ON HEAVY-METAL CONCENTRATIONS AND BIOGENIC ENRICHMENT IN MICROBIAL MAT ENVIRONMENTS

Heavy metal concentrations of a recent salina on the shore of the Medi terranean Sea near Port Said (Egypt) were investigated. Samples for th e heavy metal study were taken in different ponds of the salina. It wa s found that microbial mat dominated brine sediments concentrated and enriched heavy metal 2-3 times more than sediments lacking microbial m at developments, suggesting that cyanobacteria play a major role in th is enrichment. Heavy metal enrichment by cyanobacteria was therefore a lso studied in the laboratory environment. This study is compared with a recent study of Solar Lake and Sabkha Gavish sediments (Sinai, Egyp t). Our conclusion is that recent hypersaline environments with ambien t microbial mat (potential stromatolite) developments are ideal exampl es of present-day environments of metal accumulations.