The present study assessed whether the bivalve Ruditapes philippinarum may be appropriately deployed as a bioindicator in monitoring transitional environments, in terms of bioaccumulation potential ...and biomarker responses. The concentrations of trace metals, PAHs and PCBs were determined in sediments and clam tissue, and biomarkers were estimated at various levels of biological complexity (i.e. metallothioneins, lipofuscins, survival-in-air and reburrowing behaviour). Sediments and clams were collected biannually in 2004 and 2005 at eight sites within Venice lagoon, which were influenced differently by natural and anthropogenic impacts. Results highlighted that the broad variations of pollutant concentrations in sediments were not consistent either with the body residuals or with the biomarker responses. Consequently, on the basis of the observed weak responsiveness and sensitivity to anthropogenic stressors we suggest a more cautious use for R. philippinarum as sentinel organism, at least in estuarine sediments in the north Adriatic transitional areas.
► Clams were collected biannually at eight sites in the Venice lagoon for two years. ► Heavy metals, PAHs and PCBs were evaluated in sediments and clam soft tissues. ► Biomarkers were estimated at various biological levels from biochemical to organism. ► Contaminant levels in sediments were not consistent with body residuals and biomarkers. ► A cautious use for R. philippinarum as a sentinel organism is suggested.
Biological and chemical results on Ruditapes philippinarum used as a bioindicator suggested its cautious use in biomonitoring transitional environments.
In order to improve knowledge of the identification, distribution and abundances of microplastic particles of 1 mm or less (S-MPPs) in the coastal area of the Mediterranean region, a preliminary ...monitoring survey was carried out in a transitional environment along the north-eastern Italian coasts, the Lagoon of Venice. S-MPPs were evaluated in sediments collected from 10 sites chosen in shallow areas variously affected by natural conditions and anthropogenic influences (i.e., landward stations influenced by freshwater inputs, seaward areas near sea inlets, and sites influenced by the presence of aquaculture farms, industry and city centers). S-MPPs, extracted from bulk sediments by density separation, were counted and identified by Fourier-Transform Infrared Micro-spectroscopy (μFT-IR). The μFT-IR process included automatic surface chemical mapping and references to an infrared library database to identify the compositional spectra of particles. S-MPPs were recovered from all samples – a fact which emphasizes their extensive distribution throughout the Lagoon. Total abundances varied from 2175 to 672 S-MPPs kg−1 d.w., higher concentrations generally being observed in landward sites. Of the ten polymer types identified, the most abundant, accounting for more than 82% of total S-MPPs, were polyethylene and polypropylene. The most frequent size (93% of observed microplastics) was in the range 30–500 μm. Total S-MPP values were significantly correlated with the finer sediment fraction and with the metal pollution index.
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•Microplastics ≤1 mm extracted from bulk sediments were identified by μFT-IR.•Their occurrence and distribution were evidenced in the sediments of Venice Lagoon.•Microplastics were found in all samples, with highest concentrations in landward sites.•The most abundant polymers were polyethylene and polypropylene.
Countless submerged rocky formations are scattered in the marine coastal area of the Veneto region (Northern Adriatic Sea, Italy). They are known to be suitable substrates for supporting the ...development of highly complex fish and zoobenthic communities. However, these areas are threatened by local fishing, due to their peculiar morphology and topography which promote gear entanglement. With the aims of quantifying the impacts of abandoned, lost or otherwise discarded fishing gear (ALDFG) on these rocky habitats and monitoring the biodiversity recovery after ALDFG removal, acoustic and diving surveys were performed to map 15 selected rocky outcrops and one artificial reef (for a total surface area of 21 km2). The recovery capability of benthic and fish communities was evaluated by non-destructive techniques in 5 outcrops periodically sampled throughout 18 months. The data collected (number of individuals, species, taxa, and coverage per each species and taxon) were used to calculate three biodiversity indices (species richness, Margalef and Shannon indices) and to assess community recovery. Mapping activities verified the occurrence of 347 ALDFG distributed unevenly over half of the investigated rocky outcrops. The following cleaning operations led to the removal of 362 items, for a total dry weight of 514 kg. The study on biodiversity recovery showed that the complexity of benthic communities gradually improved. In particular, the various biodiversity indices evaluated at the end of the monitoring period generally showed values comparable, or even higher, than those recorded in the reference sites. An increase in biodiversity and species abundance was also observed for fish community; in particular, cryptic species were able to occupy cracks and fractures of rocks previously obstructed by the derelict fishing gear.
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•Presence and impact of derelict fishing gear were studied in North Adriatic outcrops.•The occurrence of derelict fishing gear was evidenced in half of the monitored areas.•A total of 362 items were removed by scuba divers.•The complexity of macro-benthic community gradually improved in the cleared areas.•Cryptic fish species occupied cracks previously obstructed by derelict fishing gear.
In the Marine Protected Area of La Maddalena Archipelago, environmental protection rules and safeguard measures for nautical activities have helped in reducing anthropogenic pressure; however, ...tourism related activities remain particularly significant in summer. With the aim of evaluating their impacts, the biomarker approach using transplanted Mytilus galloprovincialis as sentinel organisms coupled with POCIS deployment was applied. Mussels, translocated to four marine areas differently impacted by tourism activities, were sampled before, during and after the tourist season. Moreover, endocrine disruptors in passive samplers POCIS and the cellular toxicity of whole POCIS extracts on mussel haemocytes were evaluated to integrate ecotoxicological information. Lysosomal biomarkers, condition index and mortality rate, as well as metals in tissues suggested an alteration of the health status of mussels transplanted to the most impacted sites. The cellular toxicity of POCIS extracts was pointed out, notwithstanding the concentrations of the examined compounds were always below the detection limits.
•The effects of tourism activities were investigated in La Maddalena Marine Protected Area.•An active biomonitoring using mussels coupled with POCIS deployment was carried out.•The cellular toxicity of POCIS extracts was evaluated through in vitro exposition experiments.•Biomarkers evidenced altered conditions in mussels from the most impacted sites.•The cellular toxicity of POCIS extracts was highlighted in mussel haemocytes.
The effects of diet and density on growth, survival and gametogenesis of the common ragworm Hediste diversicolor (Nereididae, Polychaeta) were investigated with the aim of contributing to define ...their optimal ranges in the context of a commercial farming system. Two different experimental trials were set up: in the first one, juveniles of H. diversicolor, obtained from laboratory cultures established with specimens taken from the Venice Lagoon, were fed according to three different food regimes (two based on commercial feeds and one consisting of an homogenate of the brown alga Sargassum muticum); in the second trial the juveniles were maintained at different rearing densities (300, 1000 and 3000ind. m−2). In both trials, the effects on growth, survival and gametogenesis were evaluated at various time-intervals during the eight-week period of the experiments. Results showed that H. diversicolor might be a promising species to be commercially exploited in an indoor farming system. In particular, high-protein diets permits elevated growth rates, earlier gametogenesis and sexual maturation. Both growth and survival rates were higher at the lowest densities, whereas the processes of gametogenesis and sexual maturation were not influenced by density.
► H. diversicolor juveniles were reared at different diets and stocking densities. ► Commercial feeds and low stocking densities granted the best growth performances. ► High protein feeds determined an earlier gametogenesis and sexual maturity. ► Commercial-size organisms were obtained within 3.5-4 months from hatching.
Single walled carbon nanohorns (SWCNHs) are a black nanoscale spherical aggregate of cylindrical tubes of graphitic carbon which differ from nanotubes in their “horn-like” shape. Their peculiar ...structure makes them one of the best electronconductors at a nanoscale level. Although not commercially exploited, their rapid environmental diffusion is expected to rise significantly in the next few years. Therefore, we appraised the ecotoxicology of SWCNH powders by taking into account the ecological role of the two species that were deployed in exposure experiments: polychaetes, Hediste diversicolor, and mussels, Mytilus galloprovincialis. Adult mussels and polychaetes were exposed to three SWCNH concentrations: 1, 5, and 10mgL−1 and acute effects were measured after 24 and 48h. Sub-lethal effects were estimated at level of physiological functions such as digestion in mussels (i.e. variations in lysosomal parameters and lipofuscin content) and the antioxidant system in both species (i.e. glutathione peroxidase activity and malondialdehyde content). SWCNH suspension in sea water was also characterised, highlighting the formation of aggregates the size of which was related to SWCNH concentrations and their resident time in the medium. The results showed that SWCNH affected the oxidative and lysosomal systems on the hepatopancreas and led to lysosomal alterations on haemocytes in mussels. The biological responses were less clear in polychaetes. This preliminary investigation highlighted the need of focusing future research efforts on possible physiological impairments caused by long-term exposure to SWCNHs in marine species.
•This is the first attempt to evaluate nanohorn toxicity in model marine invertebrates.•Mussels and polychaetes were exposed to three nanohorn concentrations: 1, 5, and 10mgL−1.•Acute effects were evaluated at 24 and 48h using biochemical and lysosomal biomarkers.•Nanohorns induced sub-lethal effects to antioxidant system and lysosomes in mussels.•Polychaetes were partially responsive to oxidative stress induced by nanohorns.
In the past years, neuroinflammation has been widely investigated in Alzheimer's disease (AD). Evidence from animal, in vivo and post-mortem studies has shown that inflammatory changes are a common ...feature of the disease, apparently happening in response to amyloid-beta and tau accumulation. Progress in imaging and fluid biomarkers now allows for identifying surrogate markers of neuroinflammation in living individuals, which may offer unprecedented opportunities to better understand AD pathogenesis and progression. In this context, inflammatory mediators and glial proteins (mainly derived from microglial cells and astrocytes) seem to be the most promising biomarkers. Here, we discuss the biological basis of neuroinflammation in AD, revise the proposed neuroinflammation biomarkers, describe what we have learned from anti-inflammatory drug trials, and critically discuss the potential addition of these biomarkers in the AT(N) framework.
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