Grantee Research Project Results

Dynamical Systems Models Based on Energy Budgets for Ecotoxicological Impact Assessment

EPA Grant Number: R835797
Title: Dynamical Systems Models Based on Energy Budgets for Ecotoxicological Impact Assessment
Investigators: Nisbet, Roger M. , Muller, Erik B , Whitehead, Andrew
Institution: University of California - Santa Barbara , University of California - Davis
EPA Project Officer: Aja, Hayley
Project Period: June 1, 2015 through May 31, 2018 (Extended to May 31, 2019)
Project Amount: $799,723
RFA: Systems-Based Research for Evaluating Ecological Impacts of Manufactured Chemicals (2014) RFA Text |  Recipients Lists
Research Category: Chemical Safety for Sustainability

Objective:

We propose theoretical and experimental research that uses Dynamic Energy Budget (DEB) models to enhance understanding of how the effects of exposure to chemical stressors are expressed across levels of biological organization.

Approach:

We will: (i) develop new modular DEB models with explicit feedbacks representing regulatory processes within an organism; (ii) determine the extent to which genomic data on two model organisms (the waterflea Daphnia and the estuarine fish Fundulus for which will conduct experiments on response to combined food and chemical stress) relate to parameters in DEB models; (iii) use the new models to predict organismal and population "tipping points" caused by failure of physiological and population regulatory processes ; (iv) develop models of adaptation to stress that lead to tools for evaluating likelihood of evolutionary rescue in chronically polluted environments; and (v) evaluate the applicability of our findings to non-model organisms.

Expected Results:

The anticipated outcome is an enhanced and improved ability to identify key toxic mechanisms at various levels of biological organization and to make predictions of the implications for the sustainability of populations. Outputs will include new, rigorously tested, systems models relating organism performance to suborganismal information, especially on processes liked to bioenergetics. The models will provide a quantitative basis for Adverse Outcome Pathway analyses. Models will be tested on two model animals using both literature data and data from this project. We will conduct the first test against experimental data of the ability of a detailed bioenergetic model with toxicokinetics and toxicodynamics to predict population dynamics and adaptation in response to a chemical stressor. If models are found to have immediate predictive value, the research will enhance the capacity for using such information for evaluation of manufactured chemicals. If, as is likely, predictions require additional information on whole organisms or populations, the nature of the required higher level data will be defined.

Publications and Presentations:

Publications have been submitted on this project: View all 39 publications for this project

Journal Articles:

Journal Articles have been submitted on this project: View all 13 journal articles for this project

Supplemental Keywords:

Individual-based model, DEBtox, systems biology, adverse outcome pathways

Progress and Final Reports:

2015 Progress Report

2016 Progress Report

2017 Progress Report

Final Report