenborough's contribution to promoting wider understanding and awareness of the oceanic environment.

In Their Own Story

The series attracted some criticism when it was revealed that some of the footage was filmed at an aquarium in Wales. The series producer, Alastair Fothergill, said that around 2% of the whole series was filmed in tanks at aquariums. A BBC spokesman argued that it would have been unethical to actually disturb the breeding process of wild lobsters for one of the scenes, which was why they made the decision to use the aquarium footage.

Reader's Guide

The series was sold to over 50 countries. In the United States, it was shown as The Blue Planet: Seas of Life with the episodes in a different order, the first one being retitled "Ocean World". The series was shown on the Discovery Channel. A sequel series, Blue Planet II was aired on BBC One in 2017. In February 2017, the BBC announced a seven-part sequel had been commissioned, titled Blue Planet II, with Sir David Attenborough returning as narrator and presenter. The sequel debuted on BBC One, BBC One HD and BBC Earth channel on 29 October 2017.

Did You Know?

• The series took almost five years to make, involving nearly 200 filming locations.
• Over 400 days were spent on often unsuccessful filming trips in the open ocean.
• A newly-discovered species of phytoplankton (Syracosphaera azureaplaneta) was named in 2018 in honour of the programme and David Attenborough.
• When first transmitted on BBC One, over 12 million people watched the series and it regularly achieved an audience share of over 30%.
• Around 2% of the whole series was filmed in tanks at aquariums, according to series producer Alastair Fothergill.