Diversity and Function of Photosythetic Biofilms in the Seas of Oman

Diversity and Function of Photosythetic Biofilms in the Seas of Oman


Dr. Doris Meyerdierks (Hanse-Wissenschaftskolleg)  


  • Prof. Dr. Raeid M. M. Abed, Sultan Qaboos University, Muscat, Sultanate of Oman, and former HWK Fellow  

Core Members 

  • Dr. Dirk de Beer, Max Planck Institute for Marine Microbiology, Bremen, Germany 
  • Asst. Prof. Dr. Dagmar Wöbken, Division of Microbial Ecology, University of Vienna, Austria 
  • Univ.-Prof. Dr. Bettina Weber, Institute of Biology, University of Graz, Austria 
  • Dr. habil. Katarzyna A. Palinska, Institute of Oceanography, University of Gdansk, Poland 
  • Dr. Jürgen Köster, Institute for Chemistry and Biology of the Marine Environment (ICBM), University of Oldenburg, Germany 

Associate Members 

  • Janina C. Vogt, Institute for Biology and Environmental Sciences (IBU), University of Oldenburg, Germany 
  • Alexandra Tamm, Max Planck Institute for Chemistry, Mainz, Germany 
  • Andreas Greve, Max Planck Institute for Marine Microbiology, Bremen, Germany 
  • Dr. Dimitri Meier, Division of Microbial Ecology, University of Vienna, Austria 
  • Dr. Arjun Chennu, Leibniz Centre for Tropical Marine Research (ZMT), Bremen, Germany 
  • Dr. Judith Klatt, Max Planck Institute for Marine Microbiology, Bremen, Germany 
  • Dr. Mohamed Gomaa, Sultan Qaboos University, Muscat, Sultanate of Oman 
  • Dr. Thirumahal Muthukrishnan, Sultan Qaboos University, Muscat, Sultanate of Oman 


2016 – 2018


The coastlines of Oman, which include the coastlines of the Gulf of Oman and the Arabian Sea, are among the longest in the Middle East, with over 2,092 kilometers of coastline from the northern tip all the way to the south. The temperature in the Gulf of Oman is somewhat different than the Arabian Gulf due to the influence of the monsoons in the Arabian Sea. The lowest mean temperature in winter is around 20°C, and 45°C in hot summers. The surface salinity in the Gulf of Oman and the Arabian Sea is generally higher in other seas and oceans (ca. 5-6%), and this salinity can become extremely higher (up to 25% in upper intertidal flats), especially when evaporation rate is highest. Oman seas experience very high intensities of light and UV radiations. The Gulf of Oman is a shallow sea, thus sensitive to sea-level change and global warming. Since the gulf is located in an already extreme climate zone, future effects are expected to be clear and significant. The Gulf of Oman is susceptible to strong winds and waves, pollution with oil, nutrient input through dust storms and acidification due to increase in atmospheric CO2.  

Microbial communities dominated by phototrophic bacteria constitute, as in other seas and oceans, a vital component of the marine ecosystems in Oman. Such communities were found to cover massive areas of the intertidal flats, forming well-developed laminated mats. Phototrophic communities also form blooms in the water column, a phenomenon known as harmful algal blooms (HABs. In the Gulf of Oman and in the Arabian Sea, the occurrence of HABs has increased in intensity and frequency during the last 10 years. Photosynthetic biofilms have also been found to colonize any undefended natural and artificial susbtratum in the marine environment, a processes termed as biofouling (Wahl 1989). Biofouling in Oman is causing serious problems for industry, navy, aquaculture, fishing gears, nuclear and desalination plants. In some locations, an interesting feature of the coastlines of the Arabian Gulf and the Gulf of Oman is its very close proximity to the arid deserts of the region. This inextricable link between the marine and the terrestrial microbial ecosystems can influence both ecosystems through the possible exchange of microbes and nutrients. 


There is a missing gap in our knowledge of the microbial diversity and processes in the Arabian Gulf and the Arabian Sea, compared to other seas and oceans around the world. This international HWK study group focuses on researching one component of this ecosystem, namely photosynthetic biofilms. Given that the environmental conditions in the Gulf of Oman and the Arabian Sea are quite extreme and different, it is anticipated that this research will result in some novel findings. Our previous research in photosynthetic microbial mats from the intertidal flats of Abu Dhabi lead to the discovery of unique adaptation mechanisms and processes that have never been reported before. 

Main objectives are: 

  • To investigate the diversity and biogeography of microorganisms in photosynthetic biofilms and to find out the environmental parameters that shape up their distribution. 
  • To study the different biogeochemical cycles (Carbon, Sulfur and Nitrogen) occurring in these biofilms and their regulation by different environmental parameters.  
  • To investigate the eco-physiology and adaptation mechanisms of these microbial communities to multiple extreme conditions of salinity, temperature, irradiation and desiccation. 


Kick-off meeting: Oct. 31-Nov. 1, 2016 
2. May 11-12, 2017 
3. Jan. 8-9, 2018 
4. Dec. 19-20, 2018 

Joint field trip campaign to Oman  
Feb. 19-Mar. 6, 2018 


  1. Abed RMM, Shanti M, Muthukrishnan T, Al-Riyami Z, Pracejus B, Moraetis D (2020), The Role of microbial mats in the removal of hexavalent chromium and associated shifts in their bacterial community composition. Frontiers in Microbiology. DOI: 10.3389/fmicb.2020.00012.  
  2. Abed RMM, Muthukrishnan T, Al-Khaburi M, Al-Senafi F, Abdul Munam, Mahmoud H (2020), Degradability of oxo-biodegradable polyethylene in the planktonic and benthic zones of the Arabian Gulf. Marine Pollution Bulletin 150:110639. DOI: 10.1016/j.marpolbul.2019.110639. 
  3. Vogt JC, Abed RMM, Albach DC, Palinska KA (2019), Latitudinal gradient of cyanobacterial diversity in tidal flats. PLOS One. 14(11): e0224444. DOI: 10.1371/journal.pone.0224444.  
  4. Abed RMM, Al Fahdi D, Muthukrishnan T (2019), Short-term succession of marine microbial fouling communities and the identification of primary and secondary colonizers. Biofouling 35(5):526-540. DOI:10.1080/08927014.2019.1622004. 
  5. Abed RMM, Tamm A, Hassenrueck C, Al-Rawahi AN, Rodriguez-Caballero E, Fiedler S, Maier S, Weber B (2019), Habitat-dependent composition of bacterial and fungal communities in biological soil crusts from Oman. Scientific Reports 9:6468. DOI: 10.1038/s41598-019-42911-6. 
  6. Muthukrishnan T, M Al Khaburi, Abed RMM (2019), Fouling microbial communities on plastics compared with wood and steel: are they substrate or location-specific? Microbial Ecology 78:361-374. DOI: 10.1007/s00248-018-1303-0. 
  7. Abed RMM, Palinska KA, Köster, J (2018), Characterization of Microbial Mats from a Desert Wadi Ecosystem in the Sultanate of Oman. Geomicrobiology 35:601-611. https://doi.org/10.1080/01490451.2018.1435755 
  8. Abed RMM, Kohls K, Leloup J, de Beer D (2018), Abundance and diversity of aerobic heterotrophic microorganisms and their interaction with cyanobacteria in the oxic layer of an intertidal hypersaline cyanobacterial mat. FEMS Microbiology Ecology 94(2), 1 February 2018, fix 183. https://doi.org/10.1093/femsec/fix183 
  9. Vogt, JC, Abed RMM, Albach DC, Palinska KA (2018), Bacterial and archaeal diversity in hypersaline cyanobacterial mats along a transect in the intertidal flats of the Sultanate of Oman. Microbial Ecology 75(2): 331-347. DOI: 10.1007/s00248-017-1040-9. 
  10. Palinska, Katarzyna A., Raeid M. M. Abed, Janina C. Vogt, Gudrun Radtke, and Stjepko Golubic (2017), Microbial Endoliths on East Adriatic Limestone Coast: Morphological vs. Molecular Diversity. Geomicrobiology Journal 34:10,903-915. DOI: 10.1080/01490451.2017.1297512. 
  11. Joshi SJ, Abed RMM (2017), Biodegradation of polyacrylamide and its derivatives. Environmental Processes 4: 463-476. 
  12. Abed RMM, Al-Kindi S (2017), Effect of disturbance by oil pollution on the diversity and activity of bacterial communities in biological soil crusts from the     Sultanate of Oman. Applied Soil Ecology 110: 88-96. 
  13. Gomaa MA, Al-Haj L, Abed RMM (2016), Metabolic engineering of Cyanobacteria and microalgae for enhanced production of biofuels and high-value products. Journal of Applied Microbiology 121: 919-931. DOI: 10.1111/jam.13232.