Assessing the ecological and socioeconomic impacts of the lionfish invasion in the Wider Caribbean Region

Environmental changes of different scales and magnitudes are occurring at an alarming pace throughout the globe. As natural and human systems resist, cope, and/or adapt to global changes, new equilibrium states might be reached. To understand these changes we need to obtain information relevant to both biological and human systems and the interactions within and between them. My thesis combines approaches from ecology and socioeconomic to investigate the impacts of a specific stressor - invasive Indo-Pacific lionfish - on coral reef ecosystems. First, I explore how this invasion has changed trophic interactions and food web dynamics of coral reef fish communities. Second, I investigate how the impacts of an invasive predator can scale up to affect and change socioeconomic systems associated with natural systems. I found that the trophic niche of lionfish has changed over time, concomitant with large changes in native fish prey abundance. I also found that lionfish predation is having impacts on energy flow through coral reef fish communities even in the absence of marked changes in fish community structure. Combined, these changes could affect ecosystem function. I also present some of the first evidence of economic impacts of this invasion in regions that depend on reef-related tourism. I show that reductions in lionfish abundance through management actions should be beneficial to the reef tourism industry, and that tourist user fees are an acceptable means of financing such actions. As new management strategies are explored, the popularity of lionfish tournaments (derbies) has increased, premised on the idea that involving the public could help to tackle this invasion. However, my results show that such events are most likely to be successful only when lionfish densities are high and where there is a large pool of participants. This dissertation sheds light on the need to study and manage the impacts of biotic invasions from a multidisciplinary and integrated perspective since impacts will rarely be limited to the natural system affected by invaders.