The micro-organisms of sabkhat in Qatar

Abstract

Sabkhat are widely distributed throughout the Qatar Peninsula, and the aim of this study is to give a brief overview of their geographical distribution, geomorphology factors influencing their formation and biological characteristics within the area, with particular reference to their microorganisms. Although there are a large number of individual areas of sabkha, they tend to be small in size. The formation of sabkhat is shown to be a multifactorial process that is affected by several dynamic factors, such as geography, topography, environment and oceanography, as well as various anthropogenic ones.

The microbial communities of the sabkhat in Qatar display a conspicuous horizontal and vertical zonation. Whereas the upper-intertidal zone is composed of cyanobacterial mats, the middle-intertidal zone is dominated by the archaebacterium Halobacterium salinarium and the micro-green alga Dunaliella salina. The lower-intertidal zone is characterized by a black muddy substrate in which large quantities of sulphur and methane are produced due to the presence of certain bacteria. Analysis of the vertical zonation of the microbial profile has revealed the presence of various characteristic species of bacteria, cyanobacteria and diatoms at specific depths.