In Spain, a national project known as GUADALMED, focusing on Mediterranean streams, has been carr... more In Spain, a national project known as GUADALMED, focusing on Mediterranean streams, has been carried out from 1998 to 2005 to implement the European water framework directive (WFD) requirements. One of the main objectives of the second phase of the project (2002–2005) was to develop a predictive system for the Spanish Mediterranean aquatic macroinvertebrate communities. A combined-season (spring, summer, and autumn) predictive model was developed by using the latest improvements on the selection of best predictor variables. Overall model performance measures were used to select the best discriminant function (DF) models, and also to evaluate their biases and precision. The final predictive model was based on the best five DF models. Each one of these models involved eight environmental variables. Final observed (O), expected (E), and O/E values for the number of macroinvertebrate families (NFAM) and two biotic indices (IBMWP and IASPT) were calculated by averaging their values, previously weighted by the quality of each DF model. Regression analyses among the final O and E values for the calibration dataset showed a high proximity to the ideal theoretical model, where the final E values explained 73–84% of the variation present in the macroinvertebrate communities of the Spanish Mediterranean watercourses. The ANOVA performed among the reference (calibration and validation) and test datasets showed clear differences for the O/E values. Finally, the assessments carried out by the predictive model were sensitive to anthropogenic pressure present in the study area and allowed the definition of five ecological status classes according to the WFD requirements.
1. According to the guidelines of the European Water Framework Directive, assessment of the ecolo... more 1. According to the guidelines of the European Water Framework Directive, assessment of the ecological quality of streams and rivers should be based on ecotype-specific reference conditions. Here, we assess two approaches for establishing a typology for Mediterranean streams: a top-down approach using environmental variables and bottom-up approach using macroinvertebrate assemblages.2. Classification of 162 sites using environmental variables resulted in five ecotypes: (i) temporary streams; (ii) evaporite calcareous streams at medium altitude; (iii) siliceous headwater streams at high altitude; (iv) calcareous headwater streams at medium to high altitude and (v) large watercourses.3. Macroinvertebrate communities of minimally disturbed sites (n = 105), grouped using UPGMA (unweighted pair-group method using arithmetic averages) on Bray–Curtis similarities, were used to validate four of the five ecotypes obtained using environmental variables; ecotype 5, large watercourses, was not included as this group had no reference sites.4. Analysis of similarities (anosim) showed that macroinvertebrate assemblage composition differed among three of the four ecotypes, resulting in differences between the bottom-up and top-down classification approaches. Siliceous streams were clearly different from the other three ecotypes, evaporite and calcareous ecotypes did not show large differences in macroinvertebrate assemblages and temporary streams formed a very heterogeneous group because of large variability in salinity and hydrology.5. This study showed that stream classification schemes based on environmental variables need to be validated using biological variables. Furthermore, our findings indicate that special attention should be given to the classification of temporary streams.
The European Water Framework Directive establishes the need to define stream type-specific refere... more The European Water Framework Directive establishes the need to define stream type-specific reference conditions to identify “high ecological status”. Methods for selecting reference sites using a priori criteria have been proposed by many authors. A review of these criteria revealed that the most relevant criteria for streams and rivers were those related to riparian vegetation, diffuse and point sources of pollution, river morphology and hydrological conditions and regulation. In this work, we propose 20 criteria that reflect the characteristics of Mediterranean streams and their most frequent disturbances for the selection of reference sites in Mediterranean streams in Spain. We studied 162 sites located in 33 Mediterranean basins belonging to five stream types. Of the locations, 57% were selected as a priori reference sites by having applied the proposed criteria. Reference sites were identified for all stream types except for “large watercourses” which includes the lower reaches of some rivers in this study area. This a priori selection of reference sites was subjected to validation using the macroinvertebrate community by applying of an IBMWP threshold, which is considered to be an indicator of undisturbed sites in Mediterranean streams. This approach determined that whole of this selection (100%) could be considered valid reference sites. Furthermore, we identified differences in the reference conditions for each stream type on the basis of macroinvertebrate assemblage composition.
Se presentan los datos de los cambios en la calidad biológica del agua de dos cuencas de ríos med... more Se presentan los datos de los cambios en la calidad biológica del agua de dos cuencas de ríos mediterráneos, en los que se han estudiado 42 estaciones de muestreo desde el año 1979. Para caracterizar la calidad biológica se usa el índice FB/LL diseñado para la caracterización de la calidad de estos ríos usando macroinvertebrados acuáticos. Si se comparan los datos de los años mas recientes con respecto a los mas antiguos, se muestra que solo 2 de las 42 estaciones han aumentado su calidad biológica hasta el grado bueno o muy bueno y son las situadas en las partes altas de la cuenca. En las zonas medias bajas de la cuenca o incluso en partes altas donde el caudal es reducido, la gran inversión realizada en la construcción de depuradoras (mas de 70 en 15 años) se manifiesta en una pequeña mejora de la calidad de las aguas, pues desaparecen muchos de los lugares de calidad deficiente o muy deficiente y muchos sitios se encuentran en situación de calidad moderada pero sin poder llegar a...
A Rapid Protocol is presented for Evaluation of the Ecological Status of Andean Rivers (CERA) loc... more A Rapid Protocol is presented for Evaluation of the Ecological Status of Andean Rivers (CERA) localized over 2000 m.a.s.l. from the Northern Andes (Venezuela) through the Altiplano in the Central Andes (Bolivia). This protocol was Used in 45 sampling sites in the Guayllabamba River Basin in Ecuador and ill 42 sampling sites in the Canete River Basin in Peru. Previously, and in order to test if the sampling stations may or not be considered reference stations, We constructed a method that assesses 24 basin attributes, hydrology, reach and riverbed and that fluctuates from 24 to 120 points: sites with values higher than 100 were considered as potential reference sites. Besides the benthic macroinvertebrats' evaluation, the river habitat and riparian vegetation were also evaluated through of the application of the indices ABI (Rios et al., submitted), IHF (Pardo et al., 2002) and QBR-And, respectively. The convenience of the initial allocation of the reference sites wits evaluated ...
Culicidae (Diptera: Culicidae) of the Baix Llobregat area Six species of Cuiicidae have been iden... more Culicidae (Diptera: Culicidae) of the Baix Llobregat area Six species of Cuiicidae have been identified in the Baix Llobregat area, near Bar- celona. Coquilletiidia (C.) richiardii and Culiseta -CT.) subochtea had never been found be- fore in the area.
Science dissemination video produced by the University of Barcelona explaining the river's sa... more Science dissemination video produced by the University of Barcelona explaining the river's salinisation issue.
In Spain, a national project known as GUADALMED, focusing on Mediterranean streams, has been carr... more In Spain, a national project known as GUADALMED, focusing on Mediterranean streams, has been carried out from 1998 to 2005 to implement the European water framework directive (WFD) requirements. One of the main objectives of the second phase of the project (2002–2005) was to develop a predictive system for the Spanish Mediterranean aquatic macroinvertebrate communities. A combined-season (spring, summer, and autumn) predictive model was developed by using the latest improvements on the selection of best predictor variables. Overall model performance measures were used to select the best discriminant function (DF) models, and also to evaluate their biases and precision. The final predictive model was based on the best five DF models. Each one of these models involved eight environmental variables. Final observed (O), expected (E), and O/E values for the number of macroinvertebrate families (NFAM) and two biotic indices (IBMWP and IASPT) were calculated by averaging their values, previously weighted by the quality of each DF model. Regression analyses among the final O and E values for the calibration dataset showed a high proximity to the ideal theoretical model, where the final E values explained 73–84% of the variation present in the macroinvertebrate communities of the Spanish Mediterranean watercourses. The ANOVA performed among the reference (calibration and validation) and test datasets showed clear differences for the O/E values. Finally, the assessments carried out by the predictive model were sensitive to anthropogenic pressure present in the study area and allowed the definition of five ecological status classes according to the WFD requirements.
1. According to the guidelines of the European Water Framework Directive, assessment of the ecolo... more 1. According to the guidelines of the European Water Framework Directive, assessment of the ecological quality of streams and rivers should be based on ecotype-specific reference conditions. Here, we assess two approaches for establishing a typology for Mediterranean streams: a top-down approach using environmental variables and bottom-up approach using macroinvertebrate assemblages.2. Classification of 162 sites using environmental variables resulted in five ecotypes: (i) temporary streams; (ii) evaporite calcareous streams at medium altitude; (iii) siliceous headwater streams at high altitude; (iv) calcareous headwater streams at medium to high altitude and (v) large watercourses.3. Macroinvertebrate communities of minimally disturbed sites (n = 105), grouped using UPGMA (unweighted pair-group method using arithmetic averages) on Bray–Curtis similarities, were used to validate four of the five ecotypes obtained using environmental variables; ecotype 5, large watercourses, was not included as this group had no reference sites.4. Analysis of similarities (anosim) showed that macroinvertebrate assemblage composition differed among three of the four ecotypes, resulting in differences between the bottom-up and top-down classification approaches. Siliceous streams were clearly different from the other three ecotypes, evaporite and calcareous ecotypes did not show large differences in macroinvertebrate assemblages and temporary streams formed a very heterogeneous group because of large variability in salinity and hydrology.5. This study showed that stream classification schemes based on environmental variables need to be validated using biological variables. Furthermore, our findings indicate that special attention should be given to the classification of temporary streams.
The European Water Framework Directive establishes the need to define stream type-specific refere... more The European Water Framework Directive establishes the need to define stream type-specific reference conditions to identify “high ecological status”. Methods for selecting reference sites using a priori criteria have been proposed by many authors. A review of these criteria revealed that the most relevant criteria for streams and rivers were those related to riparian vegetation, diffuse and point sources of pollution, river morphology and hydrological conditions and regulation. In this work, we propose 20 criteria that reflect the characteristics of Mediterranean streams and their most frequent disturbances for the selection of reference sites in Mediterranean streams in Spain. We studied 162 sites located in 33 Mediterranean basins belonging to five stream types. Of the locations, 57% were selected as a priori reference sites by having applied the proposed criteria. Reference sites were identified for all stream types except for “large watercourses” which includes the lower reaches of some rivers in this study area. This a priori selection of reference sites was subjected to validation using the macroinvertebrate community by applying of an IBMWP threshold, which is considered to be an indicator of undisturbed sites in Mediterranean streams. This approach determined that whole of this selection (100%) could be considered valid reference sites. Furthermore, we identified differences in the reference conditions for each stream type on the basis of macroinvertebrate assemblage composition.
Se presentan los datos de los cambios en la calidad biológica del agua de dos cuencas de ríos med... more Se presentan los datos de los cambios en la calidad biológica del agua de dos cuencas de ríos mediterráneos, en los que se han estudiado 42 estaciones de muestreo desde el año 1979. Para caracterizar la calidad biológica se usa el índice FB/LL diseñado para la caracterización de la calidad de estos ríos usando macroinvertebrados acuáticos. Si se comparan los datos de los años mas recientes con respecto a los mas antiguos, se muestra que solo 2 de las 42 estaciones han aumentado su calidad biológica hasta el grado bueno o muy bueno y son las situadas en las partes altas de la cuenca. En las zonas medias bajas de la cuenca o incluso en partes altas donde el caudal es reducido, la gran inversión realizada en la construcción de depuradoras (mas de 70 en 15 años) se manifiesta en una pequeña mejora de la calidad de las aguas, pues desaparecen muchos de los lugares de calidad deficiente o muy deficiente y muchos sitios se encuentran en situación de calidad moderada pero sin poder llegar a...
A Rapid Protocol is presented for Evaluation of the Ecological Status of Andean Rivers (CERA) loc... more A Rapid Protocol is presented for Evaluation of the Ecological Status of Andean Rivers (CERA) localized over 2000 m.a.s.l. from the Northern Andes (Venezuela) through the Altiplano in the Central Andes (Bolivia). This protocol was Used in 45 sampling sites in the Guayllabamba River Basin in Ecuador and ill 42 sampling sites in the Canete River Basin in Peru. Previously, and in order to test if the sampling stations may or not be considered reference stations, We constructed a method that assesses 24 basin attributes, hydrology, reach and riverbed and that fluctuates from 24 to 120 points: sites with values higher than 100 were considered as potential reference sites. Besides the benthic macroinvertebrats' evaluation, the river habitat and riparian vegetation were also evaluated through of the application of the indices ABI (Rios et al., submitted), IHF (Pardo et al., 2002) and QBR-And, respectively. The convenience of the initial allocation of the reference sites wits evaluated ...
Culicidae (Diptera: Culicidae) of the Baix Llobregat area Six species of Cuiicidae have been iden... more Culicidae (Diptera: Culicidae) of the Baix Llobregat area Six species of Cuiicidae have been identified in the Baix Llobregat area, near Bar- celona. Coquilletiidia (C.) richiardii and Culiseta -CT.) subochtea had never been found be- fore in the area.
Science dissemination video produced by the University of Barcelona explaining the river's sa... more Science dissemination video produced by the University of Barcelona explaining the river's salinisation issue.
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