RESEARCH
We use data synthesis techniques like meta-analysis, field and laboratory experiments, and observational studies supported by a strong theoretical foundation and rigorous statistical frameworks to address two critical questions: (1) When, where and why does climate change exacerbate, diminish, or have negligible effects on the negative impacts of invasive species? and (2) Given the types of expected changes to biodiversity and ecosystem structure and functioning from climate change and invasive species' independent and combined effects, can we build ecosystem resilience to these perturbations?
Climate Change
The effects of increasing greenhouse gas emissions on the ocean are varied, ranging from rising sea levels and changing ocean currents and salinity, to declining pH and oxygen levels, and warming waters. These changes have serious consequences for life in the ocean. We aim to understand and predict the consequences of these changes for both human and non-human organisms.
Marine Invasions
Invasive species are one of the leading threats to native biodiversity. Concerningly, both the rate and magnitude of biological invasions are increasing due to the rise in global trade and travel. We study patterns, processes, and impacts of invasive species in marine systems as well as investigate the ecological effectiveness of management actions.
Their Intersection
Climate change and invasive species are two critical drivers of ecosystem change. These widespread 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), inhibiting our ability to predict and manage ecological changes. We aim to understand broad patterns of the influence of climate change on marine invasions, and to generate evidence of any potential for interactive effects between them.
Current Research Focus
Interactive effects of climate change and marine invasions on native biodiversity
The DECO lab current 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). The DECO lab combines 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 this research program because they are critically threatened by both stressors.
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., deoxygenation).
Our research program aims to quantify the conditions in which climate change has additive, synergistic or antagonistic effects on marine invasion success. Our 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. Our research uses empirical evidence to examine whether synergisms are as common as the dominant view suggests.