Use of benthic foraminifera as environmental indicators in the Cagliari gulf: preliminary correlation between biotic and geochemical data

Cherchi, A;Del Rio, M;Porcu, Am;BUOSI, CARLA;Mana, D;MELIS, MARIA TERESA;DA PELO, STEFANIA;Sartec, Spa

2009-01-01

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Abstract

The results from scientific literature evidence that the benthic foraminifera are excellent indicators to monitoring the marine-coastal environments (Armynot du Châtelet et al., 2004; Coccioni, 2000; Debenay et al., 2000; Kravchuk, 2006; Murray, 2006; Samir & El-Din, 2001; Scott et al., 2005). A detailed study on shallow-water benthic foraminifera of the Cagliari Gulf (work in progress) has been carried on within a research project “SARAS Ricerche e Tecnologie”, in order to have information on the environmental quality of that area. Ninety-six samples collected from sixteen transepts yielded almost 200 taxa. Relative abundance and several biotic indexes (Fisher α, Shannon-Weaver, Eveness, Equitability, Menhinick, Margalef) have been obtained; statistical analysis and a preliminary correlation between biotic and geochemical data have been carried on, too. An integrated approach among different methodologies focused on the numerical elaboration of thematic maps has been carried using the Inverse Distance Weighting (IDW) for estimate the environmental quality in the Cagliari Gulf. On the basis of a preliminary study, the spatial distribution of the foraminiferal assemblages and the geochemical data reveal from highly to less heavy metals polluted conditions in the western part of the gulf (industrial area), approximately between the Cagliari harbor and Perd’e Sali. Better environmental conditions, generally, characterize the eastern part of gulf.