Dead Sea? not exactly

Researchers who dived into the Dead Sea discovered springs teeming with life. Who are those creatures that manage to live in such an extreme environment of the sea that was nicknamed the sea of ​​death?

Danny and Sesa Galileo

Israeli and German researchers who dived to the bottom of the Dead Sea uncovered complex systems of springs that extend hundreds of meters along the coast and reach a depth of about 30 meters below the surface of the water. Around the springs, as surprising as it may be, dense and diverse microbial communities were discovered, some of which are creatures not known to science at all!

The scientists from the two countries have been cooperating for several years in the study of the fresh water springs at the bottom of the Dead Sea. "Evidence of the springs' existence has long been observed in the form of eddies on the surface of the water near the coast. What was not known is how extensive these systems are and to what depth they reach," explains Dr. Danny Ionescu from the Max Planck Institute for Marine Microbiology in Germany, one of the authors of the study.

The study of the springs began in view of the alarming drop in the water level of the Dead Sea, which loses more than a meter of its height every year. The construction of the Dagania Dam on the Jordan River, the proactive evaporation of water for the purposes of extracting minerals in the Dead Sea factories and their Jordanian counterparts, and the damming of most of the streams that feed the sea on the Jordanian side are among the factors that have undermined the balance between the supply of water to the Dead Sea and its evaporation.

All of this affects the drop in the level, because the majority of the water that feeds the Dead Sea today is rainwater washed from the mountains of Judah and Moab and groundwater that erupts as underwater springs to an unknown extent.
The Dead Sea continues to surprise

"The Dead Sea is disappearing but at the same time continues to surprise," says Professor Yonatan Laron from the Department of Geography and Environmental Development at Ben-Gurion University. "Of all the sources of water entering the Dead Sea, it is difficult to estimate the contribution of the underwater groundwater and hence the importance of our research and discovery."

Through the inclusion of divers in the research, the researchers recorded for the first time on video the underwater springs bursting out of the bottom through conical jaws with an impressive diameter of up to ten meters.

Although they intended to explore the system of springs close to the shore, when they were underwater they were surprised to discover a new world in which there are systems of caves and caverns whose entrances are even at a depth of 30 meters, where the bottom of the sea is not sandy, but covered with a thick layer of salt.

While overcoming the difficulties of "the first scientific diving ever done in the Dead Sea", according to UNESCO, the researchers carried out underwater measurements, took samples of water from the springs' mouths and samples of the bottom from their surroundings and took them for examination in their laboratory.

Using a method they developed to directly measure the flow of the springs, and by analyzing the video footage, the researchers calculated the flow of the springs and the structure of their flow and learned for the first time about their morphology as part of the question of the water balance of the Dead Sea. By analyzing the water samples they took with molecular methods, they discovered to their complete surprise an unexpected wealth of microbial species in the water near the springs.

Besides the bacteria found in the water of the springs themselves, the researchers found that layers of bacteria cover large areas (between 50 and 10 centimeters around the springs, and sometimes several square meters) of the bottom around the springs and contain a large number of species, some of which are still unknown to science.
Life in nature continues even in extreme conditions

"The bacteria in the Dead Sea water mainly belong to the archaea superkingdom and their number ranges from 1,000 to 10,000 individuals per ml, a much lower number than in normal seawater," explains Ionesco. "Never before have bacterial mats or biofilms been found in the Dead Sea and not much is known about the bacteria living at its bottom. The discovery raises new questions regarding the ability of these bacteria to survive in the Dead Sea water and regarding the sources of energy that they utilize for their survival."

It should be noted that this is not the first time that the nickname "Death Sea" turns out to be inaccurate. Already in the thirties of the last century, Benjamin Eliezer-Volkani, then a doctoral student at the Hebrew University, realized that there are microorganisms capable of surviving in the Dead Sea, when he was able to isolate a variety of algae and bacteria from the seawater.

"Under certain conditions their number can even reach enormous dimensions. In these times there is no need at all to ask if there is life in the Dead Sea; The reddish color of the water, which results from the existence of billions of red algae and bacteria in each liter, announces the answer", according to Professor Aharon Cohen from the Hebrew University, who has been studying the Dead Sea since the XNUMXs.

The current discovery only confirms what we already know: life can be found anywhere on Earth, either in the depths of the ocean under tremendous pressures, exposed to strong radiations several orders of magnitude above those that humans can withstand, deep underground with no oxygen at all, or In our Dead Sea that is drying up in the eastern courtyard of Israel.

Those extremophile creatures that thrive in extreme environments are nature's way of telling us that even if the conditions on Earth change from one end to the other, life will continue to flourish. We, on the other hand, probably won't be here to see it happen.

To watch the video taken by the researchers underwater

The full article was published in Galileo magazine, November 2011