Amazon Forgotten Fishes

Invisible network of life

Up to 30% of the Amazon Basin is made up of rivers, lakes, floodplains, wetlands, and seasonally flooded forests. Together, these interconnected freshwater ecosystems form the largest and most complex river basin in the world—home to the planet’s greatest diversity of freshwater fish—and serve as the ecological, cultural, and economic foundation of the region.

Despite their essential role, freshwater ecosystems have long remained overlooked in conservation, development, and climate strategies.

Amazonian rivers rise and fall with the seasons. 

• December – May: Floodwaters typically peak.
• June - November: Water levels recede.

These annual floods fertilize floodplain soils, connect habitats, disperse seeds, and support fish reproduction.

This cycle is essential to the lives of Amazonian communities, shaping how they approach fishing, agriculture, and transportation. At the same time, it brings risks at both extremes, through floods and droughts.

There are three main types of water in the basin:

• Whitewater rivers, which are nutrient-rich;
• Blackwater rivers, which are nutrient-poor, acidic, and rich in dissolved organic matter; and
• Clearwater rivers, which have an intermediate pH, are highly transparent, contain little to no sediment, and have very low nutrient levels.

Together, these water types create contrasting ecological conditions that shape fish diversity, productivity, and migration patterns.

The Amazon has the greatest freshwater fish diversity on Earth

Fish species across the Amazon Basin are not only extraordinarily diverse, but their composition is also unique. Approximately two-thirds (65%) are endemic to the Amazon, meaning they are found nowhere else in the world.

More than 2,700 remarkable species have been recorded throughout the Amazon Basin, representing about 15% of all known freshwater fish species globally. Dozens more are added every year as scientific exploration continues to uncover new species.

More than 100 fish species undertake long-distance migrations, with catfish and characins accounting for most of these movements. The Dorado catfish (Brachyplatystoma rousseauxii), for example, performs the longest freshwater migration in the world, traveling approximately 11,600 kilometers (7,200 miles) between the Andean Amazon and the Atlantic Ocean and back again.

Amazon fish biodiversity is as remarkable as it is overlooked. Despite their immense importance, we still know relatively little about many of these species. Fish are a key indicator of the health of the basin and the connectivity of its freshwater ecosystems. They play essential roles in nutrient cycling, seed dispersal, and sustaining local communities that depend on them for food security and livelihoods.

In Indigenous cosmology, no creature is forgotten

The Amazon River Basin is home to approximately 511 Indigenous Peoples, who serve as stewards and defenders of nature.

These Indigenous nations possess sophisticated knowledge systems that are deeply intertwined with the natural world. Here, freshwater ecosystems are essential to life. Many communities identify themselves as “water peoples” and have established their villages along rivers and lakes, which provide both sustenance and transportation.

Fish play a vital role in the diets of these societies. However, the consumption of fish and other forest animals is governed by complex cultural and spiritual norms. Not all species are considered edible, and even those that are may not be suitable for everyone or permitted at all times.

The conservation of the Amazon’s “forgotten fishes” is closely tied to the protection of Indigenous Peoples and their territories. Biocultural conservation is essential: safeguarding Indigenous cultural practices, traditional ecological knowledge, and territorial rights is inseparable from protecting fish populations and the freshwater ecosystems on which we all depend.

The Amazon: between small-scale and commercial fisheries

Over the past five decades, local communities across the Amazon have taken the lead in managing their fisheries, demonstrating that conservation and human well-being can go hand in hand.

With the exception of the industrial piramutaba fishery in the Brazilian Amazon estuary, nearly all fishing activity across the region is conducted on a small scale by riverine populations and Indigenous communities that depend directly on fish for food, livelihoods, and income.

At least 15 different fishing methods have been documented throughout the basin, most which are traditional and environmentally sustainable. Among the most widely used are gillnets, whose mesh size can be adjusted to selectively target specific species—particularly effective in slow-moving rivers and floodplain lakes—and multifilament nylon seine nets, which are deployed to encircle schools of fish in deeper waters and along sandy beaches.

The annual cycles of rising and falling water levels in Amazonian rivers directly shape where, when, and how local fishers operate. As water levels change, fishers move between floodplains and the main channels of rivers and lakes, adapting their strategies to seasonal conditions.

Women play central roles in these fisheries—not only as fishers, but also as traders, processors, and household managers—helping ensure that the benefits of fishing support families and communities alike.

Commercial fish production in the Amazon Basin is dominated by a few species and fishing grounds, though there are clear regional differences in catch composition. The dataset shows that only 30 fish species account for approximately 90% of total landings.

Factors threatening Amazonian fish

Amazonian fish habitats are under increasing pressure on multiple fronts. Human activities such as dam construction, wetland drainage, river channelization, and water diversions can dramatically transform the underwater world, destroying the areas that fish depend on for feeding, breeding, and migration.

Deforestation driven by agriculture, urban expansion, mining, and infrastructure development has significantly altered the Amazon’s wetlands and river systems. Recent basin-wide mapping indicates that approximately 7.4 million hectares of wetlands had already been deforested by 2020.

While the challenges facing the Amazon’s remarkable fish are undeniably immense, there is also real hope for the future. The key to their survival—and to maintaining the vital services they provide to millions of people—lies in restoring and protecting the freshwater ecosystems on which they depend.

The health of the Amazon basin depends on cross-border cooperation

The fate of Amazonian fish depends on our ability to understand the basin as an interconnected and constantly flowing system.

The Emergency Recovery Plan, developed by 25 authors from 14 organizations, highlights the global freshwater biodiversity crisis and outlines six priority actions to guide policy aimed at reversing biodiversity loss.

These regional and local strategies, combined with the engagement of governments, civil society, and local and international organizations, can amplify the impact of the Emergency Recovery Plan and position the Amazon as a global model for the conservation and sustainable use of freshwater resources.

The fate of Amazonian fish depends on our ability to understand the basin as an interconnected and constantly flowing system. The responsibility for safeguarding its biodiversity belongs to all of us. The first step we can take toward protecting these species is to recognize them—and remember them.