Food ecology in Amazonian rivers: temporal and spatial evaluation

Abstract

The overexploitation of fishing resources, added to impacts such as changes in habitat, has occurred in several places around the world, directly affecting not only fishing stocks, but also the trophic web and human populations that depend on fish for their food and income. As a consequence, in the tropical regions, where multispecific river fisheries occur, there may be a reduction in the size of the fish caught over time and also loss of diversity. In the Brazilian Amazon, there is already evidence of a reduction in the capture of the largest species and replacement by smaller species. The objective of this project is to analyze spatio-temporal changes in the consumption of Amazonian fish, using riverine communitiesas a reference. The emphasis of this study includes synchronic and diachronic comparisons regarding fish availability and fish consumption by riverine inhabitants, among four different periods between 1981 and 2021 (Rio Negro) and among the different rivers listed as follows. This study will focus on the region between Manaus and Novo Airão, for which there are historical records of naturalists, in addition to previous studies by the team itself for the years 1981, 2000, and 2016 (to be compared temporally with data to be collected in 2022). Eventual patterns of change in fish consumption will be compared to geographically distinct regions, in the states of Acre, Amazonas, Pará, Tocantins and Maranhão, for which we also have specific data in the period, including: Anavilhanas, Rio Unini, AM (tributary of Rio Negro , Japurá River, Mamirauá Sustainable Development Reserve, AM, Araguaia River, GO, Tocantins River, TO, MA and PA (Low and Medium Tocantins), and Alto Juruá Extractive Reserve, AC. The study also intends to verify the temporal variation in the maximum size and trophic level of fish species consumed in Rio Negro, in addition to comparing fish consumption with the composition of the ichthyofauna, using data from the literature. The interviews will be conducted in communities with 10 houses or more. Given the history of fishing exploitation, urban development, deforestation in the Amazon region and implementation of protected areas (eg, Anavilhanas National Park), we hope that historical, temporal and spatial comparisons could indicate variations in the frequency of consumption of animal protein of the riverine communities. Such comparisons may also indicate the variation in the diversity of fish used due to the possible scarcity of priority species, replacement of more common species in the diet, influence of the greater distance from the villages to the fish catching places for subsistence, in addition to the maximum sizes and level trophic of the fish consumed. (AU)