Water and Sediment Chemistry as Drivers of Macroinvertebrates and Fish Assemblages in Littoral Zones of Subtropical Reservoirs

Reservoirs are human-made ecosystems with diverse purposes that benefit humans both directly and indirectly. They however cause changes in geomorphological processes such as sediment cycling and influence the composition and structure of aquatic biota. This study aimed to identify water and sediment...

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Main Authors: Linton F. Munyai, Thendo Liphadzi, Thendo Mutshekwa, Mulalo I. Mutoti, Lubabalo Mofu, Florence M. Murungweni
Format: Article
Language:English
Published: MDPI AG 2023-12-01
Series:Water
Subjects:
Online Access:https://www.mdpi.com/2073-4441/16/1/42
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author Linton F. Munyai
Thendo Liphadzi
Thendo Mutshekwa
Mulalo I. Mutoti
Lubabalo Mofu
Florence M. Murungweni
author_facet Linton F. Munyai
Thendo Liphadzi
Thendo Mutshekwa
Mulalo I. Mutoti
Lubabalo Mofu
Florence M. Murungweni
author_sort Linton F. Munyai
collection DOAJ
description Reservoirs are human-made ecosystems with diverse purposes that benefit humans both directly and indirectly. They however cause changes in geomorphological processes such as sediment cycling and influence the composition and structure of aquatic biota. This study aimed to identify water and sediment quality parameters as drivers of macroinvertebrates and fish communities during the cool-dry and hot-wet seasons in the littoral zones of three subtropical reservoirs (Albasini, Thathe and Nandoni). Macroinvertebrates and fish were collected from three sites (<i>n</i> = 3 from each site) in each reservoir. A total of 501 and 359 macroinvertebrates and fish individuals were collected throughout the sampling period, respectively. The present study employed a two-way ANOVA in conjunction with redundancy analysis (RDA) to assess the relationships that exist between water and sediment variables, macroinvertebrates diversity and species abundances across seasons. Based on the two-way ANOVA model, significant differences were observed across reservoirs for evenness, Simpson’s diversity, and total abundance, while seasonal differences were observed for most metrics, with exception for evenness. The RDA results identified four water variables (i.e., water temperature, oxidation–reduction potential, pH and conductivity) and one sediment metal (Mg) as the most important parameters in driving the fish community structure. Field observations and metal results attest that the Nandoni reservoir shows high concentrations of metals in sediments as compared to other reservoirs, suggesting that anthropogenic activities such as car washing, brick making, recreation, fishing, wastewater treatment work and landfill site may be the major contributor of metals to the Nandoni reservoir, which accumulate in the littoral zones. Findings of this study highlight the need to analyze reservoir ecological conditions at several scales. The study of macroinvertebrates and fish, water, and sediment chemistry in the littoral zone laid the groundwork for proposing measures for conserving aquatic ecosystems.
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spelling doaj.art-c888c997c81d47d6b0b55b3efb3b08702024-01-10T15:11:26ZengMDPI AGWater2073-44412023-12-011614210.3390/w16010042Water and Sediment Chemistry as Drivers of Macroinvertebrates and Fish Assemblages in Littoral Zones of Subtropical ReservoirsLinton F. Munyai0Thendo Liphadzi1Thendo Mutshekwa2Mulalo I. Mutoti3Lubabalo Mofu4Florence M. Murungweni5School of Biology and Environmental Sciences, University of Mpumalanga, Nelspruit 1200, South AfricaDepartment of Geography and Environmental Sciences, University of Venda, Thohoyandou 0950, South AfricaDepartment of Freshwater Invertebrates, Albany Museum, Makhanda 6139, South AfricaDepartment of Environmental, Water, and Earth Sciences, Tshwane University of Technology, Pretoria 0001, South AfricaSouth African Institute for Aquatic Biodiversity (SAIAB), Makhanda 6140, South AfricaDepartment of Geography and Environmental Sciences, University of Venda, Thohoyandou 0950, South AfricaReservoirs are human-made ecosystems with diverse purposes that benefit humans both directly and indirectly. They however cause changes in geomorphological processes such as sediment cycling and influence the composition and structure of aquatic biota. This study aimed to identify water and sediment quality parameters as drivers of macroinvertebrates and fish communities during the cool-dry and hot-wet seasons in the littoral zones of three subtropical reservoirs (Albasini, Thathe and Nandoni). Macroinvertebrates and fish were collected from three sites (<i>n</i> = 3 from each site) in each reservoir. A total of 501 and 359 macroinvertebrates and fish individuals were collected throughout the sampling period, respectively. The present study employed a two-way ANOVA in conjunction with redundancy analysis (RDA) to assess the relationships that exist between water and sediment variables, macroinvertebrates diversity and species abundances across seasons. Based on the two-way ANOVA model, significant differences were observed across reservoirs for evenness, Simpson’s diversity, and total abundance, while seasonal differences were observed for most metrics, with exception for evenness. The RDA results identified four water variables (i.e., water temperature, oxidation–reduction potential, pH and conductivity) and one sediment metal (Mg) as the most important parameters in driving the fish community structure. Field observations and metal results attest that the Nandoni reservoir shows high concentrations of metals in sediments as compared to other reservoirs, suggesting that anthropogenic activities such as car washing, brick making, recreation, fishing, wastewater treatment work and landfill site may be the major contributor of metals to the Nandoni reservoir, which accumulate in the littoral zones. Findings of this study highlight the need to analyze reservoir ecological conditions at several scales. The study of macroinvertebrates and fish, water, and sediment chemistry in the littoral zone laid the groundwork for proposing measures for conserving aquatic ecosystems.https://www.mdpi.com/2073-4441/16/1/42aquatic ecosystemsbiomonitoringcommunity structurelittoral macroinvertebratesmacrozoobenthosreservoir ecology
spellingShingle Linton F. Munyai
Thendo Liphadzi
Thendo Mutshekwa
Mulalo I. Mutoti
Lubabalo Mofu
Florence M. Murungweni
Water and Sediment Chemistry as Drivers of Macroinvertebrates and Fish Assemblages in Littoral Zones of Subtropical Reservoirs
Water
aquatic ecosystems
biomonitoring
community structure
littoral macroinvertebrates
macrozoobenthos
reservoir ecology
title Water and Sediment Chemistry as Drivers of Macroinvertebrates and Fish Assemblages in Littoral Zones of Subtropical Reservoirs
title_full Water and Sediment Chemistry as Drivers of Macroinvertebrates and Fish Assemblages in Littoral Zones of Subtropical Reservoirs
title_fullStr Water and Sediment Chemistry as Drivers of Macroinvertebrates and Fish Assemblages in Littoral Zones of Subtropical Reservoirs
title_full_unstemmed Water and Sediment Chemistry as Drivers of Macroinvertebrates and Fish Assemblages in Littoral Zones of Subtropical Reservoirs
title_short Water and Sediment Chemistry as Drivers of Macroinvertebrates and Fish Assemblages in Littoral Zones of Subtropical Reservoirs
title_sort water and sediment chemistry as drivers of macroinvertebrates and fish assemblages in littoral zones of subtropical reservoirs
topic aquatic ecosystems
biomonitoring
community structure
littoral macroinvertebrates
macrozoobenthos
reservoir ecology
url https://www.mdpi.com/2073-4441/16/1/42
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