Abstract

The lionfish, Pterois volitans, population in South Caicos, Turks and Caicos Islands has been regularly monitored recording relative abundance and collecting specimens since the first individual was observed in 2007. Lionfish have been found in shallow and deep habitats, including mangroves, seagrass beds, patch and deep (> 15 m) reefs. Individuals from shallow habitats are significantly smaller than those from deep, indicating a possible ontogenetic shift. Eighty-five percent of the specimens collected had food in their stomachs and appeared to eat throughout the day. Despite control efforts, the densities and size of lionfish appear to be increasing in deeper reef habitats where large aggregations of mature individuals are regularly observed. Collections in 2011 at deep sites along South Caicos revealed 25% of the fish were ripe females compared to 0.03% in 2010 which suggests a potential increase in the breeding population. In addition, specimens caught by fishermen in 2010 and 2011 from more distant cays, only 0.04% were ripe females, which may reflect a difference in the characteristics of the reefs from which they were collected. Concurrently, native species that may be the only predators and competitors of lionfish are showing signs of exploitation. Data from finfish landings since 2008 reveal significant reduc-tions in standard length and size class distributions of grouper and snapper species. The establishment of a lionfish fishery in South Caicos could be an essential management effort needed to control the expanding population and alleviate pressure from the native species.