The researchers interviewed fishers in 18 coastal communities and along four Amazonian rivers. Begossi and colleagues interviewed adults as well as observed them on fishing trips, noted their diet, and the medicinal uses of fish.
The group discovered certain fish species, especially ones that predated other fish, were the most often mentioned as taboo, along with scaleless fish and Black prochilodus, a species that feeds at the bottom of rivers. Other species the communities avoided included catfish and piranha. The marine fishers on the Atlantic forest generally avoided tuna, rays, and sea catfish.
The researchers especially noticed that food taboos were different, depending on people's health status. Predatory fish are often tabooed for the ill, while fish that eat plant matter, invertebrates, or are omnivorous are recommended for consumption for ill people. These taboos held true for both the Amazonian fishers as well as the Atlantic Forest fishers.
According to Begossi, "Fish food taboos may have indigenous roots, or they may have been diffused through Portuguese colonists' contacts."
Food chain characteristics may help explain human food taboos, say the researchers. Most of the species avoided for the ill include species high on the food chain. These fish are more likely to accumulate toxins. The prohibitions on these species may be biologically adaptive for the people, suggest Begossi and colleagues.
Journal
Ecological Applications