@misc{01HCAF69D7AHV8382N7B6VJA1G,
  abstract     = {{Here we used a DEB-IBM to predict D. magna population dynamics exposed to Ni in a
microcosm context. Even though limited information on the food and the interactions with other
species in the community was available, the DEB-IBM reproduced the patterns observed in
the microcosm experiment, under the assumptions we took. The effect of Ni was
mechanistically implemented in the DEB-IBM, considering both lethal and sub-lethal effects.
Based on the DEB-IBM predictions, the model generally reflects the trends observed in the
microcosm experiment, although there were some deviations. The assumptions on food
availability and density-dependence are the main drivers for the deviations between the
predictions and observations. The predicted population densities seemed to largely depend
on the food availability, indicating a strong influence of bottom-op control. However, some
assumptions were made on the food availability, since information was lacking on the effect
food quality on D. magna life history traits, e.g., how the maximum surface-specific
assimilation rate varies with different algal species as food source.
Based on the validation, the implemented density-dependence is a dominant populationregulating
mechanism, meaning there is top-down regulation as well. With the implementation
of the density-dependent mortality, we can get an idea of the potential community-level impact
and what it means for the D. magna population. Even though this form of density-dependence
is a simplified implementation that does not encompass all population-regulating mechanisms
in a community context, it overall yielded good predictions for the population dynamics.
The DEB-IBM predicted no or only a limited impact of Ni to the D. magna population in the
microcosm experiment, up to and including the highest concentration of 96 μg/L, which is in
line with the original experimental observations. We conclude that the food availability and
density-dependence are more dominant drivers for the population dynamics of D. magna in
the microcosm.
In the original study, it was concluded as well that the impact of Ni on D. magna and
zooplankton in general was limited (i.e., NOEC of 96 μg/L on all timepoints, except for day 21
where the NOEC was 48 μg/L – the overall zooplankton NOEC was 48 μg/L). The predictions
with DEB-IBM revealed limited lethal impact of Ni on the D. magna population dynamics (<2%
of the total predicted mortality). The sub-lethal effects have a stronger effect on the population
(39% effect in the highest exposed treatments compared to without sub-lethal effects).
However, the predictions do not match the observations completely in terms of absolute
population density numbers, as there is a general underprediction of the density. How Ni
exactly affects the dynamics and the ecological processes within the microcosms should be
addressed with a more complex, community-scale model.
Overall, the DEB-IBM here predicts an impact of the population at 96 μg/L, as the predicted
abundance was outside of the control range most frequently. At 48 μg/L, predicted deviation
outside the control was limited to a few days. Similarly, for 12 μg/L, the abundance at a few
timepoints were predicted outside the control range. However, the predicted control range
differed from the observed control range, which was much larger for the observations. This
was mainly due to the observed abundance of 0 individuals in microcosm 2. Based on the
DEB-IBM simulations, the population-level impact of Ni is limited to 96 μg/L, meaning the DEBIBM
predicted NOEC value would be 48 μg/L. This compares to the zooplankton NOEC of 48
μg/L for Ni that was established in the microcosm experiment.}},
  author       = {{Vlaeminck, Karel and Viaene, Karel and Nys, Charlotte and Van Sprang, Patrick and De Schamphelaere, Karel}},
  language     = {{eng}},
  pages        = {{53}},
  publisher    = {{Ghent University & ARCHE Consulting}},
  title        = {{Ecorelevance : validation of mechanistic models for nickel (Ni) risk assessment : microcosm study with Daphnia magna}},
  year         = {{2022}},
}