Hommen, UdoUdoHommenKnopf, BurkhardBurkhardKnopfRüdel, HeinzHeinzRüdelSchäfers, ChristophChristophSchäfersSchamphelaere, Karel deKarel deSchamphelaereSchlekat, ChrisChrisSchlekatRogevich Garman, EmilyEmilyRogevich Garman2022-03-052022-03-052016https://publica.fraunhofer.de/handle/publica/24122110.1002/etc.3255The aquatic risk assessment for nickel in the European Union is based on chronic Species Sensitivity Distributions (SSD) and the use of bioavailability models. To test if a bioavailability-based safe threshold of nickel (the Hazardous Concentration for 5% of the species, HC5) is protective for aquatic communities, microcosms were exposed to 5 stable nickel treatments (6-96 mikrog/L) and a control for 4 mo to assess bioaccumulation and effects on phytoplankton, periphyton, zooplankton and snails. Ni concentrations in the periphyton, macrophytes and snails measured at the end of the exposure period increased in a dose-dependent manner, but did not indicate biomagnification. Abundance of phytoplankton and snails decreased in 48 and 96 mikrog Ni/L treatments, which may have indirectly affected the abundance of zooplankton and periphyton. Exposure up to 24 mikrog Ni/L had no adverse effects on algae and zooplankton while the rate of population decline of the snails at 24 mikrog Ni/L was significantly higher than in the controls. Therefore, the study-specific overall no observed adverse effect concentration (NOAEC) is 12 mikrog Ni/L. This NOAEC is approximately twice the HC5 derived from a chronic SSD considering the specific water chemistry of the microcosm by means of bioavailability models. Thus, the study provides support to the protectiveness of the bioavailability-normalized HC5 for freshwater communities.enmetalschronic exposurebiotic ligand modelshigher tier testcommunity level effects615journal article