Factors Affecting Macrobenthic Invertebrates Distribution in Badagry Creek, South Western Nigeria

Abstract

The aim of the paper is to identify macroinvertebrates distribution in response to induced stressors and physico-chemical parameters of water and sediment. The species composition of macrobenthic invertebrates as well as the physico-chemical characteristics of Badagry creek was investigated monthly. Six sampling stations selected based on different levels of human activities along the creeks stretch and samples were collected monthly from September 2006 to February 2007. The fluctuations of some of the physical and chemical parameters such as pH, dissolved oxygen, BOD and total organic carbon appeared to have been influenced by activities along the study stretch. Analysis of variance (ANOVA) for all parameters showed no significant differences (P > 0.05) in the parameters but Post hoc tests analysis using Duncan showed that there was a significant difference (P = 0.05) in the mean total of some of the parameters. pH, clay, sand and gravel were significantly correlated with other parameters while canonical correspondence analysis (CCA) model showed that the environmental variables correlated with significant part of the variations in the individual species abundance and it revealed that dominant species were found to be significantly correlated with dissolved oxygen, total dissolved solids, sand and pH.

The Benthic Macro-Invertebrate Fauna of Owalla Reservoir, Osun State, Southwest, Nigeria

“…The benthic macroinvertebrate fauna of the Owalla Reservoir is broadly similar (in terms of abundance and species composition) to that of many other Nigerian inland waterbodies (Nathaniel, 2002;Aliu, 2006;Asibor, 2008;Olomukoro, 2008;Olomukoro and Azubuike, 2009;Adedeji, 2011;Adedeji et al, 2012;Olapoju and Edokpayi, 2018). In this study, for instance, a total of 5076 individuals were recorded from the reservoir belonging to 18 different species of benthic macroinvertebrates.…”

“…The benthic species diversity is controlled by productivity, habitat heterogeneity and biotic interactions; in general, invertebrates have a clumped distribution, which is assumed to be related with the mosaic of interchanging conditions in the substratum, flow conditions/velocities, depth and the type of substrate (Moretti and Callisto, 2005;Stamou et al, 2018). Some physical and chemical features directly affect taxonomic composition and community structure; substratum particle size, substratum stability, substratum organic matter contents (Wangchuk and Dorji, 2018), habitat spatial heterogeneity and sediment characteristics such as; grain size, predator exposure and food availability are important factors regulating macro-invertebrates abundance, distribution and richness, and hence, habitat characterization is of prime importance to the knowledge of macroinvertebrate distribution (Moretti and Callisto, 2005;Olapoju and Edokpayi, 2018). The relatively high number of individuals (benthic macroinvertebrates) from Owalla Reservoir could be attributed to probably the high nutrients and organic matter levels in the sediments (organic matter content: range = 0.69 -14.10 %; Mean±S.E.…”