1,721,181 research outputs found
Ecology and effects of metazoan parasites of fish in transitional waters
No full textGiven the abundance, heterogeneity and ubiquity of parasitic organisms, understanding how they influence biodiversity, evolution, health and ecosystem functionality is crucial, especially currently when anthropogenic pressures are altering host-parasite balances. This review describes the features, roles and impacts of metazoan parasites of fish occurring in transitional waters (TW). These aquatic ecosystems are highly productive and widespread around the globe and represent most favourable theatres for parasitism given the availability of hosts (invertebrates, fishes and birds) and an increased probability of parasite transmission, especially of those having complex life cycles. Fascinating examples of how parasitism can influence different hierarchical levels of biological systems, from host individuals and populations to entire aquatic communities, through effects on food webs come from this kind of ecosystem. Edible fish of commercial value found in TW can harbour some parasite species, significantly reducing host health, marketability and food safety, with possible economic and public health consequences. Many TW are historically exploited by humans as sources of relevant ecosystem services, including fisheries and aquaculture, and they are highly vulnerable ecosystems. Alteration of TW can be revealed through the study of parasite communities, contributing, as bioindicators, for assessing environmental changes, health and restoration. Fish parasites can provide much information about TW, but this potential appears to be not fully exploited. More studies are necessary to quantify the ecological, economic and medical impacts fish parasites can have on these important ecosystems.Fil: Giari, Luisa. Università di Ferrara; ItaliaFil: Castaldelli, Giuseppe. Università di Ferrara; ItaliaFil: Timi, Juan Tomas. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; Argentin
Aspetti di ecologia delle acque interne della provincia di Ferrara in relazione alla composizione della comunità ittica
No full textCenni di ecologia delle acque dei canali della provincia di Ferrara. L'inquinamento da azoto e l'eutrofizzazione sono affrontati con finalità divulgative al fine di spiegare le relazioni tra i cambiamenti avvenuti in questi ecosistemi nel corso degli ultimi 30 anni e le variazioni della comunità ittica
Carta ittica dell'Emilia-Romagna Zone B e A
No full textLa Carta Ittica dell'Emilia-Romagna Zone B e A è la prima carta ittica realizzata nel tratto planiziale e salmastro dei fiumi e dei più importanti canali dell'Emilia e della Romagna. La presentazione dei dati è stata curata in modo da poter comparare la composizione della comunità e le abbondanze relative delle specie con lo stato di alterazione degli habitat, caratterizzato durante il campionamento ittico o da parte di ARPA.
I risultati hanno evidenziato un quadro preoccupante di generale riduzione della produttività ittica, rarefazione o scomparsa di numerose specie autoctone e dominio, in alcuni casi assoluto, di specie alloctone di recente introduzione e di origine est-europea o asiatica
EU.Water, Transnational integrated management of water resources in agriculture for the EUropean WATER emergency control
No full textEU.WATER is one of the several projects that have been approved under the framework and by the financial support of the South East Europe Transnational cooperation programme, an instrument of the "Regional Policy’s Territorial Cooperation Objective", which aims to improve integration and competitiveness in an area which is as complex as diverse. It is just for this heterogeneity that the original intent of improving the territorial integration by producing concrete answers to the problem of water consumption and contamination in agriculture, encountered the need to develop new operative tools. Therefore, since the beginning, the Project’s Partners have agreed of changing the roadmap of the project, dedicating resources also to research. Some of these already published outcomes are reported below.
Mastrocicco M., N. Colombani, E. Salemi, G. Castaldelli (2011) Reactive modelling of denitrification in soils with natural and depleted organic matter. Water Air and Soil Pollution, 222 (1-4): 205-215.
Colombani N., E. Salemi, M. Mastrocicco, G. Castaldelli, 2011. Groundwater nitrogen speciation in intensively cultivated lowland areas. In: Advances in the Research of Aquatic Environment, Lambrakis N., Stournaras G. and Katsanou K. Eds., Springer Berlin Heidelberg, 291-298 pp. Isbn: 978-3-642-24076-8.
Aschonitis V. G., M. Mastrocicco, N. Colombani, E. Salemi, N. Kazakis, K. Voudouris, G. Castaldelli (2012) Assessment of the intrinsic vulnerability of agricultural land to water and nitrogen losses via deterministic approach and regression analysis. Water Air and Soil Pollution, 223(4): 1605-1614.
Castaldelli G., Colombani N., Vincenzi F., Mastrocicco M. 2012. Linking dissolved organic carbon, acetate and denitrification in agricultural soils. Environmental Earth Sciences, 1-7. Article in Press.
Mastrocicco M., N. Colombani, E. Salemi, F. Vincenzi, G., Castaldelli. 2012. The role of the unsaturated zone in determining nitrate leaching to groundwater. In: “Groundwater Quality Sustainability”, IAH Book Series (IAH Selected Papers), edited by A. Zuber, P. Maloszewski, S. Witczak and G. Malina - Taylor & Francis Books (UK), in press.
Mastrocicco M., Colombani N., Castaldelli G. 2013. A Stepwise Approach to Assess the Fate of Nitrogen Species in Agricultural Lowlands. In Water Treatment And Pollution Prevention: Advances In Research, Chapter 15, edited by S. K. Sharma and R. Sanghi, Springer Science Dordrecht, in press
Bacterial nitrification activity directly associated with isolated benthic marine animals
No full textPotential nitrification rates (PNR) directly associated with isolated marine macrobenthic invertebrates were measured for a range of benthic epifaunal and infaunal species (bivalves, gastropods, polychaetes and crustaceans) collected from the Sacca di Goro, Po River delta, Italy. In the case of the filter-feeding bivalves,
Tapes philippinarum and Mytilus galloprovicialis the PNR associated with the shell surfaces and dissected animal tissues (gills, siphons and residual tissue) were determined separately, in order to assess the distribution of the nitrifier populations. Significant PNR was found associated with all the tested macrofaunal species with activities ranging between 12 and 2,250 nmol ind.)1 day)1 and specific activities between 150 and
18,400 nmol g)1 dry weight day)1. However, no simple relationships were observed between PNR and the animals taxonomic or functional group, or with animal comportment (infaunal or epifaunal) or size class, indicating that more complex interactions may regulate the degree of colonisation of the animals by nitrifier populations. Incubations of shells alone and dissected tissues of the bivalves T. philippinarum and M. galloprovicialis demonstrated that approximately 50% of the total PNR activity was associated with the shell surfaces and 50% with the internal animal tissues, with the highest specific activities of 950 and 1,970 nmol g)1 dry weight day)1 determined for the gills of T. philippinarum and M. galloprovicialis, respectively. Thus, specific relationships may exist between the nitrifiers and their animal hosts. Overall, our data indicate that the macrofaunal stimulation of nitrification and/or coupled nitrification–denitrification observed in previous studies may not be solely due to the animals burrow walls serving as sites for nitrification, but also to the fact that the internal and external surfaces of the animals themselves are also colonised by nitrifying bacteria. Tentative calculations based on reported animal densities in the Sacca di Goro and the determined PNRs indicate that animal-associated nitrifier populations could contribute significantly to overall nitrification rates in situ, although further experiments are required to determine to what extent the potential rates measured in this study are realised under in situ conditions
La fauna ittica delle acque di transizione protette del Delta del Po dell’Emilia-Romagna
No full textIl ruolo della zona insatura nella lisciviazione dei nitrati verso le acque sotterranee in Provincia di Ferrara
No full textAl fine di identificare i processi dominanti che determinano la lisciviazione dei nitrati nella zona del Delta
del Po, diverse prove sul campo sono state eseguite per determinare il destino e il trasporto delle specie
azotate. Azoto sotto forma di urea è stato applicato ad un tasso di 300 kg-N/ha/anno, in un sito sabbioso e in
un sito limoso-argilloso coltivati a mais, il terreno sabbioso è stato ammendato con pollina (700 kg/ha),
mentre il sito limoso-argilloso non ha mai ricevuto pollina. Ogni sito è stato dotato di sonde di umidità del
suolo, lisimetri e piezometri per quantificare la presenza di specie di azoto e di carbonio disciolto nel
sottosuolo. Una marcata lisciviazione dei nitrati è stata osservata nel terreno limoso-argilloso, mentre nel
terreno sabbioso l'elevata sostanza organica disciolta, derivante dalla decomposizione della pollina, ha
impedito la migrazione di nitrati verso la falda acquifera. I risultati evidenziano l’efficacia nell’aumentare la
materia organica labile nel suolo sabbioso, più permeabile e intrinsecamente vulnerabile per evitare la
lisciviazione di nitrati verso la falda superficiale
Estimate of gas transfer velocity in the presence of emergent vegetation using argon as a tracer: Implications for whole-system denitrification measurements
No full textDenitrification associated with emergent macrophytes is a pivotal process underlying the treatment performance of wetlands and slow-flow waterways. Laboratory scale experiments targeting N losses via denitrification in sediments colonized by emergent macrophytes require the use of mesocosms that are necessarily open to the atmosphere. Thus, the proper quantification of N2 effluxes relies on the accurate characterization of the air–water gas exchanges. In this study, we present a simple approach for direct measurements of the gas transfer velocity, in open-top mesocosms with Phragmites australis, by using argon as a tracer. Different conditions of water velocity (0, 1.5, 3, and 6 cm s−1) and temperature (8.5, 16, and 28 °C), were tested, along with, for the first time, the presence of emergent vegetation. The outcomes demonstrated that water velocity and temperature are not the only factors regulating aeration at the mesocosm scale. Indeed, the gas transfer velocity was systematically higher, in the range of 42–53%, in vegetated compared to unvegetated sediments. The increase of small-local turbulence patterns created within water parcels moving around plant stems translated into significant modifications of the reaeration process. The adopted approach may be used to improve the accuracy of denitrification measurements by N2 efflux-based methods in wetland and slow-flow waterway sediments colonized by emergent macrophytes. Moreover, the present outcomes may have multiple implications for whole-system metabolism estimations from which largely depend our understanding of biogeochemical dynamics in inland waters that have strong connections to worldwide issues, such as nitrate contamination and greenhouse gas emissions
A novel approach to an ecofunctional fish index for Mediterranean countries
No full textThe implementation of the European Water Framework Directive, especially regarding the establishment of fish indexes for riverine habitats, has taken different paths in different countries. For example, in Italy previous efforts have been directed towards a taxonomy-based index, contrarily to most other European countries where an ecofunctional approach took place. Taxonomical indexes are particularly hard to apply to Mediterranean countries, where fish taxonomy is often revised causing problems in practical implementation. Alternatively, ecofunctional characteristics of fish communities could be exploited to inform on river habitat quality and to detect anthropogenic impacts, thus reducing the index sensitivity to the taxonomical variability of the fish fauna. We therefore proposed a new, multimetric index based on ecofunctional traits of fish species (EFFI, EcoFunctional Fish Index) and tested it on 208 river sampling stations of the Emilia-Romagna region, northern Italy. Using theoretical reference communities, ecological quality ratios were estimated for the whole area expressing the ecological distance of each site from reference conditions. Perhaps unsurprisingly, this work underlined how fish communities were more degraded at lower altitudes than at higher ones. EFFI scores were remarkably close to two already-established indexes for chemical (LIM) and macrozoobenthos communities (IBE) alteration. Further work should explore the validity of this approach over a wider geographical range as well as investigate the definition of environmental class boundaries and its potential intercalibration with other indexes
Direct measurement of dissolved dinitrogen to refine reactive modelling of denitrification in agricultural soils
No full textNitrogen fertilizers used in agriculture often cause nitrate leaching towards shallow groundwater, especially in lowland areas where soil permeability, ploughing, clay content, and the flat topography minimizes surface runoff. The introduction of good agricultural practices to reduce the nitrate amount entering the groundwater system is crucial to ameliorate the kinetic control on nitrate denitrification capacity. With this aim, a series of anaerobic mesocosms, consisting of loamy and clay soils and nitrate rich water, were modelled using acetate and natural organic matter as electron donors. Acetate was chosen because it is the main intermediate in many biodegradation pathways of organic compounds, and hence it is a suitable carbon source for denitrification. To account for the spatial variability of soil parameters, the experiments were performed in triplicates. The geochemical code PHREEQC(3) was used to simulate kinetic denitrification, and equilibrium reactions of gas and mineral phases. The reactive modelling results highlighted a rapid acetate and nitrate degradation rate, a rapid production of dissolved inorganic carbon and dinitrogen, and a steady concentration of dissolved iron and sulphate, suggesting that the main pathway of nitrate attenuation is through denitrification; concomitantly excluding the occurrence of other processes leading to nitrate consumption. In the absence of acetate, the loamy soil, poor of natural organic matter, did not allow to complete the denitrification process. This modelling study investigates in detail the relationship between the denitrification process in natural soils, with excess and in limitation of organic substrates, and the occurrence and fate of dissolved dinitrogen analysed with a high precision membrane inlet mass spectrometer. Results demonstrate that modelling nitrate degradation processes as a whole, using geochemical datasets and codes, will improve the estimates of agricultural landscapes denitrification and support better nitrogen management, especially in lowland environments
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