Defining ecologically relevant water quality targets for lakes in Europe

1. The implementation of the Water Framework Directive requires EU member states to establish and harmonize ecological status class boundaries for biological quality elements. In this paper, we describe an approach for defining ecological class boundaries that delineates shifts in lake ecosystem functioning and, therefore, provides ecologically meaningful targets for water policy in Europe. 2. We collected an extensive data set of 810 lake-years from nine Central European countries, and we used phytoplankton chlorophyll a, a metric widely used to measure the impact of eutrophication in lakes. Our approach establishes chlorophyll a target values in relation to three significant ecological effects of eutrophication: the decline of aquatic macrophytes, the dominance of potentially harmful cyanobacteria and the major functional switch from a clear water to a turbid state. 3. Ranges of threshold chlorophyll a concentrations are given for the two most common lake types in lowland Central Europe: for moderately deep lakes (mean depth 3–15 m), the greatest ecological shifts occur in the range 10–12 lg L 1 chlorophyll a, and for shallow lakes (<3 m mean depth), in the range 21–23 lg L 1 chlorophyll a. 4. Synthesis and applications. Our study provides class boundaries for determining the ecological status of lakes, which have robust ecological consequences for lake functioning and which, therefore, provide strong and objective targets for sustainable water management in Europe. The results have been endorsed by all participant member states and adopted in the European Commission legislation, marking the first attempt in international water policy to move from physico-chemical quality standards to harmonized ecologically based quality targets.

Community structure and water quality in Mediterranean streams of a Natural Park (Sant Llorenç del Munt, NE Spain)

Se estudian las comunidades de macroinvertebrados de los ríos del Parque Natural de Sant Llorenç del Munt i la Serra de l'Obac (Barcelona, NE España) y su relación con las condiciones de flujo de los ríos. Hasta 78 localidades se visitaron en dos ocasiones (invierno y verano de 1996) y en 26 de ellas se tomaron muestras de macroinvertebrados. Mientras en invierno el 63 % de los kilÛmetros investigados tenía flujo continuo y menos del 1% estaba seco, en verano solo el 26% tenía flujo continuo, un 20% estaba totalmente seco y el resto presentaba pozas en su lecho. A pesar de ello el número de familias de macroinvertebrados fue de 54 en invierno y 94 en verano, siendo dominantes en este último caso los heterópteros, coleópteros, odonatos y dípteros, mientras que en invierno los tricópteros y plecópteros eran más diversos. En general, la comunidad presentó una estrategia trófica recolectora aunque la proporción de los ramoneadores y depredadores aumentó en verano. El estudio de las comunidades mediante el análisis de su abundancia en los dos perÌodos, mostró que las variables temporales (flujo, temperatura) o las relacionadas con el incremento de la producciÛn primaria (oxÌgeno, pH) explicaban la mayor parte de la variabilidad con los elementos mas reófilos propios de invierno y los leníticos de verano, mientras que otros factores fisicoquímicos no eran relevantes. Calculado el índice biológico BMWP' se demostró que los valores en verano eran superiores o similares a los de invierno lo que se explica por la mayor diversidad aunque la calificaciÛn individual de cada una de las familias encontradas en verano fuera menor que las halladas en invierno.

Bottled natural mineral water in catalonia: origin and geographical evolution of its consumption and production

During the second half of the nineteenth century a major mineral water bottling industry appeared in Catalonia which vigorously lasted until the first third of the 20th century. The fact that the industry appeared in Catalonia and in other parts of Europe and the United States almost at the same time and had not existed before can be explained by a series of factors which coincided in time. This situation encouraged producers to pack, transport and sell bottled water from their respective sources. Among these factors there is the rise of hygienism, very influential in Catalonia, the declining water quality due to industrialization, the increase in population density, the improvement in transport, the emergence of thermal tourism or the invention of better containers used to store water. This project aims to explain thoroughly all the mentioned factors, and to give some light to why, when and how the Catalan bottled water industry appeared.