Risky Business

November 04, 2016

Valery Forbes is working to improve our ability to predict impacts of human activities on organisms and ecosystems.

Valery Forbes

Valery Forbes in the lab with a tank containing Capitella teleta, a tiny worm that may be a useful ally cleaning up after oil spills. Below: Close up of Capitella teleta, which burrow into sandy sediments.

How might a new pesticide affect the balance of plant, animal and microbial life in a stream? What unanticipated changes could cascade through an ecosystem as the result of an oil spill? Finding the answers to those questions is the purview of ecological risk assessment. And improving ecological risk assessment—and so our ability to do our human business without harming nature—is a major research focus for Valery Forbes, dean of the College of Biological Sciences.

A coastal oceanographer by training, Forbes is a national leader in efforts to improve mathematical modeling to make risk assessments better able to predict impacts of stressors such as pollutants, invasive species and climate change on ecosystems. By doing so, she aims to help boost nature’s ability to withstand human onslaughts and so its capacity for keeping our planet functioning smoothly and, among other things, delivering the ecosystem services on which humans depend.

The problem with environmental risk assessment as it stands today, Forbes says, is that we know a lot about potential harms—but what we know is largely at the level of the very small and the very simple.

Capitella teleta
“Historically, most of what we know about the impacts of pollutants is at the level of individual organisms. With advances in technology, we are beginning to generate enormous amounts of data about the impact of stressors at the molecular level. But we don’t know what these molecular and organismal responses mean in terms of what matters," says Forbes. To truly be meaningful, risk assessments need to consider impacts of pollutants and other stressors not just on biochemistry or cellular function but on organisms, populations and ecosystems, as well. And they need to do so in a way that accommodates complexities such as feedback loops and synergistic interactions.

Forbes’ research focuses on taking what we know about impacts at smaller scales—say, whether an individual fish changes its feeding behavior when exposed to a particular concentration of a contaminant for a particular amount of time—and using models and experiments to predict how such changes will affect the long-term persistence of fish populations and the benefits that humans get from them (such as food or recreational enjoyment).

“Do we care if we kill an individual fish or bird? Most people would say no. But we do want populations of fish and birds to persist in space and time. So we need to be able to connect what we know about impacts on individuals with impacts at higher levels of organization,” Forbes says. “Current models used in risk assessment are very simplistic and ignore ecological complexity. We want to add some ecological realism to the equation.”

As part of this effort, Forbes leads a working group through the National Institute for Mathematical and Biological Synthesis (NIMBioS) that brings together diverse perspectives from a variety of fields and sectors, from academia and government to business, to connect the dots between organism performance and the delivery of ecosystem services in the face of environmental stressors. She’s also conducting research that looks at interactions and synergies that accrue due to other human activities. “People tend to study toxic chemicals in isolation, ignoring things like eutrophication and climate change. Obviously, all are impacting ecosystems together,” she says. “The only way you can study these complex interactions over relevant temporal and spatial scales is with modeling.”

An East Coast native, Forbes says she was “born a biologist,” spending her childhood making friends with invertebrates that washed ashore near her family’s summer home on Long Island Sound. Her focus on aquatic invertebrates remains: Among other projects ongoing in her lab is a study looking into the potential for Capitella teleta, a thumbnail-length pale pink worm found off the coasts of North America and around the world, to detoxify oil spills.

With its distribution of expertise across all levels of biological organization, Forbes says, the College of Biological Sciences is a perfect environment in which to conduct her research. And the University’s expertise in mathematics and computational capacity provide valuable resources for refining the models she’s developing. “I couldn’t do it myself,” she says. “Interdisciplinary collaboration is key—absolutely key.” — Mary Hoff