The impact of significant input of fine sediment on benthic fauna at tributary junctions: a case study of the Bermejo-Paraguay River confluence, Argentina

Blettler, Martín C. M.; Amsler, Mario L.; Ezcurra de Drago, Inés; Espinola, Luis A.; Eberle, Eliana; Paira, Aldo; Best, James L.; Parsons, Daniel R.; Drago, Edmundo E.

Abstract

This study examines the morphological features, suspended sediment inputs and hydraulic conditions within a large river in association with ecological patterns before and after a tributary confluence. In order to examine these effects, the macroinvertebrate distributions from three reaches of the Paraguay and Bermejo Rivers (Paraguay-Argentina) are investigated. The Bermejo River is a tributary that supplies significant quantities of fine sediment to the Paraguay River, primarily in suspension. Two reaches were examined on the Paraguay River, upstream and downstream of the Bermejo River junction, with the third study reach located on the Bermejo River, upstream of the confluence with the Paraguay River. The results provide clear evidence that a significantly increased loading of fine sediment at a river confluence has effects on the distribution and potential movement of benthic invertebrates in the lotic environment by representing physical barriers at affected sites. These effects may be important at both local and regional scales, and such increases in suspended sediment (especially associated with anthropogenic change) may thus pose a major threat to ecosystem integrity that has been historically underestimated.

Citation

Blettler, M. C. M., Amsler, M. L., Ezcurra de Drago, I., Espinola, L. A., Eberle, E., Paira, A., …Drago, E. E. (2015). The impact of significant input of fine sediment on benthic fauna at tributary junctions: a case study of the Bermejo-Paraguay River confluence, Argentina. Ecohydrology, 8(2), 340-352. https://doi.org/10.1002/eco.1511

• Journal Article Type: Article
• Acceptance Date: May 12, 2014
• Online Publication Date: Jun 4, 2014
• Publication Date: 2015-03
• Deposit Date: Jan 24, 2017
• Publicly Available Date: Jan 24, 2017
• Journal: Ecohydrology
• Print ISSN: 1936-0584
• Electronic ISSN: 1936-0592
• Publisher: Wiley
• Peer Reviewed: Peer Reviewed
• Volume: 8
• Issue: 2
• Pages: 340-352
• DOI: https://doi.org/10.1002/eco.1511
• Keywords: Ecohydrology, Benthic invertebrates, Fine sediment load, Confluence sediment dynamics, Large river
• Public URL: https://hull-repository.worktribe.com/output/447504
• Publisher URL: http://onlinelibrary.wiley.com/doi/10.1002/eco.1511/abstract
• Additional Information: This is the author's accepted version of an article published in: Ecohydrology, 2015, v.8 issue 2.