Trait‐based responses of Ephemeroptera, Plecoptera, and Trichoptera to sediment stress in the Tsitsa River and its tributaries, Eastern Cape, South Africa

Abstract

Elevated instream fine sediment is one of the most important water quality stressors affecting both the structure and function of aquatic ecosystems. This study evaluates whether a predictable pattern of trait distribution of Ephemeroptera, Plecoptera, and Trichoptera (EPT) can be observed along a gradient of sediment stress in eight selected sites in the Tsitsa River and its tributaries. The sites were classified into four site groups according to their fine sediment loads. One-way analysis of variance was used to test differences in the relative abundance of traits across the site groups. A predictable pattern was observed in 13 of the 27 trait attributes tested, with most traits displaying low abundances in highly disturbed site groups. The relationship between EPT traits and fine sediment stress was analysed using the multivariate RLQ analysis, and the result showed that traits such as swimming, shredding, operculate gill, small body size, and sclerotized body were the dominant traits in the sediment influenced site groups. In the less disturbed site groups, filter feeding, crawling, filamentous gill, soft and exposed body, and large body size were the dominant trait attributes. These observed relationships between EPT traits and sediment stress provide support for the potential usefulness of EPT traits as indicators of fine sediment stress in riverine ecosystems.

Can Macroinvertebrate Traits Be Explored and Applied in Biomonitoring Riverine Systems Draining Forested Catchments?

“…In the Afrotropical context, identification of macroinvertebrates remains a challenge due to scarcity of taxonomic expertise further compounding the utility of the taxonomy-based approach to freshwater biomonitoring. Some authors such as Akamagwuna et al (2019), Edegbene et al (2020a,b), and Odume (2020) have thus call for the development of the traitbased approach to complement the taxonomy-based approach in the Afrotropical region.…”

“…Globally, the trait-based approach has grown in popularity for assessing and monitoring riverine health (e.g., Statzner and Beche, 2010;Descloux et al, 2014;Kuzmanovic et al, 2017;Serra et al, 2017;White et al, 2017;Berger et al, 2018;Castro et al, 2018;Krynak and Yates, 2018;Milosevic et al, 2018;Desrosiers et al, 2019), but only few studies have attempted to develop and apply the trait-based biomonitoring approach for assessing riverine systems health in the Afrotropical region (e.g., Akamagwuna et al, 2019;Edegbene et al, 2020a,b;Odume, 2020). The studies of traits in the Afrotropical region have focused largely on assessing freshwater systems subject to urban, agricultural, and industrial pollution.…”

Developing and applying a macroinvertebrate‐based multimetric index for urban rivers in the Niger Delta, Nigeria

“…The inadequacies of physicochemical monitoring alone have necessitated the complementary use of biological monitoring (i.e., biomonitoring) tools and approaches (Arimoro, Ikomi, Nwadukwe, Eruotor, & Edegbene, ; Bonada et al, ; Serra, Graca, Doledec, & Feio, ). Biomonitoring tools/approaches widely used include single biotic indices (e.g., South African Scoring System version 5, Dickens & Graham, ) functional feeding group (FFG; e.g., Akamagwuna, Mensah, Nnadozie, & Oghenekaro, ; Baptista et al, ; Lakew & Moog, ; Ntislidou, Lazaridou, Tsiaoussi, & Bobori, ), multivariate approaches (e.g., Chowdhury, Gallardo, & Aldridge, ; Gieswein et al, ; Oliveira, Mugnai, Pereira, Souza, & Baptista, ), and multimetric indices (e.g., Bonada et al, ; Edegbene et al, ; Mereta et al, ; Monaghan & Soares, ). Of these approaches, the multimetric indices have been shown to perform extremely well particularly because they integrate information and data from multiple dimension of aquatic biota and the ecosystem as a whole (Bonada et al, ).…”

Exploring Macroinvertebrates Ecological Preferences and Trait-Based Indicators of Suspended Fine Sediment Effects in the Tsitsa River and Its Tributaries, Eastern Cape, South Africa

“…Sedimentation is among the most common freshwater ecosystem stressors impacting on macroinvertebrate communities [1][2][3]. Fine sediments' impacts on aquatic biota are wide-ranging and can be profound because their effects can be complex and are mediated by a range of factors including exposure duration, particle size distribution, sediments load, sources, geomorphological setting, and the vulnerability of resident biota [4][5][6]. Sediment effects on macroinvertebrates can be direct, e.g., clogging of fragile and exposed gills and filter-feeding structures, burial, abrasion; or indirect effects, e.g., alteration of the physical and chemical condition of streams such as reduction of dissolved oxygen and increases in turbidity [1,[7][8][9].…”

“…Globally, the taxonomy-based ap-proaches to analysing the effects of water quality impacts on macroinvertebrates are widely used [10][11][12]. The taxonomic approach compares macroinvertebrate communities across a stress gradient, and the degree of impact is inferred by assessing the deviation of the assemblages at the impacted sites from those at the control or reference sites [5,13].…”