LionfishTT

The invasive lionfish (Pterois volitans) was first sighted in Tobago’s waters in 2012. Since then its population has exploded, spreading to most coral reefs and hard bottom environments around the island; population densities as high as 326 fish/ha have been recorded for Charlotteville in North East Tobago (Alemu, 2016). The success of this invasive can be attributed to a number of life-history traits including its rapid growth rate, generalist voracious feeding habit, high fecundity, and its ability to thrive in a wide variety of habitats and depths. Additionally, lionfish are efficient hunters while they themselves remain unchecked with no known predators in the Atlantic. Venomous spines on the dorsal, anal, and pectoral fins serve as a deterrent to many potential predators. 

Lionfish impacts arise mainly from their generalist voracious feeding habits – they eat a lot and will eat anything once it can fit in their mouth.  With stomachs capable of expanding over 30 times the normal volume to accommodate prey, more than 80 different types of prey have been identified from their stomachs. Prey include juveniles of commercially important fish species such as groupers and snappers, and ecologically important species such as parrotfish. They also feed on commercially important crustaceans such as crabs, shrimps and juvenile lobsters. With nothing to keep their population levels in check, their glutenous eating habits can have ecological impacts ranging from a reduction in reef fish biomass, to an increase in algal growth due to herbivore removal, and changes to prey community structure. Overall, they can negatively impact coral reef health, fisheries, and tourism, if not controlled.

To date, in Tobago, the control of lionfish population abundance has been limited to mechanical removal via culling or spearfishing, in areas and depths accessible by free divers and SCUBA divers – methods which are both costly and labour intensive. Beyond these depths (>100ft) and areas, lionfish populations remain relatively untouched. Fishpot fishers that deploy traps in these deeper areas have reported the increasing occurrence of lionfish in their fishpots as bycatch; they have also expressed concern that lionfish maybe negatively impacting their fishery through a reduction in the biomass of targeted fish species. 

As a result, there have been suggestions to develop a commercial trap fishery to target these deeper water lionfish populations. Support for this venture comes from fishpot fishers that express an interest in targeting lionfish for commercial purposes, and several restaurants that have either included it on the menu or have expressed an interest in including it on the menu once a reliable supply could be sourced. Additionally, the use of fishpots, a more cost-effective passive fishing method in comparison to SCUBA may result in larger catches and a lower retail price.