In an attempt to create new fisheries, more than 2,000 individuals of the peacock grouper from French Polynesia were intentionally released in Hawaiian waters during the 1950s.
The peacock grouper became established and populations expanded on Hawaiian reefs, but local consumers lost interest after a number of cases of human neurological disease were traced to ciguatera poisoning linked to the species.
In the meantime, peacock grouper populations have declined where they are commercially important and ciguatera free.
As part of their University of Hawaiʻi at Mānoa doctoral research, Jan Dierking, in zoology, and Cara Campora, in cell and molecular biology, revisited the peacock grouper. The research was funded by the National Oceanographic and Atmospheric Administration and UH’s Hawaiʻi Cooperative Fishery Research Unit and published in the April 2009 issue of Pacific Science.
The researchers took samples from nearly 300 fish, hoping to find patterns in geographical location, size or condition that would allow them to predict which populations or individuals were safe for human consumption. They found lower rates of toxic fish on Oʻahu reefs compared to the Big Island, and slightly higher concentrations of the toxin in larger fish.
Unfortunately, however, the wide variability in toxicity levels for individual fish precludes identification of safe-to-fish zones or safe-to-eat catch. A commercial ciguatera test kit exists, they note, but isn’t economically viable at a cost of nearly $11 per fish.
For now, the peacock grouper is likely to stay on the reef and off the dinner plate in Hawaiʻi.