Munne A.,Catalan Water Agency |
Prat N.,University of Barcelona
Data on macroinvertebrates of selected reference sites were compiled from a long-term monitoring programme carried out in the Mediterranean Catalan Basins (NE Spain) that permitted analysis for nine years, from 1996 to 2004, using a homogeneous data collection procedure. This study aims to analyse the differences in composition and structure of macroinvertebrate communities at family level in five Mediterranean river types, and the values of biological quality metrics (IBMWP and IASPT indices, taxon richness and EPT) in reference conditions. Also differences between seasons (spring vs. summer) and between dry and wet periods were analysed. The dry and wet periods were determined using the Standardised Precipitation Index (SPI). A total of 29 reference sites were selected out of 184 sampling sites analysed, and 171 reference samples were available (from 1996 to 2004), of which 88 were sampled in dry periods, whereas 83 correspond to wet periods. Differences on community composition at family level were appreciated, clustering the rivers in three different groups: (1) rivers with a continuous flow regime located in siliceous zones; (2) rivers with a continuous flow regime located in calcareous zones; and (3) temporary rivers regardless of geology. Moreover, our results explain that the characteristics of hydrological periods (dry and wet) characterize the differences between communities better than just the season. The analysis of four biological quality metrics reveals clear differences between values obtained from dry and wet periods concerning taxon richness, EPT values and IBMWP biological indices, whereas the IASPT index does not show significant differences. The median taxonomic richness in wet periods is 32 macroinvertebrate families per sample while in dry periods this value falls to 22. Reference values of IBMWP index, the total number of taxa, and EPT metric are different between dry and wet periods in spring samples, while these differences are not relevant for IASPT index except for temporary streams. Hydrological specific conditions should additionally be considered in order to better calculate biological reference conditions, and to properly apply biological quality metrics used to establish the ecological status in Mediterranean rivers, especially in temporary ones. The use of the dry-wet period classification according to the climate characteristic results is a more accurate application of the Water Framework Directive in Mediterranean rivers. Implications of future climate change should be also considered from our results. © 2010 Elsevier Ltd. All rights reserved. Source
Murphy C.A.,University of Girona |
Casals F.,University of Lleida |
Sola C.,Catalan Water Agency |
Caiola N.,IRTA Aquatic Ecosystems |
And 2 more authors.
Bioassessments are used to measure system health and assess disturbance. While fish-based freshwater bioassessments are cost-effective and perform well in speciose systems, such bioassessments remain difficult to implement in species-poor Mediterranean regions. Population size structure metrics may provide meaningful biological information where depauperate communities preclude the richness and composition measures generally used. We focus our assessments of population size structure responses to anthropogenic perturbation on one of the most widespread native stream fish (Squalius laietanus). We explore a number of population size statistics as metrics for a Mediterranean region, where current bioassessments perform poorly. Our sampling encompassed 311 sites across Catalonia (NE Spain) where we characterized anthropogenic perturbation using a summary of impacts, including local data on stream condition and landscape indicators of degradation, via a principal component analysis. Anthropogenic perturbation in streams was collinear with altitudinal gradients and highlights the importance of appropriate statistical techniques. Of the population size structure metrics explored, average length was the most sensitive to anthropogenic perturbation and generally increased along the disturbance gradient. Although we expected to find consistent changes in variance, kurtosis, and skewness, the observed relationships were weak. River basin mediated responses suggest the importance of environmental landscape factors. The unexpected increases of mean S. laietanus body size with anthropogenic perturbation, strong effects of river basin, collinearity with spatial gradients and the species-specific nature of responses preclude the direct application of size structure in freshwater bioassessments. Although its application in fish-based freshwater bioassessments appears difficult, population size structure can provide insights in species-specific applications and management. © 2013 Elsevier Ltd. Source
Aguiar F.C.,University of Lisbon |
Segurado P.,University of Lisbon |
Urbanic G.,University of Ljubljana |
Urbanic G.,Institute for Water of the Republic of Slovenia |
And 13 more authors.
Science of the Total Environment
This paper exposes a new methodological approach to solve the problem of intercalibrating river quality national methods when a common metric is lacking and most of the countries share the same Water Framework Directive (WFD) assessment method. We provide recommendations for similar works in future concerning the assessment of ecological accuracy and highlight the importance of a good common ground to make feasible the scientific work beyond the intercalibration.The approach herein presented was applied to highly seasonal rivers of the Mediterranean Geographical Intercalibration Group for the Biological Quality Element Macrophytes. The Mediterranean Group of river macrophytes involved seven countries and two assessment methods with similar acquisition data and assessment concept: the Macrophyte Biological Index for Rivers (IBMR) for Cyprus, France, Greece, Italy, Portugal and Spain, and the River Macrophyte Index (RMI) for Slovenia. Database included 318 sites of which 78 were considered as benchmarks. The boundary harmonization was performed for common WFD-assessment methods (all countries except Slovenia) using the median of the Good/Moderate and High/Good boundaries of all countries. Then, whenever possible, the Slovenian method, RMI was computed for the entire database. The IBMR was also computed for the Slovenian sites and was regressed against RMI in order to check the relatedness of methods (R2=0.45; p<0.00001) and to convert RMI boundaries into the IBMR scale. The boundary bias of RMI was computed using direct comparison of classification and the median boundary values following boundary harmonization. The average absolute class differences after harmonization is 26% and the percentage of classifications differing by half of a quality class is also small (16.4%). This multi-step approach to the intercalibration was endorsed by the WFD Regulatory Committee. © 2013 Elsevier B.V. Source
Determination of glyphosate in groundwater samples using an ultrasensitive immunoassay and confirmation by on-line solid-phase extraction followed by liquid chromatography coupled to tandem mass spectrometry
Sanchis J.,CSIC - Institute of Environmental Assessment And Water Research |
Kantiani L.,CSIC - Institute of Environmental Assessment And Water Research |
Llorca M.,CSIC - Institute of Environmental Assessment And Water Research |
Rubio F.,Abraxis, L.L.C. |
And 4 more authors.
Analytical and Bioanalytical Chemistry
Despite having been the focus of much attention from the scientific community during recent years, glyphosate is still a challenging compound from an analytical point of view because of its physicochemical properties: relatively low molecular weight, high polarity, high water solubility, low organic solvent solubility, amphoteric behaviour and ease to form metal complexes. Large efforts have been directed towards developing suitable, sensitive and robust methods for the routine analysis of this widely used herbicide. In the present work, a magnetic particle immunoassay (IA) has been evaluated for fast, reliable and accurate part-per-trillion monitoring of glyphosate in water matrixes, in combination with a new analytical method based on solid-phase extraction (SPE), followed by liquid chromatography (LC) coupled to tandem mass spectrometry (MS/MS), for the confirmatory analysis of positive samples. The magnetic particle IA has been applied to the analysis of about 140 samples of groundwater from Catalonia (NE Spain) collected during four sampling campaigns. Glyphosate was present above limit of quantification levels in 41% of the samples with concentrations as high as 2.5 μg/L and a mean concentration of 200 ng/L. Good agreement was obtained when comparing the results from IA and on-line SPE-LC-MS/MS analyses. In addition, no false negatives were obtained by the use of the rapid IA. This is one of the few works related to the analysis of glyphosate in real groundwater samples and the presented data confirm that, although it has low mobility in soils, glyphosate is capable of reaching groundwater. © 2011 Springer-Verlag. Source
Kock-Schulmeyer M.,CSIC - Institute of Environmental Assessment And Water Research |
Ginebreda A.,CSIC - Institute of Environmental Assessment And Water Research |
Postigo C.,CSIC - Institute of Environmental Assessment And Water Research |
Garrido T.,Catalan Water Agency |
And 4 more authors.
Science of the Total Environment
Pesticide contamination of groundwater is of paramount importance because it is the most sensitive and the largest body of freshwater in the European Union. In this paper, an isotopic dilution method based on on-line solid phase extraction-liquid chromatography (electrospray)-tandem mass spectrometry (SPE-LC(ESI)-MS/MS) was used for the analysis of 22 pesticides in groundwater. Results were evaluated from monitoring 112 wells and piezometers coming from 29 different aquifers located in 18 ground water bodies (GWBs), from Catalonia, Spain, for 4. years as part of the surveillance and operational monitoring programs conducted by the Catalan Water Agency. The analytical method developed allows the determination of the target pesticides (6 triazines, 4 phenylureas, 4 organophosphorous, 1 anilide, 2 chloroacetanilides, 1 thiocarbamate, and 4 acid herbicides) in groundwater with good sensitivity (limits of detection < 5 ng/L), accuracy (relative recoveries between 85 and 116%, except for molinate), and repeatability (RSD < 23%), and in a fully automated way. The most ubiquitous compounds were simazine, atrazine, desethylatrazine and diuron. Direct relation between frequency of detection of each target compound and Groundwater Ubiquity Score index (GUS index) is observed. Desethylatrazine and deisopropylatrazine, metabolites of atrazine and simazine, respectively, presented the highest mean concentrations. Compounds detected in less than 5% of the samples were cyanazine, molinate, fenitrothion and mecoprop. According to the Directive 2006/118/EC, 13 pesticides have individual values above the requested limits (desethylatrazine, atrazine and terbuthylazine lead the list) and 14 samples have total pesticide levels above 500. ng/L. The GWB with the highest levels of total pesticides is located in Lleida (NE-Spain), with 9 samples showing total pesticide levels above 500. ng/L. Several factors such as regulation of the use of pesticides, type of activities in the area, and irrigation were discussed in relation to the observed levels of pesticides. © 2013 Elsevier B.V. Source