Isotope data for food consumption of riverine dwellers in the central Amazon region
In this study, we considered how landscape variables impacted food consumption by comparing fingernail isotopic ratios of individuals in the rural settlement of Costa do Caldeirão located in the floodplain (várzea) of the Solimões River, and in the rural settlement of Paquequer located in a non-flooded area (terra-firme) near the Madeira River banks. A total of 70 fingernails were sampled for carbon and nitrogen isotopic analysis during the low water period and again during the high water period from the same residents of the várzea and terra-firme. The consumption of C4-like resources (e.g. frozen chicken and canned meat) increased in both rural settlements during the high water period when C3-like resources (fish, cassava, rice, beans) are less available due to the flooding of lowland areas, but this difference was more pronounced in the terra-firme. The higher consumption of C4-like resources in the várzea compared to the terra-firme shows how seasonal flooding is a key factor influencing food security and health, due to stark variations in river water levels.