Declining Biodiversity Peruvian Amazon

Biodiversity Loss Threatens Human Nutrition in the Amazon

Región Loreto, Iquitos, Perú.

There are fewer and fewer fish in the Peruvian Amazon and, therefore, less food for its inhabitants. A new study of dozens of wild fish species commonly consumed in the Peruvian Amazon states that people there could suffer major nutritional shortages if ongoing losses in fish biodiversity continue.


A fisherman pre-processes fish with help from a local boy before selling his catch in a community along the Ucayali river in Loreto Peru. The boy is holding a boquichico (Prochilodus nigricans), a common but declining migratory fish species. Photo by Sebastian Heilpern.


The implications of this research go far beyond the Amazon because the diversity and abundance of food – not grown – harvested from the natural environment is decreasing in rivers, lakes and terrestrial ecosystems around the world, on which some 2 billion people depend.

Inland water fishing alone employs about 60 million people and is the main source of protein for 200 million, according to a study published last week in the journal Science Advances.


A passenger and cargo-carrying ferry is docked in the port of Iquitos, along the Amazon River. These ferries are the main conduits bringing fish from distant locations in the region and supplying much of the city of Iquitios. Photo by Sebastian Heilpern.


The investigation focused on the Department of Loreto, in the Peruvian Amazon, where most of the 800,000 inhabitants eat fish at least once a day, about 52 kilograms per year.


Loreto, Peru, Image by


Fish is a main source of protein and essential fatty acids and minerals, such as iron, zinc and calcium. Unfortunately, it does not cover the dietary needs of the inhabitants of the Amazon, where a fourth of the children suffer from malnutrition and more than a fifth of women of childbearing age are iron deficient.


A fishmonger processes a dorado catfish (Brachyplatystoma rousseauxii) in the Belén Market in Iquitos, Peru. This fish is long distant migrant that is vulnerable to overfishing and dam development. Photo by Sebastian Heilpern.


The researchers studied the vast, rural Loreto department of the Peruvian Amazon, where most of the 800,000 inhabitants eat fish at least once a day, or an average of about 52 kilograms (115 pounds) per year.

But while fish is a fundamental pillar for both indigenous peoples and modern development, it faces myriad threats, such as overfishing, to the construction of hydroelectric dams that trap large migratory fish, deforestation and contamination by toxins from mining.


Left to right: a diminutive palometa, a relative of the piranha; a doncella, a type of catfish that migrates thousands of miles; three boquichicos; a larger palometa; two sardinas; and a fasaco. The ruler shows sizes in centimeters. Photo, Sebastian Heilpern.


According to the World Wildlife Fund  (WWF),  fishery production in Loreto is adversely affected and some large migratory species are already in decline and others are on their way. And the same happens in other places: globally, a third of freshwater fish species are in danger of extinction and 80 are already known to be extinct.


The Tambopata River, Peru. Photo Wold Wide Life. Org


WWF is the world’s leading conservation organization. Born in Switzerland in 1961, the organization has a presence in more than 100 countries. With a scientific focus, WWF is distinguished by a combination of local presence and global reach, as well as innovative solutions that meet the needs of both people and nature. To achieve this, it creates long-term synergies with different sectors -governmental, business and social-, and applies the best governance and transparency practices.


Mercado de Belen, Photo by APU Productions.


WWF currently focuses their work on 13 Global Initiatives, large-scale efforts with the potential to positively impact priority species and ecoregion, and reduce the ecological footprint of humans on the environment. Among them are: The Amazon. WWF’s goals include to support the recovery and growth of important species from an ecological, economic and cultural point of view. They also promote the protection and sustainable management of the most biologically important natural places on Earth. Since animal and plant species contain different proportions of nutrients, maintaining biodiversity is key to proper nutrition.


Iquitos, Peru source Hotwire.


To study the fish in the region, Sebastian Heilpern, lead author of the research and at the time a doctoral student at Columbia University (New York), acquired 56 varieties of fish, from small fish such as ractacaras and yulillas to pomfret (from the piranha family) or catfish, which can reach one and a half meters. The study authors ranked each species based on protein, fatty acids, minerals, and nutritional value and developed multiple scenarios of how the nutrient supply in Loreto would be affected as species are lost.


Iquitos, Amazona Peruana. Source, Sin Mapa.


The study determined that, although the volume of fish has remained stable in recent years, large migratory species -the most vulnerable to human activities- are becoming less abundant and, as they disappear, they are replaced by other smaller kinds although insufficient in iron and zinc.

“Like any complex system, changes are seen. Some things are increasing, while others are decreasing. But that only lasts up to a certain point. There is a turning point, in which the species that remain can be really bad,” warns Heilpern.


Peruvian Rainforest. Wold Wide Life. Org


Implications Beyond the Amazon

The research has implications far beyond the Amazon, since the diversity and abundance of wild-harvested foods is declining in rivers and lakes globally, as well as on land. Some 2 billion people globally depend on non-cultivated foods; inland fisheries alone employ some 60 million people, and provide the primary source of protein for some 200 million.


Mercado de Belen, Iquitos photo by Gabriel Torrejon


In Loreto, catch tonnages are stagnating; some large migratory species are already on the decline, and others may be on the way. It is the same elsewhere; globally, a third of freshwater fish species are threatened with extinction, and 80 are already known to be extinct, according to the World Wildlife Fund.

Different species of animals and plants contain different ratios of nutrients, so biodiversity is key to adequate human nutrition, explain the researchers. “If fish decline, the quality of the diet will decline,” reports the study’s senior coauthor, Shahid Naeem, director of Columbia University’s Earth Institute Center for Environmental Sustainability. “Things are definitely declining now, and they could be on the path to crashing eventually.”


Mercado de Belen, Iquitos, Peru. Photo by Infy Snow.


The Earth Institute of Columbia University reports that to study the region’s fish, the study’s lead author, then-Columbia PhD. student Sebastian Heilpern, visited Belén’s retail market in the provincial capital of Iquitos and the city’s Amazon River docks.  Wholesale commerce begins at 3:30 in the morning. He and another student bought multiple specimens of as many different species as they could find, and ended up with 56 of the region’s 60-some main food species. These included modest-size scale fish known locally as ractacara and yulilla; saucer-shaped palometa (related to piranha); and giant catfish extending six feet or more, reports Eureka.

The fish were flown on ice to a government lab in Lima, where each species was analyzed for protein, fatty acids and trace minerals. The researchers then plotted the nutritional value of each species against its probability of surviving various kinds of ongoing environmental degradation. From this, they drew up multiple scenarios of how people’s future diet would be affected as various species dropped out of the mix, explains Eureka.

Heilpern adds, “Some things are going up while other things are going down. But that only lasts up to a point.” Exactly which species will fill the gaps left when others decline is difficult to predict–but the researchers project that the overall nutritional value of the catch will fall to the point where 40 of the 60 food species become scarce or extinct. “You have a tipping point, where the species that remain can be really lousy,” said Heilpern.


Mercado de Belen, Iquitos, Peru. Photo by Difusion Foto Studio.


Potential but problematic solution

Populations were wild foods are in decline are turning to farm-raised chicken and aquaculture–a trend encouraged by the World Bank and other powerful organizations. This is increasingly the case in Loreto. However, Heilpern, Naeem and their colleagues found that the move undermines human nutrition, “no single species can offer all key nutrients, a diversity of species is needed to sustain nutritionally adequate diets,” they write. They also note that chicken farming and aquaculture exert far more pressure on the environment than fishing.


Mercado de Belen. Photo by Gabriel Torrejon


Chicken farming and aquaculture damage the environment, encourage deforestation, produce greenhouse gases, and introduce fertilizers and other pollutants into nearby waters. Fish are a vital part of life in the Amazonian region as fishing is a main source of income and food for riverside communities. Predatory fishing practices have caused a scarcity of fish and some species are threatened with extinction. Pollution, commerce, projects like dams, mining and deforestation are undermining fish life. Compounding these problems are population growth and resettlement. Interventions to better understand fisheries and improve management practices are needed now. WWF is working to strengthen local community fisheries and helping establish policies and institutions that strengthen fish management and floodplain ecology.

For more information visit:

SA Heilpern et al. “The reduced diversity of wild-caught species jeopardizes dietary nutrition.” Science Advances (2021)

The Earth Institute, Columbia University mobilizes the sciences, education and public policy to achieve a sustainable earth.


Soledad Quartucci | Latina Republic

Dr. Soledad Quartucci is the founder and CEO of Latina Republic, a 501(C)3 California-based nonprofit organization. Latina Republic is a reporting, research, advocacy and charitable organization advancing human rights in the Americas. We fill the void in coverage of urgent social, political, human rights, economic and gender inequalities affecting the Americas. Through our allies in Latin America, we highlight contributions, heritage, history, leadership and innovation. Latina Republic reports on stories that integrate local strategies to the betterment of the region. We make space for and empower unheard voices and celebrate the rich histories of Latin America.