Abstract

In October 2009 lionfish (Pterois spp.) were first observed on Curacao and Bonaire, two sister islands in the Southern Caribbean, and within months the fish spread around these islands. Active elimination efforts were immediately started on Bonaire in October 2009, whereas Curacao started a similar eradication program in July 2011. While spear fishing is illegal on both islands, local authorities contracted local divers that were equipped with small modified spear guns designed to kill lionfish. In July 2011, we tested for the effectiveness of the control efforts by comparing the abundance of lionfish between fished and unfished sites on Bonaire and between the two islands as eradication efforts had not yet started on Curacao. On unfished Curacao, average lionfish biomass for various depth zones ranged between 5.2 g/m2 (15m) and 11.8 g/m2 (35m). On Bonaire, these values were on average 1.8 and 7.6 times lower respectively. The island-wide average lionfish biomass on Bonaire was 2.0 g/m2 contrasted to 8.4 g/m2 on Curacao. While lionfish abundance depends on habitat type, depth and the number of divers frequenting each zone, our results indicate that control efforts can be effective even after one year of implementation. These results indicate that effective control of invading lionfish on islands that have an active diving community is possible through involvement of this community in local control efforts.