Spatial and temporal pattern of benthic macroinvertebrate assemblages in two large Chinese freshwater lakes subjected to different degrees of eutrophication

• Published in: Journal of freshwater ecology Vol. 38; no. 1
• Main Authors: Ji, Lei, Wang, Yaru, Wang, Qiansen, Chen, Wendong, Zhang, Boyu, Chu, Jinkun, Ding, Yuansong, Shi, Haoyu, Cao, Zihan, Wang, Liangbin, Zhang, Kun, Wang, Wenping
• Format: Journal Article
• Language: English
• Published: Philadelphia Taylor & Francis 13.09.2023; Taylor & Francis Ltd; Taylor & Francis Group
• Subjects: Algae; Algal blooms; algal-dominated state; Ammonia; Ammonium; Ammonium compounds; Aquatic habitats; Aquatic insects; Aquatic plants; Benthos; Biodiversity; Chemical oxygen demand; Diversity indices; Electrical resistivity; Environmental factors; Eutrophication; Floodplains; Freshwater; Freshwater lakes; Freshwater molluscs; Habitats; Inland water environment; Lakes; Macroinvertebrates; macrophyte-dominated state; Macrophytes; Multidimensional scaling; Nutrients; Oxygen requirement; Pollution; Scaling; spatial heterogeneity; Species diversity; Species richness; Zoobenthos; Taihu Lake
• ISSN: 0270-5060; 2156-6941
• DOI: 10.1080/02705060.2023.2259229

Freshwater lakes are subjected to increasing eutrophication and algal blooms worldwide, which have dramatically impacted the aquatic biodiversity. This situation is especially true in the Yangtze River Floodplain, China. However, few researches have been focused on differences in the spatial and temporal patterns of benthic macroinvertebrates assemblages between the two adjacent lakes in this floodplain. In this study, we conducted seasonal investigations in 2021 to compare the spatial and temporal patterns of macroinvertebrates in Lakes Taihu and Lake Chaohu. Non-metric multidimensional scaling (NMDS) analyses showed Lake Taihu was found to have differences in assemblages within the lake, but Lake Chaohu was found to have uniform assemblage across the entire lake. Macrophyte-dominated lake regions (eastern Lake Taihu) were characterised by the highest species richness and diversity indices than those in other lake regions. The pollution sensitive species (e.g. EPT: Ephemeroptera, Plecoptera and Trichoptera) were only distributed in the macrophytic areas of Lake Taihu. Corbicula fluminea, polychaetes Nephtys oligobranchia and Capitella sp. were dominant in the middle central lake regions in Lake Taihu. Lake Chaohu and the northern Lake Taihu, with turbid algal-dominated state, were characterised by dominance of Oligochaetes and Chironomids. These differences were attributed to varying habitats and environmental parameters among different lake regions. Canonical correspondence analysis (CCA) demonstrated that macrophytes, chemical oxygen demand (COD Mn ), temperature, ammonium (NH 3 -N) and electric conductivity (EC) were detected as important factors influencing such macroinvertebrate assemblage patterns between these two lakes. This study contributes to the scientific knowledge of within lake habitats, community assemblages, nutrients and pollution within these lakes.