Microbial Diversity Metrics: An Insight into the Ecological Status of Different Water Resources in Anambra State Central Senatorial Zone, Nigeria

Abstract

This study evaluated the cumulative biodiversity patterns across selected seven Local Government Areas (LGAs) using multiple ecological diversity indices to determine variations in community structure and dominance. Standardized procedures were strictly adhered to during the sampling and bacteriological examination of the water samples from 21 different sampling sites. The structure of the bacterial communities was subsequently evaluated using established ecological metrics, including species richness, evenness, diversity and dominance indices. The results revealed marked spatial differences among the study areas. Awka North recorded the highest Margalef’s richness index (1.19), indicating relatively greater species richness. In contrast, Njikoka exhibited the lowest Margalef’s richness (1.05), suggesting reduced species representation. Awka South showed the lowest Simpson’s diversity index (0.45) and Simpson’s reciprocal index (1.82), reflecting lower overall diversity and higher dominance. Dunukofia had the lowest Pielou’s evenness (0.49), indicating uneven species distribution. Anaocha recorded the highest Berger–Parker dominance index (0.69) and the lowest Shannon equitability (0.46), demonstrating strong dominance by a few taxa and reduced community balance. Conversely, Idemili South exhibited the highest Simpson’s reciprocal index (3.24) and lowest Simpson’s index (0.31), suggesting comparatively higher effective diversity and lower dominance, while Idemili North and South showed the lowest Berger–Parker dominance (0.51), indicative of more evenly distributed communities. Overall, the application of multiple biodiversity indices revealed significant differences in richness, dominance, and evenness across the LGAs, underscoring the importance of multidimensional ecological assessment. The findings provide valuable insight into spatial variations in community structure and serve as a baseline for environmental monitoring and sustainable ecosystem management in the study area.