Search results for "TLA"
showing 10 items of 1764 documents
Nutrient mitigation under the impact of climate and land-use changes: A hydro-economic approach to participatory catchment management
2020
Abstract Excessive nutrient loadings into rivers are a well-known ecological problem. Implemented mitigation measures should ideally be cost-effective, but perfectly ranking alternative nutrient mitigation measures according to cost-effectiveness is a difficult methodological challenge. Furthermore, a particularly practical challenge is that cost-effective measures are not necessarily favoured by local stakeholders, and this may impede their successful implementation in practice. The objective of this study was to evaluate the cost-effectiveness of mitigation measures using a methodology that includes a participatory process and social learning to ensure their successful implementation. By …
Assessment of clogging in constructed wetlands by saturated hydraulic conductivity measurements
2019
Abstract This study aims at defining a methodology to evaluate Ks reductions of gravel material constituting constructed wetland (CW) bed matrices. Several schemes and equations for the Lefranc's test were compared by using different gravel sizes and at multiple spatial scales. The falling-head test method was implemented by using two steel permeameters: one impervious (IMP) and one pervious (P) on one side. At laboratory scale, mean K values for a small size gravel (8–15 × 10−2 m) measured by the IMP and the P permeameters were equal to 19,466 m/d and 30,662 m/d, respectively. Mean Ks values for a big size gravel (10–25 × 10−2 m) measured by the IMP and the P permeameters were equal to 12,…
Elevated nutrient concentrations in headwaters affected by drained peatland
2018
Abstract Nutrient export from drained peatland has significant impacts on aquatic environments in Nordic catchments. Spatial information on variations in nutrient concentrations across different landscapes and land uses is needed to design measures for achieving the good ecological status of the EU Water Framework Directive. In this study we determined background concentrations in natural peatland-dominated streams and examined effects of peatland use practices on water quality in headwater catchments. We quantified sources for different elements by joint analysis of water chemistry, isotopes, and hydrology for 62 small catchments in North Ostrobothnia, Finland. Concentrations of nutrients …
Emerging technologies for enhanced removal of residual antibiotics from source-separated urine and wastewaters: A review.
2022
Antibiotic residues are of significant concern in the ecosystem because of their capacity to mediate antibiotic resistance development among environmental microbes. This paper reviews recent technologies for the abatement of antibiotics from human urine and wastewaters. Antibiotics are widely distributed in the aquatic environment as a result of the discharge of municipal sewage. Their existence is a cause for worry due to the potential ecological impact (for instance, antibiotic resistance) on bacteria in the background. Numerous contaminants that enter wastewater treatment facilities and the aquatic environment, as a result, go undetected. Sludge can act as a medium for some chemicals to …
Seasonal response of vegetation on pollutants removal in constructed wetland system treating dairy wastewater
2022
Constructed wetland systems provide the ideal solution for small and medium dairy farms as they can be built close to the farm and are easy to manage and use. However, their perfomance is significantly affected by vegetation activity during the year. The aims of the present study were to assess the treatment of dairy wastewater (DWW) by a horizontal subsurface flow system (HSSFs) and the effect of plants in the removal efficiency (RE) of BOD5, COD, total N (TN) and total P (TP), in Sicily (Italy). The HSSFs treated 6/7 m3 per day of wastewater produced by a small dairy farm subsequent to biological treatment. The system included two units which were separately planted with Arundo donax L. a…
Variation in spawning time promotes genetic variability in population responses to environmental change in a marine fish.
2015
Common-garden experiments suggest that the response of Atlantic cod larvae to temperature differs among populations that spawn at different times of year. Populations appear to be adapted to the temperatures experienced during the larval stage at a small spatial scale, despite a lack of physical barriers to gene flow.
A legacy of contrasting spatial genetic structure on either side of the Atlantic-Mediterranean transition zone in a marine protist
2012
The mechanisms that underpin the varied spatial genetic structures exhibited by free-living marine microorganisms remain controversial, with most studies emphasizing a high dispersal capability that should redistribute genetic diversity in contrast to most macroorganisms whose populations often retain a genetic signature of demographic response to historic climate fluctuations. We quantified the European phylogeographic structure of the marine flagellate Oxyrrhis marina and found a marked difference in spatial genetic structure, population demography, and genetic diversity between the northwest Atlantic and Mediterranean Sea that reflects the persistent separation of these regions as well …
Taxonomic Status of Neoechinorhynchus Agilis (Acanthocephala, Neoechinorhynchidae), with a Description of two New Species of the Genus from the Atlan…
2014
2 Section of Hydrobiont Diseases, Pacifi c Research. Fisheries Center, Shevchenko str., 4, Vladivostok, 690950 Russia Taxonomic Status of Neoechinorhynchus agilis (Acanthocephala, Neoechinorhynchidae), with a De- scription of Two New Species of the Genus from the Atlantic and Pacifi c Mullets (Teleostei, Mugili- dae). Tkach, Ie. V., Sarabeev, V. L., Shvetsova, L. S. — Th e wide variability in morphological features, geographical and host ranges of mullet acanthocephalan parasite Neoechinorhynchus agilis (Rudolphi, 1819), raises the question of taxonomic status of this species. Rudolphi's type and Yamagutis voucher specimens, as well as our own material from the WW Pacifi c and NE Atlantic r…
Biodiversità vegetale degli stagni temporanei della Sicilia
2009
Gli ambienti umidi effimeri ospitano comunità vegetali specializzate e sono sede esclusiva di rare microterofite nonché autentiche stazioni di rifugio per molte specie a ciclo effimero. Per l’interesse bio-ecologico, Braun-Blanquet ha definito queste fitocenosi un gioiello floristico. Anche la Comunità Europea, con la direttiva Habitat 92/43/CEE, riconosce agli stagni temporanei mediterranei una notevole importanza e li individua come habitat prioritario (3170*). Questi ambienti, essendo stagionali, di modesta estensione, spazialmente dispersi e difficilmente cartografabili, spesso vengono trascurati negli studi a scala di paesaggio. Tali habitat, invece, rappresentano veri e propri micro-h…
Ambienti umidi effimeri e naturalità del paesaggio in Sicilia
2009
I luoghi umidi temporanei sono ambienti acquatici che alternano periodicamente una fase d’invaso ed una fase secca ed ospitano espressive fitocenosi adattate a queste peculiari condizioni. Indagini condotte tra il 2003 ed il 2009 hanno consentito di individuare, in Sicilia, oltre 200 siti, costituiti generalmente da diverse pozze o piccoli stagni. L’estrema fragilità di questi habitat li rende molto vulnerabili a qualunque tipo di alterazione ambientale e pertanto risultano essere indicatori molto sensibili della pressione antropica sul territorio. Infatti, la conservazione di questi biotopi non può prescindere da una corretta gestione del contesto territoriale che li circonda. Il presente …