Benthic Foraminifera as Bio-indicators of Coastal Marine Environmental Contamination in the Red Sea-Gulf of Aqaba, Saudi Arabia

Abstract

To assess heavy metals contamination in shallow marine environments using benthic foraminifera as bio-indicators. Forty-six species of foraminifera were found in 33 benthic samples from the Saudi Arabian coast of the Red Sea-Gulf of Aqaba. Forty-six species belonging to 27 genera and 10 families under the Textularina, Rotalina, and Miliolina suborders were recorded in the study area. The most common genera of the recorded fauna were Peneroplis (37.2%), Coscinospira (15.06%), Sorites (10.36%), and Quinqueloculina (7.76%). The influx of clastic sediments would dilute the abundance of foraminifera species, and It may be the main reason for the decrease in abundance Concentrations of Fe, Mn, Cu, Ni, Zn, Pb, Cr, Co, and Cd were measured in the four common species of benthic foraminifera (Sorites orbiculus, Peneroplis planatus, Peneroplis pertusus, and Coscinospira hemprichii) using inductively coupled plasma mass spectrometry. The average values of heavy metals in the study area show that Iron was the most abundant metal (3367μg/g), followed by Mn (142μg/g), Cu (30μg/g), Zn (24μg/g), Cr (21μg/g), Ni (14μg/g), Pb (7μg/g), Co (4.6μg/g), and Cd (0.82μg/g). Iron concentrations recorded in the foraminiferal tests in the study area were lower than those from the Jeddah area of Saudi Arabia. Other metals were found at higher concentrations than those recorded off the Red Sea coast of Saudi Arabia and Egypt. The heavy metals concentrations in the study area may be attributable to terrestrial influx or anthropogenic activities. The increase of abundance of epiphytic foraminifers and the absence of opportunistic foraminifers show normal the environment in the study area.