‘We must do something about the plastic in our oceans… now!’

The TV legend returns to present Blue Planet II

It’s been almost 20 years since the original Blue Planet series. What’s changed with the world’s oceans in that time? Two things. One is rising temperatures and the second is plastic. While filming, we’ve seen Albatrosses come back with food for their young and you think it is going to be squid but it’s plastic, so you know that chick is going to starve and die.

Are there still new things to discover? We found so many new things, particularly when down in the deep in one of those submersibles. It’s a cliche to say that the world is full of an infinite variety of animals, but it is!

Did you see anything that particularly surprised you? It has to be in episode two, when we see eels diving

into what was a lake at the bottom of the sea. It takes a bit of time to get your mind around that sort of thing. How can there be a lake at the bottom of the sea? And then it explodes like a volcano – I mean, come on!

What understandings do you hope we’ll come away with after watching the series? That every one of us has a responsibility for our oceans and that what we do has a direct affect on them. I don’t know what we’re going to do about the rise in ocean temperatures, but we could do something about the plastic in our oceans right now – and I wish we would!

✱ Blue Planet II starts Sunday 29 October, 8pm, BBC1