title: Assessment of sediment ecotoxicological status as a complementary tool for the evaluation of surface water quality: the Ebro river basin case study.
abstract: According to the European Water Framework Directive (WFD), assessment of surface water status is based on ecological and chemical status that is not always in coherence. In these situations, ecotoxicity tests could help to obtain a better characterization of the ecosystems. The general aim of this work is to design a methodology to study the ecotoxicological status of freshwater systems. This could be useful and complementary to ecological status, for a better ecological characterization of freshwater systems. For this purpose, sediments from thirteen sampling sites within the Ebro river watershed (NE Spain) were collected for ecotoxicity characterization. The ecotoxicity of pore water has been evaluated employing the test organisms Vibrio fischeri, Pseudokirschneriella subcapitata and Daphnia magna, while whole sediment ecotoxicity was evaluated using Vibrio fischeri, Daphnia magna, Nitzschia palea and Chironomus riparius. An analysis of acid-volatile sulfide (AVS) and simultaneously extracted metals (SEM) was performed to evaluate the sediment toxicity associated to bioavailable metals. Moreover, data about priority pollutants defined by the WFD in water, sediment and fish as well as data of surface water status of each sampling point were provided by the Monitoring and Control Program of the Ebro Water bodies. In general terms, whole sediment bioassays have shown more toxicity than pore water tests. Among the different organisms used, P. subcapitata and C. riparius were the most sensitive in pore water and whole sediment, respectively. Our evaluation of the ecotoxicological status showed high coincidences with the ecological status, established according to the WFD, especially when ecosystem disruption due to numerous stressors (presence of metals and organic pollution) was observed. These results allow us to confirm that, when chemical stressors affect the ecosystem functioning negatively, an ecotoxicological approach, provided by suitable bioassays in pore water and whole sediment, could detect these changes with accurate sensitivity.
authors.affiliation: Environmental Engineering Laboratory, Departament d'Enginyeria Quimica, Universitat Rovira i Virgili, Av. Països Catalans 26, 43007 Tarragona, Catalonia, Spain; Laboratory of Toxicology and Environmental Health, School of Medicine, IISPV, Universitat Rovira i Virgili, Sant Llorenç 21, 43201 Reus, Catalonia, Spain. Electronic address: neus.roig@urv.cat.
authors.forename: Neus
authors.initials: N
authors.lastname: Roig
authors.affiliation: Environmental Engineering Laboratory, Departament d'Enginyeria Quimica, Universitat Rovira i Virgili, Av. Països Catalans 26, 43007 Tarragona, Catalonia, Spain; Laboratori d'Edafologia, Facultat de Farmàcia, Universitat de Barcelona, Av. Joan XXIII s/n, 08028, Barcelona, Catalonia, Spain.
authors.forename: Jordi
authors.initials: J
authors.lastname: Sierra
authors.affiliation: Laboratory of Toxicology and Environmental Health, School of Medicine, IISPV, Universitat Rovira i Virgili, Sant Llorenç 21, 43201 Reus, Catalonia, Spain.
authors.forename: Martí
authors.initials: M
authors.lastname: Nadal
authors.affiliation: Departamento Ecología y Gestión Costera, Instituto de Ciencias Marinas de Andalucía (CSIC), Campus Rio San Pedro, 11510 Puerto Real, Cadiz, Spain.
authors.forename: Ignacio
authors.initials: I
authors.lastname: Moreno-Garrido
authors.affiliation: Departamento Ecología y Gestión Costera, Instituto de Ciencias Marinas de Andalucía (CSIC), Campus Rio San Pedro, 11510 Puerto Real, Cadiz, Spain.
authors.forename: Elena
authors.initials: E
authors.lastname: Nieto
authors.affiliation: Departamento Ecología y Gestión Costera, Instituto de Ciencias Marinas de Andalucía (CSIC), Campus Rio San Pedro, 11510 Puerto Real, Cadiz, Spain.
authors.forename: Miriam
authors.initials: M
authors.lastname: Hampel
authors.affiliation: Confederación Hidrográfica del Ebro (CHE), Paseo Sagasta 24-26, 50071 Zaragoza, Spain.
authors.forename: Elena Perez
authors.initials: EP
authors.lastname: Gallego
authors.affiliation: Environmental Engineering Laboratory, Departament d'Enginyeria Quimica, Universitat Rovira i Virgili, Av. Països Catalans 26, 43007 Tarragona, Catalonia, Spain; Laboratory of Toxicology and Environmental Health, School of Medicine, IISPV, Universitat Rovira i Virgili, Sant Llorenç 21, 43201 Reus, Catalonia, Spain.
authors.forename: Marta
authors.initials: M
authors.lastname: Schuhmacher
authors.affiliation: Departamento Ecología y Gestión Costera, Instituto de Ciencias Marinas de Andalucía (CSIC), Campus Rio San Pedro, 11510 Puerto Real, Cadiz, Spain.
authors.forename: Julián
authors.initials: J
authors.lastname: Blasco
mesh_terms: D048908:Aliivibrio fischeri; D000818:Animals; D003621:Daphnia; D054750:Ecotoxicology; D004784:Environmental Monitoring / Q000379:methods*; D005399:Fishes; D019015:Geologic Sediments / Q000737:chemistry*; D045483:Rivers / Q000737:chemistry*; D013030:Spain; D014874:Water Pollutants, Chemical / Q000633:toxicity*
chemical_list: D014874:Water Pollutants, Chemical
keywords: Ecotoxicity; Pore water; SEM/AVS; Water Framework Directive; Whole sediment