Evaluating the Risk of Ciguatera Fish Poisoning from Reef Fish Grown at Marine Aquaculture Facilities in Hawai'i

摘要

Fish grown in open ocean aquaculture facilities from two commercial farms in Hawai'i were assessed for the presence of the marine toxin ciguatoxin. Facilities were surveyed for the presence of the marine benthic dinoflagellate, Gambierdiscus spp., which is known to produce the toxin. The dinoflagellate was detected in three submerged open ocean cages operated by Hukilau Foods (formerly known as Cates International Inc.) and one open ocean cage operated by Kona Blue Water Farms at relatively low levels averaging 142 cells Gambierdiscus spp./g algae, suggesting a low probability that fish cultured in open cages would be ciguatoxic. A total of 60 individual cultured almaco jack, Seriola rivoliana, or kahala, and 10 individual cultured Pacific threadfin, Polydactylus sexfilis, or moi, grown in open ocean aquaculture facilities have been examined for the presence of ciguatoxin using two methods: an immunoassay for detecting picogram levels of ciguatoxin in fish extract, and a neuroblastoma cell assay commonly used to screen for the presence of marine toxins in fish. Using the neuroblastoma assay, none of the cultured fish were found to contain ciguatoxin. Conversely, 81 wild-caught kahala were examined using both methods with 7.4% screening positive for ciguatoxin. These findings indicate that ciguatoxin is prevented from entering the culture process for both S. rivoliana and P. sexfilis raised in open ocean aquaculture facilities even when Gambierdiscus spp. is present.