Abstract:
Following recommendations made by a brief ecological study of the invasive Lionfish (Pterois volitans) in Anguilla during 2014, the Department of Fisheries and Marine Resources (DFMR) undertook an extensive year-long population assessment for the species between July 2015 and July 2016. Biometric and stomach content analysis were also carried out for captured individuals, thus building upon the 2014 dataset. The present study found P. volitans could sustain themselves successfully on a mixed diet, or one even completely based on crustaceans, suggesting habitat flexibility and resource generality aids its invasion potential. The mean size of P. volitans in Anguilla appears to be increasing, a natural phenomenon expected while a species is establishing itself in an area. Despite this, populations are relatively low on most shallow reef areas. A number of ‘hotspots’ were however identified where P. volitans settlement appears more frequent than other areas, as even after eradication efforts they soon repopulate: Crocus Bay, Meads Bay, Anguillita and West Cay (Dog Island). Based on past habitat health mapping and other ecological survey work, P. volitans numbers in Anguilla appear to closely match areas with ‘reasonably high’ habitat health, thus their presence and/or abundance may serve as a habitat health indicator. Thus it is likely populations recorded are due to a combination of eradication efforts by DFMR and local dive operators; recreational spearfishing by residents; fishing activities by commercial fishers; and habitat suitability and/or quality. Populations on some of the wrecks were low, probably due to eradication efforts by dive operators, whereas other wrecks were also considered ‘hotspots’. Reports suggest that P. volitans populations are increasing on offshore fishing grounds where eradication efforts are not possible. However, these populations are helping to sustain supplies for a growing demand from the restaurant industry. Even though it is recognized that P. volitans are here to stay and should to be recognized as a fishery in its own right, certain management recommendations can be made to give the ecosystem time to naturally acclimatize to this highly successful and adaptable invader: DFMR eradication efforts should continue at ‘hotspots’ and recreational swimming areas; dive operators should continue to be encouraged to remove P. volitans from wrecks and other dive sites; fishers should continue to be encouraged to target P. volitans for a growing restaurant driven market; outreach materials (i.e. informative posters) should continue to be distributed as necessary, with future design revision made as appropriate.
