Abstract

First observed in Martinique in 2011, the red lionfish (Pterois volitans) has reached high densities in coastal waters of the island (480 ind/ha). The Marine Institute of Martinique (OMMM) initiated a monitoring program in 2013 to assess the efficacy of control measure efforts. Monthly lionfish culling were tested for one year on five reef patches ranging from 500 m2 to 2,500 m2. An average of 74 ± 13% of the observed population was removed each time. Despite consistent culling efforts, the lionfish population do not tend to be younger, neither to be smaller on contiguous reefs. Our results highlight how fast lionfish recolonize previously culled areas through recruitment and migration of juveniles and adults. Migration suggests low site fidelity and larger mobility of juvenile and adult lionfish compared to other invaded regions. On isolated patch reefs, regular culling tends to decrease lionfish abundance significantly while on continuous reef, such efforts maintain lionfish density ranging from 100 to 200 lionfish per hectare. Culling data collected from dive centres on two different sites for a period of two years revealed that with a constant culling effort frequency for two years (weekly and monthly respectively), the number of lionfish captured per dive doubled significantly from 2012 to 2013 at Batelière and a 4-fold significant increased capture rate at Cap Salomon. More studies are needed to assess deep lionfish population and migrating patterns of lionfish from the depths to the shallows, especially in volcanic islands.

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