About 90% of the commercial fishing landing in inland areas of the Amazon Basin is composed by migratory species. Overfishing and damming are major threats to these stocks. This project aims to implement an individual-based model to simulate the distribution patterns of two of these species, the piramutaba (Brachyplatystoma vailantii) and the dourada (B. rousseauxii). These large catfishes deserve special attention because they are the only freshwater fishes exploited by the fishing industry in Brazil and because they migrate over 3,000 km between the estuary and the white-water tributaries in the Upper Amazon. The model will be spatially explicit, representing the dendritic network structure, elevation, declivity, and flow patterns of the main rivers in the Amazon Basin. It will be modeled the process of movement, growth, reproduction and mortality at the individual level, and the patterns at the population level will be compared with catch data. In a second phase, simulations will be carried out to assess the population trajectories over different scenarios of fishing and damming. The results should provide subsidies to preserve these fish stocks, unifying information about basic biology, ecology and life-history that are currently dispersed in the literature. Moreover, the model aims to stimulate the application of this approach to other migratory fishes in different hydrographic basins in Brazil.
News published in Agência FAPESP Newsletter about the scholarship: