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

Abstract

Urban pollution of riverine ecosystem is a serious concern in the Niger Delta region of Nigeria. No biomonitoring tool exists for the routine monitoring of effects of urban pollution on riverine systems within the region. Therefore, the aim of this study was to develop and apply a macroinvertebrate‐based multimetric index for assessing water quality condition of impacted urban river systems in the Niger Delta region of Nigeria. Macroinvertebrate and physicochemical samples were collected from 11 stations in eight river systems. Based on the physicochemical variables, the stations were categorized into three impact categories namely least impacted stations (LIS), moderately impacted stations (MIS) and heavily impacted stations (HIS). Seventy‐seven (77) candidate metrics were tested and only five: Hemiptera abundance, %Coleoptera + Hemiptera, %Chironomidae + Oligochaeta, Evenness index and Logarithm of relative abundance of very large body size (>40–80 mm) were retained and integrated into the final Niger Delta urban multimetric index (MINDU). The validation dataset showed a correspondence of 83.3% between the index result and the physicochemically‐based classification for the LIS and a 75% correspondence for the MIS. A performance of 22.2% was recorded for the HIS. The newly developed MINDU proved useful as a biomonitoring tool in the Niger Delta region of Nigeria and can thus be used by environmental managers and government officials for routine monitoring of rivers and streams subjected to urban pollution.

Monitoring and Exploring the Spatio-temporal Variation of Physico-chemical Variables of River Hadejia, Nigeria; Using Statistical Approach

“…Water Physico-chemical parameters variability in water bodies had both negative and positive effect on the functional and structural composition and diversity of aquatic biota [1]. Among the various water quality variables used in assessing ecological status of rivers, surface water temperature has a direct effect on the freshwater systems as it depicts the production rate of the system as has be reported by several authors [1,2] in some selected river in the Afrotropic.…”

“…Water Physico-chemical parameters variability in water bodies had both negative and positive effect on the functional and structural composition and diversity of aquatic biota [1]. Among the various water quality variables used in assessing ecological status of rivers, surface water temperature has a direct effect on the freshwater systems as it depicts the production rate of the system as has be reported by several authors [1,2] in some selected river in the Afrotropic. Other anthropogenic factors such as urbanisation and industrialization resulting in domestic and industrial wastewater discharges and changes in the natural and geological patterns as well as soils and hydrological alteration have a debilitating effect on water physico-chemistry of riverine systems [1,3].…”

“…Among the various water quality variables used in assessing ecological status of rivers, surface water temperature has a direct effect on the freshwater systems as it depicts the production rate of the system as has be reported by several authors [1,2] in some selected river in the Afrotropic. Other anthropogenic factors such as urbanisation and industrialization resulting in domestic and industrial wastewater discharges and changes in the natural and geological patterns as well as soils and hydrological alteration have a debilitating effect on water physico-chemistry of riverine systems [1,3]. Changes resulting from natural processes due to human activities can adversely affect ecosystem structure and function [1].…”

“…Other anthropogenic factors such as urbanisation and industrialization resulting in domestic and industrial wastewater discharges and changes in the natural and geological patterns as well as soils and hydrological alteration have a debilitating effect on water physico-chemistry of riverine systems [1,3]. Changes resulting from natural processes due to human activities can adversely affect ecosystem structure and function [1]. Water physicochemical has been used to assess the health of riverine systems for decades and has been used by aquatic resources managers in managing and sustaining the aquatic systems [3][4][5].…”

“…Based on the varied importance of physicochemical variables in aquatic systems, and several studies have been conducted to determine their variation in freshwater systems [2,1,12,13,17] this study was carried out to add to the growing pool of information with regard to monitoring of freshwater systems using physicochemical variables. Therefore, the aim of this study is to explore the spatio-temporal variation of physico-chemical variables in River Hadejia in a bid to monitor to ascertain the health staus of the river.…”