00:00What are these people doing in the Colombian Caribbean Sea?
00:04Suddenly, from this perspective, they can see it a little better.
00:08Well, they're drilling into coral.
00:10These incredible animals are vital to marine ecosystems.
00:14And they are scientists.
00:16They go into the sea to dive with giant, hollow drills.
00:21to extract nuclei from some corals.
00:23Well, there are some of the secrets of the sea's past.
00:27Or as they usually say, they are like libraries of the past.
00:32The people you see here are Vinicius Méndez, a geologist, and Gabriel Castron, a chemist.
00:37They traveled from Brazil, from the University of Sao Paulo,
00:40as far as the island of Providencia, invited by the Colombian Geological Survey
00:44to look for those coral skeletons.
00:47We tackled them, and although the technique isn't new, it's a very time-consuming task.
00:52Those who do it must first accurately locate the coral's growth axis,
00:58which is right in the center, to then drill into the corals that are as hard as a rock.
01:04Well, "rock" is a general term that geologists wouldn't like.
01:08But allow me that small indulgence.
01:11In the case of Méndez and Castro, they take turns.
01:13While one drills into the coral, the other changes the compressed air tank.
01:18to which the drill is connected in order to function.
01:22They can last more than an hour. Why?
01:24Because, like the rings of tree trunks, they have markings
01:28which give scientists an indication of the age of each tree,
01:32Coral nuclei have bands that give clues to their age.
01:38and how the environmental conditions of the sea have changed.
01:41It's like we had a thermometer in the water 200 years ago
01:47and is constantly taking measurements.
01:50One of those skeletons, for example, may be 116 years old.
01:55As Méndez and Castro and the oceanographer Leticia Cabole told us,
01:59One of the project leaders will see how things have changed, for example,
02:03the temperature of water since the beginning of the industrial revolution,
02:07a period in which emissions responsible for climate change began to skyrocket.
02:12By cutting thin slices of 5 to 7 millimeters and analyzing them in a mass spectrometer,
02:20They can reconstruct proxies of what the temperature was like every two months.
02:25But not far from Providencia, another group of Colombian researchers
02:28They are also doing something very similar.
02:30In Baradero, opposite Cartagena, which is a very special place.
02:36Despite receiving all the pollution from the dike canal,
02:38with pesticides or waste from large cities,
02:42Corals still live there.
02:44There, Mónica Medina, a Colombian and professor at the University of California, Los Angeles,
02:49He has also extracted coral cores in the company of researchers such as Mateo López Victoria,
02:55Professor at Javeriana University in Cali,
02:58and Luis Parmenio Suescún, from the University of Cartagena.
03:02But they have done so with a very novel approach.
03:04For the first time, they will use the increasingly popular techniques for analyzing ancestral DNA,
03:11that have revolutionized archaeology and anthropology,
03:14And this time they will use it to study corals.
03:18What they want is to see how the microbiome of certain corals has changed.
03:23Well, corals are actually an entity made up of many more organisms,
03:29such as microalgae or bacteria that play key roles in their nutrition and health.
03:34As Medina, López, and Suescún told us,
03:37That opens the door to the possibility of understanding
03:41what is happening to the microbial ecosystem of each organism over time,
03:47and see which microorganisms have been winners and which have been losers in their life history.
03:54Perhaps in this way, with that journey to the past,
03:57They can shed more light on what kind of probiotics could be produced in the future
04:02to help restore that microbiome that is currently in serious trouble.
04:08If you want to know more about these fascinating stories of science and the environment,
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04:18Bye.
