Project: Collaborative Research: Using an Energetics Framework to Forecast the Interactive Effects of Abiotic and Biotic Stressors on Intertidal Mussels

NSF abstract:
The impacts of environmental change on animals and plants is well established, and numerous studies have shown that not only does environmental change alter the physiological health of species, it also can alter the ways in which species interact with one another. It also suggests that some of the first detectable impacts of environmental change may lie in alterations in the ability of organisms to grow and reproduce, rather than just lethality. This project will develop a framework for looking at the impacts of extreme environmental change on an ecologically and economically important bivalve species, the mussel Mytilus edulis, in the Gulf of Maine, which is warming at an unusually fast rate. Importantly, our modeling framework is, for the first time, able to account for the interactions of temperature change with the additional stresses that occur in the presence of predators. These models will therefore not only advance our basic understanding of how multiple stressors affect animals in nature, but also will provide a mechanism for predicting the impacts of environmental change under realistic field conditions that are often ignored by laboratory-only based experiments. The project also will create novel methods for teaching high school students about the impacts of extreme change on their local environments using cutting-edge virtual-reality technology coupled with hands-on experiential learning in the field.

This project seeks to develop a predictive energetics (Dynamic Energy Budget) approach to quantitatively explore the potentially interactive effects of abiotic (temperature) and biotic (risk of predation) stressors on intertidal mussels. The central question that addressed by this project is, how unreliable may predictions of the impacts of environmental change be if a focus is placed only on the isolated rather than combined influence of abiotic or biotic stressors? A framework that considers the effects of environmental change on multiple, interacting species is sorely needed. Building upon an energetics model already parameterized to quantify the effects of temperature and food availability on the mussel Mytilus edulis, this project expands the approach to examine how predation risk - the "fear of being eaten" - may alter thermal sensitivity under more realistic field conditions where predators are present. Previous work by this team has shown that the effects of predation risk are comparable to, or exceed those, caused by predicted climate scenarios, but very few attempts have been made to place these risk effects within a bioenergetics framework, especially in marine systems. This proposal capitalizes on the highly complementary approaches of two research groups to develop a predictive framework examining the cumulative effects of abiotic and biotic stressors on growth, maximum size and reproduction of an important ecosystem engineer under realistic field and trophic interaction conditions.