Defining benchmark values for nutrients under the Water Framework Directive: Application in twelve Portuguese estuaries
| Autor: | Miguel Caetano, Maria Ana Santos, Joana Raimundo, Mário Mil-Homens, Ricardo Prego, Carlos Vale, Marta Nogueira |
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| Jazyk: | angličtina |
| Rok vydání: | 2016 |
| Předmět: |
0106 biological sciences
Transitional waters Drainage basin 010501 environmental sciences Oceanography 01 natural sciences chemistry.chemical_compound Nutrient Water Framework Directive Nitrate Benchmark values Phytoplankton Environmental Chemistry Ammonium 0105 earth and related environmental sciences Water Science and Technology Hydrology geography geography.geographical_feature_category 010604 marine biology & hydrobiology Estuary General Chemistry Nutrients Salinity chemistry Environmental science |
| Zdroj: | ResearcherID Digital.CSIC. Repositorio Institucional del CSIC instname |
| Popis: | 11 páginas, 4 tablas, 6 figuras The Water Framework Directive requires the assessment of physicochemical parameters supporting the biological quality elements. To achieve this evaluation, water samples were collected in 89 sites located at 42 water bodies (WB) from 12 transitional systems in Portugal. Nitrate, nitrite, phosphate, ammonium and silicate concentrations were measured in surface and near-bottom water samples collected at high- and low-tide. The influence of salinity, biological consumption, morphology and river basin inputs was examined. Results showed that nutrient variability is estuary and site specific. To overcome this inter-specificity complexity, benchmark values for nutrients were estimated based on Portuguese estuaries previously classified with good ecological status for the phytoplankton quality element. This methodology allowed classifying the chemical status for nutrients in the WBs of the surveyed systems. Water bodies from Cávado, Ave, Douro, Tagus and Sado showed “Low” status due to ammonium that was often above the benchmark value. Comparatively, nutrient concentrations in all WBs of Minho, Ria of Aveiro, Mira and Guadiana were lower than the benchmark values and therefore a classification of High was given This study was supported by EEMA Project (Avaliação do Estado Ecológico das Massas de Água Costeiras e de Transição e do Potencial Ecológico das Massas de Água Fortemente Modificadas) financed by the INAG (Instituto da Água). Joana Raimundo acknowledges the grants by “Portuguese Science and Technology Foundation, Ministry of Education and Science” (SFRH/BPD/91498/2012) |
| Databáze: | OpenAIRE |
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