The Madeira fisheries region includes the stretch of the Madeira River from the confluence of Mamoré and Beni rivers to the Aripuanã River. The main fishing port is Porto Velho, the capital of Rondônia, Brazil. The Lower Madeira is exploited mainly by the Manaus fishing fleet, as it is closer to that city than to Porto Velho.

Data are available only for Porto Velho, a city of 426,000 people. Catches are sold mostly in Porto Velho and to a much lesser extent in other cities in Rondônia. The situation was different in the 1970s when refrigeration plants were constructed to export catfish to the southern Brazilian states of São Paulo and Paraná. Yields from the Madeira River, however, were insufficient to sustain long-term export fisheries. Fisheries catches peaked in the early 1970s before accurate data were recorded and the data below represent the period after that for which there are accurate statistics.

The population of Rondônia grew very rapidly after the late 1970s because of large-scale colonization initiatives provided by the Brazilian government to promote agricultural development. Between 1970 and 1980, Rondônia’s population increased sixteenfold. Annual catches sold in Porto Velho increased until 1986, when they reached 1,600 tons. Much of this fish, however, may have come from the Upper Madeira region that includes Brazilian and Bolivian waters, the Purus River, and elsewhere because of the new road network that connected various river basins. Since the mid-1980s catches sold in Porto Velho have decreased by about half, with occasional years (1993 and 1998) when 1,400 to 1,700 tons have been recorded. Peak years may represent imports from other regions.

Ninety percent of the catch sold in Porto Velho consists of 11 species, of which migratory characins are the most important. Curimatã, tambaqui and matrinchã represent approximately half of the total. They are exploited mainly while migrating in river channels, but also in floodplain lakes.

River channel fisheries in the Madeira River also target dourada, which accounts for 9% of total catch sold in Porto Velho. The Cachoeira de Teotônio, a large cataract 20 km upstream from Porto Velho, has traditionally been an important site for catching dourada and other migratory catfish species but has now been drowned by the new Santo Antônio Dam just downstream.