Evaluating the catch efficiency of Antillean z-traps on invasive Indo-Pacific lionfish (Pterois volitans and P. miles)

The Indo-Pacific lionfish are a highly invasive marine species that pose a serious threat to marine biodiversity, native fish communities and habitats in the Atlantic, Gulf of Mexico and the Caribbean. Current management strategies mainly consist of continuous, targeted removals by SCUBA divers via pole spears, however this method is limited to depth, time and air supply. The purpose of this study was to evaluate the capture efficiency of the invasive lionfish by Antillean Z-traps, aiming to see if this is a viable alternative removal effort. Traps were deployed throughout Biscayne National Park and the Florida Keys National Marine Sanctuary using the park’s lionfish removal via pole spear data (June 2010 – July 2016) and a benthic habitat map of the park, in order to intersect locations that have a suitable substrate to deploy the traps and have a high probability of encountering lionfish. Traps were found to be ineffective in culling lionfish, however they did capture bycatch with an average catch per unit effort (CPUE) of 0.59 species per hour (or 14.22 species per 24 hours). The average CPUE found for removing lionfish via pole spear between June and October 2016 was 8 lionfish per hour, or 1 lionfish every 13 minutes. In order for traps to be worth further investigation they would need to, at minimum, capture 16 lionfish per day, which is the equivalent to a single day of diving (average dive time of 2 hours per day). Since traps were set for an average of 24 hours, the CPUE of lionfish caught, theoretically based on the average dive time and average CPUE for pole spears, needs to be approximately 192 lionfish per deployment to be comparable to pole spears, however, current densities in the area make this an unattainable goal