Assessment of local lionfish (Pterois volitans) densities and management efforts in Bonaire, Dutch Caribbean
The Indo-Pacific lionfish Pterois volitans is an invasive species that was released along the U.S. Atlantic coast and spread to the Caribbean. Lionfish can inhabit a wide range of depths and they lack predation in their invasive range, leading to a successful invasion into their introduced range. Their large appetite combined with having no predators may pose an ecological threat to the Caribbean coral-reef ecosystem. Pterois volitans invaded Bonaire, Dutch Caribbean in 2009, and the extent of their presence and the impact they have upon the reefs surrounding Bonaire has yet to be investigated. Basic components to managing an invasive species are monitoring their occurrence and controlling their abundance. Around Bonaire, managers and diver volunteers catch and kill P. volitans to control their numbers in an attempt to reduce their negative impacts on the ecosystem. This study investigated the effectiveness of the current management strategy, P. volitans removal, by comparing their densities at frequented hunting sites with no-hunting sites. To achieve this, the densities of P. volitans at eight hunted and less frequented sites were calculated by searching for their presence in 50 x 4 m belt transects at five different depths (6 m, 12 m, 18 m, 24 m, 30 m) at selected sites along the west coast of the island. All P. volitans recorded were categorized into three size classes (small: 0-10 cm, medium: 11-30 cm, large: ≥ 30 cm). The results of this study show no significant differences between the densities of lionfish found at hunted sites (10/ha) compared to less frequented sites (16/ha). This study is the only known effort that attempts to determine the effectiveness of P. volitans removal from invaded areas in Bonaire.
This student research was retrieved from Physis: Journal of Marine Science IX (Spring 2011)19: 64-69 from CIEE Bonaire.