Transition of an estuarine benthic meiofauna assemblage 1.7 and 2.8 years after a mining disaster

PeerJ. 2023 Mar 14:11:e14992. doi: 10.7717/peerj.14992. eCollection 2023.

Abstract

Background: Estuaries are transitional coastal ecosystems that are threatened by multiple sources of human pollution. In 2015, mining tailings from an upstream dam failure caused massive metal contamination that impacted benthic assemblages on the Brazilian Rio Doce estuary.

Methods: In this study, we investigate and compare meiofaunal assemblages with eDNA metabarcoding 1.7 years (2017) and 2.8 years (2018) after the initial contamination by mine tailings in order to evaluate the continued impact of sediment mine tailing contaminants on the structure of benthic assemblages after the disaster.

Results: The community was dominated by Arthropoda and Nematoda 1.7 yr after the impacts (42 and 29% of meiofaunal sequence reads, respectively) but after 2.8 years Arthropoda (64.8% of meiofaunal sequence reads) and Rotifera (11.8%) were the most common taxa. This continued impact on meiofaunal assemblage revealed a lower phylogenetic diversity (7.8-fold) in 2018, despite overall decrease in metal concentration (Al, Ba, Cr, As, Fe, Zn, Mn, Pb, Cd, Co) in sediments. Our data suggests that differences in benthic assemblages and loss of diversity may be influenced by contaminants in sediments of this estuary, and indicate that broad eDNA assessments are greatly useful to understand the full range of biodiversity changes in dynamic estuarine ecosystems.

Keywords: Benthos; Environmental DNA; Environmental Impact; Estuary; Meiofauna; Pollution; Rio Doce.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Disasters*
  • Ecosystem*
  • Environmental Monitoring
  • Geologic Sediments / chemistry
  • Humans
  • Metals
  • Mining
  • Phylogeny

Substances

  • Metals

Associated data

  • figshare/10.6084/m9.figshare.21133567.v1

Grants and funding

This work was funded by PELD and PRONEM grants from Fundação de Amparo do Espirito Santo (790548684/2017, 84532092/2018), Coordenação de Aperfeiçoamento de Pessoal em Nível Superior CAPES and Conselho Nacional de Pesquisa e Desenvolvimento CNPq (441243/2016-9; 441107/2020-6) to AFB. Gabriel C. Coppo received a scholarship from Coordenação de Aperfeiçoamento de Pessoal em Nível Superior CAPES, and a travel grant from Fundação de Amparo do Espirito Santo (393/2021). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.