Assessment of Nematode Diversity and Abundance as Bioindicators of Pollution in Open Waste Dumpsites in Makurdi Metropolis, Nigeria

Abstract

Soil nematodes are sensitive bioindicators of soil health and environmental pollution. This research investigated the diversity, abundance, and ecological functions of nematodes in soils from active and abandoned dumpsites, comparing them with control (unpolluted) sites in Makurdi, Nigeria. The impact of open waste dumping on nematode community structure was studied by observing the nematode community structure at seven open waste dumpsites and a control (reference) site. Seven active dumpsites were selected for this study during the 2024 rainy season in Makurdi. The dumpsites were found in Government Reserved Area (GRA), Nigerian Army School of Military Engineers (NASME), Wurukum, Judges Quarters, North-Bank, Wadata Market and High-level areas. A total of 140 soil samples were randomly collected from the seven dumpsites and an additional 140 soil samples from the reference sites in each location 5 km away from each dumpsite. Twenty-four nematode genera were isolated from the total samples collected and belonged to 15 nematode families. The reference site had the highest nematode abundance (953 nematodes/composite sample) compared to the waste dumpsites. It also had the highest number of nematodes in each colonizer-persistent (c-p) group, especially of c-p 1 (181) and c-p 2 (405), suggesting a more natural or less disturbed environment. Among the seven dumpsites, the High-Level area dumpsite had the highest nematode abundance (245 nematodes/composite sample) followed by the dumpsites in GRA and Wurukum. These areas had relatively high numbers of c-p 1 and c-p 2 nematodes, indicating potential environmental conditions favouring colonizers. The dumpsites in Judges Quarters and NASME had a population of 58 and 52 relatively low nematode abundance compared to High level, GRA and Wurukum area. The least nematode abundance was observed in Wadata (Site 6) with a population of 48 nematodes/composite sample. The low numbers suggest factors such as soil disturbance, pollution, or habitat degradation affecting nematode populations. The reference site had the highest maturity index (MI) of 2.55 closely followed by the dumpsite of North Bank with an index of 2.35 suggesting more developed and stable soil conditions. The least MI was recorded in High Level (2.00) area indicating more disturbed environment. Using nematode-based indices this study present empirical evidence of the pollution levels of the dumpsites and the urgent need for government intervention, especially considering the crucial need for more sustainable land use.

Keywords: Nematode, Open waste dumpsites, Environment, Ecology, Pollution

DOI: 10.7176/JEES/15-3-06

Publication date: July 30th 2025