Effects of heavy metals on benthic bacteria in coastal marine sediments: A field result

Abstract The effects of high heavy metal concentrations (Pb, Cu, Cd, Zn) on activity and distribution of benthic bacterial communities were investigated in sediments collected in 15 stations located in an area heavily polluted by the Arno river outflow (northern Tyrrhenian Sea). Despite the high organic matter content, bacterial number and biomasses resulted to be very low. The main biochemical classes of organic compounds in the sediments facing the river estuary (i.e. lipids, proteins and carbohydrates) were closely related to the heavy metal distribution. The negative correlation between bacterial biomass and Cd concentrations indicated that the high cadmium concentrations in sediments may significantly affect bacterial development.