Biological benthic tools as indicators of coastal marine ecosystems health

Coastal marine ecosystems are increasingly subjected to environmental stress and degradation due to pollution. Several research programmes have addressed this problem and produced relevant data sets for specific areas, often including consistent sets of environmental and biological variables. The value of existing information gathered from these types of data can be largely increased by combining them into a common data set to determine globally applicable relationships. To perform this exercise, the Intergovernmental Oceanographic Commission (IOC) of UNESCO has recently formed the Ad hoc Study Group on Benthic Indicators (http://www.ioc.unesco.org/benthicindicators) with the aim of developing robust indicators of benthic health. In this paper, initial products and ongoing activities of this international initiative are described and discussed. An expansion of initial IOC/UNESCO research on benthic fauna-organic carbon relationships is also presented. As part of this follow-up research, the relationship between total organic carbon concentrations of sediment and abundance, biomass and species diversity of benthic macrofauna was evaluated using data sets from 2 different regions of the world comprising 3 different coastal marine environments. The ability of identifying threshold levels in selected variables that could serve as indicators of related adverse environmental conditions leading to stress in the benthos is envisaged within the frame of a larger joint analysis, carried out by the IOC/UNESCO Study Group on Benthic Indicators, of merged data sets from several coastal regions worldwide.     

High rate mesophilic, thermophilic, and temperature phased anaerobic digestion of waste activated sludge: a pilot scale study

The paper reports the findings of a two-year pilot scale experimental trial for the mesophilic (35°C), thermophilic (55°C) and temperature phased (65+55°C) anaerobic digestion of waste activated sludge. During the mesophilic and thermophilic runs, the reactor operated at an organic loading rate of 2.2 kgVS/m(3)d and a hydraulic retention time of 20 days. In the temperature phased run, the first reactor operated at an organic loading rate of 15 kgVS/m(3)d and a hydraulic retention time of 2 days while the second reactor operated at an organic loading rate of 2.2 kgVS/m(3)d and a hydraulic retention time of 18 days (20 days for the whole temperature phased system). The performance of the reactor improved with increases in temperature. The COD removal increased from 35% in mesophilic conditions, to 45% in thermophilic conditions, and 55% in the two stage temperature phased system. As a consequence, the specific biogas production increased from 0.33 to 0.45 and to 0.49 m(3)/kgVS(fed) at 35, 55, and 65+55°C, respectively. The extreme thermophilic reactor working at 65°C showed a high hydrolytic capability and a specific yield of 0.33 g COD (soluble) per gVS(fed). The effluent of the extreme thermophilic reactor showed an average concentration of soluble COD and volatile fatty acids of 20 and 9 g/l, respectively. Acetic and propionic acids were the main compounds found in the acids mixture. Because of the improved digestion efficiency, organic nitrogen and phosphorus were solubilised in the bulk. Their concentration, however, did not increase as expected because of the formation of salts of hydroxyapatite and struvite inside the reactor.     

Food resource partitioning in a Mediterranean demersal fish assemblage: the effect of body size and niche width

We investigated the effects of body size, feeding strategy and depth distribution on the trophic resource partitioning among the 26 dominant fish consumers in a fish assemblage on the central Mediterranean shelf-break. The fish assemblage was structured in two major trophic guilds: epibenthic and zooplanktonic feeders, according to the position of each predator along the benthos–plankton gradient. Within each main guild, the species were segregated along a prey-size or fish-size gradient into five further guilds. Fish size and prey size were strongly correlated, indicating that the prey-size niche can be well explained by predator size. Fish consumers showed a significant negative correlation between the similarity in prey type and the similarity in depth distribution; most species with similar trophic preferences segregated along the depth dimension. The only predators overlapping in both food and depth preferences were those with a more specialist trophic behavior. These results suggest that fish body size and depth preferences are the two main niche dimensions, explaining a large part of the coexistence between the Mediterranean shelf-break fish consumers.     

Environmental Pollution Due to Natural Factors: A Case Study in A Volcanic Area (Vulcano Island, Italy)

A major influence on the environment of active volcanic areas is expected from continuous input of chemical species pertaining to fumarolic activities occurring during inter-eruptive intervals.

The systematic investigations carried out during thirteen years in the island of Vulcano (Italy) showed also substantial contributions to phreatic waters and soils of minor constituents and trace metals from volcanic rocks with no negligible influence on growing crops.

Greater extents of these phenomena have been observed for products of hydromagmatic volcanic activity or of long-lasting weathering processes.     

Visible light driven mineralization of spiramycin over photostructured N-doped TiO2 on up conversion phosphors

A novel visible light-active photocatalyst formulation(NdT/OP) was obtained by supporting N-doped TiO_2(NdT) particles on up-conversion luminescent organic phosphors(OP). The photocatalytic activity of such catalysts was evaluated for the mineralization process of spiramycin in aqueous solution. The effect of NdT loading in the range 15–60 wt.% on bulk and surface characteristics of NdT/OP catalysts was investigated by several chemicophysical characterization techniques. The photocatalytic performance of NdT/OP catalysts in the removal of spyramicin from aqueous solution was assessed through photocatalytic tests under visible light irradiation. Total organic carbon(TOC) of aqueous solution,and CO and CO_2 gas concentrations evolved during the photodegradation were analyzed. A dramatic enhancement of photocatalytic activity of the photostructured visible active NdT/OP catalysts,compared to NdT catalyst,was observed. Only CO_2 was detected in gas-phase during visible light irradiation,proving that the photocatalytic process is effective in the mineralization of spiramycin,reaching very high values of TOC removal. The photocatalyst NdT/OP at 30 wt.% of NdT loading showed the highest photocatalytic activity(58%of TOC removed after 180 min irradiation against only 31% removal after 300 min of irradiation of NdT). We attribute this enhanced activity to the high effectiveness in the utilization of visible light through improved light harvesting and exploiting. OP particles act as "photoactive support",able to be excited by the external visible light irradiation,and reissue luminescence of wavelength suitable to promote NdT photomineralization activity.     

Genotypic and phenotypic diversity in populations of plant-probiotic <Emphasis Type="Italic">Pseudomonas</Emphasis> spp. colonizing roots

Several soil microorganisms colonizing roots are known to naturally promote the health of plants by controlling a range of plant pathogens, including bacteria, fungi, and nematodes. The use of theses antagonistic microorganisms, recently named plant-probiotics, to control plant-pathogenic fungi is receiving increasing attention, as they may represent a sustainable alternative to chemical pesticides. Many years of research on plant-probiotic microorganisms (PPM) have indicated that fluorescent pseudomonads producing antimicrobial compounds are largely involved in the suppression of the most widespread soilborne pathogens. Phenotype and genotype analysis of plant-probiotic fluorescent pseudomonads (PFP) have shown considerable genetic variation among these types of strains. Such variability plays an important role in the rhizosphere competence and the biocontrol ability of PFP strains. Understanding the mechanisms by which genotypic and phenotypic diversity occurs in natural populations of PFP could be exploited to choose those agricultural practices which best exploit the indigenous PFP populations, or to isolate new plant-probiotic strains for using them as inoculants. A number of different methods have been used to study diversity within PFP populations. Because different resolutions of the existing microbial diversity can be revealed depending on the approach used, this review first describes the most important methods used for the assessment of fluorescent Pseudomonas diversity. Then, we focus on recent data relating how differences in genotypic and phenotypic diversity within PFP communities can be attributed to geographic location, climate, soil type, soil management regime, and interactions with other soil microorganisms and host plants. It becomes evident that plant-related parameters exert the strongest influence on the genotypic and phenotypic variations in PFP populations.     

An ecotoxicological view on neurotoxicity assessment

The numbers of potential neurotoxicants in the environment are raising and pose a great risk for humans and the environment. Currently neurotoxicity assessment is mostly performed to predict and prevent harm to human populations. Despite all the efforts invested in the last years in developing novel in vitro or in silico test systems, in vivo tests with rodents are still the only accepted test for neurotoxicity risk assessment in Europe. Despite an increasing number of reports of species showing altered behaviour, neurotoxicity assessment for species in the environment is not required and therefore mostly not performed. Considering the increasing numbers of environmental contaminants with potential neurotoxic potential, eco-neurotoxicity should be also considered in risk assessment. In order to do so novel test systems are needed that can cope with species differences within ecosystems. In the field, online-biomonitoring systems using behavioural information could be used to detect neurotoxic effects and effect-directed analyses could be applied to identify the neurotoxicants causing the effect. Additionally, toxic pressure calculations in combination with mixture modelling could use environmental chemical monitoring data to predict adverse effects and prioritize pollutants for laboratory testing. Cheminformatics based on computational toxicological data from in vitro and in vivo studies could help to identify potential neurotoxicants. An array of in vitro assays covering different modes of action could be applied to screen compounds for neurotoxicity. The selection of in vitro assays could be guided by AOPs relevant for eco-neurotoxicity. In order to be able to perform risk assessment for eco-neurotoxicity, methods need to focus on the most sensitive species in an ecosystem. A test battery using species from different trophic levels might be the best approach. To implement eco-neurotoxicity assessment into European risk assessment, cheminformatics and in vitro screening tests could be used as first approach to identify eco-neurotoxic pollutants. In a second step, a small species test battery could be applied to assess the risks of ecosystems.     

Multivariate tools to investigate the spatial contaminant distribution in a highly anthropized area (Gulf of Naples,Italy)

Environmental Science and Pollution Research - The Gulf of Naples located in a high anthropized coastal area is subjected to an infrastructural intervention for the installation of a submarine...