Impacts of several pollutants on the distribution of recent benthic foraminifera: the southern coast of Gulf of Gabes, Tunisia

In addition to physicochemical methods, benthic foraminifera have become an essential tool for the assessment of polluted environments. The main objectives of the present work were to study the distribution of benthic foraminifera along the coastline of Skhira and Gabes (southern coast of Gulf of Gabes) and to predict the impact of pollution on these organisms. Thirty-one samples were studied and a polluted area was delimited by chemical analysis, where heavy metal, fluoride, phosphorus, nitrogen, and COT contents are very high. Thirty-four species of benthic foraminifera were identified and their response to pollution is very remarkable, in which their distribution shows barren area, corresponding to the highly polluted area. Away from the contaminated area, the density and the diversity of these organisms increase. Statistical analyses (principal component analysis (PCA)/FA and matrix correlation) show a possible control of these pollutants on biotic indices (with negative correlation), in addition to the presence of tolerant and sensitive species to pollution. A variety of test malformations were noticed especially in Ammonia beccarii, Peneroplis planatus, Sorites variabilis, and Adelosina pulchella. Unpolluted stations were dominated by species characteristic of shallow water environments with sandy sediment such Ammonia parkinsoniana, Triloculina trigonula, Quinqueloculina agglutinans, and P. planatus.