• Skip to primary navigation
  • Skip to main content
  • Skip to primary sidebar

PRESSLED

Your Leading News Source

PRESSLED
Your Leading News Source

  • Home
  • BUSINESS
  • MONEY
  • POLITICS
  • REAL ESTATE
  • US
  • Meet the Reporters
  • About/Contact

Declining biodiversity in wild Amazon fisheries threatens human diet

May 28, 2021 by Staff Reporter

IMAGE: Landing a catch along the Ucayali River in the Loreto department of the Peruvian Amazon. The boy is holding a boquichico, a commonly consumed species. (All photos: Sebastian Heilpern)
view more 

Credit: Sebastian Heilpern

A new study of dozens of wild fish species commonly consumed in the Peruvian Amazon says that people there could suffer major nutritional shortages if ongoing losses in fish biodiversity continue. Furthermore, the increasing use of aquaculture and other substitutes may not compensate. 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. The study appears this week in the journal Science Advances.

The authors 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. This is their primary source not only of protein, but fatty acids and essential trace minerals including iron, zinc and calcium. Unfortunately, it is not enough; a quarter of all children are malnourished or stunted, and more than a fifth of women of child-bearing age are iron deficient.

Threats to Amazon fisheries, long a mainstay for both indigenous people and modern development, are legion: new hydropower dams that pen in big migratory fish (some travel thousands of miles from Andes headwaters to the Atlantic estuary and back); soil erosion into rivers from deforestation; toxic runoff from gold mines; and over-exploitation by fishermen themselves, who are struggling to feed fast-growing populations. 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, say the researchers. “If fish decline, the quality of the diet will decline,” said 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.”

To study the region’s fish, the study’s lead author, then-Columbia PhD. student Sebastian Heilpern, made numerous shopping trips to the bustling Belén retail market in the provincial capital of Iquitos. He also visited the city’s Amazon River docks, where 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. (The researchers settled for chunks of the biggest ones.)

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.

Overall, the biomass of fish caught has remained stable in recent years. However, large migratory species, the most vulnerable to human activities, comprise a shrinking portion, and as they disappear, they are being replaced by smaller local species. Most fish contain about the same amount of protein, so this has not affected the protein supply. And, the researchers found, many smaller fish in fact contain higher levels of omega-3 fatty acids, so their takeover may actually increase those supplies. On the other hand, as species compositions lean more to smaller fish, supplies of iron, zinc are already going down, and will continue to decline, they say.

“Like any other complex system, you see a tradeoff,” said Heilpern. “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 nosedive around 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.

One potential solution: in many places around the world where wild foods including fish and bush meat (such as monkeys and lizards) are declining, people are turning increasingly to farm-raised chicken and aquaculture–a trend encouraged by the World Bank and other powerful organizations. This is increasingly the case in Loreto. But in a separate study published in March, Heilpern, Naeem and their colleagues show that this, too, is undermining human nutrition.

The researchers observed that chicken production in the region grew by about three quarters from 2010 to 2016, and aquaculture nearly doubled. But in analyzing the farmed animals’ nutritional values, they found that they typically offer poorer nutrition than a diverse mix of wild fish. In particular, the move to chicken and aquaculture will probably exacerbate the region’s already serious iron deficiencies, and limit supplies of essential fatty acids, they say. “Because no single species can offer all key nutrients, a diversity of species is needed to sustain nutritionally adequate diets,” they write.

Besides this, chicken farming and aquaculture exert far more pressure on the environment than fishing. In addition to encouraging clearing of forests to produce feed for the animals, animal farming produces more more greenhouse gases, and introduces fertilizers and other pollutants into nearby waters, says Heilpern.

“Inland fish are fundamental for nutrition in many low-income and food-deficit countries, and of course landlocked countries,” said John Valbo Jørgensen, a Rome-based expert on inland fisheries with the UN Food and Agriculture Organization. “Many significant inland fisheries, including those of Peru, take place in remote areas with poor infrastructure and limited inputs. It will not be feasible to replace those fisheries with farmed animals including fish.”

Heilpern is now working with the Wildlife Conservation Society to produce an illustrated guide to the region’s fish, including their nutritional values, in hopes of promoting a better understanding of their value among both fishermen and consumers.

###

The other authors of the new study are Ruth deFries and Maria Uriarte of the Earth Institute; and Kathryn Fiorella, Alexander Flecker and Suresh Sethi of Cornell University.

Scientist contacts:

Sebastian Heilpern s.heilpern@cornell.edu

Shahid Naeem sn2121@columbia.edu

Ruth deFries rd2402@columbia.edu

More information: Kevin Krajick, Senior editor, science news, The Earth Institute kkrajick@ei.columbia.edu 212-854-9729

The Earth Institute, Columbia University mobilizes the sciences, education and public policy to achieve a sustainable earth. http://www.earth.columbia.edu.

>>>ad: Don't Miss TODAY'S BEST Amazon Deals!

Originally Appeared Here

Filed Under: TECH/SCIENCE

Primary Sidebar

More to See

On Trump’s Truth Social, anti-FBI sentiment builds with little oversight

Posts on Truth Social in which users call for civil war and advocate for violence against the FBI remained online Friday, some of them days after they … [Read More...] about On Trump’s Truth Social, anti-FBI sentiment builds with little oversight

These are the best-performing S&P 500 stocks this week. Here’s where analysts see them going

The S & P 500 rose for the fourth straight week as investors cheered better-than-expected inflation numbers. The consumer price index rose 8.5% year … [Read More...] about These are the best-performing S&P 500 stocks this week. Here’s where analysts see them going

BC seeks alleged money launderer’s Vancouver real estate

Alleged money launderer Paul King Jin used a Hong Kong company to register mortgages against property he owned through shell companies, the B.C. … [Read More...] about BC seeks alleged money launderer’s Vancouver real estate

Privacy Policy | Terms and Conditions | About/ Contact
Copyright © 2022 · PRESSLED · As Amazon Associates we earn commissions from qualifying purchases · Log in

We use cookies on our website to give you the most relevant experience by remembering your preferences and repeat visits. By clicking “Accept All”, you consent to the use of ALL the cookies. However, you may visit "Cookie Settings" to provide a controlled consent.
Cookie SettingsAccept All
Manage consent

Privacy Overview

This website uses cookies to improve your experience while you navigate through the website. Out of these, the cookies that are categorized as necessary are stored on your browser as they are essential for the working of basic functionalities of the website. We also use third-party cookies that help us analyze and understand how you use this website. These cookies will be stored in your browser only with your consent. You also have the option to opt-out of these cookies. But opting out of some of these cookies may affect your browsing experience.
Necessary
Always Enabled
Necessary cookies are absolutely essential for the website to function properly. These cookies ensure basic functionalities and security features of the website, anonymously.
CookieDurationDescription
cookielawinfo-checkbox-analytics11 monthsThis cookie is set by GDPR Cookie Consent plugin. The cookie is used to store the user consent for the cookies in the category "Analytics".
cookielawinfo-checkbox-functional11 monthsThe cookie is set by GDPR cookie consent to record the user consent for the cookies in the category "Functional".
cookielawinfo-checkbox-necessary11 monthsThis cookie is set by GDPR Cookie Consent plugin. The cookies is used to store the user consent for the cookies in the category "Necessary".
cookielawinfo-checkbox-others11 monthsThis cookie is set by GDPR Cookie Consent plugin. The cookie is used to store the user consent for the cookies in the category "Other.
cookielawinfo-checkbox-performance11 monthsThis cookie is set by GDPR Cookie Consent plugin. The cookie is used to store the user consent for the cookies in the category "Performance".
viewed_cookie_policy11 monthsThe cookie is set by the GDPR Cookie Consent plugin and is used to store whether or not user has consented to the use of cookies. It does not store any personal data.
Functional
Functional cookies help to perform certain functionalities like sharing the content of the website on social media platforms, collect feedbacks, and other third-party features.
Performance
Performance cookies are used to understand and analyze the key performance indexes of the website which helps in delivering a better user experience for the visitors.
Analytics
Analytical cookies are used to understand how visitors interact with the website. These cookies help provide information on metrics the number of visitors, bounce rate, traffic source, etc.
Advertisement
Advertisement cookies are used to provide visitors with relevant ads and marketing campaigns. These cookies track visitors across websites and collect information to provide customized ads.
Others
Other uncategorized cookies are those that are being analyzed and have not been classified into a category as yet.
SAVE & ACCEPT