WEBVTT 00:02.669 --> 00:07.641 >>NARRATOR: Six years, 22 countries, 00:07.641 --> 00:11.378 close to 200 scientists, 00:11.378 --> 00:15.682 and one exceptional research vessel. 00:15.682 --> 00:18.585 The global reef expedition is on a mission to stud 00:18.585 --> 00:21.488 coral reefs around the world. 00:21.488 --> 00:24.458 >>Coral reefs are undergoing a worldwide crisis, 00:24.458 --> 00:26.393 and we are trying to understand 00:26.393 --> 00:29.329 where the healthiest reefs remain, 00:29.329 --> 00:31.465 what sort of factors make those reefs healthy, 00:31.465 --> 00:33.500 and, reefs that have been degraded, 00:33.500 --> 00:39.339 how we can help them recover and persist into the future. 00:39.339 --> 00:42.609 >>NARRATOR: To do so, expedition scientists conduct 00:42.609 --> 00:45.245 a number of studies in the field. 00:45.245 --> 00:48.382 >>We are applying a standard protocol 00:48.382 --> 00:52.085 that was developed through a consortium of scientists, 00:52.085 --> 00:56.256 and we think this will be incredibly beneficial 00:56.256 --> 01:00.994 to the world of science and management of resources, 01:00.994 --> 01:05.198 because now we can truly scientifically compare 01:05.198 --> 01:09.036 one reef to another, from one region to another. 01:11.271 --> 01:15.442 We operate under this banner of "science without borders." 01:15.442 --> 01:18.278 It is basically because there are no political boundaries 01:18.278 --> 01:20.380 between the oceans, it is all connected. 01:20.380 --> 01:23.684 And what you do in one location can affect another location. 01:23.684 --> 01:28.388 Every country we go to, we work with the government agencies 01:28.388 --> 01:31.224 and whatever universities are there to identif 01:31.224 --> 01:32.826 local participants. 01:32.826 --> 01:35.596 And we bring them out with us, first to get them to places 01:35.596 --> 01:37.531 that they can't normally get access to; 01:37.531 --> 01:39.733 second: to show them what we are doing. 01:39.733 --> 01:42.135 We try to provide training to them so that the 01:42.135 --> 01:45.205 pick up some of our methods and carry it on. 01:45.205 --> 01:48.575 >>It's a two-way street, because the local knowledge 01:48.575 --> 01:53.580 is immeasurably important to our research. 01:53.580 --> 01:58.018 And then the local scientists benefit by interacting 01:58.018 --> 02:02.522 with world-renowned scientists from very prominent universities 02:02.522 --> 02:04.591 and organizations. 02:04.591 --> 02:10.430 What every single country says is that their biggest limitation 02:10.430 --> 02:13.367 to really enacting sound conservation strategies 02:13.367 --> 02:16.370 is lack of scientific information. 02:16.370 --> 02:20.641 So our ultimate hope is that the research will influence 02:20.641 --> 02:22.075 action on the ground. 02:22.075 --> 02:25.545 And so we are acting as a catalyst. 02:25.545 --> 02:28.215 We're an accelerant to change. 02:54.441 --> 02:56.677 >>Major funding for this program was provided 02:56.677 --> 02:58.779 by the Batchelor Foundation, 02:58.779 --> 03:02.182 encouraging people to preserve and protect 03:02.182 --> 03:07.254 America's underwater resources. 03:07.254 --> 03:11.358 And by Divers Direct, inspiring the pursuit 03:11.358 --> 03:14.361 of tropical adventure scuba diving. 03:16.596 --> 03:21.435 (beachy music playing) 03:32.679 --> 03:37.184 >>NARRATOR: Tahiti, Bora Bora, the islands of French Polynesia 03:37.184 --> 03:41.521 evoke visions of an exotic tropical paradise. 03:46.460 --> 03:49.730 Located in the South Pacific, about halfway between 03:49.730 --> 03:53.734 South America and Australia, the island nation is made up 03:53.734 --> 03:57.037 of five archipelagos. 03:57.037 --> 04:01.308 >>French Polynesia has hundreds and hundreds of islands. 04:01.308 --> 04:06.279 And it is spread out in a massive geographical range. 04:06.279 --> 04:10.117 >>It is the size of western Europe, basically. 04:10.117 --> 04:16.590 >>These islands-- some of which have been studied extensively-- 04:16.590 --> 04:20.427 others have never been surveyed by scientists. 04:20.427 --> 04:25.999 And it is really exciting to go research areas 04:25.999 --> 04:30.137 that you know for a fact no other human has visited, 04:30.137 --> 04:32.639 and certainly never conducted 04:32.639 --> 04:37.677 any systematic scientific research. 04:37.677 --> 04:42.082 >>We're trying to compare reefs that are in a similar region 04:42.082 --> 04:44.718 across what I call gradients of human disturbance-- 04:44.718 --> 04:48.088 and what I mean by that is, going from very populated areas 04:48.088 --> 04:50.157 to very unpopulated areas. 04:50.157 --> 04:52.359 And it will help answer a lot of the questions that we have 04:52.359 --> 04:57.164 about resilience and how that is related to human impacts. 04:57.164 --> 05:00.167 >>NARRATOR: The global reef expedition is organized 05:00.167 --> 05:04.638 and funded by the Khaled Bin Sultan Living Oceans Foundation, 05:04.638 --> 05:07.307 a U.S.-based nonprofit established 05:07.307 --> 05:08.608 by his royal highness, 05:08.608 --> 05:12.546 Prince Khaled Bin Sultan of Saudi Arabia. 05:12.546 --> 05:16.349 >>Prince Khaled became a scuba diver, 05:16.349 --> 05:18.652 and really fell in love with the ocean 05:18.652 --> 05:22.155 and particularly coral reefs. 05:22.155 --> 05:24.191 While he was diving in the Red Sea, 05:24.191 --> 05:28.061 and he had one reef that was his favorite dive, 05:28.061 --> 05:30.597 and so he went back there a couple years later, 05:30.597 --> 05:34.568 and he saw the deterioration of the coral reef firsthand. 05:34.568 --> 05:37.804 And so that really gave him the initiative to do 05:37.804 --> 05:40.207 what he could do as a single person 05:40.207 --> 05:46.446 to try to help preserve these beautiful coral reefs. 05:46.446 --> 05:50.350 >>NARRATOR: In 2011, the global reef expedition 05:50.350 --> 05:53.153 got under way in the Bahamas. 05:53.153 --> 05:56.389 Since then, a dedicated team of researchers has worked 05:56.389 --> 05:59.025 its way across the Caribbean, the Galapagos, 05:59.025 --> 06:01.595 and to the South Pacific. 06:01.595 --> 06:04.764 In each location, science divers conduct 06:04.764 --> 06:10.170 a rapid environmental assessment to collect baseline data. 06:10.170 --> 06:12.038 >>We want to know what corals are there, 06:12.038 --> 06:14.474 what fish are there, what the bottom looks like, 06:14.474 --> 06:19.646 what other types of organisms are found there. 06:19.646 --> 06:22.315 Right now we are on Rangiroa, which is the largest atoll 06:22.315 --> 06:24.217 in French Polynesia. 06:24.217 --> 06:27.554 There is about 450 different atolls around the world, 06:27.554 --> 06:29.623 and French Polynesia has more than any other country. 06:29.623 --> 06:32.259 They have about 85 of them. 06:32.259 --> 06:34.728 >>NARRATOR: Atolls are ring-shaped coral reef islands 06:34.728 --> 06:37.264 that surround a lagoon. 06:37.264 --> 06:39.699 >>On these atolls, we look inside the lagoon 06:39.699 --> 06:43.236 and we look outside the lagoon on the fore-reef. 06:54.648 --> 06:56.516 >>NARRATOR: At each site, the divers work 06:56.516 --> 06:59.319 in a 100-square-meter area. 06:59.319 --> 07:05.191 Dive buddy teams collect different types of data. 07:05.191 --> 07:10.163 One team collects information on fish. 07:10.163 --> 07:12.565 >>We lay a 30-meter transect line. 07:12.565 --> 07:15.268 This is attached to us as we swim along the reefs. 07:20.106 --> 07:21.741 >>NARRATOR: As the divers work their wa 07:21.741 --> 07:24.778 along their transect lines, they identify and count 07:24.778 --> 07:29.049 all of the fish species they see within a four-meter radius. 07:29.049 --> 07:31.017 >>We try to do as many as we can. 07:31.017 --> 07:33.787 Typically, we would be able to cover maybe four transects 07:33.787 --> 07:35.522 during one dive. 07:35.522 --> 07:38.725 Around Rangiroa, we find a lot of sharks, 07:38.725 --> 07:40.660 which is typical for the area. 07:40.660 --> 07:43.263 At the same time, we also find a lot of herbivores, 07:43.263 --> 07:48.134 such as surgeonfishes and rabbitfishes or parrotfishes. 07:48.134 --> 07:50.036 These species occur in large schools 07:50.036 --> 07:51.738 that swim around the reef. 07:51.738 --> 07:53.373 And they are also very significant in that 07:53.373 --> 07:57.210 they have important roles on the reef. 07:57.210 --> 07:59.112 >>NARRATOR: Another team of divers is conducting 07:59.112 --> 08:02.382 benthic surveys, which means they are studying 08:02.382 --> 08:06.519 what lives on the sea floor. 08:06.519 --> 08:08.755 >>I lay out a ten-meter-long transect line, 08:08.755 --> 08:10.390 and every ten centimeters 08:10.390 --> 08:12.726 I record what is directly underneath that point. 08:12.726 --> 08:15.996 And I do this to accurately record 08:15.996 --> 08:17.564 what is on the bottom of the reef, 08:17.564 --> 08:19.666 and that helps us determine how much of it's coral, 08:19.666 --> 08:22.268 how much of it's sand, how much of it's algae. 08:22.268 --> 08:24.237 And then we do this at different depths, 08:24.237 --> 08:25.972 at every single reef, multiple times, 08:25.972 --> 08:27.440 and then that really helps us 08:27.440 --> 08:32.512 to assess what each reef looks like. 08:32.512 --> 08:36.449 >>And then the third survey approach focuses specificall 08:36.449 --> 08:40.653 on the corals, and we again use a transect. 08:40.653 --> 08:43.356 We lay out a line that is ten meters long, 08:43.356 --> 08:46.292 and we assess every coral that's within one meter 08:46.292 --> 08:47.694 of that line. 08:47.694 --> 08:50.730 So we are looking at a ten-square-meter area. 08:50.730 --> 08:52.999 And for all these corals, we will identify what type 08:52.999 --> 08:54.701 of coral it is. 08:54.701 --> 08:57.937 We then measure its size, and then we record information 08:57.937 --> 08:59.339 on how healthy that coral is. 08:59.339 --> 09:01.741 By measuring size, it gives you information 09:01.741 --> 09:05.145 on the current status of that reef, 09:05.145 --> 09:07.614 the past history of the reef, and the direction 09:07.614 --> 09:09.549 it is likely to go in the future. 09:09.549 --> 09:12.385 And so an ideal reef would be one that 09:12.385 --> 09:15.955 has a lot of different species together, and it also has 09:15.955 --> 09:20.627 a wide range of sizes. 09:20.627 --> 09:21.961 >>NARRATOR: Other divers conduct 09:21.961 --> 09:24.164 what are called photo-transects. 09:24.164 --> 09:27.500 To do so, they use a one-square-meter quadrat 09:27.500 --> 09:32.272 made from PVC pipes. 09:32.272 --> 09:33.573 >>And we will put that quadrat down, 09:33.573 --> 09:35.075 and we just flip that over ten times 09:35.075 --> 09:38.578 and take ten pictures. 09:42.549 --> 09:45.051 Because we are limited on time, you can only do 09:45.051 --> 09:47.087 so many belt transects in there. 09:47.087 --> 09:49.522 We get the same information from these quadrats. 09:49.522 --> 09:53.593 We can get cover and we can get size of the corals. 10:07.440 --> 10:09.008 >>The reason we collect all this data 10:09.008 --> 10:11.377 is because the more you know about the reef, 10:11.377 --> 10:13.446 the better you can manage the reef. 10:19.119 --> 10:20.720 >>We know that one of the major factors 10:20.720 --> 10:24.124 responsible for the global coral reef crisis is climate change. 10:24.124 --> 10:27.193 Seawater is getting hotter than it has ever been before, 10:27.193 --> 10:29.462 and so it is causing corals to bleach and die. 10:29.462 --> 10:31.698 Storms are getting more intense. 10:31.698 --> 10:33.766 There is a growing threat from where the oceans 10:33.766 --> 10:35.702 are getting much more acidic. 10:35.702 --> 10:38.304 >>That is a global problem that is hard for reef managers 10:38.304 --> 10:40.073 to really tackle. 10:40.073 --> 10:42.675 But while that is a problem, what they can do is make sure 10:42.675 --> 10:46.146 that other factors aren't a problem to the reef. 10:46.146 --> 10:49.182 >>If we address a lot of those, if we improve water qualit 10:49.182 --> 10:50.683 in areas where a lot of people live, 10:50.683 --> 10:53.286 if we address some of the fishing pressure issues, 10:53.286 --> 10:54.754 if we do coastal development 10:54.754 --> 10:56.489 in a more environmentally friendly way, 10:56.489 --> 10:59.125 I think we could reduce those human impacts and make 10:59.125 --> 11:05.131 the reefs more likely to persist in light of climate change. 11:07.100 --> 11:09.235 >>NARRATOR: Fortunately for French Polynesia, 11:09.235 --> 11:12.405 its coral reefs are doing fairly well compared to reefs 11:12.405 --> 11:14.707 in other parts of the world. 11:14.707 --> 11:18.278 While they have been impacted by coral bleaching, 11:18.278 --> 11:20.780 intense storms, and other natural factors, 11:20.780 --> 11:26.452 human impacts are very low. 11:26.452 --> 11:29.589 One of the biggest challenges to marine research is access 11:29.589 --> 11:32.058 to remote locations. 11:32.058 --> 11:35.028 Conducting research at sea is very expensive, 11:35.028 --> 11:39.666 which is why many areas are understudied. 11:39.666 --> 11:42.635 To make the global reef expedition possible, 11:42.635 --> 11:47.640 Prince Khaled Bin Sultan donated the use of one of his yachts... 11:53.713 --> 11:58.751 ...the 220-foot "M.Y. Golden Shadow." 11:58.751 --> 12:01.588 >>The "Golden Shadow" really has an amazing suite 12:01.588 --> 12:04.157 of capabilities. 12:04.157 --> 12:08.728 There is a large stern elevator that operates on hydraulics, 12:08.728 --> 12:13.299 and that stern elevator can lower right down in the water. 12:13.299 --> 12:17.170 And its purpose was to recover and launch 12:17.170 --> 12:19.305 a Cessna caravan seaplane, 12:19.305 --> 12:25.111 and that 12-ton stern elevator can also be used to launch 12:25.111 --> 12:29.215 some of the bigger tenders, the dive boats that we use. 12:33.553 --> 12:37.690 The principle dive boat is a 36-foot catamaran 12:37.690 --> 12:40.560 that we can put up to 18 scuba divers 12:40.560 --> 12:47.400 to do our surveys on the coral reefs. 12:47.400 --> 12:52.138 The ship has a very large dive locker where we can 12:52.138 --> 12:54.274 fill our dive tanks. 12:54.274 --> 12:57.043 And in the event of decompression sickness, 12:57.043 --> 13:02.315 we have a recompression chamber, which really is useful 13:02.315 --> 13:06.052 when we are in remote locations of the world and we don't have 13:06.052 --> 13:10.189 medical facilities readily available. 13:10.189 --> 13:13.192 Also, one of the assets of the ship 13:13.192 --> 13:17.664 is extremely long endurance, and so we can travel 13:17.664 --> 13:22.769 about 10,000 miles with one filling of fuel, 13:22.769 --> 13:29.642 which allows us to access remote areas of the world. 13:29.642 --> 13:31.377 >>NARRATOR: In recent years, 13:31.377 --> 13:35.148 many of the traditional funding sources for scientific research, 13:35.148 --> 13:39.786 such as large government grants, have declined. 13:39.786 --> 13:44.123 >>I'm seeing more and more private individuals 13:44.123 --> 13:48.094 start to engage in things like oceanographic research. 13:48.094 --> 13:52.532 So when you see these foundations stepping up 13:52.532 --> 13:56.369 and filling this void, it is very encouraging. 14:10.416 --> 14:12.085 >>NARRATOR: Another important aspect 14:12.085 --> 14:15.254 of the global reef expedition involves the creation 14:15.254 --> 14:19.058 of large-scale maps of the sea floor. 14:19.058 --> 14:22.095 >>And the way we do that is we start to acquire 14:22.095 --> 14:24.063 satellite imagery about a year before 14:24.063 --> 14:26.332 we come to the location with the ship. 14:26.332 --> 14:30.336 So that's a very long process to acquire pictures of the earth, 14:30.336 --> 14:33.206 which aren't confounded by clouds. 14:33.206 --> 14:35.742 It's a very high resolution and new satellite, 14:35.742 --> 14:37.710 and the imagery allows us to differentiate 14:37.710 --> 14:39.312 the character of the sea floor. 14:39.312 --> 14:42.515 So we can separate sea grass from coral from sand 14:42.515 --> 14:45.184 to all the typical benthic habitats you find 14:45.184 --> 14:47.687 in a coral reef environment. 14:47.687 --> 14:50.089 >>NARRATOR: The mapping project is spearheaded 14:50.089 --> 14:52.458 by Dr. Sam Purkis and his team 14:52.458 --> 14:54.594 from Nova Southeastern University's 14:54.594 --> 14:59.031 Oceanographic Center in Ft. Lauderdale, Florida. 14:59.031 --> 15:01.100 Once they have all the high-resolution images 15:01.100 --> 15:06.539 of an area in hand, they begin ground-truthing on location. 15:06.539 --> 15:10.143 >>We come in to the field on the ship to start to relate 15:10.143 --> 15:12.211 what the satellite is seeing from orbit 15:12.211 --> 15:14.981 to what is really happening on the coral reef itself, 15:14.981 --> 15:16.149 on the sea floor. 15:16.149 --> 15:17.350 We can then start to get 15:17.350 --> 15:19.218 even finer resolution differentiating 15:19.218 --> 15:22.188 between areas of coral, which are live and vibrant 15:22.188 --> 15:26.058 and healthy, versus those which are in not such good shape, 15:26.058 --> 15:28.027 or perhaps even completely dead. 15:28.027 --> 15:29.595 So we can make a snapshot, 15:29.595 --> 15:32.565 a large-scale, regional-scale audit 15:32.565 --> 15:36.068 of the state of the coral reef at this point of time. 15:36.068 --> 15:37.737 >>One of our primary instruments 15:37.737 --> 15:39.472 is an acoustic depth sounder, 15:39.472 --> 15:42.008 and that is this instrument here. 15:42.008 --> 15:45.311 And he is set up so that he can swing in to the water, 15:45.311 --> 15:46.712 as I am doing now. 15:46.712 --> 15:49.415 And this instrument pings a couple times a second, 15:49.415 --> 15:52.585 as we're moving along. 15:52.585 --> 15:55.621 And you see he is pinging quite quickly right now. 15:55.621 --> 15:57.356 And right now it's about 14 meters deep. 15:57.356 --> 15:59.559 And here you can see the surface. 15:59.559 --> 16:02.462 It is quite flat, so that tells us that we are over sand. 16:02.462 --> 16:06.299 Here you have the position, the latitude and longitude 16:06.299 --> 16:08.701 of each depth sounding as it is being recorded. 16:13.272 --> 16:16.542 >>So what I am getting ready to do is to drop this camera 16:16.542 --> 16:18.177 into the water. 16:18.177 --> 16:20.313 It is a high-resolution video camera with a weight 16:20.313 --> 16:24.450 on the bottom and a fin to keep it stable on 50 meters of cable. 16:24.450 --> 16:27.420 So what we can do is, we are going to lower 16:27.420 --> 16:29.188 this into the water down to just above the seafloor 16:29.188 --> 16:31.090 and fly it along. 16:31.090 --> 16:34.026 The camera is linked in to a very accurate GPS 16:34.026 --> 16:36.596 at the back of the boat so we know exactly where it is, 16:36.596 --> 16:39.198 and the bearing and the speed that it is flying. 16:39.198 --> 16:41.767 And that's the information that we're collecting 16:41.767 --> 16:44.103 to validate what we see from the satellite. 16:44.103 --> 16:45.738 >>Sam, when you're ready. 16:45.738 --> 16:47.473 >>All right then, neutral. 16:47.473 --> 16:48.674 >>That means neutral. 16:48.674 --> 16:50.176 >>Here we go. 16:58.518 --> 17:01.387 >>How's that, Jeremy? 17:01.387 --> 17:03.089 >>Hold there. 17:03.089 --> 17:07.727 >>Holding. 17:07.727 --> 17:10.062 >>We can see where we are on the satellite image live, 17:10.062 --> 17:12.331 and we can see the video feed coming from the tethered camera 17:12.331 --> 17:16.435 on the sea floor as well, so we know exactly what is going on. 17:16.435 --> 17:17.603 >>All right, done. 17:17.603 --> 17:19.472 >>Coming up. 17:26.779 --> 17:29.115 >>Okay, that's done. 17:29.115 --> 17:31.017 The last piece of the puzzle is we have 17:31.017 --> 17:33.286 a very low-frequency acoustic sounder, 17:33.286 --> 17:35.221 and we use that to examine what's going on 17:35.221 --> 17:38.724 beneath the sea floor itself, so we can see how thick 17:38.724 --> 17:40.393 a coral reef framework is. 17:40.393 --> 17:42.695 And that gives us some idea as to whether, 17:42.695 --> 17:45.565 if we see a reef today which is not very healthy, 17:45.565 --> 17:48.234 we can see how well that reef has been faring 17:48.234 --> 17:51.137 over the last 10,000 to 6,000 years of growth. 17:51.137 --> 17:53.105 And then we can see whether it is anomalous, 17:53.105 --> 17:55.241 whether the reef today is unhealthy or not, 17:55.241 --> 17:57.944 or really is it just not a very good area 17:57.944 --> 17:59.145 for a reef to be developing. 18:03.683 --> 18:06.152 The technique of mapping the ocean floor from satellites 18:06.152 --> 18:08.187 is routinely used but not at this scale. 18:08.187 --> 18:10.556 Typically we look at areas 18:10.556 --> 18:14.527 of 100 square kilometers or so per year. 18:14.527 --> 18:17.363 We are now covering 25,000 square kilometers. 18:17.363 --> 18:19.599 And so these are the largest applications 18:19.599 --> 18:21.634 of the technology to date, and that is very exciting 18:21.634 --> 18:27.540 to be involved with. 18:27.540 --> 18:29.175 >>NARRATOR: When all of the fieldwork is done, 18:29.175 --> 18:31.043 the scientists work up their data 18:31.043 --> 18:35.114 at the university's lab in Ft. Lauderdale. 18:35.114 --> 18:37.583 >>That is a fairly lengthy process involving 18:37.583 --> 18:40.319 computer programming, and so there is 18:40.319 --> 18:42.755 a mathematical manipulation of the data set. 18:42.755 --> 18:46.626 >>NARRATOR: Using a variety of different computer programs, 18:46.626 --> 18:49.662 the experts link the depth values collected 18:49.662 --> 18:52.131 in the field with the light values depicted 18:52.131 --> 18:55.735 in the satellite imagery to create accurate bathymetry, 18:55.735 --> 18:57.970 or depth maps. 18:57.970 --> 19:03.042 >>We use the bathymetry that we gathered in the field 19:03.042 --> 19:08.247 to train an algorithm that then says this amount of light 19:08.247 --> 19:11.117 is an estimate for this type of depth. 19:11.117 --> 19:12.752 The ground-truthing becomes our training set, 19:12.752 --> 19:14.520 is what we call it. 19:14.520 --> 19:17.223 So this says, we know in these areas that this is what is here, 19:17.223 --> 19:20.693 this is the water depth, and from this... 19:20.693 --> 19:23.696 now I need to extrapolate to all of these other polygons 19:23.696 --> 19:26.766 and pixels in my area to make sure that 19:26.766 --> 19:29.468 I am estimating things properly. 19:29.468 --> 19:31.704 Our field efforts tend to be intense, 19:31.704 --> 19:33.973 because we need to get as much information as possible 19:33.973 --> 19:36.308 out there, to make sure that when we come back 19:36.308 --> 19:39.111 and do the statistics and the math, 19:39.111 --> 19:41.280 we have a strong set coming out. 19:41.280 --> 19:44.183 >>NARRATOR: The team also creates habitat maps 19:44.183 --> 19:47.053 by assigning groups of pixels in the image 19:47.053 --> 19:51.290 to different habitat classes, such as corals or sand. 19:51.290 --> 19:54.060 >>And in this program, I use the drop cam videos 19:54.060 --> 19:58.130 and some of my own knowledge to assign classes in the image. 19:58.130 --> 20:03.469 So here I just select a bunch of sand, and then classify it, 20:03.469 --> 20:05.571 so now it is marking it so that I know 20:05.571 --> 20:08.007 that he has been called sand. 20:08.007 --> 20:10.443 And I do that over different depths so that 20:10.443 --> 20:15.614 we have quite a range. 20:15.614 --> 20:18.484 And here I will just assign some reef. 20:18.484 --> 20:22.588 >>NARRATOR: Using algorithms and a variety of software, 20:22.588 --> 20:25.524 the computer can then extrapolate habitat classes 20:25.524 --> 20:28.327 for the entire image. 20:28.327 --> 20:30.262 >>It uses spectral values or depth values 20:30.262 --> 20:32.631 to then group the pixels together, 20:32.631 --> 20:35.634 saying this should be a reef, this should be sand, 20:35.634 --> 20:38.137 this should be land. 20:38.137 --> 20:40.773 What this allows us to do is to use only a few examples 20:40.773 --> 20:44.076 from the image itself to classify the entire image. 20:44.076 --> 20:46.378 >>NARRATOR: Once the process is complete, 20:46.378 --> 20:49.749 the experts have created two kinds of maps 20:49.749 --> 20:53.219 that can be combined to make a three-dimensional map 20:53.219 --> 20:55.187 of the seafloor. 20:55.187 --> 20:56.489 >>The fantastic thing about the maps 20:56.489 --> 20:59.759 is they're digital, and they can be tendered 20:59.759 --> 21:02.228 to the public through the internet. 21:02.228 --> 21:05.598 They can be housed in government computer systems, 21:05.598 --> 21:09.235 or they could be printed into very large-format posters 21:09.235 --> 21:11.704 or atlases. 21:11.704 --> 21:14.039 >>You can see there is a bathymetric map on the left, 21:14.039 --> 21:16.142 a habitat map on the right. 21:16.142 --> 21:19.278 Here on the water depth, the red are the shallower areas, 21:19.278 --> 21:24.383 with blue being moderate depths, and blue being the deepest areas 21:24.383 --> 21:26.152 that we can see. 21:26.152 --> 21:29.421 And on the right, when the habitat yellow is sand, 21:29.421 --> 21:33.392 the reds and oranges are different coral frameworks. 21:33.392 --> 21:35.594 Green is algae or sea grass. 21:35.594 --> 21:39.031 >>The data is very powerful because the maps 21:39.031 --> 21:42.301 we are producing set a baseline which then can be revisited 21:42.301 --> 21:43.669 through time to look 21:43.669 --> 21:49.508 for regional-scale ecological change. 21:49.508 --> 21:51.243 >>NARRATOR: Another science component 21:51.243 --> 21:54.046 that will be incorporated into the mapping process 21:54.046 --> 21:58.350 is a study of the sediments found on the sea floor. 21:58.350 --> 22:03.989 What this is able to kind of show us is a spatial pattern. 22:03.989 --> 22:05.758 You can make sediment maps 22:05.758 --> 22:08.594 using the sediment composition dataset. 22:08.594 --> 22:11.530 So we are able to map the different gradients of sand 22:11.530 --> 22:15.367 and how they are correlated with the coral cover, 22:15.367 --> 22:18.771 algal cover, and any sort of storm disturbance. 22:18.771 --> 22:22.241 >>NARRATOR: Nova Southeastern University graduate student 22:22.241 --> 22:27.213 Alexandra Dempsey collects sediment samples on each dive. 22:27.213 --> 22:31.650 >>We try to sample around three to five vials of sand. 22:31.650 --> 22:33.552 >>Collecting sediment on the coral reef 22:33.552 --> 22:37.356 is a little bit like taking a blood sample for a human. 22:37.356 --> 22:39.191 With a blood sample, you can tell the condition 22:39.191 --> 22:42.161 of the body and the health and so on and so forth. 22:42.161 --> 22:46.198 A coral reef, by the way, it grows and decays. 22:46.198 --> 22:47.733 It produces sediment. 22:47.733 --> 22:50.436 And by collecting that sediment, we can start to understand 22:50.436 --> 22:53.339 the history of the reef. 22:53.339 --> 22:56.342 It may seem like a rather mundane thing to sample, 22:56.342 --> 22:58.711 but we can gather great insight about the coral reef 22:58.711 --> 23:03.249 and its history by examining it. 23:03.249 --> 23:04.617 >>When we return back from the field 23:04.617 --> 23:06.318 after collecting sediment samples, 23:06.318 --> 23:09.054 we go ahead and we wash them and dry them in this lab, 23:09.054 --> 23:11.123 and we run them through this machine called the camsizer. 23:11.123 --> 23:15.261 What a camsizer does is measure each individual grain 23:15.261 --> 23:20.432 to the shape of the grain, its actual dimensions and area. 23:20.432 --> 23:23.002 And it is able to tell us what percentage of the sample 23:23.002 --> 23:25.070 is a certain grain size. 23:25.070 --> 23:27.339 You can tell a lot by how large the grain sizes 23:27.339 --> 23:30.075 are in a sediment sample, where they come from, 23:30.075 --> 23:32.544 if they are from a specific type of coral, 23:32.544 --> 23:36.448 or from an algae, or from sponges. 23:36.448 --> 23:39.218 >>NARRATOR: Alexandra can also take a closer look 23:39.218 --> 23:41.420 at sediment samples under a microscope 23:41.420 --> 23:44.056 to better understand what may have happened 23:44.056 --> 23:47.059 in a certain area over time. 23:47.059 --> 23:50.796 >>If most of the reef is dead and we really don't have 23:50.796 --> 23:54.099 an explanation for it, we can go ahead and look 23:54.099 --> 23:58.037 into the sediment sample and you can see what factors 23:58.037 --> 24:02.174 have contributed to the downfall of that specific site. 24:04.143 --> 24:06.278 >>NARRATOR: One of the big threats to the reefs 24:06.278 --> 24:09.682 in French Polynesia is crown of thorns sea stars, 24:09.682 --> 24:14.053 which can eat large amounts of coral in a short amount of time. 24:14.053 --> 24:18.157 >>If we can see crown of thorns spines, we can sa 24:18.157 --> 24:21.193 that's one of the factors, or the main contributing factor 24:21.193 --> 24:27.132 to why a reef is no longer healthy. 24:27.132 --> 24:29.368 >>NARRATOR: All of the data collected on each mission 24:29.368 --> 24:33.005 is combined into a geographic information system 24:33.005 --> 24:36.175 that is available online. 24:38.510 --> 24:41.080 >>And that is also handed to the country itself. 24:41.080 --> 24:44.416 So we are trying to provide them all these geospatial tools 24:44.416 --> 24:50.356 that they can then use to implement conservation. 24:50.356 --> 24:55.160 >>The global reef expedition is really only the start of things. 24:55.160 --> 24:57.763 We are gaining great advanced knowledge 24:57.763 --> 24:59.765 of how these ecosystems function, 24:59.765 --> 25:01.600 and how healthy they are. 25:01.600 --> 25:05.137 But people will be able to use these data, 25:05.137 --> 25:08.574 I say, hundreds of years in the future. 25:11.977 --> 25:13.545 >>I really hope this research that we do 25:13.545 --> 25:15.781 and all these resources that we are providing to the country, 25:15.781 --> 25:19.985 that they are going to be used; that these maps can help create 25:19.985 --> 25:22.421 better management for the reefs, and that the reports 25:22.421 --> 25:25.024 we give them helps the local stakeholders here 25:25.024 --> 25:29.428 know their reefs better, and therefore protect them better. 25:29.428 --> 25:32.331 >>We have had a few success stories already, 25:32.331 --> 25:34.266 where some of the science that we have collected, 25:34.266 --> 25:36.568 they needed the information in order to take 25:36.568 --> 25:38.270 some sort of conservation step. 25:38.270 --> 25:40.039 That's what's really rewarding. 25:40.039 --> 25:41.373 When I see that we have done this work, 25:41.373 --> 25:43.242 it's good information for them. 25:43.242 --> 25:44.810 But when they take the next step, 25:44.810 --> 25:47.046 and then do something that is really going to protect 25:47.046 --> 25:49.148 these reefs for the future. 25:53.118 --> 25:56.555 Captioning sponsored by WPBT. 25:56.555 --> 26:00.225 Captioned by Media Access Group at WGBH. 26:00.225 --> 26:03.729 access.wgbh.org 26:11.470 --> 26:14.106 >>Major funding for this program was provided 26:14.106 --> 26:16.008 by the Batchelor Foundation, 26:16.008 --> 26:19.378 encouraging people to preserve and protect 26:19.378 --> 26:24.316 America's underwater resources. 26:24.316 --> 26:28.554 And by Divers Direct, inspiring the pursuit 26:28.554 --> 26:32.554 of tropical adventure scuba diving.