How Chemicals Affect Ecosystems: A UCSB theoretical ecologist receives an EPA grant to study the biological and ecological consequences of exposures to chemicals in the environment

September 8, 2015
Roger Nisbet. Credit: Sonia Fernandez
Roger Nisbet. Credit: Sonia Fernandez

The U.S. Environmental Protection Agency has awarded an $800,000 Science to Achieve Results (STAR) grant to UC Santa Barbara’s Roger Nisbet. He will use the funding to develop a model to better understand biological and ecological consequences of exposure to metals, nanoparticles and certain flame retardants in industrial and consumer products. Such materials could pose a threat to human and environmental health.

“Most ecological risk assessments of chemical stressors are motivated by the societal need to avoid unacceptable impacts on natural populations and ecosystems from exposure to manufactured chemicals,” said Nisbet, a professor in UCSB’s Department of Ecology, Evolution, and Marine Biology. “A major challenge is that ecological change usually occurs on long time scales and involves many interacting species, but the data available for risk management typically comes from short-term studies on individual organisms or on biochemical processes.”

Nisbet’s project — “Dynamical Systems Models Based on Energy Budgets for Ecotoxicological Impact Assessment” — is expected to enhance the understanding of how the effects of exposure to chemical stressors are expressed ecologically. New mathematical models will be developed with feedback representing physiological control processes within an organism and interactions among species in an ecosystem.

“The anticipated expected outcome is an enhanced and improved ability to identify key toxic mechanisms within individual organisms and to make quantitative predictions of the implications for the sustainability of populations,” Nisbet said. “If models are found to have predictive value, this will enhance the capacity for using such information for evaluation of chemicals. If, as is likely, reliable predictions require additional information on whole organisms or populations, the nature of the required information will be defined.”