Total mercury levels in invasive lionfish, Pterois volitans and Pterois miles (Scorpaenidae), from Florida waters

Indo-Pacific lionfish, Pterois spp., are opportunistic carnivores that have established invasive populations off the southeastern United states, The bahamas, the caribbean, and off the northern coast of south America. because lionfish have few natural predators in their invasive range, a proposed option for controlling populations and limiting ecological damage is to establish directed fisheries for the species and promote their consumption by humans. However, carnivorous marine fishes can contain high levels of mercury, a toxic, heavy-metal pollutant that can cause neurological and behavioral impairment in humans. We analyzed total mercury levels in dorsal muscle tissue from 260 lionfish collected along Florida's Gulf of Mexico and Atlantic coasts. Fish were collected from offshore waters corresponding to four coastal regions—the southeast Atlantic, the Florida Keys, the southwest Gulf of Mexico, and the Florida Panhandle. Fish ranged in size from 63 to 262 mm standard length (mean = 153 mm), and mercury levels ranged from 0.01 to 0.34 mg kg^–1 (mean = 0.07 mg kg^–1). The mean mercury level in fish larger than 180 mm standard length, which are commonly represented in Florida's commercial fisheries, was 0.09 mg kg^–1. Mercury levels increased logarithmically with fish length in all regions. Mercury levels did not differ between males and females, but there were differences among regions, with the greatest concentrations seen in fish from the Florida Keys and highest bioaccumulation rates from the southwest Gulf of Mexico study region. Mercury levels in lionfish were similar to those in marine and estuarine species that fall under Florida's least restrictive consumption advisory levels for the general human population.