Captain Charles Moore of the Algalita Marine Research and Education, a non-profit marine organisation in Long Beach, California explains the islands of rubbish mounting up in our oceans.
We just don’t worry about what happens to the millions of plastic bags, bottles, toothbrushes, plastic things that we throw away, as if it’s not really our business. Some of these plastics ends up being thrown into the sea, and that seems to be the end of the story, except that it isn’t. One man, Captain Charles Moore has very successfully highlighted the massive problem of plastic waste at sea, and analysed the so called Great Pacific Garbage Patch, which is one of the five huge expanses of drifting plastic in the world’s oceans.
What are the garbage patches made up of? How big are they?
Charles Moore: Basically, anything that flows is going to find its way there eventually. A very high percentage of everything entering the Pacific Ocean from the Pacific Rim, whether it’d be Russia, Japan, China, Indonesia on the western Pacific, or whether it’d be Alaska, Canada, the US, Central America on the eastern Pacific – those Pacific Rim countries are scoured by the ocean currents.
And it is phenomenal that these detritus items make their way to a central part of the Pacific, known as the Central Pacific Gyre. The North Pacific Subtropical Gyre is the synonym for that. And this particular current phenomenon has a period of rotation of 6 years around the periphery, but there are a lot of little swirling whirlpools on the inside.
And so it happens: it is off Japan and halfway between Hawaii and the US there are these eastern and western garbage patches where this stuff resides for decades. And that’s the one I had the misfortune or fortune, as it may be, to cross in 1997.
And back then, how big was it? I know you’ve been back recently. Has it grown in size? Give us an idea. The size of a football pitch, or what are we talking about?
Charles Moore: First of all, we are talking about oceanic currents. And they are relatively stable. So, the currents that create this vortex, this kind of toilet that doesn’t flush, these are stable currents that don’t really grow or contract that much. So, we have this stable phenomenon which is about twice the size of the continental US that is prone to accumulate debris.
And in 1997 when I crossed there, that was the occasional item. But you might have to wait for five minutes or so, before you saw another one. It wasn’t like an icebreaker plowing through the stuff, it was just an occasional bit here and bit there.
Now, in 2014 it is like an icebreaker plowing through. There is so much crap out there, that you can’t actually get away from it. It’s got tyres and we’ve even found an actual island you could walk on, made of 70 large buoys from an oyster farm that was dislodged during the Japanese tsunami.
So, it’s grown in the sense of the concentration, the spatial extent however has not grown. However, we did see much closer to the coast of California large spots of the debris, than we’ve seen before. We would see occasional shards of it, but now we are seeing large spots of debris closer to the mainland than we ever had before.
So, the ocean is turning into a big toilet?
Charles Moore: 7 billion people, half of them attempt to live within 50 miles from the coast, because the ocean does provide moderations in climate. Large bodies of water tend to moderate the climate. Human beings like that moderate climate. They live near the coasts. And the world is going to continue to have storms and tsunamis, and this stuff is going to continue to pile up, and go into the ocean, until we begin manufacturing and remanufacturing with an end of life for this material.
How long do the plastic wastes float around for before they degrade?
Charles Moore: First of all, we have to understand why we use so much plastic. It is because it is a moisture barrier and a vapor barrier, and because it resists biodegradation. If we could wrap everything in paper and keep it stored in a pristine condition, we would. It’d be much easier. But we can’t, because the vapors invade the paper, it absorbs moisture and the products wrapped in it won’t survive.
So, we use most of our plastic for packaging. And packaging does a very good job of keeping things in pristine condition. You can have a factory in Timbuktu and send it to the center of consumption, and it arrives in a pristine condition. So, it is what I call a key lubricant of globalization – this plastic packaging.
Now, because of its virtue of being so difficult to penetrate with water and so difficult to degrade, it lasts a long time. The estimates are that if, say, you put plastic in your compost, about 1-2% of it would go away each year. So, even in terrestrial environment where the bacteria, fungus and insects are active, it is a very slow process.
In the ocean the process is much slower. And it is also dependent on the depth. At the bottom of the ocean even paper doesn’t biodegrade. But in the surface waters biodegradation takes place at much slower rate than in a compost pile. It is cooler, the bacteria are spread out and there is very little fungus, and really only one insect – the Halobates – which is actually increasing now, because they lay their eggs on this trash. But it is kind of a water-strider that lives in the deep oceans.
So, we really don’t have the arsenal of degraders in the ocean that would biodegrade this material. So, it is taking a long time to go away. And it breaks into tiny, little, micro-size bits, which then are disappearing. The recent study by a Spanish group has highlighted the issue that I've been talking about for 15 years, which is that the smaller particles of plastic don’t correspond to the amount we think should be there. In other words, if you crumble up a cookie, you get a lot of cookie crumbs. But we are not seeing the crumbs out there, in the smaller size classes, even though we know all these plastics are crumbling up.
What is the effect on us?
Charles Moore: The fitness of the fish in the ocean is decreasing, as they consume plastic or fish and invertebrates, like zooplankton, that have consumed plastic. That’s a nonnutritive substance that accumulates toxicants. So, you are basically feeding them a bunch of poisoned pills that give them no nutritional value, and accumulating those toxins, and sending them up the food web to us.
In addition to changing the nature of the ocean itself, you can’t go back into the historical record and find sediment cores in the ocean bottom, where it reveals how the earth has handled synthetic polymers. These synthetic polymers are modern human invention and they are taking over the ocean, and we have no historical record to rely on, to understand what that means.
So, this is a brand new field of study and we don’t even have the scientists. We've only graduated one or two PhDs remotely associated with this kind of a study. So, we've got a long way to go in understanding what happens.
