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Publications: 2021

PostersCrop Protection2021

Impact of Climate Change on the Relevance of OECD Crosswalks

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Session:  Extended submission 3 – Environmental chemistry and exposure assessment: analysis, monitoring, fate and modeling

Abstract:  Climate change studies confirm that the earth is warming up and that shifts in rainfall patterns is occurring. Various computer models predict that Earth’s average temperature will rise between 1.8° and 4.0° Celsius (3.2° and 7.2° F). Consequently, these warmer temperatures will cause a higher rate of evaporation, resulting in a predicted increase of average global rainfall by 3-5%. Under OCED guidance, TFD studies conducted in one country can be applicable to other countries if the characteristics of overlapping ecoregions are the same. These assessments are conducted using the OECD ENASGIPS tool. If these characteristics change, so will the similarity assessment and therefore the potential relevance of TFD sites. With increase rainfall, TFD sites in the Southeastern US, which typically have few similar areas, may become more relevant because other areas are getting wetter. Likewise, TFD sites in arid ecoregions may see a decrease in similarity scores. In this presentation we show that TFD studies in arid regions in the US remain relevant for foreseeable future.The objective of this assessment was to determine if climate change will impact the relevance of TFD studies and OECD ENASGIPS crosswalks ecoregion similarity scores. Specifically, we were interested in determining if ecoregions overlapping TFD sites remain the same over time in terms of precipitation, temperature, and ecoregion similarity. Both statistical analysis and ecoregion crosswalk assessments were conducted. In this presentation we will focus on an arid in California’s Central Valley using the intermediate IPCC RCP4.5 and worse case RCP8.5 climate change scenarios. Results indicate that under moderate climate change scenario the arid ecoregion has an increase in the number of similar ecoregion over time but a decrease is observed under the worse case scenario. In the short-term, 30 to 40 years, TFD studies are not predicted to see an impact by of climate change and data obtained from these TFD studies can be used for registration and reregistration of pesticides for the foreseeable future.

Authors:  Cornelis Hoogeweg, Amy Ritter, Raghu Vamshi, Dean Desmarteau (Waterborne).  SETAC Europe 2021.

PostersCrop Protection2021

Identification of Patterns in Mesocosm Data: An Analysis of Untreated Control Ecosystems Across Multiple Studies

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Session: Effect Modelling for Regulatory Environmental Risk Assessment of Chemicals: Where Are We and What Comes Next?

Abstract: For risk assessment, experimental mesocosms provide valuable insights into the complex responses of aquatic ecosystems to stressors. Similarly, aquatic systems models (ASMs) represent food web interactions in an aquatic species community and interactions with abiotic environmental conditions. In the context of a study to simulate mesocosms using ASMs, an analysis of control mesocosm data was conducted to identify patterns in temporal dynamics in the species communities. Control data from six mesocosm studies were anonymized, collated, and characterized using visual and statistical analyses. The data were generated during studies conducted in 2016, 2018 and 2019 by MESOCOSM GmbH. During these studies, physical parameters of temperature, oxygen, pH, water level and conductivity were measured over the study duration. Nitrate, ammonium, and phosphate concentrations and water hardness were measured prior to the beginning of each study. Additionally, weekly samples were collected for taxon and species abundance evaluation. The resulting dynamics of phytoplankton, periphyton, macrophytes, zooplankton and macroinvertebrates were analyzed for each study data set and across studies. Correlation matrices were constructed and used to examine the data and identify consistent patterns of biotic and abiotic interactions. The trends observed within and across the studies show considerable temporal variability in species composition and abundance. The characterization and understanding of similar and repeated temporal patterns in the untreated aquatic mesocosms is an important foundation for the simulation of mesocosm studies using ASMs. We provide perspectives on the challenges associated with variability observed in mesocosm controls, and offer possible explanation and insights for managing these challenges in modeling.

Authors: Farah Abi-Akar (Waterborne), Amelie Schmolke (Waterborne), Peter Ebke (Mesocosm GmbH), Jürgen Schmidt (Mesocosm GmbH), Nika Galic (Syngenta), Steven Bartell (Cardno), Isabel O’Connor (EBP), Simon Spycher (EBP), Nele Schuwirth (EAWAG), Tido Strauss (Gaiac), Damian Preziosi (Integral), Robert Pastorok (Integral), Roman Ashauer (Syngenta).  SETAC Europe 2021.

PresentationsCrop Protection2021

Modelling Ecosystems in Mesocosms: A Ring Study Approach With Four Aquatic Systems Models

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Session: Effect Modelling for Regulatory Environmental Risk Assessment of Chemicals: Where Are We and What Comes Next?

Abstract:  Aquatic systems models (ASMs) represent food-web interactions in an aquatic community and interactions with environmental conditions. Ecological models, including ASMs, are valuable tools in pesticide risk assessments because they can be applied to a range of biotic and abiotic conditions, as well as to a variety of exposure scenarios which would be impractical to test empirically. Four ASMs (Streambugs, AQUATOX, CASM, and StoLam with STREAMcom) that have been developed, published and applied in pesticide risk assessments and other contexts are the subjects of this ring study. Model inputs and outputs are compared among the ASMs, using mesocosm data generated and provided by MESOCOSM GmbH. The ASM ring study includes: a) analysis and preparation of mesocosm control and treatment data, b) definition of the food web represented across ASMs, c) parameterization of the ASMs, d) calibration of the ASMs to mesocosm control data, e) validation of the calibrated ASMs against mesocosm control data not used in the calibration, f) calibration of the ASMs to mesocosm treatment data. All steps are documented in detail, following the recommendations of the good modeling practice. We will present methods and results of the steps a) – d). We outline an approach for defining a mesocosm food web that can be represented by multiple ASMs, and the parameterization and calibration of the ASMs to the available mesocosm data. The approach provides important insights into the strengths and limitations of different ASMs for this particular modelling exercise through comparison of the model outputs with each other and with empirical data. In the next steps of the ring study, we will evaluate the ASMs using independent mesocosm data from the same test site, and simulate treatment effects for an example pesticide.

Authors: Amelie Schmolke (Waterborne), Nika Galic (Syngenta), Steven Bartell (Cardno), Isabel O’Connor (EBP), Simon Spycher (EBP), Nele Schuwirth (EAWAG), Tido Strauss (Gaiac), Damian Preziosi (Integral), Robert Pastorok (Integral), Peter Ebke (Mesocosm GmbH), Jürgen Schmidt (Mesocosm GmbH), Farah Abi-Akar (Waterborne), Jennifer Collins (Waterborne), Roman Ashauer (Syngenta).  SETAC Europe 2021.