Behaviour of Metal(loid)s at the Sediment-Water Interface in an Aquaculture Lagoon Environment (Grado Lagoon, Northern Adriatic Sea, Italy)

Abstract

The cycling of metal(loid)s at the sediment–water interface (SWI) was evaluated at two selected sites (VN1 and VN3) in an active fish farm in the Grado Lagoon (Northern Adriatic, Italy). In situ experiments using a transparent benthic chamber and the collection of short sediment cores were performed, to investigate the behavior of metal(loid)s in the solid (sediments) and dissolved (porewaters) phases. Total and labile concentration of metal(loid)s were also determined in sediments, to quantify their potential mobility. Comparable total concentrations were found at both sites, excluding As, Mn, Pb and V, which were higher at VN3. Metal(loid) porewater profiles showed a diagenetic sequence and a close dependence with redox (suboxic/anoxic) conditions in the surface sediments. Positive diffusive fluxes along with benthic fluxes, particularly at the more oxic site, VN1, were found for almost all metal(loid)s, indicating their tendency to migrate towards the overlying water column. Despite sediments at two sites exhibiting high total metal(loid) concentrations and moderate effluxes at the SWI, the results suggest that they are hardly remobilized from the sediments. Recycling of metal(loid)s from the SWI would not constitute a threat for the aquatic trophic chain in the fish farm.

Dissolved fluxes of nutrients and carbon at the sediment-water interface in the Adriatic Sea: review of early data and methods from the Italian National Research Council (CNR)

“…The study focuses on research carried out from 1982 on the Italian side of the Central and Northern Adriatic Sea (Barbanti et al, 1995;Bertuzzi et al, 1996;Bertuzzi et al, 1997;Cermelj et al 1997;Cermelj et al, 2001;Frascari et al, 1995;Giordani and Hammond, 1985;Giordani et al, 1994;Giordani et al, 1996;Hammond et al, 1999;Spagnoli and Bergamini 1997;Tahey et al, 1996;Spagnoli et al, 2010) (Figure S3, Table S1). Previous papers on dissolved benthic fluxes in the Adriatic basin have addressed transitional ecosystems (Covelli et al, 1999;Covelli et al, 2011;De Vittor et al, 2012;Petranich et al, 2018;Petranich et al, 2021), specific elements (Ciceri et al, 1992;Covelli et al, 2008;Emili et al, 2011;Emili et al, 2014;Epping and Helder, 1997;Zago et al, 2000), or else have reworked previous data (Cermelj et al, 1997, Ogrinc andFaganeli, 2006;Testa et al, 2020) or examined other areas of the Adriatic Sea not considered in this paper (Baric et al, 2006;Giordani et al, 2002). This work addresses nutrients and DIC as well as iron and manganese fluxes at the SWI in the Northern and Central- Western Adriatic Sea.…”

Special Issue on Contaminants in Coastal Environments: From the Sediment-Water Interface to the Trophic Chain

“…Petranich et al [3] evaluated the cycling of metal(loid)s at the sediment-water interface (SWI) in an active fish farm in a Northern Adriatic lagoon environment by means of in situ experiments using a transparent benthic chamber. Although sediments showed high total metal(loid) concentrations and moderate effluxes at the SWI, the results suggested that they are barely remobilized from the sediments and would not constitute a threat to the aquatic trophic chain in the fish farm.…”