University of SaskatchewanHARVEST
  • Login
  • Submit Your Work
  • About
    • About HARVEST
    • Guidelines
    • Browse
      • All of HARVEST
      • Communities & Collections
      • By Issue Date
      • Authors
      • Titles
      • Subjects
      • This Collection
      • By Issue Date
      • Authors
      • Titles
      • Subjects
    • My Account
      • Login
      JavaScript is disabled for your browser. Some features of this site may not work without it.
      View Item 
      • HARVEST
      • School of Environment and Sustainability
      • School of Environment and Sustainability
      • View Item
      • HARVEST
      • School of Environment and Sustainability
      • School of Environment and Sustainability
      • View Item

      High Rates of Mercury Biomagnification in Fish from Amazonian Floodplain-Lake Food Webs

      Thumbnail
      View/Open
      Nyholt_et_al_accepted.pdf (739.0Kb)
      Access to this file is currently restricted.
      Date
      2022-04-11
      Author
      Nyholt, Kelsey
      Jardine, Timothy 
      Villamarin, Francisco
      Jacobi, Cristina Mariana 
      Hawes, Joseph 
      Campos-Silva, Joao V.
      Srayko, Stephen
      Magnusson, William 
      Publisher
      Science of the Total Environment
      Type
      Article
      Peer Reviewed Status
      Peer Reviewed
      Peer Reviewed
      Metadata
      Show full item record
      Abstract
      Despite a global phase out of some point sources, mercury (Hg) remains elevated in aquatic food webs, posing health risks for fish-eating consumers. Many tropical regions have fast growing organisms, potentially short food chains, and few industrial point sources, suggesting low Hg baselines and low rates of trophic magnification with limited risk to people. Nevertheless, insufficient work on food-web Hg has been undertaken in the tropics and fish consumption is high in some regions. We studied Hg concentrations in fishes from floodplain lakes of the Juruá River, Amazonas, Brazil with three objectives: 1) determine rates of Hg trophic magnification, 2) assess whether Hg concentrations are high enough to impact humans eating fish, and 3) determine whether there are seasonal differences in fish Hg concentrations. A total of 380 fish-muscle samples were collected from 12 floodplain lakes during the low-water (September 2018) and falling-water (June 2019) seasons and analyzed for total Hg and stable nitrogen (N) isotopes. The average trophic magnification factor (increase per trophic level) was 10.1 in the low-water season and 5.4 in the falling-water season, both well above the global average for freshwaters. This high rate of trophic magnification, coupled with higher-than-expected Hg concentrations in herbivorous species, led to high concentrations (up to 17.6 mg/kg dry weight) in predatory pirarucu and piranha. Nearly 70% of all samples had Hg concentrations above the recommended human-consumption guidelines. Average concentrations were 42% higher in the dry season than the wet season, but differences varied by species. Since Hg concentrations are higher than expected and fish consumption in this region is high, future research should focus on Hg exposure for human populations here and in other tropical-rainforest regions, even in the absence of local point sources of Hg.
      Citation
      Nyholt, K., Jardine, T. D., Villamarín, F., Jacobi, C. M., Hawes, J. E., Campos-Silva, J. V., ... & Magnusson, W. E. (2022). High rates of mercury biomagnification in fish from Amazonian floodplain-lake food webs. Science of The Total Environment, 155161.
      URI
      https://hdl.handle.net/10388/13957
      DOI
      http://dx.doi.org/10.1016/j.scitotenv.2022.155161
      Subject
      Trophic magnification
      Methylmercury
      Arapaima
      Subsistence fishing
      Low-water season
      Falling-water season
      Collections
      • School of Environment and Sustainability
      University of Saskatchewan

      University Library

      The University of Saskatchewan's main campus is situated on Treaty 6 Territory and the Homeland of the Métis.

      © University of Saskatchewan
      Contact Us | Disclaimer | Privacy