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

Abstract

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.

Update on Methodologies Available for Ciguatoxin Determination: Perspectives to Confront the Onset of Ciguatera Fish Poisoning in Europe

“…A CIEA format enabled a LOD of approximately 5 pg mL −1 of equivalent CTX per mg of extract (corresponding to 5 × 10 −12 M), which lies in the range of the neuroblatoma cell assay. Moreover, the CIEA yielded consistent results when compared to this assay using flesh extract of fish caught in natura or raised in aquaculture farm [ 149 , 150 ].…”

“…For instance, RBA values for CTX toxicity determination correlated well with those obtained using an analytical approach, MBA or CBA [ 4 , 146 – 148 ]. A comparative study between enzyme-linked immunoassay (ELISA) and CBA also indicated a high correlation between both methods [ 149 , 150 ]. The same remark applies to CTX determination using CBA in parallel with LC-MS/MS analysis [ 119 , 151 ].…”

Aquatic food animals in the United States: Status quo and challenges

“…Large carnivorous finfish, such as amberjack, snapper, grouper, and mackerel, which live in shallow tropical and subtropical waters, can accumulate CTX (Friedman et al., 2017). Around 4% of finfish from the U.S. Virgin Islands (Loeffler et al., 2018) and 7.4% of wild‐captured kahala fish from Hawaii (Campora et al., 2010) had CTX levels that exceeded the FDA action level. The CTX toxicity and profile were not significantly different between frozen and cooked finfish (Abraham et al., 2012).…”

Alternative Methods for the Detection of Emerging Marine Toxins: Biosensors, Biochemical Assays and Cell-Based Assays

“…When analyzing flesh fish, the most commonly used protocol for toxin extraction is a modification of that for MBA [ 91 ]. All protocols are based in acetone extraction, followed by evaporation and two solvent partitions with methanol:water and hexane, and ethanol:water and diethyl ether, to remove fatty acid and polar compounds [ 103 , 151 , 152 , 153 ]. Additional steps with solid-phase extraction (SPE) cartridges can be also performed for further purification [ 154 ] or instead solvent partition for rapidity [ 155 , 156 ].…”