The Brazilian Institute of Environment and Renewable Natural Resources (Ibama) has officially designated the pirarucu fish as an invasive species in the region above the Santo Antônio dam on the Madeira River, located in Porto Velho. This regulatory change, published in the Official Gazette, allows for the capture and killing of pirarucu without any restrictions on quantity, size, or time of year. This move is part of broader efforts to control the population of the species in the area, as invasive species can have significant ecological impacts.

With the new guidelines, both professional and artisanal fishermen are now permitted to catch pirarucu without limitations, meaning there is no cap on the amount they can extract from the river. Additionally, any caught pirarucu in this designated area must be slaughtered; they cannot be returned to the water where they were caught. This creates a significant shift in fishing practices for the region, as previously there may have been regulations aimed at conservation or management of fish populations.

Moreover, the commercial distribution of pirarucu is restricted; fishermen can only sell the caught fish within the same state where they were captured. Any pirarucu transported to another state will be confiscated. The ruling also allows local governments to promote fish farming initiatives, aiming to control the impact that the invasive species has on local ecosystems, while also trying to benefit local economies through regulated fishing practices.