Chronic trace metals effects of mine tailings on estuarine assemblages revealed by environmental DNA
- Published
- Accepted
- Subject Areas
- Environmental Impacts, Biological Oceanography
- Keywords
- Benthos, Meiofauna, Impacts, Pollution, Estuary, Samarco, Rio Doce
- Copyright
- © 2019 Bernardino et al.
- Licence
- This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, reproduction and adaptation in any medium and for any purpose provided that it is properly attributed. For attribution, the original author(s), title, publication source (PeerJ Preprints) and either DOI or URL of the article must be cited.
- Cite this article
- 2019. Chronic trace metals effects of mine tailings on estuarine assemblages revealed by environmental DNA. PeerJ Preprints 7:e27924v1 https://doi.org/10.7287/peerj.preprints.27924v1
Abstract
Mine tailing disasters have occurred worldwide and contemporary release of tailings of large proportions raise concerns of the chronic impacts that trace metals associated with tailings may have on the aquatic biodiversity. Environmental metabarcoding (eDNA) offers an yet poorly explored opportunity for biological monitoring of impacted aquatic ecosystems from mine tailings and contaminated sediments. eDNA has been increasingly recognized to be an effective method to detect previously unrecognized small-sized Metazoan taxa, but their ecological responses to environmental pollution has not been assessed by metabarcoding. Here we evaluated chronic effects of trace metal contamination from sediment eDNA of the Rio Doce estuary, 1.7 years after the Samarco mine tailing disaster, which released over 40 million m3of iron tailings in the Rio Doce river basin. We identified 123 new sequence variants (eOTUs) of benthic taxa and an assemblage composition dominated by Nematoda, Crustacea and Platyhelminthes; typical of other estuarine ecosystems. We detected environmental filtering on the meiofaunal assemblages and multivariate analysis revealed strong influence of Fe contamination, supporting chronic impacts from mine tailing deposition in the estuary. This was in contrast to environmental filtering of meiofaunal assemblages of non-polluted estuaries. Here we suggest that the eDNA metabarcoding technique provides an opportunity to fill up biodiversity gaps in coastal marine ecology and may become a valid method for long term monitoring studies in mine tailing disasters and estuarine ecosystems with high trace metals content.
Author Comment
This is a submission to PeerJ for review. This is a preprint submission to PeerJ Preprints.
Supplemental Information
List of Metazoan taxa determined from eDNA
Table S1. List of marine eOTUs of aquatic Metazoan taxa recovered from sediment eDNA samples from the Rio Doce estuary. Note: unassigned species identities are indicated as notID.
List of dominant meiofaunal eOTUs
Table S2. Dominant meiofaunal OTUs with > 0.1% of sequence variant reads included in multivariate analysis
Spearman correlation tests of trace metals in sediments of the Rio Doce estuary in August 2017
Table S3. Results of paired spearman correlation analysis of trace metals concentrations in sediment samples from the Rio Doce estuary in August 2017.Variables were considered co-variating when the correlation coefficient (Pearson’s r) was not equal to 0 with p ≤ 0.05. Significant results (p < 0.05) are in bold.
Number of sequence variant reads from Metazoan taxa from the Rio Doce estuary in August 2017
Number of sequence variant reads from Metazoan taxa from the Rio Doce estuary in August 2017, distributed across sites sampled