08/06/2016 10:46 BST | Updated 09/06/2017 06:12 BST

This World Oceans Day Is Time to Stem the Plastic Tide

When geologists from the future come to date the beginning of the Anthropocene, our current, human-dominated epoch, it is likely they will not bother looking for trace radiation from nuclear testing when our planet is so clearly shrink wrapped by a thin layer of faded plastic.

Huge amounts of plastic waste, carelessly thrown or blown into our waterways, ends up in our oceans. It breaks down into tiny particles known as 'microplastics'. These are ingested by marine life and, eventually, us.

One in four fish contain plastic, and that number is rising. But it could be worse. In fact, it is worse. We have made this process far more efficient by allowing manufacturers to include plastic microbeads in their products. Microbeads are not designed to go through our waste disposal systems. They wash straight down the plughole and out to sea.

We don't have to wait for them to break down into microplastics, because they already are.

Today, Greenpeace, the Marine Conservation Society, EIA and Fauna & Flora International are handing in more than 310,000 signatures calling for a ban on microbeads to Downing Street. We're confident that, sooner or later, we'll get one, because we can't think of any argument in microbeads' favour.

But a ban on microbeads is only one small step towards cleaning plastics from our oceans and removing the risk they pose to marine life, and those of us who eat marine life.

On World Oceans Day it is worth underlining how deeply worrying these risks are. Some juvenile fish have been recorded as preferring microplastics to their natural food of plankton, despite their inability to digest it or extract any nutrition. It seems as though human juveniles are not the only species with a taste for junk food!

Fish exposed to high levels of microplastics have changed behaviour patterns, have lower life expectancy and lower reproductive rates.

We don't yet know what effects the higher concentrations in the predator fish humans tend to eat might have.

Then there are the zombie pollutants. Various highly toxic chemicals which have been banned decades ago due to their health impacts. They are still floating around in the environment, in gradually decreasing volumes. These chemicals bind to plastics, particularly microplastics with their higher ratio of surface to volume. So the microbeads act as pollutant collectors, and the food chain acts as a pollutant concentrator.

On the positive side, we are finally removing PCBs and other dangerous poisons from the oceans.

Once microbeads are banned, we need to make sure we don't mistake that small step as the complete journey. They are to plastic pollution what 4X4s are to traffic pollution - the most obviously wrong part of the problem but not the main source. If we believe some estimates, current rates would mean by 2050 there could be, by tonnage, as much plastic in the ocean as fish.

So what is the answer? Today Greenpeace can exclusively reveal that it's the same as it's always been. Reduce, re-use, recycle. And the reason why we have such a huge problem, when we have had the solution for decades, is that we have never really tried implementing it. Parts of Europe recycle effectively, and all credit to them. But that's only one third of the answer and the option you should only use when the other two have failed.

People taking their own coffee cups to Starbucks and their own bags to Sainsbury's may not look like radical environmentalism, but those are two of the very few areas where we can see people looking beyond recycling to re-using and, as a consequence, reducing overall plastic production.

Other forms of packaging can be reduced without the need for a re-usable replacement. We laugh at plastic wrapped bananas and oranges, but we are all suckers for the same con. Why do expensive biscuits, chocolates or perfumes require three times as much packaging as the cheaper versions? Could it be to make the contents look more valuable? Yet every extra penny a company spends on packaging is a penny less spent on the contents.

Huge quantities of pointless plastic wrapping, there to market rather than protect the product, are already illegal. But prosecutions are rare and fines rarely make it into four figures. Consumer power can help, and it is helping, but the problem is urgent, and we need government to take this issue seriously as well.