Bioenergetics and trophic impacts of the invasive Indo-Pacific lionfish.

Indo-Pacific lionfish, the Red Lionfish Pterois volitans and the Devil Firefish P. miles, are nonnative marine fish that have invaded the western North Atlantic Ocean, Caribbean Sea, and Gulf of Mexico. Rapid population growth of this invasive predator threatens native fish communities. A bioenergetics model was developed for lionfish (i.e., both species) and then applied to estimate the potential impact of these predators on a reef fish community. We conducted a series of laboratory trials to evaluate consumption and respiration rates between 14 degrees C and 32 degrees C for lionfish weighing from 20 to 400g. Water temperature greatly influenced consumption; mean daily consumption rates increased from 14 degrees C to 29.7 degrees C and declined at 32.5 degrees C. Energy density of the prey was the most sensitive parameter in the model and estimates of food consumption corresponded with empirical and laboratory estimates. To realize population-level impacts, we applied the bioenergetics model to a size-structured virtual population of 393 lionfish/ha on a reef in the Bahamas. Model simulations estimated that this population would annually consume 929kg of prey/ha when feeding at 60% of maximum consumption. This model provides the first comprehensive assessment of lionfish bioenergetics accounting for the effects of size and temperature on prey consumption and improves the capacity to evaluate the trophic impacts of lionfish in the Atlantic Ocean.