Mobilization of aluminium and deposition on fish gills during sea salt episodes--catchment liming as countermeasure

Episodic events may be critical with respect to aluminium (Al) toxicity in moderately acidified salmon rivers. The present work demonstrates that sea salt episodes enhance the toxicity of Al in acidic rivers. The documented sea salt episode (300 [micro sign]M Cl) mobilized positively charged Al species (0.4 to 1.1 [micro sign]M Al(i)), enhanced the Al accumulation on fish gills (0.9 to 10 [micro sign]mol g(-1) dw) and caused increased stress responses (6 to15 mM blood glucose) in fish. Accumulated Al on gills remained high several days after the episode. The presented results are based on a six-week field study in two tributary rivers on the west coast of Norway. Changes in the river water qualities and Al speciation were followed using in situ fractionation techniques. Al accumulation on gills and stress responses were followed for Atlantic salmon (Salmo salar) kept in tanks continually exposed to the changing water quality. The potential mobilization of Al from the two catchments was studied by extracting soils with diluted seawater (salinity of 3). To counteract Al toxicity, one of the tributary catchments has been limed. The potential mobility of Al by sea salt was lower in limed soils compared to acid soils, and the Al deposition on fish gills (<3.5 [micro sign]mol g(-1) dw) and associated stress responses stayed low during the sea salt episode in the river draining the limed catchment. Thus, for acid river systems in coastal areas, catchment liming should be considered as a useful countermeasure for Al toxicity.     

Acute ecotoxicity and genotoxicity assessment of two wastewater treatment units

Environmental Science and Pollution Research - Water contamination by discharge of untreated or poorly treated wastewater into water bodies is a current issue that may cause harm to humans. Water...     

Von der Erkenntnis zur Entscheidung

This contribution highlights the role and importance of ecotoxicology in regulatory decisions of chemicals legislation focussing on the responsibilities of the German Federal Environmental Agency (UBA). Therefore, organisational structures and processes relevant for making decisions concerning the risks of chemicals to men and the environment are described. As any regulatory decision starts with scientific findings, a brief overview of UBA’s activities with regard to own research and to initiate research in the area of ecotoxicology is provided. In addition, the vast importance of standardisation and international harmonisation of guidelines for testing and assessment of chemicals is illustrated, including the time- and ressource consuming character of these harmonisation processes. Subsequently, the involvement of regulatory decision making in intense and controversial scientific and political debates is emphasised. The transparency of these discussions and the independence of science is critically addressed in this context. In a final chapter the job requirements and options for qualification in Germany are described, ending up with a brief summary of the positive experiences with UBA’s contribution to the new advanced training course in ecotoxiciology realised by GDCh/SETAC GLB. A summary of the discussions on these different topics emphasises the specific challenge in regulatory ecotoxicology: To generate knowledge relevant for decision making, while acting in an area of conflict between scientific demands and economical as well as political interests.     

Zur Entwicklung einer Prüfstrategie auf sexual-endokrine Wirksamkeit einer chemischen Substanz bei Fischen

Ohne Zusammenfassung Hintergrundinformation Umweltbundesamt (2007). Abschlussbericht des Forschungsprojektes „Charakterisierung endokrin vermittelter Wirkungen in Fischen: Relevante Parameter für die Entwicklung einer neuen OECD-Testmethode und in der Anwendung in der gesetzlichen Umweltrisikobewertung“ im Auftrag des Umweltbundesamtes (F?rderkennzeichen 206 67 470). Online erh?ltlich unter     

Fish mortality during sea salt episodes--catchment liming as a countermeasure

Aluminium (Al) toxicity is usually associated with acid rain and acidified freshwater systems. The present work demonstrates that acute fish mortality (50%) also occurs in moderate acidified salmon rivers during sea salt episodes. Furthermore, catchment liming was proved to be an efficient measure to counteract the fish toxicity. The impact of sea salt episodes on river water qualities and on Atlantic Salmon (Salmo salar L.) was studied in two rivers situated at the west coast of Norway. During February-May 2002, fish were kept in tanks and continually exposed to the changing water qualities. Changes in Al-species were followed using in situ fractionation techniques. During storm events and high sea salt deposition, the sea salt concentration increased (190 to 580 microM Cl), pH decreased (pH 5.3 to 4.6) and the concentration of low molecular mass (LMM) cationic Al-species (Al(i)) increased (0.7 to 3.0 microM) in the river. Subsequently, Al accumulated in fish gills (6 to 19 micromol g(-1) dw) causing ionoregulatory and respiratory failures as well as mortality. In water the concentration of LMM Al(i) stayed enhanced during four weeks, while the physiological stress responses in surviving fish remained high for a longer time (>eight weeks). To counteract Al toxicity, one of the tributary catchments had been limed four years earlier. Due to catchment liming (1000 kg ha(-1)) the water concentration of LMM Al(i)(<0.7 microM) and the Al accumulation in gills remained relatively low (<7 micromol g(-1) dw) during the storm and no fish mortality occurred.     

Trace elements and organochlorine pollutants in selected fish species from Lake Phewa,Nepal

Lake water and fish livers and gills of sahar (Tor putitora), spiny eel (Mastacembelus armatus), African magur (Clarias gariepinus), and tilapia (Oreochromis niloticus) from Lake Phewa, Nepal, were assessed for the concentrations of trace metals/elements and persistent organic pollutants. The lake water was neutral with low ionic and metallic concentrations as compared to high-altitude lakes of Nepal. The four elements Cu, Zn, Se, and Cd had highest concentrations in livers, indicating uptake from diet, whereas four other metallic elements Cr, Mn, Ni, and Pb had highest concentrations in gills, indicating uptake from lake water. O. niloticus tended to have most of trace metals in the liver at higher concentrations than the other species but significant differences among the different species were found only for Mn, Ni, and Zn in the gills. A pilot study on the concentrations of persistent organic pollutants in muscle revealed that dichlorodiphenyltrichloroethane and related compounds were the dominant organochlorine pesticides, having highest concentrations in C. gariepinus and lowest in O. niloticus.