Ecological interactions affecting population-level responses to chemical stress in Mesocyclops leuckarti
Authored by Udo Hommen, Thomas G Preuss, Devdutt Kulkarni, Andreas Schaeffer
Date Published: 2014
DOI: 10.1016/j.chemosphere.2014.04.062
Sponsors:
European Union
Platforms:
Delphi
Model Documentation:
ODD
Flow charts
Mathematical description
Model Code URLs:
Model code not found
Abstract
Higher tiers of ecological risk assessment (ERA) consider population and
community-level endpoints. At the population level, the phenomenon of
density dependence is one of the most important ecological processes
that influence population dynamics. In this study, we investigated how
different mechanisms of density dependence would influence
population-level ERA of the cyclopoid copepod Mesocyclops leuckarti
under toxicant exposure. We used a combined approach of laboratory
experiments and individual-based modelling. An individual-based model
was developed for M. leuckarti to simulate population dynamics under
triphenyltin exposure based on individual-level ecological and
toxicological data from laboratory experiments. The study primarily
aimed to-(1) determine which life-cycle processes, based on feeding
strategies, are most significant in determining density dependence (2)
explore how these mechanisms of density dependence affect extrapolation
from individual-level effects to the population level under toxicant
exposure. Model simulations showed that cannibalism of nauplii that were
already stressed by TPT exposure contributed to synergistic effects of
biotic and abiotic factors and led to a twofold stress being exerted on
the nauplii, thereby resulting in a higher population vulnerability
compared to the scenario without cannibalism. Our results suggest that
in population-level risk assessment, it is easy to underestimate
toxicity unless underlying ecological interactions including mechanisms
of population-level density regulation are considered. This study is an
example of how a combined approach of experiments and mechanistic
modelling can lead to a thorough understanding of ecological processes
in ecotoxicology and enable a more realistic ERA. (C) 2014 Elsevier Ltd.
All rights reserved.
Tags
Dynamics
sensitivity
Food
Daphnia-magna
Life-history
Reproduction
Density-dependence
Cyclopoid copepods
Marine copepod
Triphenyltin