Ecological implications of accumulation of PTEs and PAHs deriving from fuel exhausts in coastal marine primary producers

Abstract

Anthropogenic activities, mainly in the form of local fuel exhausts and inputs from the coastline, heavily affect ecosystems at the interface between terrestrial and marine realms, impairing their functionality and the services they provide. Due to the central role of primary producers in trophic webs, their sessile nature and ethical concerns implied in experiments on animals, pollutant analyses in both sediments and macrophytes assume special relevance in assessing pollutant transfers from the abiotic to biotic compartments and their possible transfer through trophic webs. With a view to clarify the accumulation of inorganic and organic pollutants deriving from fuel exhausts on primary producers, the concentrations of Cu, Fe, Zn, phenanthrene and benzo[a]pyrene were determined in sediments and macrophytes collected from sites along the Cilento coast, in western Mediterranean Sea, characterized by different levels of anthropogenic pressures. The 18 species analysed, belonging to Cyanobacteria, Chlorophyta, Rhodophyta, Heterokontophyta and Embryophyta, exhibited different accumulation capabilities toward pollutants, with average concentrations of Cu, phenanthrene and benzo[a]pyrene in all the divisions (17.6 ± 2.3 μg g−1 d.w., 34.3 ± 2.1 ng g−1 d.w., 61.5 ± 9.4 ng g−1 d.w., respectively) higher than those measured in sediments (4.0 ± 0.7 μg g−1 d.w., 11.6 ± 0.9 ng g−1 d.w., 14.8 ± 1.0 ng g−1 d.w., respectively) and more than one order of magnitude higher in Embryophyta for Cu (62.9 ± 7.1 μg g−1 d.w.) and in Cyanobacteria for benzo[a]pyrene (181 ± 2 ng g−1 d.w.). The obtained findings constitute a reference for the accumulation capabilities of different taxa and for the behaviour of different fuel exhaust pollutants in marine coastal environments, with implication for their transfer across trophic webs.