Grant: Discovery Grants Program - Individual

Interactive effects of climate change and marine invasions on native biodiversity My proposed research examines multiple stressor interactions in the ocean with a long-term aim to predict how these interactions will affect marine ecosystems. Stressors may not act independently, as their combined effect can be greater than (synergism) or less than (antagonism) the sum of each stressor effect (additive). My lab will combine data synthesis techniques with mesocosm experiments to quantify the interplay of two global drivers of environmental change: climate change and bioinvasions. Caribbean coral reefs are a relevant model system for my research program. Climate change is thought to benefit the success of invasive species. The rationale is that the same traits and life-history characteristics that allow an invasive species to thrive in a novel environment also allow them to prosper under changing salinity, pH, temperature, and dissolved oxygen levels expected in the oceans with climate change. If invasion success is enhanced under climate change, the combined effect of climate change and invasive species on native biodiversity will lead to synergistic impacts. This expectation might not be met, however, if less frequently examined climate stressors other than temperature - the climate-related stressor most often considered - has deleterious effects on invasion success (e.g., ocean deoxygenation). My research program aims to quantify the conditions in which climate change has additive, synergistic or antagonistic effects on marine invasion success. My short-term objectives are to determine if: (1) climate change facilitates marine invasions, (2) multiple climate stressors with opposing effects on invasive species and climatic extremes challenge predictions of enhanced invader success under climate change, and (3) the combined effect of deoxygenation and invasive species on native biodiversity is antagonistic instead of synergistic and can cascade down marine food webs. Conservation and invasion biologists often assume the worst-case scenario of synergistic effects between multiple stressors on marine biodiversity, which can influence management decisions. Managing an antagonistic interaction as if it were synergistic, for example, can exacerbate an environmental problem. This research proposal uses empirical evidence to examine whether synergisms are as common as the dominant view suggests.