Simulated Effects of Indo­Pacific Lionfish (Pterois volitans and P. miles) Invasions on Parrotfish (Scaridae family) Populations on Coral Reefs in the Caribbean

Abstract

The introduction of invasive species in marine environments is rare but detrimental to the existence of native species. The Indo-Pacific lionfish species (Pterois volitans and P. miles) recently has invaded coral reefs across the Atlantic and Caribbean at an alarming rate. One keystone species currently being affected by the lionfish invasion is the parrotfish (Family Scaridae). The parrotfish plays a vital role in the stabilization of coral reef ecosystems by preventing a phase shift from coral to macroalgal dominated reefs. Our objective was to study the dynamics of parrotfish populations in response to the lionfish invasion in the Caribbean. Using published literature to obtain recent demographic parameters for both the lionfish and parrotfish, we developed an age-/stage-structured population dynamics model for each species, and finally integrated the two models by adding negative effects the lionfish population had on the recruitment rate of the lionfish model. The integrated model was used to quantify the potential effects of lionfish invasions on parrotfish population dynamics on coral reefs in the Caribbean. After 120 months post-invasion, projections show that the parrotfish population will be on the onset of decline, while the lionfish population will continue to grow exponentially. If the lionfish invasion continues at its current rate, our model suggests that there will be a direct 2 deleterious effect to the Scaridae population; potentially leading to the compositional downfall of the coral reef ecosystem as we know it.