WEBVTT FILE 1 00:00:00.000 --> 00:00:00.520 [MUSIC] 2 00:00:00.520 --> 00:00:05.040 Something strange has been happening to the beaches across the Caribbean in recent years. 3 00:00:05.480 --> 00:00:08.920 Large amounts of a brown seaweed, called Sargassum, 4 00:00:09.120 --> 00:00:11.600 have been washing up on shorelines. 5 00:00:11.600 --> 00:00:15.000 Normally found in the open ocean, Sargassum causes 6 00:00:15.000 --> 00:00:18.840 a whole host of issues for coastal ecosystems and communities. 7 00:00:19.480 --> 00:00:22.360 So where is this seaweed coming from? 8 00:00:22.360 --> 00:00:24.080 Let's find out. 9 00:00:24.080 --> 00:00:29.080 Historically, Sargassum was found in scattered patches outside its main range. 10 00:00:29.360 --> 00:00:31.560 But then something strange happened. 11 00:00:31.560 --> 00:00:37.160 In the winter of 2009 to 2010, unusual wind patterns pushed water eastward 12 00:00:37.160 --> 00:00:40.720 from the Sargasso Sea towards the Strait of Gibraltar, where a portion 13 00:00:40.720 --> 00:00:44.680 was transported southward by the Canary Current along the coast of Africa, 14 00:00:45.080 --> 00:00:48.600 delivering a large Sargassum population to the tropical Atlantic, 15 00:00:48.640 --> 00:00:51.640 where it thrived on nutrients from various sources. 16 00:00:51.680 --> 00:00:55.440 This established a new, separate, population of the seaweed 17 00:00:55.640 --> 00:00:57.160 and gave rise to... 18 00:00:57.160 --> 00:01:00.101 ROY: The Great Atlantic Sargassum Belt 19 00:01:00.101 --> 00:01:01.728 That's Roy Armstrong, a professor 20 00:01:01.760 --> 00:01:05.240 in the Department of Marine Sciences at the University of Puerto Rico. 21 00:01:05.680 --> 00:01:09.200 Roy has been trying to figure out the impacts of Sargassum blooms 22 00:01:09.200 --> 00:01:11.800 that have been washing up on Caribbean coastlines. 23 00:01:11.800 --> 00:01:16.240 ROY: Sargassum is an essential habitat in the open ocean. 24 00:01:16.400 --> 00:01:19.360 Think of it as an oasis in the middle of the desert, 25 00:01:19.360 --> 00:01:23.680 it provides shelter, for turtles, for many fishes. 26 00:01:23.840 --> 00:01:28.360 VO: Problem is, when fueled by excess nutrients, Sargassum can quickly grow 27 00:01:28.360 --> 00:01:32.480 and upend the ecology around the islands, which can have negative consequences 28 00:01:32.480 --> 00:01:35.480 for near-shore communities and their economies. 29 00:01:35.680 --> 00:01:39.960 One of the biggest threats is the pungent and toxic hydrogen sulfide 30 00:01:39.960 --> 00:01:43.920 gas that Sargassum releases when it decomposes on shorelines. 31 00:01:44.640 --> 00:01:48.760 There is so much Sargassum that now regularly washes up on the coast, 32 00:01:48.920 --> 00:01:51.880 that local governments are searching for ways to estimate 33 00:01:51.880 --> 00:01:55.640 the size and location of blooms - and their trajectories, 34 00:01:55.840 --> 00:01:58.840 so they can better predict when it will reach the shoreline. 35 00:01:59.680 --> 00:02:02.520 ROY: Because, we cannot deal with all the Sargassum. 36 00:02:02.520 --> 00:02:08.040 So what we need is to prioritize - if you can track with satellites 37 00:02:08.480 --> 00:02:11.720 a patch that you know is going to impact 38 00:02:12.080 --> 00:02:16.440 a very sensitive area, then you know that that's the highest priority. 39 00:02:16.440 --> 00:02:20.120 Now you want to intercept that Sargassum before it comes to shore. 40 00:02:20.360 --> 00:02:24.240 VO: Computer models can rewind the clock to see how currents transport water 41 00:02:24.240 --> 00:02:28.720 across the Atlantic, and help researchers piece together where blooms originate. 42 00:02:30.200 --> 00:02:32.760 Additionally, instruments on NASA satellites 43 00:02:32.760 --> 00:02:36.720 can detect the signatures of large blooms as they move across the ocean. 44 00:02:37.000 --> 00:02:40.640 ROY: The remote sensing technology of NASA is very important 45 00:02:40.640 --> 00:02:43.920 first, to detect Sargassum, and then to track it. 46 00:02:44.400 --> 00:02:48.200 And this way we will have a pretty good idea if 47 00:02:48.200 --> 00:02:53.280 a large patch has the potential of coming to the coast and accumulating, 48 00:02:53.600 --> 00:02:57.496 and therefore impacting the marine ecosystems. 49 00:02:57.496 --> 00:02:58.720 VO: PACE, one of NASA's 50 00:02:58.720 --> 00:02:58.760 and therefore impacting the marine ecosystems Pace, one of NASA's 51 00:02:58.760 --> 00:03:02.400 newest satellites, can add to our growing knowledge of Sargassum blooms, 52 00:03:02.720 --> 00:03:05.720 further helping researchers decipher this new threat. 53 00:03:07.680 --> 00:03:09.640 ROY: Sargassum in general, I don't think it's 54 00:03:09.640 --> 00:03:13.640 something that we're going to see go away because 55 00:03:13.640 --> 00:03:18.920 that new population is in an area that is perfect for growth. 56 00:03:19.360 --> 00:03:23.920 So the the issue is how we're going to deal with the Sargassum problem, 57 00:03:24.440 --> 00:03:28.600 And that's one of the reasons that satellite remote sensing 58 00:03:28.920 --> 00:03:31.085 could be very beneficial. 59 00:03:31.085 --> 00:03:33.254 VO: Sargassum continues to threaten coastal communities 60 00:03:33.254 --> 00:03:33.280 could be very beneficial VO: Sargassum continues to threaten coastal communities 61 00:03:33.280 --> 00:03:37.200 around the Caribbean, but satellites and instruments can track how and why 62 00:03:37.200 --> 00:03:40.520 these blooms occur, and help us better safeguard coastal 63 00:03:40.520 --> 00:03:43.640 ecosystems, and the communities that rely on them.