Bacteria in the Bottom Sediments of the Dead Sea

Abstract

IN order to investigate the presence of different physiological groups of bacteria in the different layers of the bottom sediments of the Dead Sea^1,2,3, it was essential to obtain profiles of mud samples. With a coring instrument designed according to the device of Emery and Dietz⁴ a number of profiles 10–170 cm. long, were obtained from depths of 70–330 m. at different places in the Dead Sea during December 1941. It was found that the thickness of the mud layer covering the surface of the bed of the Sea varies in different places from a few centimetres to more than 170 cm. In one place about 6 km. south-west from the northern shore, a profile 170 cm. long was obtained from a depth of 100 m. On dissecting the profile longitudinally, a beautiful 'spectrum of layers', of different colours—black, dark-blue, grey, brown, and white—was revealed (Fig. 1). It is interesting to note that the zones of sedimentation, though distinctly seen, form no seasonal repeat pattern, as, for example, the annual rings of trees.