@misc{01HC9R8YQVTSNDNF9E0X1KN0VQ,
  abstract     = {{The Ecorelevance 3 project aims to apply population models to a wide array of species, thus increasing the ecological relevance of available Ni toxicity data. For nickel, Lemna minor was chosen as a primary producer for the application of population models and to simulate the population response for more ecologically relevant conditions. The toxicity dataset from Nys et al. 2016 was chosen, where Lemna was exposed to nominal concentration of 3.2 – 320 μg/L Ni at two pH levels, 8.2 and 8.7.
The Lemna model was based on the Lemna growth model developed by Schmitt et al. 2013. Ni was added to the model as an additional stressor for primary production. Two population endpoints were chosen for the simulation period of one year: maximum population growth rate and maximum population biomass increase.
In addition to extrapolation of the toxicity test to a reference scenario (Wageningen), three additional ditch scenarios (Opheusden, Sinderhoeve, Zetten) were simulated, each with their unique nutrient (nitrogen and phosphorus) conditions.
Extrapolation of the available laboratory toxicity data for nickel to realistic field conditions resulted in lower predicted effects on maximum population growth rate and biomass. Typically NOEC or EC10 values of the Lemna test are used for risk assessment. The EC10 based on the Nys et al. 2016 data was 32 and 29 μg/L for pH 8.2 and 8.7, respectively. With the Lemna model, EC10s >70.2 (for pH 8.2) and >81.1 μg/L(for pH 8.7) were derived for the population endpoints. The ratio of the population EC10 / toxicity test EC10 is thus >2.2 for maximum population growth rate and >5.6 for maximum population biomass.
Scenario simulations for different nutrient conditions indicate that nickel effects on maximum biomass are predicted to be more pronounced at lower nutrient levels, although effects were still lower compared to the toxicity test (EC10 for biomass increase always >3.1 fold higher). This suggests that a risk assessment based on the results of the original toxicity test will overpredict the effects of nickel on Lemna minor populations even at low nutrient concentrations.}},
  author       = {{Viaene, Karel and De Schamphelaere, Karel}},
  language     = {{eng}},
  pages        = {{16}},
  publisher    = {{Ghent University & ARCHE Consulting}},
  title        = {{Ecorelevance 3 : population effects of nickel on Lemna minor}},
  year         = {{2022}},
}