DAMING IN THE HIDRO WEB AS PREDICTORS OF CHANGES TO FISHING PRODUCTION IN THE GUAPORÉ RIVER BASIN (RONDÔNIA, BRAZIL)
Amazon region, Guaporé river, fishery landings, dams.
The Amazon basin has a vast network of river channels, housing the greatest ictic diversity in the world. However, these aquatic ecosystems demand measures that guarantee their conservation and preservation in the face of growing anthropogenic activities that may be acting as environmental filters, changing the distribution and abundance of fish species native to this region. Therefore, the monitoring of the commercial fishing landings records can provide useful information to complement and strengthen the management of the fishing activity, having been considered for this study a section of the Guaporé River (tributary of the Madeira River), where they were verified, through the records seasonal effects of local fisheries production if there are patterns that indicate possible changes in fisheries between the periods Pre and Post construction of hydroelectric projects in the Madeira River basin and fish farms installed in river corridors in the state of Rondônia. Thus, the objective of this study was to analyze the variation of fisheries production in view of the seasonality of the level of the Guaporé river and the trophic plasticity, using information contained in the records of fisheries landings in the fisheries colonies of the area under study, considering two Pre-damming periods 2000 to 2008) and Post-damming (2009 to 2019) of the Madeira River by the hydroelectric projects of Jirau and Santo Antônio as well as the existing dams for the practice of fish farms. Obtaining more in-depth knowledge about the influences of water network dams on fish assemblages in the Guaporé river basin is of fundamental importance for the production of relevant information for the development of strategies aimed at the management of aquatic environments. Thus, the present research tested the following hypotheses: i) there are no changes in preference for fish species in the fisheries in the Guaporé River basin, which can be perceived through the trophic levels of the species recorded in the landings that occurred in the decades Pre and Post the year 2009; ii) The dams of rivers and streams in the state of Rondônia do not affect fisheries production between the periods Pre and Post the peak of their facilities. The results showed significant differences between the values of ictic productivity, phases of the hydrological cycle of the Guaporé River and in the reorganization (trophic plasticity) of the diversity of fish, which occurred in the periods Pre and Post-dams, indicating that the water dams are negatively influencing stocks fisheries in that region.