Institute for Water Research, Rhodes University, Grahamstown (Makhanda), 6140, South Africa.
Department of Biological Sciences, Federal University of Health Sciences, Otukpo, Nigeria.
Environ Sci Pollut Res Int. 2022 Feb;29(10):15068-15080. doi: 10.1007/s11356-021-16748-4. Epub 2021 Oct 8.
Forested catchments surround most of the riverine systems in the Niger Delta area of Nigeria. Presently, there are no biomonitoring tools to assess the ecological health of forested rivers in the area. Hence, this study is aimed at developing a macroinvertebrate-based multimetric index for assessing the health forested riverine systems in the Niger Delta area of Nigeria. Physico-chemical variables and macroinvertebrates were sampled from 18 sites in 11 rivers. Physico-chemical variables were used to categorise river sites into three ecological classes, which include near natural sites (NNS), slightly disturbed sites (SDS) and moderately disturbed sites (MDS). Fifty-four(54) macroinvertebrate candidate metrics in four groups which include abundance, composition, richness and diversity were selected for the development of the Niger Delta forested rivers multimetric index (FoMIND). Of the 54 metrics selected, four were integrated into the FoMIND, and they include EPT/Chironomidae abundance, %ETOC, Diptera richness and evenness index. Correlation of integrated metrics with physico-chemical variables on redundancy analysis (RDA) ordination showed that EPT/Chironomidae abundance and evenness index positively associated with dissolved oxygen at NNS which confirmed the near-natural conditions of most of the forested riverine systems in the Niger Delta. Therefore, FoMIND is recommended as a rapid diagnostic tool for monitoring and assessing water quality conditions of rivers within forested catchments in Nigeria.
尼日利亚尼日尔三角洲地区的大多数河流系统都被森林覆盖。目前，该地区还没有生物监测工具来评估森林河流的生态健康状况。因此，本研究旨在开发一种基于大型底栖无脊椎动物的多指标指数，以评估尼日利亚尼日尔三角洲地区森林河流系统的健康状况。从 11 条河流的 18 个地点采集了理化变量和大型底栖无脊椎动物样本。理化变量被用来将河流站点分为三类生态类群，包括近自然站点（NNS）、轻度干扰站点（SDS）和中度干扰站点（MDS）。在四个组中选择了 54 种大型底栖无脊椎动物候选指标，包括丰度、组成、丰富度和多样性，用于开发尼日尔三角洲森林河流多指标指数（FoMIND）。在所选择的 54 个指标中，有 4 个被整合到 FoMIND 中，它们包括 EPT/摇蚊科丰度、%ETOC、双翅目丰富度和均匀度指数。基于冗余分析（RDA）排序的综合指标与理化变量的相关性表明，EPT/摇蚊科丰度和均匀度指数与 NNS 处的溶解氧呈正相关，这证实了尼日尔三角洲地区大多数森林河流系统的近自然条件。因此，FoMIND 被推荐作为一种快速诊断工具，用于监测和评估尼日利亚森林集水区内河流的水质状况。
