Chemical Composition of Particulate Matter In the Coastal Waters off Alexandria, Egypt


  • A.R. Abdel-Moati


Particulate matter, POC, carbonate, biogenic silica, sewage stress, aluminosilicates, Alexandria coast


Particulate matter from 13 stations was sampled seasonally during 1986-87 from the coastal waters of Alexandria city. Samples were analysed for particulate organic carbon, particulate inorganic carbon and particulate AI, Si, Ca, Mg, Fe and Mn. Variations in the particulate matter abundance and distribution indicate the presence of different types of suspensoids. About 97%, of the chemical components of total particulate matter (TPM) were identified. Particulate organic matter is the major component representing about 43%, half of which is particulate organic carbon. Biogenic silica constituted between 4 and 11%k of TPM in surface waters but did not exceeded I% in the bottom layer where the non-biogenic silica fraction (Aluminosilicate) dominated contributing between 35 and 41% of total particulate matter content. Excess concentrations of biogenic Si and Ca support their incorporation with marine plankton. Spatial and seasonal variations in total particulate matter components are affected mainly by the amount of unprocessed sewage discharged to the area as well as biological cycles and circulation patterns. Comparison with reference area proved deviations in particulate matter structure.