Search

The aim of the present work is to demonstrate the practical importance of a multidisciplinary approach and weighted criteria to synthesize and integrate different typologies of data (or lines of evidence, LOEs), including chemical levels in marine sediments, their bioavailability to specific indicator species, ecotoxicological effects measured through subcellular biomarkers and batteries of bioassays, and potential impacts of pollution on local benthic communities. The area of Bagnoli (Gulf of Naples, Southern Italy) was selected as a model case-study, as it is a coastal area chronically impacted by massive industrial contamination (trace metals and hydrocarbons), and dismissed decades ago without any subsequent remediation or habitat restoration. The results of each LOE were elaborated to provide specific hazard indices before their overall integration in a weight of evidence (WOE) evaluation. Levels of some trace metals and PAHs revealed a severe contamination in the entire study area. Bioavailability of hydrocarbons was evident particularly for high molecular weight PAHs, which also caused significant variations of cellular biomarkers, such as cytochrome P450 metabolization in fish, lysosomal membrane destabilization in mussels, genotoxic effects both in fish and molluscs. The results of a battery of bioassays indicated less marked responses compared to those obtained from chemical and biomarkers analyses, with acute toxicity still present in sediments close to the source of contamination. The analysis of benthic assemblages showed limited evidence of impact in the whole area, indicating a good functioning of local ecosystems at chronic contamination. Overall, the results of this study confirm the need of combining chemical and biological data, the quantitative characterization of various typologies of hazard and the importance of assessing an integrated environmental WOE risk, to orientate specific and scientifically-supported management options in industrialized areas.

Pollutants alter marine systems, interfering with provisioning of ecosystem services; understanding their interaction with ecological communities is therefore critical to inform environmental management. Here we propose a joint compositional- and interaction-based analysis for ecological status assessment and apply it on the benthic communities of the Bagnoli Bay. We found that contamination differentially affects the communities’ composition in the bay, with prokaryotes influenced only by depth, and benthos not following the environmental gradient at all. This result is confirmed by analyses of the community structure, whose network structure suggest fast carbon flow and cycling, especially promoted by nematodes and polychaetes; the benthic prey/predator biomass ratio, adjusted for competition, successfully synthesise the status of predator taxa. We found demersal fish communities to separate into a deep, pelagic-like community, and two shallow communities where a shift from exclusive predators to omnivores occurs, moving from the most polluted to the least polluted sampling units. Finally, our study indicate that indices based on interspecific interactions are better indicators of environmental gradients than those defined based on species composition exclusively.

Brown macroalgae belonging to the genus Cystoseira (Fucales: Sargassaceae) are canopy-forming organisms the recent decline of which at a basin and local scale has been widely documented, which urgently calls for research to fill knowledge gaps and support new and effective measures for protection. We, hereby, characterised the molluscan assemblages associated with three Cystoseira taxa (C. amentacea, C. compressa and C. crinita) from Ischia Island (Italy, Tyrrhenian Sea), and tested whether different congeneric taxa may syntopically support a different biota. In particular, these assemblages were compared among three Cystoseira species, between two times of sampling (June–July 2015 and June–July 2016), and among six sites in terms of multivariate structure (identity and relative abundances of constituting taxa combined, and presence–absence composition), as well as for synthetic measures of diversity, including the total richness of taxa, the exponential Shannon index and the reciprocal Simpson index. In total, 24736 molluscan individuals were collected, overall belonging to 52 taxa. The majority of the identified species included micrograzers and filter feeders, which is in agreement with similar previous studies. The composition of associated molluscan assemblages, which was mainly represented by juvenile individuals, differed among the three Cystoseira species, suggesting that even congeneric taxa do not support an analogous benthic fauna. The present findings have shed light on the molluscan biota associated with Cystoseira taxa in the Gulf of Naples and strengthened the importance of such habitat-forming macroalgae in structuring the local infralittoral invertebrate biodiversity and as a nursery for species-specific associated molluscs.

Nitric oxide is a versatile and powerful signaling molecule in plants. However, most of our understanding stems from studies on terrestrial plants and very little is known about marine autotrophs. This review summarizes current knowledge about the source of nitric oxide synthesis in marine photosynthetic organisms and its role in various physiological processes under normal and stress conditions. The interactions of nitric oxide with other stress signals and cross talk among secondary messengers are also highlighted.

Systematic relationships of some taxa within the subfamily Sabellinae (Polychaeta: Sabellidae) based on the sequence of the Cl domain of the 28S rDNA coding gene are assessed, and the cladogram obtained are discussed in the light of some reproductive and morphological features. Sixteen different species belonging to 12 genera, were analysed. The cladograms, obtained with different methods (distance UPGMA, maximum parsimony and maximum likelihood) are consistent, except for the ambiguous position of Amphiglena. Three main groups of species, showing similarity in reproductive features and sperm morphology (acro-some structure) were identified, the taxa included in group A (Myxicola, Chone, and Euchone) show different reproductive strategies and sperm morphology with elongated nucleus, rounded mitochondria and pointed acrosome. Group B contains large sized free-spawning forms, generally with an ect-aquasperm type of spermatozoa (Bispira, Sabella, Sabellastarte, and Branchiomma). Taxa included in group C (Eudistylia, Schizobranchia, Pseudopotamilla, Perkinsiana and Demonax) show high variability in sperm morphology, but with a peculiar acrosome structure. The position of Amphiglena is variable, being closer to group A in the distance and maximum parsimony trees, and to group C in the maximum likelihood tree. From previous morpho-functional analyses, the genera clustering in group A represent the most plesiomorphic taxa, while those in group C contain the most apomorphic ones. Although the general patterns obtained with this preliminary molecular analysis are highly consistent with those arising from the morpho-functional characters available form the literature, the resolution among genera and species within each of the main groups identified is not consistent, and some of the polytomies and phylogenetic problems among taxa still remain unresolved. © 2003 Taylor & Francis Group, LLC.