![\"Indigenous](\"https:\/\/dialogue.earth\/content\/uploads\/2025\/07\/20250717_Belo-Monte-Xingu-Brazil_map_EN-v2.jpg\")
<\/div>\u201cBecause we live here, we were born here, we grew up here; we know the region very well. So, if anything changes, we notice it very quickly,\u201d says Josiel Jacinto Pereira Juruna, the report\u2019s lead author. He is also the vice-leader of Miratu, a village of around 90 people on the Xingu\u2019s west bank. \u201cOur elders warned us that over time this would happen. And once the dam opened, it did.\u201d<\/p>\n\n\n\n
These riverside communities say they are no longer able to depend on the river\u2019s natural flooding cycle.<\/p>\n\n\n\n
Distrustful of the official impact assessments produced by the dam operators, members of the communities have been conducting independent research since 2013. As part of these efforts, Juruna co-created an organisation, the Independent Territorial Environmental Monitoring of the VGX (MATI-VGX), in 2022.<\/p>\n\n\n\n
Norte Energia<\/a>, the private consortium that built and operates the dams, disputes many of the claims made in the study. It argues the dams \u201cdo not promote drought in the Xingu\u201d. It also insists that changes documented by the researchers were considered before construction began and are being dealt with.<\/p>\n\n\n\n It told Dialogue Earth: \u201cThe monitoring carried out by MATI-VGX, despite having relevant methodological gaps, has indicated changes that were already foreseen in the environmental licence and for which Norte Energia is developing mitigation and compensation actions.\u201d Norte Energia did not elaborate on these methodological gaps.<\/p>\n\n\n\n The community monitoring programme installed water-level gauges at nine piracema <\/em>sites. These are the seasonally flooded habitats that are crucial for fish reproduction, feeding and shelter. The stations followed protocols used by Brazil\u2019s National Water Agency (ANA<\/a>), as part of a drive to combine scientific rigour with local ecological knowledge about fish behaviour and spawning.<\/p>\n\n\n\n \u201cThe monitoring is done daily or weekly, by the local monitors, who are Indigenous people and riverside dwellers who live in the affected region,\u201d says Camila Cherem Ribas, a senior researcher at the National Institute for Amazonian Research (INPA<\/a>) in Manaus, and a co-author of the paper.<\/p>\n\n\n\n In natural conditions, the South American monsoon system triggers river flooding that begins in November. Many fish begin to spawn in December, when water levels reach critical thresholds. The Conservation Biology paper says the dams\u2019 water diversions delay this flooding by between one and four months.<\/p>\n\n\n\n According to the research, at one piracema <\/em>near Z\u00e9 Maria Island, fish require water levels of at least 103cm to enter spawning areas. This level was not reached until February in 2022 and April in 2023 \u2013 long after the natural spawning season should have begun. The paper argues that these delays either prevent spawning entirely, or cause fish eggs and larvae to die due to insufficient water, food availability and shelter.<\/p>\n\n\n\n \u201cIt is forbidden to flood Indigenous land, but drying out Indigenous land is not in that law,\u201d says Ribas. \u201cThese environments have unique characteristics and depend on the flooding cycle. So, the lack of flooding starts to kill the environment. The Indigenous people clearly noticed this.\u201d<\/p>\n\n\n\n Norte Energia\u2019s statement says its own studies with local fishers have identified 140 existing piracema <\/em>areas in the Volta Grande do Xingu: \u201cAs foreseen in the environmental impact assessment, a large part of these areas will be flooded at the start of the season, guaranteeing suitable conditions for the reproduction of many species. Furthermore, it is important to note that several species of fish do not depend on the piracemas <\/em>to reproduce.\u201d<\/p>\n\n\n\n This disruption of the flooding affects the broader ecosystem, according to the communities\u2019 research. Most trees in seasonally flooded forests typically synchronise their fruiting with rising water levels, providing crucial food for aquatic animals and allowing their seeds to be dispersed by fish. When flooding is delayed, fruits fall before water arrives, breaking this essential ecological connection and reducing food availability for fish and other aquatic animals.<\/p>\n\n\n\n \u201c[The locals] not only collect the data, they also decided what needed to be monitored, what the strategies should be,\u201d explains Ribas. \u201cWhen they decided what should be monitored, they had much more ecological vision than traditional scientific monitoring, which is very compartmentalised in western science.\u201d<\/p>\n\n\n\n Fishing yields in local communities also saw a dramatic decline. The researchers compared data collected by Norte Energia before the dam was operational (2001-2008) to the communities\u2019 post-dam data (2020-2023). The overall catch per unit effort figure dropped from 11.1kg per fisher per day before 2009 to 4.53kg from 2020.<\/p>\n\n\n\n Catch per unit effort (CPUE) is a metric<\/a> used in fisheries science to try and establish fish abundance in a given location. It measures how much effort is required to catch a certain amount of fish. Fish can be measured by number or weight, while effort is measured depending on the fishing technique. For example, fish caught per 1,000 hooks per day or per hour of trawling.<\/p>\n<\/div><\/div><\/div>\n\n\n\n Average catches plummeted. Pescada (Plagioscion<\/em>) catches dropped from nearly 100kg per fishing trip to 1.66kg, whilst curimat\u00e1 (Prochilodus nigricans<\/em>) declined from 68kg to 5.4kg.<\/p>\n\n\n\n The composition of catches changed significantly. Tucunar\u00e9 (Cichla<\/em>), a large fish native to the Amazon, previously made up 29% of catches. This has fallen to just 5.5%, according to the community monitoring data.<\/p>\n\n\n\n These changes forced adaptations in fishing practices. For example, instances of gillnet catches among the Altamira commercial fleet, representing the primary city in the area affected by the dams, increased from 22% to 47%.<\/p>\n\n\n\n A vertical wall of netting kept upright by floats and weights. The mesh size of gillnets are chosen depending on the target species, though bycatch is a recurrent problem. Gillnets are used all over the world in both small- and large-scale fisheries.<\/p>\n<\/div><\/div><\/div>\n\n\n\n Meanwhile, hook-and-line fishing declined from 47% to 35%. Gillnets are often reported to be a less sustainable fishing method<\/a> than hook-and-line, due to the amount of non-target species they can inadvertently snare. <\/p>\n\n\n\n Norte Energia says: \u201cMost species have maintained the proportion of mature fish over 13 years of study in the Volta Grande do Xingu region. Some species had changes in their reproduction pattern, a scenario foreseen in the project\u2019s environmental impact assessment. However, no fish species have become extinct in the areas of influence of the project.\u201d<\/p>\n\n\n\n \u201cMany of the harms of Belo Monte were underestimated in the formal [environmental impact assessment],\u201d counters Eve Bratman, a professor of environmental studies at Franklin and Marshall College in the US. She was not involved in the Conservation Biology paper.<\/p>\n\n\n\n \u201cScholarly researchers and community members had completely predicted that the dam would be an ecological disaster as well as a social tragedy,\u201d she adds. \u201cIt was absolutely preventable, had the government and its contractors done a better job of listening to civil society voices from the get-go.\u201d<\/p>\n\n\n\n The communities\u2019 study proposes specific criteria for a new operational framework for the power plant and the region. It balances energy production with ecological respect. For example, matching the river\u2019s dam-controlled water levels to fluctuations that would have occurred naturally, supporting fish migration and synchronising flooding with the natural fruiting periods of riverine vegetation.<\/p>\n\n\n\n Both the local researchers and their academic colleagues say policy change is necessary. Hydropower is presented as a green option, vital to reducing fossil-fuel emissions, and Belo Monte is estimated to represent around 5%<\/a> of Brazil\u2019s electricity-generation capacity. But the researchers say their study shows hydropower has consequences that are often neglected.<\/p>\n\n\n\n \u201cIn the Amazon, at least, hydroelectric energy is not clean energy,\u201d says Ribas. \u201cThe environmental and social costs are very high. The Amazon depends on the flood cycle and dams, by nature, interrupt it. We think a change in the sharing of water in the Volta Grande is the only option.\u201d<\/p>\n\n\n\n Norte Energia strongly defends its project\u2019s environmental credentials:<\/p>\n\n\n\n \u201cThe amount of water earmarked for the Volta Grande do Xingu was studied and established by the Brazilian government as part of the concession auction [for the dams] and is an integral part of the environmental licensing process. The current model was developed based on 11 different hydrological scenarios evaluated in the environmental impact assessment and is an environmental mitigation measure, with the aim of ensuring, among other things, the flooding of the piracema <\/em>areas and the maintenance of the river\u2019s ecological cycles.\u201d<\/p>\n\n\n\n Norte Energia says its monitoring meets the criteria established by Brazil\u2019s environmental regulator, the Brazilian Institute of the Environment and Renewable Natural Resources (Ibama<\/a>). Furthermore, the consortium says its research has resulted in 36 scientific articles in national and international journals and 39 abstracts presented at academic conferences.<\/p>\n\n\n\n Norte Energia says it has taken mitigatory action including compensation to protect and maintain reproductive and feeding sites for fauna; setting up ecology and fish-reproduction laboratories; restoring vegetation to maintain reproduction and feeding environments; strengthening subsistence production actions with riverside families and fishers; and improving water supply and sewage systems. The company says its socio-environmental investments in the region total BRL 8 billion (USD 1.4 billion).<\/p>\n\n\n\n Ibama, meanwhile, tells Dialogue Earth that it \u201ccontinuously monitors compliance with the environmental conditions established in the Belo Monte hydroelectric power plant licence\u201d by \u201cmonitoring data generated by the programmes provided for in the licensing process\u201d.<\/p>\n\n\n\n Ibama continues: \u201cTo date, the aforementioned document and the data produced by the MATI-VGX Programme have not been included in the records of the Belo Monte hydroelectric power plant licensing process, which makes it impossible for Ibama to make any technical statement.\u201d<\/p>\n\n\n\n Whatever happens with Belo Monte\u2019s piracema <\/em>sites, the researchers hope their collaborative model for monitoring them will spread.<\/p>\n\n\n\n Juruna says he hopes this partnership of riverside communities, Indigenous people and scientists can become a reference for other studies, to show that science can incorporate the local knowledge of traditional peoples.<\/p>\n\n\n\n Beyond this, Juruna hopes for national solidarity:<\/p>\n\n\n\nWaiting for the floods<\/h2>\n\n\n\n
It is forbidden to flood Indigenous land, but drying out Indigenous land is not in that law<\/blockquote>Camila Cherem Ribas, a senior researcher at the National Institute for Amazonian Research (INPA<\/a>) in Manaus<\/cite><\/div><\/div>\n\n\n\n
![\"hydropower](\"https:\/\/dialogue.earth\/content\/uploads\/2025\/07\/Belo-Monte-hydroelectric-power-plant_Roney-Vieira_Flickr_53970374222-scaled.jpg\")
<\/div>Catching less<\/h2>\n\n\n\n
No fish species have become extinct in the areas of influence of the project<\/blockquote>Norte Energia<\/cite><\/div><\/div>\n\n\n\n
Monitoring and mitigation<\/h2>\n\n\n\n
![\"An](\"https:\/\/dialogue.earth\/content\/uploads\/2025\/07\/Yudja-man_Pedro-Prado_Flickr_45112132044.jpg\")
<\/div>Integrating traditional knowledge<\/h2>\n\n\n\n