The Response of Benthic Foraminifera to Pollution: an Example from the Naples Harbour (Southern Italy).

Foraminifera are the most abundant marine protozoa. They show high biodiversity and abundance as an effect of their different ecological requirements. They may respond to environmental changes, leading to high production of specimens under favourable environmental conditions and to their disappearance under strongly unfavourable conditions. This paper represents a detailed investigation carried out on the benthic foraminiferal assemblages, in the highly contaminated marine sediments of the Naples Harbour (southern Campania).The aim of the research is to assess the response of foraminifera to organic and inorganic pollution. Combined use of multivariate canonical, cluster and principal component analysis provided an appropriate approach to explore the role played by contaminants (Heavy metals, PAHs, VOCs, TRPHs, PCBs) and physical parameters (grainsize, pH, Eh, TOC) on the spatial distribution of the benthic foraminifera. Obtained results provide evidence for a high and systematic non-linear response of the biota to the effects of the different pollutants. The reduced number of specimens per sample, their small dimensions and low diversity, testify the negative effects of a highly contaminated environment. In particular the results underline an important effect of the VOC on the distribution of some species, but also demonstrate that any kind of oversimplification would cancel the strong complexity of the biotic response to combined effects of different contaminants.