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

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 area of
Nigeria. Macroinvertebrate and physico-chemical samples were collected
from 11 stations in eight river systems. Based on the physico-chemical
variables, the stations were categorised 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 data set showed a correspondence of 83.3% between the index
result and the physico-chemically-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.