USE OF CAGED MUSSEL MYTILUS GALLOPROVINCIALIS IN AN ECOTOXICOLOGICAL APPROACH TO ASSESS ENVIRONMENTAL IMPACT IN OFF-SHORE ACTIVITIES

Abstract Mediterranean mussels, Mytilus galloprovincialis, are well recognized bioindicator organisms which can be easily caged in investigated areas to assess the impact of anthropogenic activities. In this work a monitoring protocol was developed for off-shore installations in the Adriatic sea. Integration of chemical analyses with a wide range of biomarkers analysed in mussels caged at 2 platforms, allowed to evaluate the biological disturbance and confirmed the utility of the ecotoxicological approach for monitoring off-shore activities. Keywords : Bio-indicators, Adriatic Sea. Several environmental issues are associated with the off-shore oil and gas industry, from the impact caused during installation to various form of disturbance related to daily ship traffic, extraction activities, maintenance of structures and, finally, decommissioning of old platforms. During the last year a monitoring protocol with caged mussels, Mytilus galloprovincialis, has been developed, to evaluate the potential ecotoxicological effects caused from the off-shore platform "Giovanna" in the Adriatic sea. Obtained results allowed to exclude marked biological disturbance and demonstrated the suitability of this approach. In this respect considering "Giovanna" as model platform, the monitoring protocol with caged mussel has been extended including also another off-shore installation, the "Emilio" platform. In this work native mussels were collected on a seasonal basis from a reference site on the Adriatic coast (Portonovo, Ancona) and transplanted for 4-6 weeks in both the sampling area and to the investigated platform "Giovanna" (42 • 46' 060N, 14 • 27' 750E) and Emilio (42 • 56' 305 N; 14 • 13' 915 E). After the translocation period, mussels were recovered dissected tissues frozen in liquid nitrogen and maintained at -80 • C until analyses. Chemical analyses on trace metals (arsenic, cadmium, chromium, copper, iron, mercury, manganese, nickel, lead, zinc) in mussels tissues An overall evaluation of results confirmed the absence of marked biological effects caused by the activities of "Giovanna" platform, as already demonstrated during the previous monitoring project. More variations were observed in mussels translocated to "Emilio", i.e. higher activities of glutathione S-transferases, catalase and peroxisomal proliferation decrease of oxyradical scavenging capacity toward hydroxyl and peroxyl radicals and lysosomal destabilization (inhibition of neutral red retention time), indicating an onset of impairment condition in the organisms. Compared to mussels transplanted at the reference site, those from "Emilio" platform did not exhibit more elevated concentrations for the various metals and only for zinc and cadmium an higher bioavailability was detected close to the platform, suggesting the influence of galvanic anodes for cathodic protection. The overall results of this work confirmed the utility of using caged mussels as an additional contribution for monitoring off-shore activities and provided an ecotoxicological protocol based on cellular biomarkers for the early detection of biological disturbance

First record of Musellifer profundus (Gastrotricha) in the Italian seas.

Several specimens of Musellifer profundus were found during a survey of the meiobenthos in the Northern Adriatic Sea. The finding bears relevance with respect to the biogeography and biology of marine gastrotricha as it widens the distributional boundaries of a rare species (thus far known only from the North and Baltic seas and from off Marseille), at the same time allowing new insights into the arrangement and functioning of the hermaphroditic sexual apparatus in a genus for which data in this regard are scanty

Biomonitoring of a dumping area: the meiobenthic community

Meiofauna abundance and community structure were investigated in a sea disposal site in the Ligurian Sea, 1 year after the dumping of material dredged from the harbour of Leghorn. Faunistic analysis of cores taken in three stations subject to sediment discard and one in a control site found in all cases the Nematoda as the dominant taxon followed by the Harpacticoida Copepoda. While ANOVA could not detect statistically significant differences among stations, except station H5, the number of taxa and their density were higher than values obtain from samples collected two weeks and two months after the dumping. Sites H5 previously indicated as the most impacted site showed the higher density of total meiofauna and the most well-balanced repartition of taxa. Overall data support the working hypothesis of a progressive but differentiated faunistic recovery of the impacted sites

Monitoring of a dredged material disposal site: evidence of rapid meiofaunal recolonization of the dumped sediments

The research was carried out at a sea disposal site located in the Ligurian Sea, some miles off the northern coast of Tuscany, Italy. In the site is preferentially dumped material dredged from the harbor of Leghorn. A faunistic survey of sediment cores taken in three impacted stations found evidence of rapid meiofaunal recolonization of the damped material; furthermore, two weeks after the dumping we cannot detect statistically significant differences between density of total meiofauna and most major taxa in the impacted vs a control site

Biological effects of diethylene glycol (DEG) and produced waters (PWs) released from off-shore activities: a multi-biomarker approach with the sea bass Dicentrarchus labrax.

Diethylene glycol (DEG) is largely used during oil and gas exploitation by offshore platforms. The aim of this work was to investigate if this compound induces direct molecular/cellular effects in marine organisms, or indirectly modulate those of produced waters (PWs). Sea bass (Dicentrarchus labrax) were exposed to DEG dosed alone or in combination with PWs from an Adriatic platform. A wide array of analysed biomarkers included cytochrome P450-dependent enzymatic activity, bile metabolites, glutathione S-transferases, acetylcholinesterase, peroxisomal proliferation, antioxidant defences (catalase, glutathione reductase, glutathione peroxidases, glutathione), total oxyradical scavenging capacity, malondialdehyde and DNA integrity (single strand breaks and frequency of micronuclei). Results did not reveal marked effects of DEG, while PWs influenced the biotransformation system, the oxidative status and the onset of genotoxic damages. Co-exposures caused only limited differences of biomarker responses at some experimental conditions, overall suggesting a limited biological impact of DEG at levels normally deriving from offshore activities