A study of the frequency of ciguatoxicity in the Main Hawaiian Islands nature of variability associated with different seasons

摘要

Decades following its introduction, the peacock grouper (Cephalopholis argus) developed a reputation for causing ciguatera fish poisonings in Hawaii. This study examined the frequency of ciguatoxicity in this carnivorous reef species, and the nature of variability in ciguatoxicity associated with season, location (i.e., island : island, leeward : windward), temperature, and specimen size. Overall, 36.4% of the 1,447 specimens were positively ciguatoxic. The frequency of ciguatoxic fish showed only modest seasonal differences. No sampled portion of any coastline was free of ciguatoxic fish. The frequency of ciguatoxic specimens from leeward areas (38%) was roughly twice that for windward areas (18%). Roughly 50% more samples were collected from leeward areas; such disproportional fishing effort in leeward areas contributes to an exaggerated public perception of ciguatera differences between leeward and windward areas. Though there was a higher frequency of ciguatoxic fish in larger specimens, there was no correlation between the calculated ciguatoxin concentrations and fish body weight. These ciguatoxicity-size data refute the popular expectation that the smaller specimens should be safe to eat. The average thermal regime showed negligible (<0.2°C) differences between windward and leeward areas, and only modest (~2.1°C) seasonal variation. We conclude that seasonal and/or spatial differences in temperature are of insufficient magnitude to elicit a perceptible change in the propensity for ciguatoxic fish in the Main Hawaiian Islands such as has been observed in Caribbean and South Pacific localities.