Polycyclic aromatic hydrocarbons in marine macrophytes from the Cilento coast

Coastal ecosystems, due to their proximity to anthropogenic activities, are exposed to complex mixtures of pollutants that can affect marine habitats, communities, and related ecosystem processes. In particular, polycyclic aromatic hydrocarbons (PAHs) are organic compounds that can enter food chains and induce alterations of ecological system dynamics. Their assessment in the first trophic level can thus shed light on related potential threats to marine ecosystems and, besides, provides indication on the possible use of different species in biomonitoring and bioremediation applications. To this end, the present research investigated the concentrations of 15 PAHs in 16 native macrophytes from the eulittoral and upper infralittoral zones of the Cilento coast (southern Italy), in sites differing in anthropogenic pressure. Irrespective of the systematic position (seagrasses, green, brown and red algae) all macrophytes showed comparable total PAH concentrations (IQR = 1.18-1.33 µg/g d.w.), with little variations among sites. Laurencia microcladia showed concentration gradients comparable to Posidonia oceanica, indicating its suitability in biomonitoring studies, whereas Taonia atomaria, a species found only in a harbour, accumulated the highest PAH concentrations (1.77 ± 0.04 µg/g d.w.) in respect to the other algae colonizing the site (1.16-1.42 µg/g d.w.), suggesting its possible use in bioremediation applications.