Multi-metric biomonitoring of a seasonally flooded Baraila wetland using benthic macroinvertebrates as indicator organisms in the middle Ganga River Basin (Vaishali), India

Human encroachment, urban and agricultural expansion, frequent droughts, eutrophication, infestation of weeds, and overexploitation of resources has predominantly impacted the water quality and biodiversity of the Baraila wetland. The present seasonal study has aimed to explore an under-researched subject of analyzing the water quality of the wetland through multi-metric biomonitoring approaches in 2022. A total of 24 water and benthic samples were collected from the four sampling locations. All the water parameters were within a suitable range to support diverse range of flora and fauna, except total suspended solids (TSS) and nutrient, indicating toward the impact of agricultural expansion in the wetland's area. Out of the 13 identified families of benthic macroinvertebrates, the semi-tolerant family of Viviparidae and Bithyniidae has dominated the wetland, with a relative abundance of 27.04 and 37.77%, respectively, in the comparative seasons. Moreover, the indices used in the study has categorized the wetland under moderately polluted condition. The Hierarchical Cluster Analysis (HCA) analysis has revealed the sensitivity toward organic pollution and habitat preferences has played major role in the species-specific assemblage of benthic community. The Mantel's correlogram further validates that the moderately polluted status of wetland has favored semi-tolerant to tolerant fauna in the wetland.