Science & Tech · Science & Environment · 4 hrs ago
Invasive mussel found in a new stretch of Brazil’s São Francisco River
Researchers found 113 invasive golden mussels in a new stretch of the São Francisco River in northern Minas Gerais, Brazil.
The mussel comes from Asia and reproduces quickly, forming dense colonies on underwater surfaces.
The new finding is about 1,000 kilometres from the nearest earlier record in the river basin, near the Sobradinho dam.
The mussels were found in samples from São Francisco and São Romão, but not at sites sampled in Ibiaí, Pirapora or the Três Marias reservoir.
Dense colonies can block pipes and equipment used by hydropower plants, water suppliers and farms, increasing maintenance costs and potentially disrupting operations.
The species can also compete with native animals for food and space, affecting river ecosystems.
Researchers suspect small boats may carry the mussels over long distances, but this is a hypothesis based on the pattern of where they were found.
Researchers found 113 golden mussels at sites in São Francisco and São Romão, in northern Minas Gerais.
The discovery marks a new stretch of the São Francisco River about 1,000 kilometres from the nearest previous record in the basin.
The study was based on fieldwork conducted from July 2024 to April 2025 and was published in the journal Check List.
The invasive species can form dense colonies that obstruct water pipes, irrigation systems and equipment at hydroelectric plants.
Researchers say small boats may have transported the mussels over long distances, but this remains a hypothesis.
- Who
- Researchers from the State University of Montes Claros (Unimontes) recorded the mussels.
- What
- They found 113 golden mussels at sites along a new stretch of the São Francisco River.
- When
- The research was conducted from July 2024 to April 2025. The study was reported on October 22, 2026.
- Where
- In São Francisco and São Romão, in northern Minas Gerais, Brazil.
- Why
- The discovery raises concern because the invasive mussel can affect native species and obstruct water and power infrastructure.
This story does not have two clearly opposing sides.
Golden mussels reached South America, probably in ships’ ballast water entering the Rio de la Plata in Argentina.
The nearest previous record in the São Francisco basin was made near the Sobradinho dam, between Bahia and Pernambuco.
Researchers conducted five field expeditions and collected samples at 16 stations across four municipalities in Minas Gerais.
A study on the Tocantins River reported that mussel density had risen from 88 to more than 15,000 individuals per square metre over a year.
Reports on the Unimontes study described the new São Francisco River record.
- Mussels found
- 113 specimens
- New locations
- São Francisco and São Romão, Minas Gerais
- Distance from previous record
- About 1,000 kilometres
- Fieldwork period
- July 2024–April 2025
- Sampling effort
- Five expeditions at 16 stations in four municipalities
- Study journal
- Check List
3 sources
What people are saying
With the presence of the invasive species, we could face serious economic losses, because the golden mussel can compromise and obstruct water intake and irrigation pipes, the pipes of hydroelectric plants, and damage fishing nets.
This is the first record of the species in the Upper Middle São Francisco. The distance of about 1,000 kilometres from the previous occurrence point, near the Bahia-Pernambuco border, indicates a much faster and more complex expansion than imagined.