NCCOS and their partners have developed a new method for detecting ciguatoxins in fish that does not rely on the typical use of radioisotopes, which are highly regulated and often unavailable in remote tropical regions where ciguatera incidence is high.More than 50,000 people suffer from ciguatera fish poisoning each year by consuming fish tainted with ciguatoxins produced by the algae Gambierdiscus, making this the most common form of algal-induced seafood poisoning.

The commercialized ciguatoxin test kit, transitioned through the women-run company SeaTox. Credit: NOAA

The new method - a fluorescent receptor binding assay (RBA) - is non-toxic, non-radioactive, and reduces screening time from two-and-a-half days to only three hours compared to the current radioisotope method. The assay yields the same results as the current test, and, since the assay uses commonly available equipment, it can be more easily added to seafood safety monitoring programs in tropical island nations.

Color micrographs of Gambierdiscus, an algae widely distributed in the Caribbean, Gulf of Mexico, and the southeast Atlantic coast that produces ciguatoxins. Credit: NOAA.​

The RBA method is currently being used to screen ciguatoxin concentrations in invasive lionfish in the Caribbean. Lionfish are causing extensive damage to reefs in the region, and policy decisions regarding whether fishing can be used to control this invasive species will depend on the levels of ciguatoxin lionfish accumulate.

SeaTox researcher Dr. Jennifer McCall demonstrates using the ciguatoxin test kit. Credit: NOAA

The new assay, expected to be implemented worldwide, is the resultof a collaboration among NOAA, U.S. FDA, Institut Louis Malardé, North Carolina State University, and the University of North Carolina at Wilmington. Partial funding for the project was provided by the NCCOS ECOHAB program. The RBA method is described in the scientific journal PLOS ONE , and will soon be available as a test kit from Sea Tox Research, Inc., a women-run biotech company.

For more information, contact Rance.Hardison@noaa.gov.