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Report: Amount Of Plastic In Sediment Has Doubled Every 15 Years

 September 4, 2019 at 10:52 AM PDT

Speaker 1: 00:00 Since World War Two the use of plastics has soared in the United States and around the world coupled with a huge surge in population, especially along the coast. It's not surprising that plastic pollution in the ocean is exploding as well. A new study by researchers at Scripps Institution of oceanography at UC San Diego reveals how quickly plastics are accumulating. It's published today in the journal Science advances and joining me to discuss the findings is scripts, microplastics biologist Jennifer Brandon, lead author of the study. Welcome to midday edition. Thank you for having me. Well, you looked at the accumulation of plastic and sediments from the floor of the Santa Barbara Basin. Why did you pick that location and how did you go about gauging the accumulation of plastic over the years? Speaker 2: 00:48 The Santa Barbara Basin is a really unique place and sedimentary wise because there's no oxygen at the bottom of the basin, so sediment falls there and then there's no animals there that are living there and kind of stirring up the sediment. And so things live at the top of the water. They fall into the sediment and they just kind of fall in these perfect yearly layers. And so we can look at really fine scale changes in sedimentary lagers and over just something like the last 75 years since World War Two. Um, whereas if we were to do this study in another place, the sedimentary layers are too big, each layers a hundred years or a thousand years and you wouldn't be able to see a trend in plastic. Speaker 1: 01:31 And what did you find in examining the record on the s on the sea floor off Santa Barbara dating from World War II forward. Speaker 2: 01:37 The study went from World War Two to 2010 and I found this exponential increase in plastic. So it went from almost no plastic on the sea floor around the end of world war two to a huge increase and te in basically modern day. And, and then when I tied that exponential increase to the exponential increase in world plastic production over that same time, there's a very tight correlation. So what that means is the plastic we're producing on land and consuming on land is leaving a plastic imprint. In our sedimentary record, Speaker 1: 02:13 and you note that the surgeon microplastics in the ocean might serve as a marker for the great acceleration within the new geological epic known as the Anthropocene. Explain what that means. Speaker 2: 02:25 So geologists believe that since World War Two we have so greatly changed and human civilization, human population and consumption patterns that we're truly creating a new geological epoch. We are changing where populations are, how big populations are, and how we consume materials that we really might be changing our geological signatures. And why plastics makes such a good geological proxy for this is that plastic lasts forever. It doesn't degrade. And so when I find it in these, in the sediment, it means that you know, future civilizations might find plastic forever. As our kind of fossil record, we could really be known as the plastic age, like the, you know, ancient iron age or copper age. Speaker 1: 03:13 Your study shows most of the plastic a was found in the form of clothing fibers that might surprise most people who think of plastic bags and straws and containers, soda, soda bottles, so forth as making up the bulk of plastic pollution. How much plastic is in clothing and how does it get into the ocean? Speaker 2: 03:30 We were more and more synthetic fabric these days. And so our clothes are actually being made of plastic. And then what happens is when you wear clothes that are made out of synthetic fibers, you wash them and little microfibers come off of then they're too small to be filtered out at the wastewater treatment plant. When you wash your clothes, they washed down the drain, they go to the wastewater treatment plant and they're too small to get filtered out. And so we did find the vast majority of our samples were these microfibers. Um, so yeah, you're not just littering on the beach and adding to this problem. Your clothes are actually adding to the problem too. Speaker 1: 04:09 How can that be prevented? Speaker 2: 04:11 It can be prevented on a variety of ways. You can actually do things at your individual household level. You can add a filter to your washing machine, you can wash your clothes in specific microfiber catching bags. But it can also be prevented at the larger level of companies looking at how they make their clothes. And then at the much larger level as us working on engineering, different ways to catch microfibers at waste water treatment plants. And that is much harder to do. But there's some engineers really working on that. Speaker 1: 04:43 The study is among many regarding plastic pollution in the oceans. What are some of the key findings regarding the number of tons of plastic entering oceans each year and at what depth is plastic being discovered? Speaker 2: 04:54 So one of the main studies that talks about how much plastic is entering the ocean each year kind of gives it a rounded estimate of four to 12 million tons entering the ocean per year. And when you think about that, that sounds like a huge number, but it's actually even a kind of larger, crazier number when you think about how light plastic really is and how much of that plastic are these tiny microplastics. So to get a ton of microplastics and microfibers is literally trillions of pieces. So we are adding a ton of plastic to the ocean. It is a kind of mind bending problem when you think about it Speaker 1: 05:34 and it's being found at great depths, right? Speaker 2: 05:36 Yes, we have found plastic at the bottom of the Marianas trench. So the deepest spot in the ocean, we found it in rivers. We found it in new CIS kind of everywhere. We look for it, unfortunately. Um, so this problem is not contained just to the great Pacific garbage patch like we once thought it is a Oceanwide and really planet wide problem. Speaker 1: 05:58 And your study didn't examine this, but the effects of plastic and marine life of all kinds should frighten us. All right? Speaker 2: 06:04 Absolutely. So my study was done in a place where there isn't a lot of marine life and that's why the sediment core is relatively undisturbed. But this same plastic is falling onto areas with lots of s of marine life in the bottom. Um, areas where there is coral reefs and muscle beds and kelp forests. And the fact that our plastic is entering the ocean at these high densities and on this kind of exponential rate of increase means that those animals are getting really high doses of plastic into their ecosystems. Speaker 1: 06:34 Now there's a big push to end the use of plastic bags, straws, containers, many other items in California and elsewhere. The expect this could have a significant effect to slow down the plastic pollution of the oceans. Speaker 2: 06:45 Um, I think it'll have an effect. I don't know if it is the final solution. I think it's more of a bandaid to the problem. I think it's important for us to do, but I think there is bigger things at stake and when there's this much plastic out there than just bending each item by item. But it's certainly important to attack this from multiple angles. Speaker 1: 07:07 So what would be something that wouldn't have a major significant impact on plastic pollution? Speaker 2: 07:12 I think, um, one of the things that would have a major impact is putting more of the onus on the companies. Having some companies that produce a lot of the plastic, have them have a plastic tax, have them be an, maybe I'm in charge more of the plastic cleanup, have it really go back to who is producing all of this plastic that's ending up in the ocean as opposed to kind of playing whack-a-mole with individual bands. Speaker 1: 07:38 I've been speaking with microplastics, biologist, Jennifer Brandon of Scripps Institution of oceanography at UC San Diego. Thanks very much. Speaker 3: 07:50 [inaudible].

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A new study published in the journal Science Advances by researchers at Scripps Institution of Oceanography at UC San Diego analyzed sediment from the Santa Barbara Basin.
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