A research project led by Prof. Hamad Al-Saad Al-Kuwari, Director of the Environmental Science Center of Qatar University, is revealing a completely different and unexpected picture.
In these sabkhas, a multitude of microbes that are too small to be seen with the naked eye have found strategies to survive under the extreme conditions imposed by the hot temperature and arid climate. Even more surprisingly, such microbes are apparently playing a key and, as yet, highly underestimated role for the formation of minerals and sedimentary rocks that are of great importance not only for the field of sedimentology and microbiology, but also for oil geology, material sciences, and even for the search of life on Mars.
The project, titled “Geobiological Processes in the Sabkhas of Qatar” was started in 2015, funded by Qatar National Research Fund (QNRF) under the National Priority Research Program (NPRP), initiating a truly multidisciplinary and international collaboration among scientists affiliated with prestigious universities and research institutes, including: Qatar University and ExxonMobil Research Center in Qatar, the ETH Zurich and the Space Exploration Institute in Switzerland, the NASA Jet Propulsion Laboratory in the USA, and the University of Toronto in Canada. After a successful first phase, the same line of research will continue during the forthcoming years, thanks to a new grant awarded during the 13th NPRP cycle.
The modern sabkhas of Qatar are among the rare environments on Earth where it is possible to study the formation of carbonate and evaporite minerals, which is a commonly found mineral association in ancient sedimentary sequences and, furthermore, constitutes economically important gas and oil reservoir rocks. These reservoirs are often located at depth in the subsurface, making their characteristic and physical properties difficult to evaluate and predict. Thus, the study of the Qatari sabkhas, where the same sedimentary sequence is forming today close to the surface, is of great benefit for geologists and engineers engaged in the exploration and exploitation of similarly constituted hydrocarbon reservoirs. Moreover, the sedimentary rocks forming in the sabkhas may be an analogue to sediments that have been identified by various robotic rovers and orbiters on the surface of Mars, and whose origin is yet to be fully understood. For these reasons, the sabkhas of Qatar represent unique “natural laboratories” or “modern terrestrial analogues” where it is possible to test hypotheses and implement new proxies useful both for the technical challenges of the energy industry and for answering fundamental scientific questions. In contrast to previous studies, the one orchestrated by Prof. Hamad Al-Saad Al-Kuwari was the first to investigate the sabkhas not only from a purely physicochemical perspective, but also focusing on the role that biology may have in these extremely inhospitable environments.
Numerous field campaigns have been conducted in various coastal areas of Qatar, leading to the identification of the Dohat Faishakh sabkha (Figure 1) and the Khor Al Adid sabkha (Figure 2) as the two places with the highest potential for conducting the planned research. Samples of sediments and microbial mats have been described and collected from these sites, which often required long days of work in the field, hampered by the sun and the challenging logistics. The collected samples have been subsequently analyzed in the laboratories of Qatar University, as well as those of the other collaborating research institutes, using techniques from the field of sedimentology, geochemistry, microbiology and molecular biology. This work allowed for discovering unexpected microbe-mineral interactions, demonstrating the importance that these microscopic primitive microorganisms have in the formation of minerals like dolomite, a common Mg-rich carbonate that is often a major constituent of oil and gas reservoirs (Figure 3). The same research also provided new insight into the microbial diversity and survival strategies that microbes were able to adopt to survive in these extreme environments. Interestingly, microbes in the sabkhas also create unusual textures and sedimentary structures that may potentially be found in a “fossil form” on the surface of Mars (Figure 4). Several findings done in the past years suggest that billions of years ago the conditions on the surface of Mars may have been not so dissimilar to that characterizing today’s Qatari sabkhas, which are therefore seen as ideal places to train for the forthcoming Mars exploration missions.
Besides the scientific importance, Prof. Hamad Al-Saad Al-Kuwari hopes that continuing to study the sabkhas of Qatar will contribute to drive the attention on this peculiar environment, increasing the general awareness about the importance of valorizing, and taking actions to preserve, such a delicate ecosystem. The sabkhas, so rare and unique worldwide, should be considered as a natural and valuable heritage of the country.
Figure 1. Location map of the Dohat Faishakh sabkha, NW Qatar. The dark area is the microbial mat zone.
Location map of the Dohat Faishakh sabkha, NW Qatar. The dark area is the microbial mat zone.
Figure 2. Location map of Khor Al Adid estuary in southern Qatar. The dark area is the microbial mat zone. The photo shows also the Broccoli delta in the estuary.
Combination of microbial mats, clay minerals and dolomite showing the importance of bacteria in the formation of some mineral assemblages.
Figure 3. Combination of microbial mats, clay minerals and dolomite showing the importance of bacteria in the formation of some mineral assemblages.
Scientists are looking for such bacteria produced textures in rocks from Mars to see if the planet hosted some microbial life at a certain stage in its history.
Figure 4. Scientists are looking for such bacteria produced textures in rocks from Mars to see if the planet hosted some microbial life at a certain stage in its history.
Source: QATAR UNIVERSITY