- Christopher A. Mebane (1)
- Dick Belgers (1)
- Paul Brink Van den (1)
- Laura Buijse (1)
- Paula C. Reis Oliveira dos (1)
- Ralf C.M. Verdonschot (2)
- Marie Claire Boerwinkel (1)
- Piet F.M. Verdonschot (3)
- Andreas Focks (1)
- Harm G. Geest van der (1)
- Laury Gauthier (1)
- Michiel H.S. Kraak (1)
- Paul J. Den Brink van (1)
- Judith J. Westveer (2)
- Sandrine Joachim (1)
- Jean Marc Bonzom (1)
- Sofia Naranjo (1)
- Ivo Roessink (1)
- Hélène Roussel (1)
- Eric Thybaud (1)
Calibration and validation of toxicokinetic-toxicodynamic models for three neonicotinoids and some aquatic macroinvertebrates
Focks, Andreas ; Belgers, Dick ; Boerwinkel, Marie Claire ; Buijse, Laura ; Roessink, Ivo ; Den Brink, Paul J. van - \ 2018
Ecotoxicology 27 (2018)7. - ISSN 0963-9292 - p. 992 - 1007.
Aquatic ecotoxicology - Macroinvertebrates - Neonicotinoids - Time-variable exposure - Toxicokinetic-toxicodynamic modelling
Exposure patterns in ecotoxicological experiments often do not match the exposure profiles for which a risk assessment needs to be performed. This limitation can be overcome by using toxicokinetic-toxicodynamic (TKTD) models for the prediction of effects under time-variable exposure. For the use of TKTD models in the environmental risk assessment of chemicals, it is required to calibrate and validate the model for specific compound–species combinations. In this study, the survival of macroinvertebrates after exposure to the neonicotinoid insecticide was modelled using TKTD models from the General Unified Threshold models of Survival (GUTS) framework. The models were calibrated on existing survival data from acute or chronic tests under static exposure regime. Validation experiments were performed for two sets of species-compound combinations: one set focussed on multiple species sensitivity to a single compound: imidacloprid, and the other set on the effects of multiple compounds for a single species, i.e., the three neonicotinoid compounds imidacloprid, thiacloprid and thiamethoxam, on the survival of the mayfly Cloeon dipterum. The calibrated models were used to predict survival over time, including uncertainty ranges, for the different time-variable exposure profiles used in the validation experiments. From the comparison between observed and predicted survival, it appeared that the accuracy of the model predictions was acceptable for four of five tested species in the multiple species data set. For compounds such as neonicotinoids, which are known to have the potential to show increased toxicity under prolonged exposure, the calibration and validation of TKTD models for survival needs to be performed ideally by considering calibration data from both acute and chronic tests.
Sediment composition mediated land use effects on lowland streams ecosystems
Reis Oliveira, Paula C. dos; Kraak, Michiel H.S. ; Geest, Harm G. van der; Naranjo, Sofia ; Verdonschot, Piet F.M. - \ 2018
Science of the Total Environment 631-632 (2018). - ISSN 0048-9697 - p. 459 - 468.
C/N ratio - Deposition zone - Food quality - Macroinvertebrates - Runoff - Sediment respiration
Despite the widely acknowledged connection between terrestrial and aquatic ecosystems, the contribution of runoff to the sediment composition in lowland stream deposition zones and the subsequent effects on benthic invertebrates remain poorly understood. The aim of this study was therefore to investigate the mechanisms by which runoff affects sediment composition and macroinvertebrates in deposition zones of lowland stream ecosystems. To this end, sediment from runoff and adjacent instream deposition zones from streams with different land use was chemically characterized and the biological effects were assessed at the species, community and ecosystem level. Runoff and deposition zone sediment composition as well as biological responses differed clearly between forest and agricultural streams. The stream deposition zone sediment C/N ratio reflected the respective runoff sediment composition. Deposition zones in the forest stream had a higher C/N ratio in comparison to the agricultural streams. Growth of Hyalella azteca and reproduction of Asellus aquaticus were higher on forest stream sediment, whereas chironomids and worms suffered less mortality on the agricultural sediments containing only natural food. The forest stream deposition zones showed higher values for indices indicative of biological integrity and had a lower sediment oxygen demand. We concluded that agricultural land use affects lowland stream ecosystem deposition zones at the species, community and ecosystem level via altered food quality (C/N ratio) and higher oxygen demand of the sediment.
Biotic interactions enhance survival and fitness in the caddisfly Micropterna sequax (Trichoptera : Limnephilidae)
Westveer, Judith J. ; Verdonschot, Piet F.M. ; Verdonschot, Ralf C.M. - \ 2018
Hydrobiologia 818 (2018)1. - ISSN 0018-8158 - p. 31 - 41.
Biodiversity - Ecosystem functioning - Interspecific facilitation - Macroinvertebrates - Niche complementarity
Patches of coarse particulate organic matter in lowland streams are inhabited by many different macroinvertebrate species, yet knowledge of interactions among the members of these assemblages is scarce. In a mesocosm experiment we aimed to determine the effect of interspecific interactions on species survival and fitness of two caddisfly species. It was hypothesized that, as a result of positive interactions, mixed species populations would yield higher survival and fitness than single species populations. Larvae of two caddisfly species, Micropterna sequax and Potamophylax rotundipennis, were reared in single species and mixed species populations. Emergence rate was recorded and adult fitness was measured in terms of wingspan and biomass. We found that in mixed populations, emergence rate, wing length and biomass of M. sequax were higher than in single species populations. P. rotundipennis was only significantly, yet negatively, affected in terms of biomass of the male individuals. This study showed that occurring together with other species holds advantages for M. sequax, and emphasizes the importance of species diversity in streams. Furthermore, the observed positive effects on survival and fecundity might influence population sizes of the interacting species, in turn affecting macroinvertebrate-mediated ecosystem processes such as leaf litter decomposition.
Substrate homogenization affects survival and fitness in the lowland stream caddisflies Micropterna sequax and Potamophylax rotundipennis : A mesocosm experiment
Westveer, Judith J. ; Verdonschot, Piet F.M. ; Verdonschot, Ralf C.M. - \ 2017
Freshwater Science 36 (2017)3. - ISSN 2161-9549 - p. 585 - 594.
Functional traits - Habitat heterogeneity - Habitat preference - Macroinvertebrates - Substrate patchiness - Trichoptera
Loss of substrate heterogeneity or patchiness is common in lowland streams with disturbed hydrological regimes. At the reach scale, peak discharges tend to homogenize the stream bed and decrease the availability of specific microhabitat types. This spatial shift in habitats toward a more homogeneous landscape could have large negative effects on species that perform essential ecosystem processes. We conducted an aquatic mesocosm experiment to test the effect of habitat homogenization on survival and fitness of 2 species of Trichoptera (Micropterna sequax and Potamophylax rotundipennis). We used caddisflies as model organisms because of their abundance in lowland streams, their representativeness of the total shredder community, and their important role in leaf-litter decomposition. We reared larvae in artificial recirculating channels containing leaf and sand patches in 3 spatial configurations, differing in homogeneity of substrates, varying from few large patches to many small patches. We used emergence rate as a measure of survival and biomass and wing span of the adults as fitness correlates. For M. sequax, survival was lower in the homogeneous than in the heterogeneous configurations, but patch configuration did not affect fitness. For P. rotundipennis, spatial configuration of the patches did not affect survival, but the longest forewings for both males and females were found in the homogeneous configuration. Our results suggest that both species experience intraspecific resource competition arising from the spatial distribution of patches, expressed as an investment in wing development (e.g., dispersal capacity) in P. rotundipennis and resulting in lower survival rates in M. sequax. Our results indicate the importance of knowledge of trait-based responses and highlight the effects of the configuration of stream bottom substrate for its inhabitants on microscale.
A long-term copper exposure in a freshwater ecosystem using lotic mesocosms : Invertebrate community responses
Joachim, Sandrine ; Roussel, Hélène ; Bonzom, Jean Marc ; Thybaud, Eric ; Mebane, Christopher A. ; Brink, Paul Van den; Gauthier, Laury - \ 2017
Environmental Toxicology and Chemistry 36 (2017)10. - ISSN 0730-7268 - p. 2698 - 2714.
Copper - Emerging insects - Macroinvertebrates - Mesocosms - Recovery - Tolerance - Zooplankton
A lotic mesocosm study was carried out in 20-m-long channels, under continuous, environmentally realistic concentrations of copper (Cu) in low, medium, and high exposures (nominally 0, 5, 25, and 75μgL-1; average effective concentrations <0.5, 4, 20, and 57μgL-1 respectively) for 18mo. Total abundance, taxa richness, and community structure of zooplankton, macroinvertebrates, and emerging insects were severely affected at Cu treatment levels of 25 and 75μgL-1. Some taxa were sensitive to Cu, including gastropods such as Lymnaea spp. and Physa sp., crustaceans such as Chydorus sphaericus, Gammarus pulex, and Asellus aquaticus, rotifers such as Mytilina sp. and Trichocerca sp., leeches such as Erpobdella sp., and the emergence of dipteran insects such as Chironomini. Other taxa appeared to be tolerant or favored by indirect effects, as in Chironimidae larvae, the emergence of Orthocladiinae, and the zooplankter Vorticella sp., which increased in the 25 and 75μgL-1 treatments. After approximately 8mo of Cu exposure, the macroinvertebrate community in the high treatment was decimated to the point that few organisms could be detected, with moderate effects in the medium treatment, and very slight effects in the low-Cu treatment. Subsequently, most taxa in the high-Cu exposure began a gradual and partial recovery. By the end of the study at 18 mo, macroinvertebrate taxa richness was similar to control richness, although overall abundances remained lower than controls. After 18mo of copper exposure, a no-observed-effect concentration at the community level for consumers was set at 5μgL-1 (4μgL-1 as average effective concentration), and a lowest-observed-effect concentration at 25μgL-1(20μgL-1 as average effective concentration).