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Scientists: Up To 25,000 Barrels At DDT Dump Site In Pacific

 April 29, 2021 at 10:20 AM PDT

Speaker 1: 00:00 A decades, long suspicion that barrels of DDT had been dumped off the coast of Catalina Island is now closer to being proven. DDT has been banned as a pesticide for agricultural use in the U S for nearly 50 years. But environmentalist say the dumping may have gone on for years before the ban scientists from scripts have captured images that resemble more than 25,000 barrels of suspected DDT waste on acres of sea floor, between Catalina and Los Angeles. High amounts of DDT contamination have been found in the regions, ocean sediments and Marine mammals for years. But this is the first time that the exact location and extent of the dumping has been discovered. Journey may is Eric Terrell. He's chief scientist of the expedition and director of the Marine physical laboratory at Scripps institution of oceanography. Eric, welcome to the program. Thank you for having me. How did you conduct this search on the C4? Speaker 2: 01:01 So we used robotic tools which really would not be even available. So 10 years ago to try to conduct this type of survey where, um, these autonomous underwater vehicles were able to be launched and recovered from our research vessel Sally ride and Sally ride actually provided very high precise navigation signals down to these robots as they were conducting the surveys using a sonar technique called side scan, sonar and side scan. Sonar is a type of imaging sonar that's really advanced through the years. And in this case, we were looking to the right and the left of each vehicle out to 150 meters down to, you know, tens of centimeters of object detection scale. So we, we had, uh, you know, objects as small as a coffee cup. We could actually see them a seabed with tools like this. And I want to say that we saw coffee cups out there. Speaker 2: 01:52 I'm just trying to give you a perspective of the size of objects that we can actually detect with this type of sonar. What kind of images did you see? First activity we did was really to get on station well, um, there were some known barrels and begin mapping it with the summer and, you know, the, the sheer numbers that we began seeing in the data, um, you know, indicated that there was barrels located there and have the shape and dementia. And the acoustic brightness associated with the barrels, you know, really was first pulled this whole. We need to make sure sonar is working properly. So we had to, uh, do some various calibration and, you know, convinced herself. So I was working right. There's just this many barrels on the seabed. And the course of the two weeks we began to unravel of the full spatial extent of the debris field, uh, that, you know, went on for, you know, the dumping from the historical records, which went over for decades, you know, seemed to be concerned, concerned by the data that we saw Speaker 1: 02:53 And how wide an area are we talking about. Speaker 2: 02:56 So one of the unique features of the dumpsite while we know debris fields, dumping not only just by the acoustic targets is they, they have that they're distributed on the seabed in linear fashion, you know, consistent with a ship underway, copying things, um, as it's sailing along. And some of those, uh, kind of fields that are are long linear features, you know, extended up to 11 miles a like Speaker 1: 03:23 Now the barrels you discovered seemed likely to have contained a DDT, but you're still not sure is that right? Speaker 2: 03:32 Well, I think first and foremost for the public, it's really important to realize this dump site was used for a lot of industrial purposes. So we don't know what's inside these barrels because I don't have one example of a historical document from 1949 where, you know, barrels in the Montrose chemical corporation, which was the producer of DDT in the LA basin had dumped 20,000 barrels during that year or that salvage company dumped 20,000 barrels down. But the petrochemical industry in the same area, also the same salvage company dumped, you know, an excess of 140,000 barrels. So, so it's, yeah, as a scientist, we gotta be very careful how we project our data and what the nuances are of it. And, you know, kind of my message to the, to the public is there the one of barrels on the seabed more than likely there was some faction of those have DDT or were associated with a D to T manufacturing, but there was a lot of other industrial uses and we just don't know what's contained within all those barrels. Speaker 1: 04:36 Do you know if this side could possibly be cleaned up, Speaker 2: 04:41 You know, that, that, that would be a stretch for me to extrapolate at this point. You know, what we're hopeful for is knowing where to look on the C4. Cause we, you know, we're 13 days, we're able to kind of unravel the full extent of the debris field and what we need to do next is start conducting scientific studies. You know, I think there's a whole of government and a whole of community response here. That's really required to go after understanding that, um, the impacts and condition of the waste field and how that might be impacting the environment. Speaker 1: 05:15 And what's it like for a Marine scientist to see the ocean use this way as a dumping ground, Speaker 2: 05:22 You know, as a, uh, as an oceanographer and a scientist, you know, we're, we're charged with having very objective looks at and interpreting the data and presenting it accurately to the environment now as a ocean easiest and, and how to another planet, you know, it did begun a little depressing or humbling while we were out there. Um, yeah, I would say the, the entire scientific team as we began unraveling kind of the full field, you know, it's it, you know, I don't think at the time people probably thought they were doing the right thing in terms of they were dumping and fast-forward, you know what we know, no. Um, you know, maybe maybe changes that, that outlook on, you know, that sort of management, uh, approach that was taken back then, and it is certainly humbling to see what man can do with the environment. And, you know, the, the positive step is I think, you know, we've got capabilities and science that can be applied to these problems and hopefully, you know, right. Some of the potential longs that happened in the past, Speaker 1: 06:24 I've been speaking with Eric Terrell. He was chief scientist of the expedition and director of the Marine physical laboratory at Scripps institution of oceanography. Eric, thank you very much.

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Marine scientists say they have found what they believe to be as many as 25,000 barrels that possibly contain DDT dumped off the Southern California coast near Catalina Island.
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