National Marine Week – What Actually Happens to Ocean Plastic?

Around 8 million tonnes of plastic enters the ocean every year. Some sources say it’s 11. 

This really hard to imagine but it’s as if lorry full of rubbish unloaded it straight into the ocean. And do it again a minute later. For the whole day. Actually, ever single day, all year round. 

Most of that plastic doesn't wash up somewhere for everyone to see, and it doesn't sink to the seabed and simply stay there either. It’s worse than that. It breaks apart – into smaller pieces, then smaller again, then small enough that no clean-up effort could ever collect it back out.  

Normal items, nothing out of ordinary. Regular packaging, some fishing gear, a bottle left on a beach. But that was before the sea got hold of it.  

That's the part we often don’t understand about ocean plastic. It isn't really a bunch of bottles bobbing on the surface.  

It's mostly fragments too small to see, spread through water that looks perfectly clear. And that’s the problem. 

What Is National Marine Week 

National Marine Week is run by The Wildlife Trusts, a federation of 46 wildlife trusts covering the UK, Alderney and the Isle of Man. It's grown into an annual fixture over the decades, with local trusts each running their own programme of coastal events under one shared banner. 

First big surprise is… It’s not really a week. It actually runs for 16 days, timed around the UK's varying tides so more coastlines get a decent low tide during the event.  

The events themselves are hands-on:  

Each year has its own on a theme.  

For 2026, that's "Incredible Journeys" – the migrations marine animals make each year, from humpback whales and Arctic terns to species that barely move at all, like limpets returning to the exact same spot on a rock after every tide.  

The point isn't really the distance travelled. It's what those journeys show about how connected – and how fragile – the systems supporting them actually are. 

What Happens Once Plastic Hits the Water 

Sunlight and waves do most of the damage. UV light breaks down the bonds holding the polymer together, the surf grinds the already weakened pieces into smaller elements, and the fragmentation carries on long after the object stops looking like anything at all. 

That’s how microplastic happens, one of the main drivers of water pollution. 

How quickly does it happen? The timelines depend heavily on the material, and they run longer than most people expect. 

The phrase "breaks down" is a bit of a stretch. According to NOAA's Marine Debris Program, plastic in the ocean mostly fragments into progressively smaller pieces rather than disappearing outright, and some of it may never fully break down at all.  

Multiply that across the tonnes entering the ocean every year, and it stacks into decades of plastic overlapping with more decades of plastic, none of it clearing before the next lot arrives.  

That's the mechanism behind microplastics. Not plastic vanishing – plastic getting small enough to stop looking like plastic. 

Biodegradable Doesn't Mean What We Think 

"Biodegradable" on packaging reads like a promise that none of the above applies. It usually isn't one. 

Most biodegradable plastics need particular conditions to break down as intended – an industrial composting facility, sustained heat, the right microbes in the right concentration.  

NOAA is blunt about this: plastics labelled compostable, bio-based, or biodegradable may only break down under very specific conditions, and the open ocean rarely provides them.  

Once that packaging is floating instead of composting, it behaves like ordinary plastic – same fragmentation, same microplastic endpoint, different label on the way in. 

CleanHub’s Mission 

We work with CleanHub, and we want to be specific about what that means - or what they do.  

CleanHub funds waste collection in coastal regions of Indonesia, India and Cambodia, where household waste often isn't collected at all and ends up burned or dumped near rivers that carry it out to sea.  

The process runs in three stages. 

Every kilogram is tracked from collection through to final disposal, and the process is independently audited. One of CleanHub's recovery centres in Kerala aims to recover 6,000 tonnes of plastic waste a year – the kind of volume a single beach clean-up can't come close to matching.  

It isn't a beach clean-up, and it isn't undoing plastic already in the ocean. This is about stopping the plastic from reaching the water in the first place. 

The Textile Connection Nobody's Packaging Mentions 

None of the above touches what comes out of a washing machine, and that runs on a different mechanism entirely. 

Synthetic fabric – polyester, acrylic, nylon – sheds microplastic fibres every time it's washed. A single wash cycle can release hundreds of thousands of them, small enough to pass straight through most wastewater treatment systems and out into rivers and eventually the sea. That’s what we’re up against. 

The IUCN puts textile laundering at roughly a third of all primary microplastics entering the ocean – not fragments breaking off larger litter over decades, but plastic released as plastic from the very first wash. 

Natural fibres don't do this. Organic cotton and bamboo break down as organic matter when they eventually wear out, not as plastic fragments still circulating in a few hundred years.  

It's the difference between swapping a synthetic striped beach towel for an organic cotton beach towel or a set of bamboo towels. That’s the choice better for the planet – and the owners. The effects of exposure to microplastics are still being studied, but the results are getting more alarming than initially anticipated. 

Washing machine filters and wash bags can catch some shed fibres, but the simplest reduction happens before any fibre gets shed at all – buying fabric that was never plastic to begin with.  

Our wider eco towels range runs on that same logic: if it isn't shedding plastic in the wash, it isn't adding to the problems. 

The Part Anyone Can Control 

National Marine Week runs from 25 July to 10 August, and the dates are really just a prompt to look at something that happens every day regardless of the calendar.  

The plastic already in the ocean isn't going anywhere fast – some of it won't finish breaking down for centuries. That is, unless new technologies open up new venues and give us new possibilities. In the meantime – this is our, and our Planet’s, reality.