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Viruses are the most abundant life forms in the world's oceans and they are key drivers of biogeochemical cycles, but their impact on the microbial assemblages inhabiting hydrothermal vent ecosystems is still largely unknown. Here, we analysed the viral life strategies and virus-host interactions in the sediments of a newly discovered shallow-water hydrothermal field of the Mediterranean Sea. Our study reveals that temperate viruses, once experimentally induced to replicate, can cause large mortality of vent microbes, significantly reducing the chemoautotrophic carbon production, while enhancing the metabolism of microbial heterotrophs and the re-cycling of the organic matter. These results provide new insights on the factors controlling primary and secondary production processes in hydrothermal vents, suggesting that the inducible provirus-host interactions occurring in these systems can profoundly influence the functioning of the microbial food web and the efficiency in the energy transfer to the higher trophic levels.

The Lessepsian bivalve Brachidontes pharaonis is considered as one of 100 worst invasive species in the Mediterranean rapidly colonizing the most part of the Basin. Its current distribution seems primarily due to ship transport of carrying larvae by ballast waters and/or in the fouling attached beneath the ship-keels. Although humanmediated transport seems to potentially in!uence dispersal of invasive species, habitat suitability, temperature, salinity and food availability (i.e. in terms of quality and quantity of organic matter) seem to represent decisive factors in determining survivorship and distribution of this species. Physiological tolerance of B. pharaonis to temperature and salinity changes has been demonstrated to be very large, while scant information available about its physiological response to food availability changes. In this paper, we report the #rst experimental mesocosmal dataset on B. pharaonis’s scope for growth (SFG) as a function of di"erent concentrations of chlorophyll-a from 0.9 – 1.0 to 3.9 – 4.0 μg l-1. B. pharaonis’s SFG varied from negative values at 0.1 μg l-1 [CHL-a] to positive values at > 0.9 μg l-1 [CHL-a]. In addition, by interpolating , SFG data and large satellite dataset of CHL-a values obtained from the Environmental Marine Information System (EMIS), we estimated on a very small spatial scale (8.1 nmi) the potential dispersal and distribution of this specie along Sicilian coastlines.

L’utilizzo del mussel cleaning che sfrutta le caratteristiche fisiologiche dei molluschi filtratori per la mitigazione degli impatti derivanti da reflui particellati di origine antropica, ed in particolare delle attività di piscicoltura, è stato introdotto di recente in diversi paesi europei. Tale procedura si basa sull’ipotesi che la filtrazione operata da elevate biomasse di molluschi eduli posti nei pressi degli impianti di pescicoltura possa ridurre il carico organico in eccesso proveniente dal surplus di mangime fornito ai pesci allevati e che in certa parte inutilizzato tende a sedimentare al di sotto delle gabbie di allevamento. In questo studio abbiamo analizzato in due periodi differenti (Luglio e Ottobre 2006) le differenze nel carico e nella composizione biochimica del particellato in sospensione in siti posti nelle vicinanze di gabbie di allevamento di pesci associate a filari per l’allevamento di bivalvi (mitili ed ostriche) ed in siti di controllo lontani dalle gabbie ma caratterizzati dalla presenza di filari di molluschi. Né quantità né composizione biochimica del particellato sospeso differiscono significativamente tra siti interessati dai reflui della piscicoltura e relativi controlli. Questi risultati suggeriscono che la presenza di elevate biomasse di filtratori possa avere un certo effetto nella riduzione del carico organico associato ai reflui di maricoltura.

Questo studio è stato condotto nella primavera del 2006 in due località del Golfo di Palermo (Arenella e Bandita) a differente grado di impatto antropico. All’interno di ogni località, sono stati scelti siti a differente inclinazione (orizzontale vs verticale). Sono stati campionati i popolamenti mesolitorali dei massi frangiflutti che, insieme a quelli della frangia infralitorale, risentono maggiormente dell’eventuale presenza di inquinamento organico. Le comunità algali nelle due località hanno mostrato differenze in funzione delle diverse caratteristiche ambientali e dei diversi livelli di impatto antropico, in termini di copertura %, strutturazione e diversità specifica. Sono stati inoltre evidenziati effetti significativi della differente inclinazione sulla strutturazione delle comunità indagate, con una più elevata ricchezza specifica riscontrata nei siti con inclinazione verticale rispetto a quelli orizzontali.

I substrati duri artificiali sono idonei per verificare la risposta ecologica degli organismi del benthos a differenti livelli di variabilità dell’interazione tra fattori antropici, abiotici e biotici. La combinazione tra impatto umano e inclinazione del substrato può influenzare la struttura di comunità. Lo studio è stato condotto nella primavera 2006 nel Golfo di Palermo, nel quale sono state individuate due località a diverso grado di impatto antropico derivante da attività industriali e da reflui urbani. In ogni località, sono stati scelti siti a differente complessità geometrica (inclinazione orizzontale vs verticale). I campionamenti sono stati effettuati sulla fascia mesolitorale di massi frangiflutti con un grattaggio di una superficie di 400 cm . Gli organismi raccolti ad ogni livello di interazione tra impatto e inclinazione sono stati contati e classificati ed i dati ottenuti sono stati analizzati con una ANOVA. Le comunità nelle due località a differente livello di impatto sono risultate differenti sia in termini di abbondanza che di composizione. I principali gruppi erano poliplacofori, gasteropodi, malacostraci, cirripedi e bivalvi; questi ultimi dominavano la comunità nei siti impattati, mentre i cirripedi dominavano la comunità nei siti non impattati. L’inclinazione dei substrati ha mostrato avere un effetto significativo sulla distribuzione degli organismi e partecipa in modo significativo nella strutturazione delle comunità indagate.

The present study was carried out close to a fish farming area in the Gulf of Castellammare (N-W Sicily) in summer 2004. Specimens of Mytilus galloprovincialis were transplanted in putatively impacted areas and controls to test the recycler capability of bivalves for reducing the impact of waste on the surrounding environment.Mussels cultivated close to farms grew quicker than mussels in controls transforming waste OM in edible biomass and those positioned at 3 meters depth reached higher levels of secondary production than those at 9 meters.

Polychaetes of the genus Sabellaria (Annelida, Sabellariidae) are gregarious bioconstructors that build reefs by assembling rigid tubes with sand grains in shallow waters. Sabellarid bioconstructions provide important ecosystem services such as sediment stabilization, water filtration and the mitigation of coastal erosion as well as nursery areas, shelter and feeding grounds for several marine species. Moreover, sabellarid reefs are exposed to both natural and anthropogenic disturbance and are therefore listed by international directives among the marine habitats deserving protection. We conducted a pilot study to assess the feasibility of habitat restoration with the sabellarid reef through a novel transplantation method. Fragments of S. spinulosa reef were collected at 1 m depth, fixed using epoxy putty into terracotta vases and then attached on the landward side of the two breakwaters in a coastal marine area enclosed in a Site of National Interest (SNI) of the central-western Adriatic (Mediterranean Sea). Overall, 14 of the 24 transplanted fragments (54.2%) survived during the study period (17 months). The total area of the transplanted reef fragments reduced during the early phase, appearing stable toward the end of the experiment. The transplantation method resulted effective given the survival rate observed, however, we did not observe the expected increase in the reef surface. Small-scale variation in environmental conditions such as organic load, sediment granulometry and hydrodynamics might have affected the growth capacity of the transplanted reef fragments. Further studies considering the microscale environmental requirements of this species are needed to better understand the feasibility of sabellarid reef restoration and its large-scale implementation.

Present and past industrial activities in coastal areas have left us a legacy of contamination and habitat degradation with potential implications for human health. Here, we investigated a coastal marine area enclosed in a Site of National Interest (SNI) of the central-western Adriatic (Mediterranean Sea), where priority actions of environmental remediation are required by governmental laws due the high environmental and human risk, and that is off-limits to any human activity since 2002. In particular, our investigation was focused on an area located in front of a chemical industry dismissed more than 3 decades ago. We report that the concentrations of heavy-metal and organic contaminants in the investigated sediments were generally lower than those expected to induce detrimental biological effects. Meiofaunal abundance, biomass and community structure changed among stations, but regardless of the distance from the abandoned industrial plant. Taxa richness within the SNI did not change significantly compared to the controls and the lack of some taxa in the SNI transects was not due to the contamination of the SNI area. The results of this study suggest a natural recovery of the marine area over 2 decades of restrictions on human activities, including fishing and shipping bans. If the hypothesis of the natural recovery of this SNI will be further confirmed by other studies, the plans for the identification and monitoring of the most polluted areas in Italy should necessarily be redefined also in the light of the Water Framework, the Marine Strategy Framework and the Environmental Quality Standard Directives.

Marine ecosystems are globally threatened by human activities, but some areas, such as those affected by abandoned industrial plants, show an overlap of acute and chronic impacts, which determine a considerable deterioration of their health status. Here we report the results of a research conducted on coastal sewers that discharge their loads in the highly contaminated area of Bagnoli-Coroglio (Tyrrhenian Sea, Western Mediterranean). The sampling area is characterized by heavy industrial activities (a steel plant using coal, iron and limestone) started in 1905 and ceased in 1990, which left widespread heavy metals and hydrocarbon contamination. After taking into account the potential influence of sediment grain size ranges through their inclusion as covariates in the analysis, we tested the potential impact of sewage discharge on the total abundance and multivariate structure of meiofaunal assemblages, as well as on the abundance of single taxa. The organic matter was analysed in terms of total phytopigment and biopolymeric carbon concentrations. Nematoda, Copepoda (including their nauplii), and Tardigrada were the most abundant meiofaunal taxa at all sites, but nematodes did not show a consistent pattern relative to the sewage outfalls. However, the sewer located in the historically most contaminated area showed a minimal abundance of all taxa, including nematodes, while copepods were relatively less abundant at the two southernmost sewers. Comparing the north vs. south site of the sewers, higher meiofaunal abundances were observed in the southward part, likely as a result of the local circulation. The results of this study indicate the general adaptation of meiofauna to multiple stressors (sewage discharge, superimposed to chronic industrial contamination) and its likely modulation by other local processes. They also provide relevant baseline information for future restoration interventions that would take into account the spatial variation of target organisms as needed.

The effects of contaminants on marine organisms have been documented since decades, but the long-term responses and recovery rates of benthic communities to mixtures of contaminants, several years after the cessation of industrial activities, need to be further investigated. Bagnoli-Coroglio Bay (Gulf of Naples, Tyrrhenian Sea) is a typical example of historically contaminated coastal area due to industrial activities stopped at the beginning of nineties. In the present study we carried out a fine spatial scale analysis of the distribution of meiofaunal (and nematodes) assemblages along five bathymetric transects located at increasing distance from the historical source of contamination in relation with the polycyclic aromatic hydrocarbon and heavy metal concentrations present in the sediment. Meiofaunal abundance and biomass changed widely along transects but independent from the distance from the source of contamination. Even when the contamination levels were expected to induce significant detrimental biological consequences, meiofaunal abundance and biomass were similar to those reported in unpolluted benthic coastal areas worldwide. Conversely, biodiversity in terms of meiofaunal taxa richness was generally low (range: 5–8 taxa in 12 of the overall 15 stations investigated). This was explained by the lack of sensitive groups such as ostracods, gastrotrichs and tardigrades commonly encountered in benthic coastal ecosystems, thus reflecting an overall poor/moderate environmental quality of the investigated area. Nematode (structural and functional) diversity was also low, particularly at stations characterized by higher contamination levels. At the same time, nematode species composition did not change significantly among stations suggesting a widespread effect of contaminants able to reduce the variability (i.e., turnover diversity) within the assemblages of the whole study area. Overall, our results indicate that even decades after the cessation of contaminant emissions, benthic biodiversity was affected in terms of both meiofaunal taxa and nematode species. These findings strongly reinforce the call for reducing sources of chronic pollution in marine ecosystems and provide new insights for a better understanding of the ecological recovery of historically contaminated marine environments.

Underwater noise is one of the most widespread threats to the world oceans. Its negative impact on fauna is nowadays well established, but baseline data to be used in management and monitoring programs are still largely lacking. In particular, the acoustic assessment of human-impacted marine coastal areas provides complementary information on the health status of marine ecosystems. The objective of our study was to provide a baseline of underwater noise levels and biological sounds at two sites within the Gulf of Naples (Italy), one of which is located in Bagnoli-Coroglio, a Site of National Interest (SIN) for its high contamination levels. Within the SIN, sounds were recorded both before and during sediment coring activities (vibrocorer sampling), in order to investigate the potential acoustic impact due to such operations. Acoustic recordings were analyzed following the European Marine Strategy Framework Directive indications as defined in the frame of the Descriptor 11. Results reported here show that the investigated area is characterized by a high anthropogenic noise pressure. Ambient noise levels were principally driven by shipping noise and biological sounds of invertebrates (e.g., snapping shrimps). Sounds referable to other biological activity were difficult to detect because heavily masked by shipping noise. Coring activity determined a substantial introduction of additional noise at a local spatial scale. This study expands underwater noise baseline data to be further implemented in future monitoring programs of coastal areas affected by anthropogenic impacts. In addition, it proposes new cues for using underwater acoustic monitoring tools to complement traditional methodologies for evaluating health status of ecosystems and for investigating recovery rates after restoration/reclamation programs.

As has been shown for other ecosystems, the ecological and socio-economic impacts of climate change on Mediterranean intertidal habitats are highly variable in space and time. We conducted field and laboratory measurements of cellular, ecophysiological and behavioural responses of selected intertidal invertebrates (mussels, gastropods and sponges) and completed a literature review to determine what is known of socioeconomic consequences of these biological changes. Results suggest significant gaps in our knowledge that may impede a complete understanding of likely impacts (physical, biological, and socioeconomic) and that sufficient data for such an analysis is available only for mussels. Application of ecological models for native mussels Mytilaster minimus and invasive Brachidontes pharaonis bivalves indicates that the current distribution of these species is linked to the availability of food and local temperature. Choosing Israel as a case study, the study focused on the identification of ecosystem services and goods provided by the Mediterranean rocky intertidal and on the assessment of conservation approaches. Intertidal systems were poorly represented in the socio-economic literature and there was low awareness of the value of these ecosystems among stakeholders. Subsequently, conservation efforts for intertidal communities were minimal. While climate change will very likely continue to impact these systems, our predictive capacity for the extent and locations of such impacts, and of any derived socio-economic consequences, remains limited.

International audience; While several studies point at off-shore aquaculture as a possible source of impacts on the local marine environment, very few have analysed its effects at large scales such as at the bay, gulf or basin levels. Similar analyses are hampered by the multiple sources of disturbance that may concomitantly affect a given area. The present paper addresses these issues taking the Gulf of Castellammare (Southern Tyrrhenian Sea) as an example. Nitrogen (N) and phosphorous (P) loads were calculated for the period 1970-2007, and compared to chlorophyll-a concentration as measured inside and outside the Gulf over the same period. Results indicate that N and P catchment loading has constantly decreased because of improved environmental management. Nevertheless, nutrient concentration in the Gulf has steadily increased since the establishment of aquaculture facilities in 1999. Chlorophyll-a concentration followed this trend, showing a marked increase from 2001 onwards. In the same period, chlorophyll-a concentrations measured inside and outside the Gulf have significantly diverged. As all the other possible causes can be ruled out, aquaculture remains the sole explanation for the observed situation. This paper demonstrates for the first time ever that off-shore aquaculture may affect the marine ecosystem well beyond the local scale and provides an additional element of concern to be kept into consideration when allocating oceans' space for new fish farming activities.

The ecological tangible effect of the complex interaction between sediments and water column in shallow waters is represented by turbidity which is a common feature of most aquatic ecosystems: it varies both temporally and spatially; it can cover a huge area and persist for a long period or it can be very localized and temporary. Among many factors able to generate turbidity, wind generated wave action and water mass movements due to tides seem important in causing resuspension of sediments. Although there is much research spent in last decades on this topic and many models to explain the complexity of the wind-water-sediment interaction, some interactive aspects are too site specific and then still poor understood. On the other hand, this interaction involves many physical, chemical and trophic aspects like water flow velocity, turbulence, boundary layer thickness, environmental stresses and, in turn, resuspension, transport, and deposition of particulate matter, mechanical limits to size, larval dispersion, food availability. To get further knowledge on these aspects, we carried out in March 2007 a 5-day-experiment in a Mediterranean shallow area (The Stagnone di Marsala, Western Sicily) by collecting data on wind and water velocities, their directions and the contextual response of the water column in term of turbidity, chlorophyll-a and suspended solids (by ignition). To analyse the interaction, we proceeded step by step. Firstly, we studied data from the two current meters (an acoustic doppler velocimeter 40 ± 2 cm deep, and an electromagnetic current meter 20 ± 2 cm deep). From this data, the water column had the following features: i) during the big semidiurnal tidal transitional phase, the flow field followed a behaviour leading us to hypothesize a logarithmic layer defined by the law of the wall and to obtain friction velocity values with linear regression in good agreement with calculated ones with covariance and TKE method, while ii) during the small tidal transition and at high and low tides, a not-well defined gradient was present (i.e., the mean deviation of the direction of the two water velocities was more than 30° and the flow magnitude at 40 cm was less than that measured at 20 cm implying high values of turbulence intensity). The second step analysed data from multiprobe, ADV, meteorological station and considered turbidity (NTU) as proxy of food availability for consumers. NTU followed a one-day-period and the lower the turbidity, the higher the turbulence (both at 20 and 40 cm).

The effect of boat noise on the behaviour of bluefin tuna Thunnus thynnus was investi- gated in the Egadi Islands, Sicily, during spring 2005 using a fixed tuna trap set near shipping routes. Tuna behaviour was observed when exposed to both natural ambient sound and sound generated by hydrofoil passenger ferries, small boats and large car ferries. Acoustical and behavioural analyses were conducted with and without extraneous sound to define a list of behavioural categories. Each vessel produced different engine sounds with regard to their composition and bandwidth, and all were distinctly different from ambient sound levels. In the absence of boat noise, tuna assumed a con- centrated coordinated school structure with unidirectional swimming and without a precise shape. When a car ferry approached, tuna changed swimming direction and increased their vertical move- ment toward surface or bottom; the school exhibited an unconcentrated structure and uncoordinated swimming behaviour. Hydrofoils appeared to elicit a similar response, but for shorter periods. Ago- nistic behaviour was more evident when exposed to sounds from outboard motors of small boats. This study showed that local noise pollution generated by boats produced behavioural deviations in tuna schools. Schooling enhances tuna homing accuracy during their spawning migration, and an alter- ation in schooling behaviour can affect the accuracy of their migration to spawning and feeding grounds.

Fouling species richness, abundance and composition and biomass were chosen as the descriptors of effect of fish farm organic enrichment. The study was carried out in September 2004 in the Gulf of Castellammare (South Tyrrhenian, Mediterranean). The fouling species were sampled from plastic buoys spaced throughout the study area both up- [UP] and down-stream [DOWN]. The results showed that fouling community responded to the chronic input of allochthonous organic matter experiencing local changes more or less significantly with regard to abundance, species composition and general community diversity. Upper fouling would work as a first filter naturally opposed by environment resistance assimilating and facilitating the accommodation of most organic surplus. In highly hydrodynamic and sufficiently deep systems, the transport of organic particles produced from farms would have an effect along the horizontal axis rather than along the vertical axis, involving upper located benthic organisms rather than sedimentary benthic organisms.