THE film-maker Ed Webb-Ingall has an important question to ask - who owns the sea? – and he’s been to Arran to try to find the answer. Some people on the island told him nobody owns it. Others told him the sea belongs to all of us: the people. A few even suggested the sea is probably owned by the Queen. And in a way, they were all right.

The answer, as Webb-Ingall discovered while making his new short film for an arts project about coastal communities, is that the water that makes up the sea belongs to no one, while the seabed around the shore, out to 12 nautical miles, belongs to the Crown Estate. Beyond that, various governments have the right to use the seabed, to extract oil and gas and exploit it in other ways; on the surface too there are many competing interests. As Webb-Ingall says, it’s complicated. “I got myself into real knots trying to make sense of it,” he says.

The idea of knots and entanglement is one that comes up a few times while Webb-Ingall is talking. The Glasgow-based artist says his film, called I Walk There Every Day But I Never Saw It That Way, was designed to explore all the different perspectives and competing interests in, on, and around the sea in Arran and other coastal communities. All of the perspectives and ideas and opinions co-exist in a tangle, he says, like a fishermen’s net or seaweed and it was impossible to come down on one side on the other. What Webb-Ingall could do, though, with his camera, was try to understand where people were coming from and what the sea means to them.

One of Webb-Ingall’s first conclusions was that none of us is immune from the sea’s powers. He himself is a huge fan of wild sea swimming, something he discovered when he was growing up in Yorkshire, and he still does it whenever he can.

“I can’t see a body of water and not want to go in,” he says. “It’s a physical release to be submerged in water, it’s like a connection with nature, a close connection. It’s also a way of relating differently to the landscape and feeling smaller and more involved. You become very aware of your scale.”

Webb-Ingall also knows the statistics about the importance of water – and the sea specifically - to all of us. About 70 per cent of the Earth’s surface is covered in water and 97 per cent of that is found in the ocean; on top of that, about 60 per cent of the human body is water too. “Someone I spoke to said we should be called sealings rather than earthlings,” says Webb-Ingall.

Webb-Ingall has tried to convey this importance of water in his film, which is on a tour of Scotland along with another film Chladach by the American film-maker Margaret Salmon. Called Shore: How We See the Sea, one of the aims of the project is to explore the importance of Marine Protected Areas (MPAs), stretches of water that are managed to protect and restore marine species and the ecosystems they rely on - there's an MPA around the south of Arran, for example, where Webb-Ingall made his film.

One of the stated aims of MPAs is to tackle the problem and effects of pollution, which are strong themes in both Webb-Ingall’s and Salmon’s films. Salmon films a local in Ullapool asking why volunteers in the community are the ones left to clean up the rubbish that’s washed up on their beaches, including debris from fish farming. It is an issue the locals on Arran face too.

“One of the questions on Arran was: shouldn’t the people who make the rubbish be responsible for their own rubbish, but it’s not as simple as that,” says Webb-Ingall. “If you take that argument and scale it up, it wouldn’t work – because everyone creates rubbish all the time and it’s about everyone being more vigilant generally.”

He says the biggest issue that came up when he was making the film was plastic waste and welcomes the idea of raising the charge for plastic bags from 5p to 10p. “That will make a difference,” he says. He also credits some of the recent reductions in the use of plastics to David Attenborough's Blue Planet series, which showed the shocking effects of plastic in the ocean.

“David Attenborough is held as a god in all these places,” he says. “The number of people who watched Blue Planet and talked about it mean he is such an important figurehead to the argument.” One of the most striking moments in Ed’s film is when a sailor considers the problem of pollution. “You just have to look at the sea,” says the sailor, “and you can see how unhappy it is.”

What Webb-Ingall has realised in making his film, though, is that every potential answer on pollution, and other problems facing the sea, is complicated, including marine protected areas.

“Whenever you draw a line with an MPA, you are always going to be leaving someone out,” he says. “I also knew I couldn’t make a film about marine protected areas and not talk about fishermen. You can’t make a film about the sea and not talk to people who work in it and rely on it.”

One young fisherman in the film is particularly interesting. Webb-Ingall had just been around Arran asking people what they saw as the main threat to the sea and most said pollution or fish farming, but the young fisherman said “the price of fishing licences”. It's because for him the sea is a vital source of income and he worries that young people may not be able to afford to carry on the tradition. Another fisherman in the film complains that people can’t see what is happening under the sea so it’s fishermen who often become the targets of people’s anger because they are visible.

Webb-Ingall says the Shore project is about trying to change that and says that he was impressed by the fact that, although they might have competing interests, everyone he spoke to had a shared motive: to protect the sea – they just want to do it in different ways.

Webb-Ingall’s hope is that the Shore films can also help people to think about what they can’t see when they look out to the ocean: its scientific, mystical, local, and global importance, all the competing interests, the contradictions sloshing around, the tangle of the net. “We’re all connected by the sea,” he says. “We all have a relationship with it. We all relate in different ways to the same thing.”

Shore: How We See The Sea is at Barra, on Saturday, September 8, Gairloch on Saturday, October 20, Ullapool on Monday, October 22, and on national tour thereafter. For more information, see invisibledust.com/project/shore-how-we-see-the-sea/