Skip to main content
  • Submit
  • About
    • Editorial Board
    • PNAS Staff
    • FAQ
    • Rights and Permissions
    • Site Map
  • Contact
  • Journal Club
  • Subscribe
    • Subscription Rates
    • Subscriptions FAQ
    • Open Access
    • Recommend PNAS to Your Librarian
  • Log in
  • My Cart

Main menu

  • Home
  • Articles
    • Current
    • Latest Articles
    • Special Features
    • Colloquia
    • Collected Articles
    • PNAS Classics
    • Archive
  • Front Matter
  • News
    • For the Press
    • Highlights from Latest Articles
    • PNAS in the News
  • Podcasts
  • Authors
    • Information for Authors
    • Purpose and Scope
    • Editorial and Journal Policies
    • Submission Procedures
    • For Reviewers
    • Author FAQ
  • Submit
  • About
    • Editorial Board
    • PNAS Staff
    • FAQ
    • Rights and Permissions
    • Site Map
  • Contact
  • Journal Club
  • Subscribe
    • Subscription Rates
    • Subscriptions FAQ
    • Open Access
    • Recommend PNAS to Your Librarian

User menu

  • Log in
  • My Cart

Search

  • Advanced search
Home
Home

Advanced Search

  • Home
  • Articles
    • Current
    • Latest Articles
    • Special Features
    • Colloquia
    • Collected Articles
    • PNAS Classics
    • Archive
  • Front Matter
  • News
    • For the Press
    • Highlights from Latest Articles
    • PNAS in the News
  • Podcasts
  • Authors
    • Information for Authors
    • Purpose and Scope
    • Editorial and Journal Policies
    • Submission Procedures
    • For Reviewers
    • Author FAQ

New Research In

Physical Sciences

Featured Portals

  • Physics
  • Chemistry
  • Sustainability Science

Articles by Topic

  • Applied Mathematics
  • Applied Physical Sciences
  • Astronomy
  • Computer Sciences
  • Earth, Atmospheric, and Planetary Sciences
  • Engineering
  • Environmental Sciences
  • Mathematics
  • Statistics

Social Sciences

Featured Portals

  • Anthropology
  • Sustainability Science

Articles by Topic

  • Economic Sciences
  • Environmental Sciences
  • Political Sciences
  • Psychological and Cognitive Sciences
  • Social Sciences

Biological Sciences

Featured Portals

  • Sustainability Science

Articles by Topic

  • Agricultural Sciences
  • Anthropology
  • Applied Biological Sciences
  • Biochemistry
  • Biophysics and Computational Biology
  • Cell Biology
  • Developmental Biology
  • Ecology
  • Environmental Sciences
  • Evolution
  • Genetics
  • Immunology and Inflammation
  • Medical Sciences
  • Microbiology
  • Neuroscience
  • Pharmacology
  • Physiology
  • Plant Biology
  • Population Biology
  • Psychological and Cognitive Sciences
  • Sustainability Science
  • Systems Biology
Research Article

Heightened levels and seasonal inversion of riverine suspended sediment in a tropical biodiversity hot spot due to artisanal gold mining

View ORCID ProfileEvan N. Dethier, Shannon L. Sartain, and David A. Lutz
PNAS November 26, 2019 116 (48) 23936-23941; first published November 11, 2019 https://doi.org/10.1073/pnas.1907842116
Evan N. Dethier
aDepartment of Earth Sciences, Dartmouth College, Hanover, NH 03755;
  • Find this author on Google Scholar
  • Find this author on PubMed
  • Search for this author on this site
  • ORCID record for Evan N. Dethier
  • For correspondence: evan.n.dethier.gr@dartmouth.edu
Shannon L. Sartain
aDepartment of Earth Sciences, Dartmouth College, Hanover, NH 03755;
  • Find this author on Google Scholar
  • Find this author on PubMed
  • Search for this author on this site
David A. Lutz
bEnvironmental Studies Program, Dartmouth College, Hanover, NH 03755;cEcology, Evolution, Ecosystems, and Society Program, Dartmouth College, Hanover, NH 03755
  • Find this author on Google Scholar
  • Find this author on PubMed
  • Search for this author on this site
  1. Edited by Andrea Rinaldo, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland, and approved October 6, 2019 (received for review May 6, 2019)

  • Article
  • Figures & SI
  • Info & Metrics
  • PDF
Loading

This article requires a subscription to view the full text. If you have a subscription you may use the login form below to view the article. Access to this article can also be purchased.

Significance

Artisanal-scale gold mining (ASGM) operations are expanding across the planet, leading to widespread riparian deforestation and excavation, and hastening sediment transport into nearby rivers. Here, we show that ASGM operations have led to major increases in river suspended-sediment concentrations across a wide region of the Peruvian Amazon. The magnitude of suspended-sediment increase we detect implies detrimental and long-lasting impacts on aquatic biota, particularly behavior and community structure of fish populations, and increased riverine transport of ASGM-contributed, mercury-laden sediments. Our data document that ASGM has rapidly decreased water quality in this large region since the 1980s, indicating a pressing need for biogeochemical and ecological evaluations of ASGM-affected rivers worldwide in order to quantify indirect consequences on aquatic species and human health.

Abstract

In recent years, rising gold prices have exacerbated the global proliferation of artisanal-scale gold mining (ASGM), with catastrophic consequences for human and ecological health. Much of this burgeoning industry has occurred in biodiversity hot spots, notably in the tropical forests of South America. While the loss of tropical forests and floodplains as a result of ASGM has been well characterized, ASGM impacts on riverine hydrological properties are less understood. Previous fieldwork on ASGM-affected and gully-eroded tropical streams and rivers has demonstrated that increases in suspended-sediment concentration (SSC) can substantially impact fish diversity and aquatic community structure, yet our understanding of the timing and scope of impacts of such increases is limited by the lack of long-term records of SSC. To address this challenge, we present a 34-y analysis of the direct effect of ASGM on 32 river reaches in the Madre de Dios region of Peru, which has been heavily impacted by ASGM since the 1980s. We evaluate spatial and temporal patterns of impacts using estimated SSC derived from Landsat satellite imagery. We find that 16 of 18 stretches of river impacted by ASGM show significant increasing trends in SSC (P < 0.05), while only 5 of 14 unaffected sites do so. Additionally, ASGM appears to reverse natural seasonal cycles of SSC, which may imperil aquatic species. Overall, our findings indicate that ASGM is fundamentally altering optical water quality dynamics of a critical tropical biodiversity hot spot and provide guidance for future regulation of these activities.

  • tropical biodiversity hot spot
  • rivers
  • suspended sediment
  • remote sensing
  • Amazon

Footnotes

  • ↵1To whom correspondence may be addressed. Email: evan.n.dethier.gr{at}dartmouth.edu.
  • Author contributions: E.N.D., S.L.S., and D.A.L. designed research; E.N.D. and S.L.S. performed research; E.N.D. contributed new reagents/analytic tools; E.N.D., S.L.S., and D.A.L. analyzed data; and E.N.D., S.L.S., and D.A.L. wrote the paper.

  • The authors declare no competing interest.

  • This article is a PNAS Direct Submission.

  • Data deposition: The data used in this analysis have been deposited at HydroShare, http://www.hydroshare.org/resource/0efe95f8326d497eb427e97a58b1b577/. Appropriate metadata are also included.

  • This article contains supporting information online at www.pnas.org/lookup/suppl/doi:10.1073/pnas.1907842116/-/DCSupplemental.

Published under the PNAS license.

View Full Text

Log in using your username and password

Forgot your user name or password?

Purchase access

You may purchase access to this article. This will require you to create an account if you don't already have one.

Subscribers, for more details, please visit our Subscriptions FAQ.

Please click here to log into the PNAS submission website.

Back to top
Article Alerts
Email Article

Thank you for your interest in spreading the word on PNAS.

NOTE: We only request your email address so that the person you are recommending the page to knows that you wanted them to see it, and that it is not junk mail. We do not capture any email address.

Enter multiple addresses on separate lines or separate them with commas.
Heightened levels and seasonal inversion of riverine suspended sediment in a tropical biodiversity hot spot due to artisanal gold mining
(Your Name) has sent you a message from PNAS
(Your Name) thought you would like to see the PNAS web site.
Citation Tools
Heightened levels and seasonal inversion of riverine suspended sediment in a tropical biodiversity hot spot due to artisanal gold mining
Evan N. Dethier, Shannon L. Sartain, David A. Lutz
Proceedings of the National Academy of Sciences Nov 2019, 116 (48) 23936-23941; DOI: 10.1073/pnas.1907842116

Citation Manager Formats

  • BibTeX
  • Bookends
  • EasyBib
  • EndNote (tagged)
  • EndNote 8 (xml)
  • Medlars
  • Mendeley
  • Papers
  • RefWorks Tagged
  • Ref Manager
  • RIS
  • Zotero
Request Permissions
Share
Heightened levels and seasonal inversion of riverine suspended sediment in a tropical biodiversity hot spot due to artisanal gold mining
Evan N. Dethier, Shannon L. Sartain, David A. Lutz
Proceedings of the National Academy of Sciences Nov 2019, 116 (48) 23936-23941; DOI: 10.1073/pnas.1907842116
del.icio.us logo Digg logo Reddit logo Twitter logo CiteULike logo Facebook logo Google logo Mendeley logo
  • Tweet Widget
  • Facebook Like
  • Mendeley logo Mendeley
Proceedings of the National Academy of Sciences: 116 (50)
Current Issue

Submit

Sign up for Article Alerts

Article Classifications

  • Physical Sciences
  • Earth, Atmospheric, and Planetary Sciences
  • Biological Sciences
  • Ecology

Jump to section

  • Article
    • Abstract
    • Results
    • Discussion
    • Methods
    • Acknowledgments
    • Footnotes
    • References
  • Figures & SI
  • Info & Metrics
  • PDF

You May Also be Interested in

News Feature: Getting the world’s fastest cat to breed with speed
Cheetahs once rarely reproduced in captivity. Today, cubs are born every year in zoos. Breeding programs have turned their luck around—but they aren’t done yet.
Image credit: Mehgan Murphy/Smithsonian Conservation Biology Institute.
Adaptations in heart structure and function likely enabled endurance and survival in preindustrial humans. Image courtesy of Pixabay/Skeeze.
Human heart evolved for endurance
Adaptations in heart structure and function likely enabled endurance and survival in preindustrial humans.
Image courtesy of Pixabay/Skeeze.
Viscoelastic carrier fluids enhance retention of fire retardants on wildfire-prone vegetation. Image courtesy of Jesse D. Acosta.
Viscoelastic fluids and wildfire prevention
Viscoelastic carrier fluids enhance retention of fire retardants on wildfire-prone vegetation.
Image courtesy of Jesse D. Acosta.
Water requirements may make desert bird declines more likely in a warming climate. Image courtesy of Sean Peterson (photographer).
Climate change and desert bird collapse
Water requirements may make desert bird declines more likely in a warming climate.
Image courtesy of Sean Peterson (photographer).
QnAs with NAS member and plant biologist Sheng Yang He. Image courtesy of Sheng Yang He.
Featured QnAs
QnAs with NAS member and plant biologist Sheng Yang He
Image courtesy of Sheng Yang He.

Similar Articles

Site Logo
Powered by HighWire
  • Submit Manuscript
  • Twitter
  • Facebook
  • RSS Feeds
  • Email Alerts

Articles

  • Current Issue
  • Latest Articles
  • Archive

PNAS Portals

  • Classics
  • Front Matter
  • Teaching Resources
  • Anthropology
  • Chemistry
  • Physics
  • Sustainability Science

Information

  • Authors
  • Editorial Board
  • Reviewers
  • Press
  • Site Map
  • PNAS Updates

Feedback    Privacy/Legal

Copyright © 2019 National Academy of Sciences. Online ISSN 1091-6490