The influence of environmental conditions on the benthic foraminiferal distribution from the recent sediments of Lake Bardawil, Eastern Mediterranean Sea, Egypt

Abstract

Lake Bardawil, similar to the other Mediterranean Egyptian lakes, is a unique wetland, separated from theMediterranean Seaby a narrowsandbarwith very restricted water exchange that allowed the development of a shallow-hypersaline lagoon. Late Pleistocene tectonics activities divided the lake into two main basins; the eastern and western basins. Twelve surface sediment samples were collected along the Lake and subjected to sediment texture and benthic foraminiferal analyses. In general, benthic foraminifera were abundant in the surface sediments of Lake Bardawil and were characterized by low diversity. The statistical analysis revealed two biotopes that distinguished between the eastern and western basins' environments. The eastern basin biotopes were characterized by fine bottom sediments with the predominance of salinity-tolerant assemblages, thus demonstrating hypersaline stressful restricted environment. The western biotope exhibited coarser bottom sediments associated with relatively narrow salinity-tolerant assemblages. This reflected sandy and less saline sediment of uncontaminated environments, as the western basin was exposed to active hydrodynamic regime that developed more magnitudes of water exchange with the Eastern Mediterranean Sea through the western inlet. Based on the results of this study, the biomonitoring of Lake Bardawil could be assessed by the analysis of its benthic foraminifera as a bioindicator tool that may help in the improvement of the Lake's conditions.