In his seven decades traversing our incredible planetâand having species named for him along the wayânatural historian Sir David Attenborough has seen more of what Earth has to offer than most. However, even he was in for some surprises while working on the new feature-length documentary Ocean with David Attenborough. From stunning underwater ecosystems teeming with life, to the harmful effects of bottom trawling, the film shows that the mighty ocean still has a lot to teach usâeven someone with credentials like Attenborough.Â

âAfter living for nearly 100 years on this planet, I now understand the most important place is not on land, but at sea,â Attenborough states at the start of the film.
To learn more about the making of the film, Popular Science sat down with Toby Nowlan, one of the filmâs directors, and marine ecologist and National Geographic Explorer Enric Sala. Answers have been condensed for clarity.
Laura Baisas: What was the most surprising thing you learned about our oceans throughout the course of working on the film?
Toby Nowlan: For me, there were two big take homes that really hit me hard as soon as I started making the film that got me really, really excited. The biggest one was how capable the ocean is of recovery. The process of protecting the ocean is very different from protecting the same area of land. When you protect an area of ocean, that space fills back up with life again, quicker and in a more spectacular fashion than anything anyone had dared to imagine was possible. And not only that, but it floods out, overflows, spills out into surrounding areas of ocean, and revives huge other areas of ocean. That process is a winning process for everyone, for every living thing on earth, for all the fishing communities, for all marine life, for all terrestrial life, for our breathable atmosphere, stable climate. The other thing that hit me was just that understanding that the ocean does not belong to a single person, does not belong to a group of people, group of companies or individuals or governments. It is for everyone on Earth. Itâs our greatest shared asset.Â
Enric Sala: For me, Iâve been working on ocean science and conservation for more than 35 years, but I had not seen bottom trawling underwater. That was the surprising thing for me. Even though I knew about the impacts of bottom trawling, I had never seen it. Even for a scientist who is used to working with data to understand things, there is nothing like seeing things with your own eyes.

LB: Thatâs a perfect segue to my next question. Why did you feel that showing bottom trawling was so important?
TN: Itâs the story of the generation. Weâre talking about something that was invented here off the south coast of the United Kingdom 700 years ago, and we knew it was a bad thing. There were these letters of complaint to the king 700 years ago, but back then it was these small boats with sails on. Fast forward 700 years, and itâs still happening, and not just that, but on a huge scale, thousands of times every day, around the ocean. Itâs been happening just below the surface, below the waves, and for that simple reason, itâs been concealed from the world. So it was a really clear mission. Weâre literally just showing what is happening around our ocean every single day.Â
ES: As Toby said, in the 1300s people started bottom trawling, but we didnât measure the catch really, until recently, just a few decades ago. But when scientists started looking at historical catches, we realized that today, for every hour spent bottom trawling, we are catching just 6 percent of what we did 120 years ago. Imagine what was there 700 years ago, right? This practice in the North Sea, for example, and English channel has been conducted non stop on a weekly basis, for almost seven centuries.Â
[ Related: Humans have only seen 0.001 percent of the ocean floor. ]
TN: Itâs just worth adding to that that this film actually isnât an anti-fishing film. If anything, itâs a pro-fisheries film, itâs a pro ocean abundance film, ocean full of life, pro-thriving planet. And bottom trawling our protected areas is not how we get there.
LB: What was the biggest technical and scientific challenge?
TN: The trawling was technically difficult. Youâre dealing with depth, filming in low light, a lot of movement. Thereâs so much turbulence down there that youâre dealing when. Then you see the violence of the process. These things are just thundering along the seabed, smashing into every rock and boulder and become this sort of self-created bulldozer. It took a lot of finessing to make sure it was at exactly the right depth, exactly the right distance behind the boat, and that it was just completely flat.Â

ES: Scientifically, the challenge was to select the minimum number of facts to tell a story. Finding the science to tell a story was the easy part, because we have so many studies telling us what the impacts on the ocean are, and hundreds of scientific and economic studies showing the benefits of protected areas. Every statement in the film is supported by peer reviewed scientific studies.
LB: What do you hope people take away from the film and learn about our oceans in general?
TN: The take away is hope, and this is real. The process of recovery in the ocean is quicker and bigger and really works more than weâd ever thought possible. Itâs already happening at every scale around the world. Wherever weâve protected the ocean, itâs recovering faster on a greater scale than weâd ever imagined possible.Â
ES: Protecting the land is very different from protecting the sea. If you create a national park on land, you protect mostly what lives within the boundaries of the protected area, so things canât get out. But in the ocean, because of the water, many fish and lobster and scallops, they produce all these eggs. They release eggs into the water that can be dispersed for hundreds to 1,000s of miles, and that power of regeneration beyond the boundaries of the protected area, thatâs the biggest difference between protecting a place.

LB: Finally, if you could be one sea creature for a day, what would it be and why?
ES: I wouldnât like to be one of those mackerel on a bait ball, for sure! Iâd like to be one of the curious dolphins, because they seem to have this permanent smile.
TN: Iâm an absolute bird geek and mine would be the nice and albatross that you see from the PapahÄnaumokuÄkea Marine National Monument in the middle of the Pacific Ocean. These are the longest lived birds in the world, and when they feed their chicks, they can disappear for weeks at a time and cover hundreds of 1,000s of miles. They probably see more of the ocean than any other living thing, these birds, and I love that. So, theyâre the ultimate ocean travelers.
Ocean with David Attenborough will debut on June 7 and stream globally the next day on Disney+ and Hulu on Worldâ Oceans Day.Â