Nicinha was a leader of the MAB fighting for the rights of the people displaced by the Jirau dam, denouncing the effects of the dam on fishing activity in the Madeira River. In 2011, the "ribeirinha" community of fisherfolk of Mutum Paraná, in the district of Porto Velho, upstream from the city of Porto Velho on the Madeira River, near Abuna on the border with Bolivia, was displaced because of flooding from the reservoir of the hydroelectric dam of Jirau, owned by Energia Sustentável do Brasil (ESBR). The community was in theory relocated in a place called Nova Mutum Paraná, a housing project for up to six thousand inhabitants, meant for people displaced. The relocation process did not go well - some of the houses were commercialized  in favour of other people. Faced with a precarious situation, a group of families affected by the dam, occupied empty houses in Nova Mutum Paraná, in 2014. The settlement, that already suffered from water logging and lack of drinkable water, was submerged by a terrible flood along the whole Madeira River in 2014. In this context of adversities and injustices, Nilce de Souza Magalhães, better known as Nicinha, became a local leader of the MAB, the Brazilian movemement of "atingidos por barragens", those affected by dams. She had arrived in Porto Velho 50 years before, as a child from a seringueiro family in Acre. Together with two colleagues, Lurdilane Gomes da Silva (Ludma) and Iza Cristina Bello (Índia), they formed a Comissão de Defesa da Ocupação, and with help from the attorney general (Ministério Público) of the state of  Rondônia, some local politicians and the MAB they confronted the firms controllings the dams, defending the rights of affected families. Over the years several claims were made, thanks to the leadership of fisher folks who participated in public hearings and demonstrations pointing out the serious impacts made on fishing activity in the Madeira River. The accusations led to two civil investigations carried out by the Federal and State Public Prosecution offices. One is regarding the non-implementation of the state’s program to support fishing activity. The second investigation of a more criminal nature points to the data manipulation in monitoring reports of fishing activity in the Madeira River.

Displaced fisherfolk from the Jirau dam in Porto Velho fought to get a better deal, with support from the Movimento dos Atingidos por Barragens. Those from Mutum Paraná were to be displaced to Nova Mutum. This resettlement programme failed. One of leaders of the displaced, Nicinha, was cruelly killed in January 2016.