Search

During 2006–2008, a pipeline was buried in Vallona lagoon in the Northern Adriatic Sea (Italy). A Before-During-After environmental monitoring programme was scheduled to monitor possible alterations. Bioaccumulation of metal(loid)s, BTs (butyltins) and HMW-PAHs (High Molecular Weight Polycyclic Aromatic Hydrocarbons), and biological responses (Condition index, air Survival—LT50, Acetylcholinesterase, Micronuclei—MN, acyl-CoA oxidase, catalase, malondialdehyde—MDA, and the total oxyradical scavenging capacity—TOSCA) were investigated in Manila clams (Ruditapes philippinarum) from November 2005 to June 2015. In opera (IO) results showed higher levels of HMW-PAHs (73 ± 13 ng/g), BTs (90 ± 38 ng Sn/g) and increasing levels of Pb (6.7 ± 0.7 mg/kg) and Zn (73.6 ± 6.08 mg/kg) probably linked to works. Other contaminant alterations, especially metal(loid)s, before (AO) and after (PO) the burial, were attributed to a general condition of the area and mostly unrelated to works. In addition, LT50, MN and TOSCA showed alterations, probably due to hotspots occurring in IO. TOSCA and MDA increases, right after the burial, were considered delayed responses of IO, whilst other biological responses detected later were connected to the general condition of the area. Comparisons between results of Principal Component Analyses (PCAs) highlighted partial overlapping of AO and IO, whilst PO differed only for contaminants. Visual correlations between PCAs highlighted the biomarkers' latter response. [ABSTRACT FROM AUTHOR]

Eutrophication represents one of the most impacting threats for the ecological status and related ecosystem services of transitional waters; hence, its assessment plays a key role in the management of these ecosystems. A new multi-index method for eutrophication assessment, based on the ecological index MaQI (Macrophyte Quality Index), the trophic index TWQI (Transitional Water Quality Index), and physicochemical quality elements (sensu Dir. 2000/60/EC), was developed including both driver and impact indicators. The study presents a large-scale implementation of the method, which included more than 100 Italian lagoon sites, covering a wide variability of lagoon typologies and conditions. Overall, 35% of sites resulted in eutrophic status, 45% in mesotrophic, and 25% in oligotrophic status. [ABSTRACT FROM AUTHOR]

Large lagoons usually show a salinity gradient due to fresh water tributaries with inner areas characterized by lower mean values and higher fluctuation of salinity than seawater-dominated areas. In the Venice Lagoon, this ecotonal environment, characterized in the past by oligo-mesohaline waters and large intertidal areas vegetated by reedbeds, was greatly reduced by historical human environmental modifications, including the diversion of main rivers outside the Venice Lagoon. The reduction of the fresh water inputs caused a marinization of the lagoon, with an increase in salinity and the loss of the related habitats, biodiversity, and ecosystem services. To counteract this issue, conservation actions, such as the construction of hydraulic infrastructures for the introduction and the regulation of a fresh water flow, can be implemented. The effectiveness of these actions can be preliminarily investigated and then verified through the combined implementation of environmental monitoring and numerical modeling. Through the results of the monitoring activity carried out in Venice Lagoon in the framework of the Life Lagoon Refresh (LIFE16NAT/IT/000663) project, the study of salinity is shown to be a successful and robust combination of different types of monitoring techniques. In particular, the characterization of salinity is obtained by the acquisition of continuous data, field campaigns, and numerical modeling. [ABSTRACT FROM AUTHOR]

The Venice lagoon is the main Manila clam (Venerupis philippinarum) production site in Europe. Following the unsustainable exploitation of this site (free-access fishery) local authorities have been striving to regulate fishing activities and most clams are produced using mollusc culture techniques based on wild spat harvesting and on its seeding in appropriate, designated culture areas. Therefore, the quality and abundance of wild clam stocks are critical factors that could limit the full development of this activity. The present study aims at assessing Manila clam stocks (spat, adults per square meter) using ordinary kriging, in an area of the Venice lagoon located near the Porto Marghera industrial zone. Previous studies have identified this area as one of the most important natural clam settlement sites in the Venice lagoon. The study area was approximately 1085 ha; 46 sampling stations were examined. Stock assessment (animals were grouped by size and age group), biomass and correlation with sediment texture were evaluated. The results obtained and comparisons with studies from the literature enabled an estimation of clam recruitment potential and an analysis of the conservation status of clam stocks. Thereafter, in view of a full reclamation and an ecological restoration of the study area, different measures are proposed for the sustainable use of this area that include the establishment of a biological protection area and a shared and rational management of the nursery area; these measures could potentially increase the sustainability of clam culture in the Venice lagoon. [ABSTRACT FROM AUTHOR]

Abstract: The southern Venice lagoon has been affected by an increase of several anthropogenic activities (dockyards, harbours and marina) which have contributed to enrich sediments with metals in the recent years. The contamination of metals in the surface sediments along with their accumulation in the gastropod Nassarius reticulatus were investigated. Highest metal concentrations of Cu, Zn, Pb and Cr found in the dockyards and marina sites suggest their possible past and recent use as biocides in the antifouling paints. The enrichment factor (EF) showed highest values (EF>10) near the dockyards, harbour and marina sediments for Cu, where the use of the antifouling tin free paints has been more relevant. High levels of metals were also found in the target gastropods. Biota-Sediment-Accumulation-Factor and correlation analyses pointed out a significant mobilization of metals, particularly Cu, from sediments and their accumulation in the gastropods. [Copyright &y& Elsevier]