Gulf Of La Spezia Research Articles

Oceanographic and anthropogenic variables driving marine litter distribution in Mediterranean protected areas: Extensive field data supported by forecasting modelling

Marine litter concentration in the Mediterranean Sea is strongly influenced both by anthropogenic pressures and hydrodynamic factors that locally characterise the basin. Within the Plastic Busters MPAs (Marine Protected Areas) Interreg Mediterranean Project, a comprehensive assessment of floating macro- and microlitter in the Pelagos Sanctuary and the Tuscan Archipelago National Park was performed. An innovative multilevel experimental design has been planned ad-hoc according to a litter provisional distribution model, harmonising and implementing the current sampling methodologies. The simultaneous presence of floating macro- and microlitter items and the potential influences of environmental and anthropogenic factors affecting litter distribution have been evaluated to identify hotspot accumulation areas representing a major hazard for marine species. A total of 273 monitoring transects of floating macrolitter and 141 manta trawl samples were collected in the study areas to evaluate the abundance and composition of marine litter. High mean concentrations of floating macrolitter (399 items/km2) and microplastics (259,490 items/km2) have been found in the facing waters of the Gulf of La Spezia and Tuscan Archipelago National Park as well in the Genova canyon and Janua seamount area. Accordingly, strong litter inputs were identified to originate from the mainland and accumulate in coastal waters within 10–15 nautical miles. Harbours and riverine outfalls contribute significantly to plastic pollution representing the main sources of contamination as well as areas with warmer waters and weak oceanographic features that could facilitate its accumulation. The results achieved may indicate a potentially threatening trend of litter accumulation that may pose a serious risk to the Pelagos Sanctuary biodiversity and provide further indications for dealing with plastic pollution in protected areas, facilitating future management recommendations and mitigation actions in these fragile marines and coastal environments.

Shellfish sanitation monitoring in La Spezia gulf: Chemometric evaluation of data from 2015 to 2021

Shellfish sanitary controls are very important to guarantee consumer health because bivalve molluscs (BVM) are filter-feeders so they can accumulate pathogens, environmental contaminants and biotoxins produced by some algae, causing infections and food poisoning in humans after ingestion. The purpose of this work was to analyse with chemometric methods the historical data relating to routine analyses carried out by the competent authority (Liguria Local Health Unit, National Health Service) on the BVM reared in a shellfish farm located in the Gulf of La Spezia (Italy). Chemometric analysis was aimed at identifying any correlations between the variables, as well as any seasonal trends and similarities between the stations, in order to be able to provide further material for a more accurate risk assessment and to improve the monitoring organization for example by reducing sampling stations and/or sampling frequency. The dataset used included 31 variables classified as biotoxicological, microbiological and chemical variables, measured twice a week, monthly or half yearly respectively, for a total of 6 years (from 2015 to 2021), on samples of Mytilus galloprovincialis coming from 7 monitoring stations. The results obtained by the application of principal component analysis have shown positive alga-biotoxin correlations, as well as seasonal trends linked to algae growth, with a greater algal biomass and their toxins during the spring months. In addition, periods characterised by low rainfall were found to affect algal development, promoting especially species such as Dinophysis spp. Considering the microbiological and biotoxicological variables, significant differences between the monitoring stations were not found. However, stations could be distinguished on the basis of the nature of the predominant chemical pollutants.

The Alpi Apuane and their surroundings: a tale of the origins of modern Italian geological maps and of a missed ‘early recognition’ of nappes in the Apennines

Abstract The northernmost coastal sector of the Italian peninsula from the La Spezia Gulf to Monte Pisano, including the Alpi Apuane mountain range, represents a special morpho-structural domain of the inner northwestern Apennines. Described by naturalists since the Roman age, its location on the land and sea track of the Italian Grand Tour makes it a special zone in the Italian peninsula that was visited by some of the most eminent European geologists of the nineteenth century, including Brongniart, Buckland, De la Beche, Hoffman, Escher von der Linth, Murchison and Lyell. The area has been also the homeland of naturalists and scientists who played a significant role during the nineteenth century in the advancement of geological studies in Italy. Thanks to Capellini's ‘Geological map of the La Spezia Gulf and surroundings’ (1863) and Zaccagna's ‘Geological maps of the Alpi Apuane’ (1879–97), the area became central in the history of the foundations of modern Italian geological maps. However, the opportunities provided by early mapping and palaeontological discoveries for developing tectonic concepts were squandered by Italian Apennines geologists, who remained stuck on explanations of autochthonism, thus missing an early recognition of nappe tectonics that was only accepted in the middle of the twentieth century.

Full-duplex underwater acoustic communications via self-interference cancellation in space

Traditionally, underwater acoustic communications are half-duplex (HD), i.e., the hydrophones and transducers operate in non-overlapping time-slots/frequency-bands in one direction. To double the spectral efficiency into the full-duplex (FD) mode, which transmit and receive signals simultaneously, a self-interference cancellation (SIC) technique in space is introduced and deployed. Specifically, a novel underwater acoustic system is proposed to perform FD-SIC efficiently via an integrated design combining underwater acoustic vector sensor (AVS) and phased array transducer (PAT) to realize the spatial SIC. The energy focusing function of the beamformer (BF) helps PAT avoid self and mutual spatial interference. The AVS keeps updating the direction of arrival information to let BF adjust the steering angle via an adaptive protocol. The field-programmable gate array (FPGA) Direction of Arrival Estimation (DOA) estimation is done by a 12-element AVS, run-time is 1.22×10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">−4</sup> s by MUSIC method, which is promising for real-time applications. In this work, phase-shift keying (PSK) and PSK-based orthogonal frequency-division multiplexing (OFDM) are deployed as the FD transmission modulation methods in the spacial SIC. The proposal is evaluated and verified via both simulations and emulations in real underwater acoustic channels collected in the Gulf of La Spezia, Italy, and it is able to achieve 59 dB SIC while modulating with binary phase-shift keying (BPSK) with carrier wave frequency 80 kHz and AVS steering angle −5°. Moreover, it has at least 37 dB SIC within the steering angle region.

Effect of Predation on Fouling Communities in an Italian Hotspot of Non-Indigenous Species

The role of native predators in controlling or facilitating non-indigenous species (NIS) growing in a fouling assemblage was investigated with a 70-day caging experiment in a marina inside the Gulf of La Spezia (Italy). Submerged PVC panels were divided into three experimental treatment levels: “control panels”, “open-caged panels” and “caged panels”, to assess the predation effect on the fouling assemblages growing on the panels. Predation effect was observed for two investigated variables. The Shannon Index was significantly higher in caged panels in comparison with controls, while an opposite trend was observed for the coverage area of native species. When testing single NIS abundance, both facilitation and limitation of individual NIS settlement has been observed. Mean coverage of the sabellid Branchiomma luctuosum was significantly higher in caged than in uncaged or open-caged panels, while the ascidian Styela plicata was prevalent in open-caged panels. In general, a predation effect was observed when considering the whole fouling assemblage, including different trends in NIS coverage among treatment levels. The results of this first attempt performed in the Mediterranean Sea encourage further experiments to investigate the biotic resistance provided by native predators against NIS.

Alien Travel Companies: The Case of Two Sea Slugs and One Bryozoan in the Mediterranean Sea

Mediterranean marine fauna is constantly changing due to the entry of non-indigenous (NI) species and the loss of endemic biodiversity. In this framework, it is very important to monitor this constant change and investigate possible new pathways of dispersion. Marinas and ports are considered key stations to detect and study some important ecological aspects, such as NI and invasive species, the effects of climate change, and pollution. Here, we reported the case of a group of NI species that presumably reached the Mediterranean Sea together, each of them being ecologically associated with one another. The bryozoan Amathia verticillate and the sea slugs Favorinus ghanensis and Polycerella emertoni were found in the shallow waters of Fezzano’s marina in the gulf of La Spezia (Ligurian Sea, Mediterranean Sea). Molecular analyses were carried out to exclude cryptic diversity and to investigate the phylogenetic relationships occurring between closely related taxa. The spreading of these two NI sea slugs into the Mediterranean Sea was confirmed and the first record of P. emertoni from the Ligurian Sea reported. These findings shed some light on the poorly known ecology of these species that could be useful for future monitoring and conservation strategies.

Design strategies for the recovery and enhancement of lighthouse: some case studies of the Ligurian Sea

This paper presents the first results of ongoing research analysing some coastal lighthouses in the territorial jurisdiction of the Northern Maritime Command of La Spezia, located between the Island of Elba and the Gulf of La Spezia. The research is inspired by the “Valore Paese - Fari” initiative, launched in 2015 by the Agenzia del Demanio, with Difesa Servizi S.p.a, to promote in the real-estate market several currently disused lighthouses by granting them to overcome the management and maintenance problems. Some of the lighthouses on the Italian coasts are now affected by a gradual abandonment caused by the spread of current geo-localisation technologies and remote control and management systems. The research aims to highlight the historical and cultural importance of lighthouses, identifying possible valorisation strategies and development potential in terms of flexibility and ability to adapt to a radical functional transformation. The article firstly outlines a typological atlas of lighthouses and highlights their technical constructional characteristics. Subsequently, the design strategies of the lighthouses under study are defined for their recovery and valorisation in compliance with architectural and economic requirements. Starting from an organic and systematic classification that filled the great lack and fragmentation of available information, a detailed survey was carried out using HBIM throughout the knowledge phase, and the Value Analysis method was used to define design solutions that meet pre-established financial requirements and limits. In summary, the research shows how the lighthouse architectures are linked to the coastal context area, especially to the construction techniques concerning the different local cultures, and can lead to interesting economic and social revitalisation processes of the surrounding areas.

Monitoring Non-indigenous Species in Port Habitats: First Application of a Standardized North American Protocol in the Mediterranean Sea

Baseline port monitoring for fouling communities is an essential tool to assess non-indigenous species (NIS) introduction and spread, but a standardized and coordinated method among Mediterranean and European countries has not yet been adopted. In this context, it is important to test monitoring protocols that allow for the collection of standardized and directly comparable data, replicated across time and space. Here, for the first time in the Mediterranean Sea, we tested a standardized protocol developed by the Smithsonian Environmental Research Center (SERC) and used now in several countries. The 3-year monitoring survey (2018–2020) was conducted in the Gulf of La Spezia (Ligurian Sea, Italy), with the deployment of a total of 50 PVC panels per year in five different sites (a commercial harbor, three marinas and a site in the proximity of a shellfish farm). A total of 79 taxa were identified, including 11 NIS, ranging from zero to seven NIS for each panel. In comparison with previous surveys, new NIS arrivals were observed in the Gulf of La Spezia: Botrylloides cf. niger, Branchiomma sp., Branchiomma luctuosum, Paraleucilla magna, and Watersipora arcuata. At the end of the 3-year monitoring, mean richness? and percent cover of NIS were measured, and both measures differed across the monitoring sites, with higher values in two marinas and in the commercial harbor. Among years, richness of NIS was relatively stable at each monitoring site. The structure of the fouling was influenced more by native and cryptogenic species than by NIS. Moreover, among the monitoring sites, the density of artificial structures was not a reliable predictor or proxy for local NIS abundance. This first application of the SERC method in the Mediterranean Sea, demonstrates both pros and cons, including the detection of new NIS reported here. Further direct comparisons with other NIS monitoring tools are recommended, and additional tests to assess its effectiveness in this biogeographical area are encouraged. A broader application of this and other standard methods across temporal and spatial scales in the Mediterranean basin should be implemented, providing critical data needed to assess changes in the structure of fouling communities.

DIVE: A distributed ID assignment and topology discovery protocol for underwater acoustic networks

This paper presents the DIVE protocol, which is designed to self assign unique node IDs in an underwater acoustic network. DIVE, which stands for Distributed Id assignment and topology discoVEry, is fully distributed and does not assume any prior knowledge of the network. One of the objectives of the DIVE protocol is the assignment of short IDs to the node, thus reducing the number of bits required to encode this information. Link quality information is explored to increase the robustness of the protocol against message losses. While discovering the network and assigning short node IDs, control data is shared to collect additional information about the network nodes, such as the type (static or mobile) and the number of hops to reach them. This information then can be used to support network operations. The protocol performance has been evaluated via simulations and during two at-sea campaigns: the 2016 Recognized Environmental Picture exercise (REP16), conducted in the Atlantic Ocean, and the 2017 Communications Network trial (CommsNet17), conducted by the NATO Science and Technology Organization Centre for Maritime Research and Experimentation (CMRE) in the Gulf of La Spezia, Italy. A variety of networking scenarios have been explored to validate the proposed solution, including node mobility as well as node addition and removal. The results show that DIVE is an efficient and reliable solution for node ID assignment and network discovery that scales with the network size in the presence of an unreliable communication channel. Additionally, when compared to a state-of-the-art solution, the usage of short IDs can significantly reduce the energy consumption and prolong the network lifetime.

After the Fall: The Demographic Destiny of a Gorgonian Population Stricken by Catastrophic Mortality

In recent years, the frequency of mass mortality events in marine ecosystems has increased, and several populations of benthic organism have been affected, reducing their density and changing their size and age structure. Few details are known about the dynamics of these populations over long time intervals. In late summer of both 1999 and 2003 two drastic mass mortality events, co-occurring with anomalous temperature increases, affected the northwestern Mediterranean rocky coastal communities. Due to these events the Paramuricea clavata population living at the western edge of La Spezia Gulf (Italy) was stricken, and 78% of the colonies died. This population was monitored from 1998 (pre-mortality) until 2013. This paper deals with the photographic sampling of permanent plots carried out in 2013. The findings were compared with those from the previous sampling series. This long-term, non-destructive sampling highlights the demographic trajectory of the octocoral population there after two anomalous mortality events, indicating that some new drop-point between local extinction and complete recovery may be have been reached. Long-term monitoring (including pre-mortality data) could allow evaluating the effects of global climate change on the conservation of impacted populations.

Late Quaternary Landscape Dynamics at the La Spezia Gulf (NW Italy): A Multi-Proxy Approach Reveals Environmental Variability within a Rocky Embayment

The Gulf of La Spezia (GLS) in Northwest Italy is a rocky embayment with low fluvial influence facing the Mediterranean Sea. Past landscape dynamics were investigated through a multi-proxy, facies-based analysis down to a core depth of 30 m. The integration of quantitative ostracod, foraminifera, and pollen analyses, supported by radiocarbon ages, proved to be a powerful tool to unravel the late Quaternary palaeoenvironmental evolution and its forcing factors. The complex interplay between relative sea-level (RSL), climatic changes, and geomorphological features of the embayment drove four main evolution phases. A barrier–lagoon system developed in response to the rising RSL of the Late Pleistocene (likely the Last Interglacial). The establishment of glacial conditions then promoted the development of an alluvial environment, with generalised erosion of the underlying succession and subsequent accumulation of fluvial strata. The Holocene transgression (dated ca. 9000 cal year BP) caused GLS inundation and the formation of a low-confined lagoon basin, which rapidly turned into a coastal bay from ca. 8000 cal year BP onwards. This latter environmental change occurred in response to the last Holocene stage of global sea-level acceleration, which submerged a morphological relief currently forming a drowned barrier-island complex in the embayment.

Comparison of Sea Wave Measurement Systems Based on Marine Radar and Microseismic Technologies

Sea state affects the coasts of all maritime regions, and it impacts anthropic infrastructures and influences the activities carried out in the sea as well as in its proximity. Sea-state monitoring is therefore important for a number of reasons, including the need to validate weather forecast models and study the impact of sea waves on anthropic infrastructures such as ports. In this letter, we combined the measurements of sea state collected with Ocean Seismic Integrated System (OS-IS), a seismic-based system developed by AGI (Assist in Gravitation and Instrumentation) srl and INGV (National Institute for Geophysics and Volcanology), with those obtained using a Wave Radar system. The aim was to prove that this combination could enhance the efficacy and reliability of sea monitoring, thanks to the complementarity of the two types of measurements in terms of area covered and spatial resolution. More specifically, the sea-state parameters provided by OS-IS were compared with those provided by a Wave Radar system. OS-IS data were collected from three microseismic stations installed near the Gulf of La Spezia, on the Ligurian Coast, whereas the Wave Radar system was installed at the center of the Cinque Terre National Park at about 12 km from the OS-IS system. The comparison between the measurements of significant wave height ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$H_{s}$ </tex-math></inline-formula> ) and peak period ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$T_{p}$ </tex-math></inline-formula> ) showed a good agreement, with a correlation index close to 0.9. The residual difference highlights the complementarity of the two systems and the potential of an integrated system that includes both. In particular, OS-IS provides measurements over large, offshore areas, whereas the Wave Radar System provides high spatial-resolution measurements over areas near the coast.

Microbiological and Histological Analysis for the Evaluation of Farmed Mussels (Mytilus galloprovincialis) Health Status, in Coastal Areas of Italy

Shellfish farming is a relevant economic activity in Italy. The Gulf of La Spezia is one of the major production areas for mussels: the area is characterized by the presence of numerous human activities that could harm the quality of seawater. Additionally, the presence of potentially pathogenic microorganisms may influence the health status of animals, which must be constantly monitored. To have a clear view of the health conditions of the mussels (Mytilus galloprovincialis) farmed in this area, microbiological, parasitological, and histological analyses were performed. The study was conducted from November 2016 to October 2017. Overall, despite the presence of potentially pathogenic microorganisms for mussels, abnormal mortality rates were not reported during the monitoring period and the histological examination revealed no significant lesions. Our study confirms that studying different aspects together is a useful tool for assessing the health conditions of mussels and points out the importance of adverse environmental conditions for the expression of the pathogenicity of microorganisms.

Analysis of the sanitary survey 2015-2017 conducted in the gulf of La Spezia (Italy): Reclassification of the areas of production of live bivalve molluscs.

The sanitary survey is aimed at classifying and monitoring the production areas of live bivalve molluscs (LBM) and it is performed using standards that are provided by the Centre for Environment, Fisheries and Aquaculture Science’s Guide to Good Practice. In this study, data from the sanitary survey carried out by the Asl5 Spezzino on the production areas of the gulf of La Spezia during the period 2015-2017 were analysed. The number and type of the analysis performed both on the total sampling and on the individual target species, as well as the number and type of found non-compliance (assessed on both mandatory parameters and on parameters fixed by the local monitoring plan) were considered. Data were also compared with those from the sanitary survey 2012-2014. Appropriate statistic tests were used to evaluate data from E. coli and Norovirus monitoring. Overall, 4306 analysis were performed, especially on the species M. galloprovincialis (89%) and they were mostly focused on to the search of biological agents. 160 NC were detected. Most of the NC concerns the Norovirus’s positivity (93.75%) in M. galloprovincialis and C. gigas. A correlation between the levels of E. coli and rainfall/ seasonality (higher levels in the colder months) was proved, especially in the sampling points located in the inner part of the dam and in the Portovenere Bay. Class B was reconfirmed for M. galloprovincialis, the production areas of C. gigas were reclassified as A and those of V. verrucosa were definitively closed. The sanitary survey was therefore confirmed as a useful tool for reclassification and for monitoring LBM production areas.

Marine litter detection and correlation with the seabird nest content

A 3 year monitoring programme, realized in a citizen science context, from 2014 until 2016, allowed us to gather information on the prevalent quantities and qualities of anthropogenic waste in five Mediterranean coastal areas within the Pelagos Sanctuary, three of them located in Liguria, near La Spezia Gulf, and the other two in Tuscany. Here, we present results concerning the Polymeric Articles’ abundances registered during the survey. Moreover, we show the results of the first study devoted to describe and quantify the anthropogenic content of the nest of a pair of Northern Gannets (Morus bassanus), a pelagic bird that, starting from some years, has been reproducing regularly in La Spezia Gulf. This breeding is atypical for this species, as is associated with artificial structures such as piers, floating docks, or boats; the material used in the construction of the nest reflects the “anthropogenic” link with the chosen location and objects of polymeric origin in particular abound. We detect the existence of a correlation between the most abundant types of Anthropogenic Marine Debris found in the Northern Gannet’ nest (fragments of polypropylene nets) and one of the productive activities of the zones.

Uncertainty evaluation of CTD measurements: a metrological approach to water-column coastal parameters in the Gulf of La Spezia area

The ENEA Marine Environment Research Centre of S. Teresa has been involved since the ‘70s in monitoring, analysis and comprehension of physical, chemical and biological processes in marine environment. The purpose of this work is to describe the recently-implemented metrological approach aimed at evaluating the uncertainty associated with measurements performed by a Conductivity-Temperature-Depth profiler (CTD) during routine coastal campaigns in the Eastern Ligurian Sea, close to the Gulf of La Spezia. Main effort of this work is focused on applying, to each involved parameter, the standard framework for uncertainty evaluation as prescribed by the Guide to the expression of uncertainty in measurement. To this aim, an appropriate uncertainty evaluation is performed by combining type A and B contributions, evaluated from experimental data obtained in reproducibility conditions and from calibration certificates periodically supplied by manufacturer, respectively. Concerning in situ measured practical salinity, probability density functions modelling water pressure, temperature and conductivity, from which salinity depends, are propagated by application of the Monte Carlo method for propagation of distributions, hence obtaining the salinity uncertainty.

Assessing the health status of farmed mussels (Mytilus galloprovincialis) through histological, microbiological and biomarker analyses.

The Gulf of La Spezia (northern Tyrrhenian Sea, Italy) is a commercially important area both as a shipping port and for mussel farming. Recently, there has been increased concern over environmental disturbances caused by anthropogenic activities such as ship traffic and dredging and the effects they have on the health of farmed mussels. This paper reports the results of microbiological and histological analyses, as well as of measurement of several biomarkers which were performed to assess the health status of mussels (Mytilus galloprovincialis) from four rearing sites in the Gulf of La Spezia. Mussels were collected between October 2015 and September 2016 and histological analyses (including gonadal maturation stage), as well as the presence of pathogenic bacteria (Vibrio splendidus clade, V. aestuarianus and V. harveyi), viruses (Herpes virus and ostreid Herpes virus 1) and protozoa (Marteilia spp., in the summer season only) were carried out on a monthly basis. Conversely, biomarker responses in haemocyte/haemolymph (total haemocyte count, haemocyte diameter and volume, lysozyme and lactate dehydrogenase activities in cell-free haemolymph, and micronuclei frequency) and in gills and digestive gland (cortisol-like steroids and lipid peroxidation levels), were evaluated bimonthly. Microbiological data indicated that mussels contain a reservoir of potentially pathogenic bacteria, viruses and protozoa that in certain environmental conditions may cause a weakening of the immune system of animals leading to mortality episodes. The percentage of parasites detected in the mussels was generally low (9.6% for Steinhausia mytilovum, that is 17 samples out of 177 examined females; 3.4% for Proctoeces maculatus; 0.9% for Mytilicola intestinalis and 2% for ciliated protozoa), while symbiont loads were higher (31% for Eugymnanthea inquilina and Urastoma cyprinae). Interestingly, a previously undescribed haplosporidian was detected in a single mussel sample (0.2%) and was confirmed by in situ hybridization. Cells morphologically similar to Perkinsus sp. trophozoites were observed in 0.7% of the mussels analysed; however, infection with Perkinsus spp. could neither be confirmed by ISH nor by PCR. Different pathological aspects, such as host defence responses and regressive/progressive changes were detected in the gills, digestive glands, gonads and mantle. Only one single case of disseminated neoplasia (0.2%) was observed. As for the biomarker evaluation, the MANOVA analysis revealed the statistically significant effect that the variable "sampling site" had on the biological parameter measured, thus suggesting that the multibiomarker approach was able to differentiate the rearing sites.

First Evaluation of Microplastic Content in Benthic Filter-feeders of the Gulf of La Spezia (Ligurian Sea)

ABSTRACTThe ingestion and retention of microplastics of filter-feeder organisms represent a risk for the final consumers and the environment. Biomonitoring is necessary to deal with the effects of plastic material pollution. The selection of the monitored organisms strongly affects the relevance of the results and the understanding of the environmental conditions. The results discussed in this paper highlight the differences in the estimate of microplastic pollution depending on the species subject of study. Ascidia spp. specimens retained a value five-fold higher (0.62 MP/g) than bivalve species (Crassostrea gigas 0.11 MP/g; Mytilus galloprovincialis 0.05 MP/g; Anomia ephippium 0.12 MP/g).

Antifouling biocides (Irgarol, Diuron and dichlofluanid) along the Italian Tyrrhenian coast: Temporal, seasonal and spatial threats

The occurrence of three common antifouling biocides (Irgarol, Diuron and dichlofluanid) was investigated, both in winter and summer, in two Italian coastal areas bordering the Tyrrhenian Sea: the Gulf of Napoli (Southern Italy) and the Gulf of La Spezia (Northern Italy).Dichlofluanid was always below the limit of detection, while Irgarol and Diuron were detected in the Gulf of Napoli, at concentrations ranging from 0.8 ng/L to 134.5 ng/L, and from 1.6 ng/L to 34.8 ng/L, respectively.In the Gulf of La Spezia, the amounts were in the range <1.0 -28.2 ng/L, for Irgarol, and <0.2 and 9.7 ng/L, for Diuron.Overall, the biocide levels increased from winter to summer (the boating season), mostly in the Gulf of Napoli.In addition, the temporal trend for the selected biocides in the Gulf of Napoli showed a sharp decrease of the Diuron contamination, in winter and summer.Based on the field concentrations, a negligible risk to the aquatic environment in the Gulfs of Napoli and La Spezia was highlighted by probabilistic Ecological Risk Assessment.

Seasonal variability of different biomarkers in mussels (Mytilus galloprovincialis) farmed at different sites of the Gulf of La Spezia, Ligurian sea, Italy

Mussels (Mytilus spp.) are worldwide utilized in marine biomonitoring by a multi-biomarker approach. However, for a correct interpretation of different biomarker responses, information is needed on their natural seasonal variability due to environmental/physiological factors.In this work, the seasonal variations of different biomarkers were investigated in M. galloprovincialis from 4 different sites from the gulf of La Spezia (Ligurian sea, Italy), an intensive rearing area in the north-western Mediterranean near La Spezia harbor, an important commercial and touristic port. Lysosomal membrane stability-LMS, stress on stress-SoS, phagocytosis, tissue metallothionein-MT content, oxidative stress related enzyme activities (GST, catalase), and nitric oxide (NO) production were evaluated. The results underline the importance of LMS and SoS as core descriptors of the mussel health status in relation to seasonal variations in temperature and reproduction. These data represent the baseline information for ongoing biomonitoring studies related to dredging activities in this area.