Pierluigi Strafella

Seabed litter composition, distribution and sources in the Northern and Central Adriatic Sea (Mediterranean)

Detecting the origin of marine benthic litter is fundamental for developing policies aimed at achieving the Good Environmental Status in European Seas by 2020, as requested by the Marine Strategy Framework Directive (MSFD). The abundance and composition of benthic litter in the Northern and Central Adriatic Sea were investigated at 67 stations with bottom trawl nets. Average density of benthic litter was 913±80items/km2, ranking the Adriatic as one of the most polluted basins worldwide. Plastic was dominant in terms of numbers (80%) and weight (62%), and mainly consisted in bags, sheets and mussel nets. Higher quantities of litter were found in coastal areas, especially in front river mouths, coastal cities and mussel farms. In deep waters, litter hotspots were associated with most congested shipping lanes, indicating an additional litter input to the basin. Benthic litter composition resulted to be largely driven by the vicinity to local sources, i.e. mussel farming installations and most congested shipping routes. These findings provide useful insights to set measures to manage marine litter in the Adriatic region, and possibly to minimize this anthropogenic pollution.

Comparative Effects of Ingested PVC Micro Particles With and Without Adsorbed Benzo(a)pyrene vs. Spiked Sediments on the Cellular and Sub Cellular Processes of the Benthic Organism Hediste diversicolor

The plastic microliter represents an emerging contaminant as well as multiple stress agent in the aquatic environments. Microplastics are found even in the remote areas of the world. Together with their occurrence in all environmental compartments, there is a growing concern about their potential of adsorbing pollutants co-occurring in the environment. Currently, little is known about this source of exposure for aquatic organisms in the benthic environment. Exposure conditions were set up mimicking the contribution of microplastics in different exposure routes. The potential biological effects were investigated in the model organism: the annelid Hediste diversicolor. Cellular effects including alterations of immunological responses, lysosomal compartment, mitochondrial activity, oxyradical production and onset of genotoxicity were assessed in coelomocytes while temporary and permanent effects of oxidative stress were also performed at tissue level. In this study polyvinylchloride (PVC) microplastics were shown to adsorb benzo(a)pyrene with a time and dose-dependent relationship. Results also indicated a marked capability of contaminated microplastics to transfer the model organic chemical to exposed model organism under physiological gut conditions and concentrated in tissues. The elevated bioavailability of the model pollutant after the ingestion induced a clear pattern of biological responses. Toxicity mainly targeted impairment of cellular functioning and genotoxicity in ragworm’s coelomocytes, while permanent effects of oxidative stress were observed at tissue level. Coelomocytes responded faster and with a higher degree of sensitivity to the adverse stimuli when compared with responses observed in whole tissue samples. The results showed that microplastic particles in sediments may play a significant role as vectors for organic pollutants. The highest adverse responses were observed in those ragworms exposed to sediments spiked with PVC particles pre-incubated with B[a]P when compared against sediments spiked with B[a]P and microplastics separately.

Non-indigenous macrozoobenthic species on hard substrata of selected harbours in the adriatic sea

The intense shipping traffic characterising the Adriatic Sea favours the spread of marine organisms. Yet, a study of 12 Adriatic ports (4 on the western side and 8 on the eastern side of the basin) found that non-indigenous species (NIS) accounted for only 4% of the benthic communities settled on hard substrates. The cirripeds Amphibalanus amphitrite and Balanus trigonus, found in 8 harbours, were the most common invaders followed by Amphibalanus eburneus, the ascidian Styela plicata, and the bivalve Magallana gigas. The highest percentage of NIS was recorded in Venice and Ploče, the harbours with the least rich native communities; the lowest percentage was retrieved in Trieste, Koper, Pula, and Rijeka, the harbours hosting the highest species diversity. In contrast, the ports of Bari and Ancona showed both high NIS percentages and highly diversified communities.

Quantity and biochemical composition of sedimentary organic matter around offshore gas extraction platforms of the Adriatic Sea

ABSTRACT Gas platforms can exert relevant effects on various ecosystem properties of the hosting area, modifying patterns of productivity and particle sedimentation. We hypothesised that the presence of gas platforms is associated with higher organic matter (OM) contents and we tested the null hypothesis by which benthic trophic conditions do not vary significantly among gas structures with different architectural characteristics. To test these hypotheses, we investigated sedimentary OM contents and biochemical composition at increasing distance from two distinct structures: one subsea well-site and one four-leg platform (FLP). We found that sediments surrounding the structures were characterised by similar OM contents, but different biochemical compositions, and that sedimentary OM compositional change with increasing distance from the structure is confirmed only at the FLP. These results suggest that: (i) benthic eutrophication is not consistent among different structures; (ii) OM biochemical composition changes are more evident than those in OM quantity; and (iii) the effect, wherever present, disappears at a very narrow distance from the platform. As biochemical composition of OM reflects food availability for benthic organisms, our results suggest that the enrichment of macrozoobenthic communities around these structures could be the consequence of increased nutritional quality of resources.