Benthic foraminifera response and geochemical characterization of the coastal environment surrounding the polluted industrial area of Portovesme (South-Western Sardinia, Italy)

Gut microbial CAZymes markers for depression

Major depressive disorder (MDD) is a serious mental illness, characterized by disturbances of gut microbiome, it is required to further explore how the carbohydrate-active enzymes (CAZymes) were changed in MDD. Here, using the metagenomic data from patients with MDD (n = 118) and heath controls (HC, n = 118), we found that the whole CAZymes signatures of MDD were significantly discriminated from that in HC. α-diversity indexes of the two groups were also significantly different. The patients with MDD were characterized by enriched Glycoside Hydrolases (GHs) and Polysaccharide Lyases (PLs) relative to HC. A panel of makers composed of 9 CAZymes mainly belonging to GHs enabled to discriminate the patients with MDD and HC with AUC of 0.824. In addition, this marker panel could classify blinded test samples from the two groups with an AUC of 0.736. Moreover, we found that baseline 4 CAZymes levels also could predict the antidepressant efficacy after adjusted confounding factors and times of depressive episode. Our findings showed that MDD was associated with disturbances of gut CAZymes, which may help to develop diagnostic and predictive tools for depression.

Hemp Cultivation in Soils Polluted by Cd, Pb and Zn in the Mediterranean Area: Sites Characterization and Phytoremediation in Real Scale Settlement

Polluting activities affect, directly or indirectly, large areas of agricultural lands. Metal polluted soils could be managed by phytoremediation using hemp (Cannabis sativa L.). To know the phytoremediation capability of industrial hemp in metal polluted soils under semiarid environments, an experimental project with the support of local farmers was conducted in Sardinia (Italy). This work was carried out in three main steps: (i) identification and selection of the study sites, (ii) field trials, at local farms, both on contaminated and non-polluted sites, (iii) evaluation of heavy metals contents accumulated in the different parts of the plants. Five study sites were chosen. Three of them were severely polluted by heavy metals. Concentrations of Zn and Cd in plants generally were positively correlated with soil content and were different in each part of the plant. The higher values of Zn and Cd were detected in leaves of plants grown in polluted sites (Zn > 950 mg kg−1 and Cd > 6.8 mg kg−1). High values of Pb were also detected in plants grown in non-contaminated soils: this contamination may be due to atmospheric deposition related to polluting sources far to the cultivation.

Benthic Foraminifera as Environmental Indicators in Mediterranean Marine Caves: A Review

Marine caves are characterized by wide environmental variability for the interaction between marine and continental processes. Their conditions may be defined as extreme for inhabiting organisms due to the enclosed morphology, lack of light, and scarcity of nutrients. Therefore, it is necessary to identify reliable ecological indicators for describing and assessing environmental conditions in these habitats even more than elsewhere. This review aims to provide the state of art related to the application of benthic foraminifera as proxies in the (paleo)ecological characterization of different habitats of marine caves. Special attention was addressed to a research project focused on Mediterranean marine caves with different characteristics, such as extent, morphology, freshwater influence, salinity, sediment type, oxygenation, and organic matter supply. This review aims to illustrate the reliability of foraminifera as an ecological and paleoecological indicator in these habitats. They respond to various environmental conditions with different assemblages corresponding to a very detailed habitat partitioning. Because marine caves may be considered natural laboratories for environmental variability, the results of these studies may be interpreted in the perspective of the global variability to understand the environmental drivers of future changes in marine systems.

Benthic foraminifera geochemistry as a monitoring tool for heavy metal and phosphorus pollution - A post fish-farm removal case study

Measuring environmental contaminants in coastal areas is critical for monitoring and managing their impacts. Commonly used techniques involve repetitive field sampling, which provides a single moment in time during each effort. In this study, we examine the potential for using foraminifera in monitoring and risk assessment as recorders of bioavailable pollutants. Geochemical analysis of benthic foraminifera (Operculina ammonoides) shells sampled annually at a previous fish farm location showed extremely high levels of copper (Cu), zinc (Zn), and phosphorus (P) during the three years following the fish cages removal, with a general reduction afterwards. Levels of Cu/Ca were still more than 4-fold higher than background levels 10 years after the removal of the fish cages. Based on our finds, it is concluded that the geochemical analysis of recent benthic foraminifera shells can serve as a powerful monitoring tool of bioavailable contaminants in seawater. Additionally, the results highlight the need for heavy metal monitoring near marine aquaculture facilities and suggest that long-term effects extend spatially and temporally far beyond the original point source. Finally, we observed variations in micro-distribution of elements within the top 1-2 μm of the shells, where Cu/Ca, Zn/Ca and P/Ca are consistently higher in the chamber wall than in the septa. This observation is relevant for studies conducting single chamber analyses.

Natural vs. Anthropic Influence on the Multidecadal Shoreline Changes of Mediterranean Urban Beaches: Lessons from the Gulf of Cagliari (Sardinia)

Urban Mediterranean beaches are often characterized by a fragile and unstable equilibrium that can be easily altered by ongoing climate change and by the increase in human pressure. This may pose serious threats to the survival of beach systems that cannot accommodate these modifications. In this paper, the spatio-temporal shift of the shoreline was investigated along two urban beaches in the Gulf of Cagliari (Poetto and Giorgino; southern Sardinia, western Mediterranean Sea) across a time frame of 62 years (1954–2016). The Digital Shoreline Analysis System (DSAS) ArcGIS™ extension was used to extract different statistical parameters which allowed us to quantify the erosion and accretion rates. These data were further examined in relation to a number of anthropic and natural forcings in order to disentangle the factors controlling shoreline evolution. Eight sectors with interchanging net erosive and accretion trends were identified along the Poetto and Giorgino beaches. In six decades, some sectors of the two study sites appeared to have undergone great shoreline modification as a result of the intense anthropogenic activities impacting these coastal areas. The westernmost portions of both beaches were found to be the most vulnerable to erosion processes; such conditions were likely controlled by the interplaying of local hydrodynamics and by the intense coastal development which affected these sectors. The highest retreat rates (mean end point rate (EPR) = −0.51/year) were recorded in the western limit of Giorgino beach. Along the western limit of Poetto beach, EPR erosion rates (mean EPR = −2.92/year) considerably increased in the years after the artificial beach nourishment carried out in 2002, suggesting that the majority of the nourished material was lost offshore or partly redistributed along the beach. Coastal structures, urban development, river catchment modification, industrial and port activities, beach cleaning and touristic and recreational activities have been identified as the ongoing causes of coastal alteration. If these factors remain constant, under projected climate change scenarios, these beaches are at risk of further increased flooding and erosion. In this context, the application of DSAS appeared as an essential tool, supporting a monitoring system able to provide understanding and, potentially, predictions of the short- to long-term evolution of these beach systems.

The distribution of benthic foraminifera in Bel Torrente submarine cave (Sardinia, Italy) and their environmental significance

The use of benthic foraminifera as ecological indicators in submarine caves of temperate seas have never been studied before and it represents a new approach, verified by this research. The Bel Torrente submarine cave (Gulf of Orosei, Sardinia, Italy) was surveyed by GUE (Global Underwater Explorers) scuba divers in order to georeferencing the cave before positioning the sampling stations, from the entrance to 430 m inside the cave. A total of 15 water samples were collected to investigate abiotic parameters (temperature, salinity, pH) while 15 sediment samples were collected to analyze grain size and benthic foraminifera. Benthic foraminifera, investigated for the first time in a submarine cave of temperate areas, were exclusively found from the entrance to 300 m inside the cave. Species distribution and assemblage diversity have been found to be correlated to the environmental gradient towards the inner cave, mainly due to the decreasing of temperature and salinity and the increasing of the flow energy. Water acidification seems responsible for the transition from a calcareous hyaline-dominated assemblage to an agglutinant-dominated one, occurring between 120 and 150 m from the entrance. Common taxa of the Sardinian coastal marine area are present only close to the entrance of the cave, while species found in the inner part are nearly exclusively epifaunal clinging/attached or infaunal taxa, with tolerance for wide variability of environmental parameters, such as Gavelinopsis praegeri, and opportunist infaunal taxa such as Eggerella advena. The agglutinant taxa found in the cave are conversely very rare in coastal marine assemblages of the area. This suggests a very efficient dispersal mechanism for the colonization of the caves, involving probably juvenile foraminifera at a "propagule" stage.

Benthic Foraminifera as bio-indicators of anthropogenic impacts in coastal environments: Acqua dei Corsari area case study (Palermo, Italy)

This study investigates living benthic foraminiferal assemblages as bio-indicators of anthropogenic activities in a coastal area within the Gulf of Palermo (Sicily, Italy), affected by industrial and urban activities, and evaluates the environmental quality through the calibration of a Tolerant Species index (%TS_std). Sediments from 6 stations were sampled along a bathymetric transect from the coast to offshore. Sediment grain size, TOC, major, minor and trace elements and polycyclic aromatic hydrocarbons (PAHs) were compared to benthic foraminiferal assemblages and species at each station. Diversity and density of benthic foraminiferal assemblages were not affected by the presence of pollutants, while tolerant species increased with organic (TOC and PAHs) or chemical (As and Pb) concentrations. Moreover, the calibration of the %TS_std formula to >125μm foraminiferal assemblage, gives a detailed description of environmental quality along the transect, representing a good and sensitive tool to evaluate marine coastal environment.

Heavy metal accumulation in surface sediments at the port of Cagliari (Sardinia, western Mediterranean): Environmental assessment using sequential extractions and benthic foraminifera

Superficial sediments were taken at the port of Cagliari (Sardinia, Italy), which includes the oil terminal of one of the largest oil refineries in the Mediterranean. Significant trace metal concentrations were found in the whole port area. Sequential extraction of metals from the different sediment fractions (BCR method) showed a higher risk of remobilisation for Cd, which is mostly bound to the exchangeable fraction. Foraminiferal density and richness of species were variable across the study area. The living assemblages were characterized by low diversity in samples collected close to the port areas. Ammonia tepida and bolivinids, which were positively correlated with concentrations of heavy metals and organic matter content, appeared to show tolerance to the environmental disturbance. The sampling sites characterized by the highest values of biotic indices were located far from the port areas and present an epiphytic and epifaunal biocoenosis.

Honey Bees (Apis mellifera, L.) as Active Samplers of Airborne Particulate Matter

Honey bees (Apis mellifera L.) are bioindicators of environmental pollution levels. During their wide-ranging foraging activity, these hymenopterans are exposed to pollutants, thus becoming a useful tool to trace the environmental contaminants as heavy metals, pesticides, radionuclides and volatile organic compounds. In the present work we demonstrate that bees can also be used as active samplers of airborne particulate matter. Worker bees were collected from hives located in a polluted postmining area in South West Sardinia (Italy) that is also exposed to dust emissions from industrial plants. The area is included in an official list of sites of national interest for environmental remediation, and has been characterized for the effects of pollutants on the health of the resident population. The head, wings, hind legs and alimentary canal of the bees were investigated with Scanning Electron Microscopy coupled with X-ray spectroscopy (SEM-EDX). The analyses pointed to specific morphological and chemical features of the particulate, and resulted into the identification of three categories of particles: industry -, postmining -, and soil –derived. With the exception of the gut, all the analyzed body districts displayed inorganic particles, mostly concentrated in specific areas of the body (i.e. along the costal margin of the fore wings, the medial plane of the head, and the inner surface of the hind legs). The role of both past mining activities and the industrial activity close to the study area as sources of the particulate matter is also discussed. We conclude that honey bees are able to collect samples of the main airborne particles emitted from different sources, therefore could be an ideal tool for monitoring such a kind of pollutants.

Interpretation of coastal sediment quality based on trace metal and PAH analysis, benthic foraminifera, and toxicity tests (Sardinia, Western Mediterranean)

An integrated approach for the assessment of coastal sediment quality was utilised in three areas of Sardinia (Western Mediterranean, Italy). Sediments were analysed for trace metals and polycyclic aromatic hydrocarbons (PAHs), while benthic foraminifera were used as bioindicators. Furthermore, the embryo-toxicity test was used to provide ecologically relevant information using rapid and cost-effective screening tools. The aim was to evaluate the usefulness of coupling different analytical tools. The results revealed the presence of polluted sediments in areas exposed to petrochemical industries, smelters or military settlements. However, while foraminifera have presented similar indications for chemical analysis of contamination levels in the different areas, the toxicity test exhibited a poor relationship with the contaminants measured individually. The results raise questions concerning the bioavailability of contaminants released by sediments in the water column. Overall, the toxicity rate was significant in many samples in comparison with other sites studied in other Mediterranean regions.

Benthic foraminifera for environmental monitoring: a case study in the central Adriatic continental shelf

A study of benthic foraminifera was carried out in sediment samples collected from the central Adriatic coast of Italy, near the Ancona harbour and the Falconara Marittima oil refinery, in order to validate and support their use as bioindicators of ecosystem quality. On the basis of a principal component analysis (PCA), three biotopes (following the bathymetric gradient) have been documented, showing that the distribution pattern of benthic foraminifera is principally related to riverine inputs, organic matter contents at the seafloor, and sediment grain size. We observed higher abundances of opportunistic, low-oxygen tolerant taxa along the coastline, thus being representative of polluted environmental conditions. Near the Falconara Marittima oil refinery, the microfaunal assemblages is characterized by the absence of living specimens and by a low diversity associated with the dominance of opportunistic species. At this site, aberrant tests were also found. The data point out that Ammonia parkinsoniana and Quinqueloculina seem to be the most sensitive taxa and can be considered as good bioindicators of environmental stress in this area. This study confirms that faunal composition and morphology of benthic foraminifera respond to human-induced environmental perturbations, making their study potentially useful for biomonitoring in coastal-marine areas.

Assessment of the health quality of Ria de Aveiro (Portugal): heavy metals and benthic foraminifera

This work analyses the distribution of heavy metals in the sediments of Ria de Aveiro (Portugal) assessed by total digestion and sequential chemical extraction of the sediments. The influence of environmental parameters on the living benthic foraminiferal assemblages was studied. The most polluted parts in the Ria de Aveiro are areas where the residence time is high and cohesive sediments are deposited. Organic matter, which is an excellent scavenger for a number of metals, is in general more abundant in the finer deposits of this lagoon, which act as sinks of anthropogenic pollutants. This condition is observed in Aveiro canals and Murtosa channel where sediments with the highest concentrations of Zn, Pb, Cu, and Cr are found. The sediments of Murtosa channel are also enriched in As, Co and Hg. In Aveiro canals the enrichment of heavy metals is mostly related to the past industrial production at their margins (ceramic and metallurgy), whereas in Murtosa channel with effluent discharges of the Chemical Complex of Estarreja. Foraminiferal density and diversity reach higher values near the lagoon mouth under higher marine influence and decline in general under very low-oxygen conditions. Some species seems to be indifferent to the increasing of TOC (e.g. Haynesina germanica and Ammonia tepida) and some have an opportunistic behaviour in areas with very depressed levels of oxygen (e.g. A. tepida and Quinqueloculina seminulum) whereas other species can better tolerate sulphide/reducing conditions (e.g. H. germanica, Bolivina ordinaria, Buliminella elegantissima, Bulimina elongata/gibba and Nonionella stella) a widespread condition in this lagoon. Foraminiferal density and some species are negatively correlated with concentrations of heavy metals. A most sensitive group of species to higher concentrations of heavy metals is identified (such as B. ordinaria, B. pseudoplicata and B. elongata/gibba) and another one of more tolerant species (such as H. germanica A. tepida and Q. seminulum). Foraminifera are more tolerate higher available concentrations (AC) of Zn in any phase than higher AC of Cu adsorbed do clay minerals (F1) and associated with Fe and Mn oxides (F2) and of Pb in F2; the phase F2, probably the most mobile phase, and even phase F1 seems to be more toxic than the increasing of metals in organic matter (F3).

Sediment characterization of the highly impacted Augusta harbour (Sicily, Italy): modern benthic foraminifera in relation to grain-size and sediment geochemistry

The Augusta harbour is affected by high anthropogenic impact due to intense harbour activity and a large chemical and petrochemical pole. Thirty-seven sediment samples were collected during an environmental characterization project and analyzed for grain size, chemical parameters (Al, As, Cd, Cr, Cu, Fe, Hg, Ni, Pb, Zn and V) and foraminifera, the last one generally being used as ecological indicators of environmental quality. Anthropogenic enrichment was recognized for As, Cu, Hg, Pb and Zn and, among these, Hg showed very high concentrations (up to 191 mg kg(-1) d.w.) often associated in the southern sector of the study area to very high PCB levels (up to 0.83 mg kg(-1)). In this area, an assemblage dominated by Rosalina bradyi and Quinqueloculina lata was recognized. This assemblage shows a clear decrease of foraminiferal density and diversity and, at the same time, increased dominance with respect to the assemblage characterizing the central and northern less polluted sectors, in which Miliolinella subrotunda prevails. Quinqueloculina lata was demonstrated to be a stress-tolerant species because it was not influenced by sediment texture, but positively correlated with the concentration of Hg, PCBs and PAHs. The environmental stress shown by the high-dominance of the Ammonia tepida assemblage was attributed mainly to the influence of stream mouths, which determine environmental instability. Foraminiferal assemblages showed a clear response to environmental degradation in the most polluted area but, at the same time, they demonstrated a high adaptation to pollution.

Testing benthic foraminiferal distributions as a contemporary quantitative approach to biomonitoring estuarine heavy metal pollution

Biomonitoring of estuarine pollution is the subject of active research, and benthic foraminifera are an attractive group to use for these purposes due to their ubiquitous presence in saline water and wide diversity. Here, we describe a case study of biomonitoring using benthic foraminifera in the French Mediterranean lagoon, Bages-Sigean lagoon. In this case, the major pollutants of interest are heavy metals in the sediment, particularly contaminated by Cu and Cd derived from industrial and agricultural sources. The foraminiferal assemblages of the Bages-Sigean lagoon are typical of normal paralic environments, but unusually almost completely lack agglutinated forms. The density of benthic foraminifera was shown to be more influenced by the sediment characteristics rather than heavy metal pollution. However, the relative abundance of Quinqueloculina bicostata was shown to increase in the most polluted areas and we propose that this taxon may be used as an indicator of heavy metal pollution.

The impact of the Bagnoli industrial site (Naples, Italy) on sea-bottom environment. Chemical and textural features of sediments and the related response of benthic foraminifera

The coastal zone of the disused industrial site of Bagnoli, has been studied since 1999 in order to highlight chemical and ecological features of pollution, mainly due to a steel plant. This further study was performed in order to check the foraminiferal response to changes in sediment grain-size and contaminant concentrations and to recognise the actual effects of the environmental stress determined by industrial pollution on the foraminiferal assemblages. This was attained by considering a wider area than in the previous studies so as to recognise the possible reference conditions. Very high contamination, mainly due to Cu, Fe, Hg, Mn, Ni, Pb, Zn and PAHs, was recorded in the marine sediments close to the steel plant. Contaminant concentrations and sediment composition were recognised as important factors influencing the foraminiferal response by means of statistical analysis. The foraminiferal abnormality index (FAI) is positively correlated with heavy metals concentration, exceeding the natural threshold in front of the plant. Furthermore, increasing pollution levels correspond to the increase of pollution-tolerant species in the assemblage.