STORY-TRÅD·ekonomi

Amazon home to over 2,700 species of fish, study finds

The Amazon basin is home to more than 2,700 species of freshwater fish – about 15 percent of all known species in the world. Approximately two-thirds of them are found exclusively in the region. The data can be found in the fourth edition of the report Peixes Esquecidos da Amazônia (“Forgotten Fishes of the Amazon”), led by The Nature Conservancy (TNC), which brings together information from over 50 experts representing 30 organizations. According to the authors, the Amazon is one of the world’s last major river basins where it is still possible to prevent large-scale biodiversity loss and maintain extensive, connected river systems. To achieve this, however, action must be intensified before more complex and costly restoration efforts become necessary, explains TNC scientist and lead author of the report Fernanda Silva. Notícias relacionadas:Deforestación cero en el 60% de las tierras indígenas de la Amazonía.List of threatened fish, invertebrates updated.Freshwater migratory fish rank among world’s most threatened species.“Around the world, conservation efforts are increasingly focused on restoring ecosystems after damage has occurred. The Amazon offers a different opportunity – to protect a freshwater system of global importance while it is still fully functioning,” Silva declared. The report combines scientific evidence with traditional ecological knowledge. This approach shows that fish are directly linked to the maintenance of ecosystems, food security, cultures, livelihoods, and the economies of the people living in the region. Fish help maintain the forest According to the survey, fish are indicators of a healthy Amazon and contribute to the forest’s functioning. Tambaquis, pacus, and matrinxãs, for example, enter flooded forest areas to feed on fruits and can disperse seeds over long distances. Other species transport nutrients and energy between aquatic and terrestrial environments. A decline in these populations can trigger a chain reaction affecting vegetation and animals that depend on fish, such as river dolphins, giant otters, and birds. River connectivity is another key element. The gilt-head bream (known in Portuguese as dourada), one of the species analyzed, undertakes the longest exclusively freshwater migration ever recorded. A single individual can travel over 11,000 km during its lifetime, connecting the headwaters near the Andes to the Amazon estuary. When these connections are severed, the impacts can be significant. On the Madeira river, for example, dams have blocked the dourada’s historic migration routes and contributed to the decline in fish stocks and the virtual disappearance of a historic fishing industry in the Cachoeira do Teotônio region. Biodiversity under pressure Despite this biodiversity, the study highlights significant gaps in our knowledge of Amazonian species. The International Union for Conservation of Nature (IUCN) Red List includes 144 threatened species in the region, while another 334 are classified as data-deficient. The lack of monitoring and collaboration among countries in the basin may mean that the risks are greater than currently understood. These threats act in combination. Hydroelectric dams, deforestation, pollution, and overfishing can disrupt river connectivity, fragment habitats, alter natural flow regimes, and degrade water quality. Climate change tends to exacerbate this scenario. Projections in the report indicate that annual river discharge could decrease by more than 40 percent in some key regions, such as the headwaters of the Madeira river. Prolonged droughts can hinder fish reproduction and migration, reduce the oxygen available in the water, and concentrate contaminants. In the Andes, rising temperatures also threaten endemic species adapted to cold waters. Gold mining adds another source of pressure. According to data compiled in the study, artisanal gold mining accounts for 83 percent of mercury emissions caused by human activities in South America. The contaminant collects in the food chain, and fish consumption is identified as the primary route of human exposure to mercury in the Amazon. Fish and food security River conservation also has a direct impact on Amazonian populations. In some remote riverside communities, fish consumption exceeds 600 grams per person per day. Fish is among the most accessible sources of animal protein for low-income families and provides important nutrients for development and health. Fishing also drives the regional economy, although a significant portion of the activity does not appear in official statistics because it is artisanal, small-scale, or subsistence-based. At least 200 species are caught commercially, while the ornamental fish trade exports tens of millions of specimens per year and supports thousands of families. The report also highlights women’s participation in the various stages of the supply chain and in community associations. River conservation also has a direct impact on Amazonian populations. In some remote riverside communities, fish consumption exceeds 600 grams per person per day - Nayara Jinknss/Greenpeace Indigenous knowledge The study highlights the knowledge of indigenous peoples and traditional communities regarding rivers. According to Fany Kuiru Castro, general coordinator of the Coordination of Indigenous Organizations of the Amazon Basin (COICA), local governance practices help protect rivers and maintain their connectivity in the face of growing pressures. “For indigenous communities, fish are not simply a resource. They are part of our identity, our food systems, our stories, and our relationship with living rivers,” said Castro. She emphasized that any strategy to conserve the Amazon must recognize indigenous territorial rights, as well as “respect ancestral knowledge and strengthen indigenous leadership in protecting the waters that connect the entire basin.” The report identified at least 155 community-based fisheries management initiatives in Brazil, Peru, Bolivia, and Colombia. Together, they cover nearly 13 million hectares and involve more than 1,200 communities and 21,000 fishing workers. According to the study, these initiatives are associated with increased fish abundance and species richness, as well as economic and social benefits. Among the measures highlighted are the protection of free-flowing rivers, the restoration of natural flow regimes, the restoration of habitats and species, the improvement of water quality, and the prevention of the spread of non-native species. Since rivers, fish, sediments, and nutrients cross national borders, the authors advocate for coordinated actions across the entire watershed, with the formal participation of indigenous peoples and local communities in river management. As Paula Caballero, TNC’s regional managing director for Latin America, notes, conservation brings benefits to various sectors. “The report makes it clear that protecting the Amazon’s freshwater systems is not only an environmental imperative but also an economic and social necessity,” she pointed out.