Original Research

Diversity and distribution of benthic invertebrates dwelling rivers of the Kruger National Park, South Africa

Nabil Majdi, Lizaan de Necker, Hendrika Fourie, Ané Loggenberg, Edward C. Netherlands, Jasmine Bunte-Tschikin, Walter Traunspurger, Gerhard C. du Preez
Koedoe | Vol 64, No 1 | a1702 | DOI: https://doi.org/10.4102/koedoe.v64i1.1702 | © 2022 Nabil Majdi, Lizaan de Necker, Hendrika Fourie, Ané Loggenberg, Edward C. Netherlands, Jasmine Bunte-Tschikin, Walter Traunspurger, Gerhard C. du Preez | This work is licensed under CC Attribution 4.0
Submitted: 04 December 2021 | Published: 27 June 2022

About the author(s)

Nabil Majdi, Department of Animal Ecology, Faculty of Biology, University of Bielefeld, Bielefeld, Germany
Lizaan de Necker, Unit for Environmental Sciences and Management, North-West University, Potchefstroom, South Africa; and, South African Institute for Aquatic Biodiversity, Makhanda, South Africa
Hendrika Fourie, Unit for Environmental Sciences and Management, North-West University, Potchefstroom, South Africa
Ané Loggenberg, Unit for Environmental Sciences and Management, North-West University, Potchefstroom, South Africa
Edward C. Netherlands, Unit for Environmental Sciences and Management, North-West University, Potchefstroom, South Africa
Jasmine Bunte-Tschikin, Department of Animal Ecology, Faculty of Biology, University of Bielefeld, Bielefeld, Germany
Walter Traunspurger, Department of Animal Ecology, Faculty of Biology, University of Bielefeld, Bielefeld, Germany
Gerhard C. du Preez, Unit for Environmental Sciences and Management, North-West University, Potchefstroom, South Africa

Abstract

Meiobenthos (or meiofauna) are microscopic invertebrates that inhabit biofilms and interstitial spaces in rivers. They are diverse and extremely abundant, and they perform essential ecological functions by linking microbial production to higher trophic levels (e.g. macrobenthic invertebrates and fishes). However, meiobenthic communities remain poorly studied in Africa. Here, we sampled meio- and macrobenthic invertebrate communities associated with biofilms and sediments across an upstream–downstream gradient along the Olifants, Sabie and Crocodile rivers flowing through the Kruger National Park (KNP). We expected to link differences in community structure to environmental gradients as those rivers show different degrees of anthropogenic stress as they enter the park. Both meio- and macrobenthic communities differed across rivers and also structured along an upstream–downstream gradient. The upstream sites, which were the closest to the park borders, consistently showed a lower diversity in all three rivers. There, the invasive snail Tarebia granifera strongly dominated (making up 73% – 87% of the macrobenthos), crowding hard substrates, while concomitantly the abundances of biofilm-dwelling meiobenthos like nematodes and rotifers were substantially reduced. Nevertheless, the diversity and evenness of communities then tended to increase as water flowed downstream through the park, suggesting a beneficial effect of protected river reaches on benthic invertebrate diversity. However, for the Crocodile River, which makes up the southern border of the park, this trend was less conspicuous, suggesting that this river may experience the greatest threats. More generally, benthic invertebrate communities were driven by the concentrations of phosphates, sulphates, ammonium and organic matter and by substrate characteristics.

Conservation implications: Meiobenthic organisms are very abundant in KNP rivers and react to environmental gradients; thus, they should be more considered for bio-monitoring or conservation of comprehensive assemblages of animals. Interestingly, protected reaches tended to show a reduced dominance of the invasive T. granifera and a higher diversity of benthic invertebrates.


Keywords

biodiversity; aquatic ecology; community structure; meiofauna; macrofauna; invasive species; pollution

Metrics

Total abstract views: 2817
Total article views: 2098

 

Crossref Citations

1. Aquatic invertebrate community structure and functions within a Ramsar wetland of a premier conservation area in South Africa
Lizaan de Necker, Kelly Dyamond, Richard Greenfield, Johan van Vuren, Wynand Malherbe
Ecological Indicators  vol: 148  first page: 110135  year: 2023  
doi: 10.1016/j.ecolind.2023.110135