Effect of anthropogenicity on the composition and diversity of aquatic insects of a municipal river in North Central Nigeria

Abstract

Composition and diversity of aquatic insects as influenced by anthropogenic activities in River Chanchaga, Niger State, Nigeria was investigated for a period of six months spanning from April through September, 2014 in three stations. Habitat and water quality were done using qualitative habitat evaluation index (QHEI) and America public health association (APHA) method of water analysis respectively. Aquatic insects were sampled with a kick net of about 250 μm mesh size. QHEI values in the three stations showed that the stations were moderately impaired with station 1 having the highest value (64.3%), while canopy cover of the three sampled stations were relatively poor. Physicochemical parameters values were within the maximum permissible limit of water quality variables by Federal Environmental Protection Agency (FEPA), Nigeria and Standard Organisation of Nigeria (SON) except dissolved oxygen and pH. A total of 6 orders, 16 families, 19 taxa and 101 individuals of aquatic insects were recorded during the study. The overall abundance, distribution and composition of aquatic insects were poor. Station 1 had the highest number of species composition (55) while station 3 had only 6 individuals of aquatic insects. Simpson dominance (D) and Shannon-weiner index were highest in station 1. Station 3 was more even in aquatic insect distribution (0.8965) while station 1 had the highest margalef richness index (d) of 4.969. The pollution sensitive species in the group of Ephemeroptera, Plecoptera and Trichoptera (EPT) were poorly represented or even absent in some case probably owing to the deteriorating state of the sampled stations as a result of various human activities. Canonical correspondence analysis (CCA) showed a very weak relationship between the insects’ abundance and distribution and environmental variables measured. Coelhydrus sp., Chlorostidae, Chironomus sp., Philodytes sp., Cordulidae and Neoperla sp. were strongly associated with axis 1 and this association was explained by dissolved oxygen, phosphate and water depth. Bray-curtis similarity index performed revealed that samples were more clustered by months than by stations. The research was able to provide a baseline study as a biomonitoring tool for the assessment of the integrity of water bodies in Niger State and Nigeria in general. Citation: Edegbene AO, Arimoro FO, Odoh O and Ogidiaka E (2015). Effect of anthropogenicity on the composition and diversity of aquatic insects of a municipal river in North Central Nigeria. Biosciences Research in Today’s World 1(1): 55-66. Received May 31, 2015; Accepted July 2, 2015; Published July 19, 2015. Copyright: © 2015 Edegbene et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. BRTW is the official journal publication of BRSF. Competing Interests: The authors have declared that no competing interests exist. * E-mail: ovieedes@gmail.com This research work was presented at the Biosciences Research Support Foundation (BRSF)’s 1st International Conference on Biosciences Research (ICBR), Awka, Nigeria, 25-27 May 2015.