Invasions by exotic vertebrate predators can have striking effects on native communities that are typically far greater than those of other exotic taxa. They also provide unique opportunities to understand several ecological and evolutionary aspects of predator-prey interactions. For example, if one knew that an invasion was imminent, planned pre-invasion measurements could be compared to different post-invasion stages to watch the ecological and evolutionary impacts of a novel predator unfold in real time. The purpose of this investigation is to answer two fundamental questions: 1) What characteristics of native communities influence biotic resistance to colonization by exotic predators? and 2) What are the evolutionary responses of prey to novel predators? The investigator willl use the ongoing invasion of shallow-shelf habitats in the Caribbean basin by lionfish (Pterois volitans) as a model system. Lionfish, a predator from the central and western Pacific ocean, were first sighted in 1992 off Florida and have been spreading rapidly throughout the Caribbean. By consuming young reef fish, lionfish appear to negatively affect coral reef ecosystems. This research will primarily take place on the Mesoamerican reef in Belize. To answer question 1 25 sites along the Belizean reef tract will be surveyed during early summer 2009. At each site the investigtor will quantify a variety of factors that could potentially influence invasibility including fish density, juvenile abundance and composition, structural complexity and benthic community structure. He will then perform surveys for local presence once lionfish have become established on reefs in this region. To investigate rapid evolutionary responses of prey to novel predators, he will perform a series of assays using in situ video monitoring and gut content analyses to measure prey avoidance behavior and predator efficacy immediately after lionfish colonize local sites and grow large enough to consume native fish and crustacean prey. These baseline performance and behavior data can then be compared to post-invasion assays that will be performed in the Bahamas and through time in Belize.
The region-wide invasion by lionfish poses the greatest threat to Caribbean reefs and Atlantic hard bottom communities since the urchin and coral disease outbreaks of the 1980s. By understanding the factors that influence the ability of lionfish to invade a new site, this work has direct, applied value. Some of the work will be focused on mangrove tidal creeks, which are critical nursery habitats for countless species. Several UNC undergraduate students will participate in this research and collaboration with NGO partners in Belize and the Bahamas will promote awareness of the lionfish threat and educate the public on how to safely catch and consume them.
