Study on Water Quality Parameters and Benthic Fauna Diversity of Otamiri River in Owerri, Imo State, Nigeria.
ABSTRACT
The study on the physic-chemical parameters and benthic fauna diversity of Otamiri River, Nigeria was carried out from June to December 2015. Water and benthic organisms samples were collected monthly from three sampling stations along the stream.
Dissolved oxygen bottles of 1000 ml were used to collect water samples which were fixed with wrinkle’s reagent at the sampling stations. Eckman grab, scoop net, hook and line, cast net, traps and dugout canoe with paddle were used to collect the benthic macro fauna for six months (June-August and October to December).
The results of the study yielded 229 benthic organisms belonging to 15 species and 14 families. In relation to stations, Station 3 had more species and higher abundance of benthic organisms than other sampled stations.
In Station 1, only six species of benthic organisms were recorded while Station 2 had 11 species and Station 3, 13 species of benthic organisms. Majority of the sampled benthic organisms were localized and restricted to one sampled station which was Station 3.
The abundance of benthic organisms in Otamiri River was dependent on season. More benthic organisms were recorded in dry season than in rainy season. The diversity indices yielded high diversity in Station 3 than the other two studied stations.
More species dominated with high diversity index in dry season than in wet season in all the sampled stations. Mean
values of surface water temperature 26.67±0.63 0C, depth 1.96±0.48 m, COD 25.11±0.24 mg/L, BOD 5.47±0.04 mg/L, DO 5.91±0.19 mg/L, Alkalinity 10.66±0.21 mg/L, pH 6.73±0.16, TDS 315.2±48.5 mg/L, Hardness 0.64±0.08 mg/L, Turbidity 4.52±0.16 NTU and TSS 8.68±0.75 mg/L were recorded.
There were fluctuations between the physico-chemical parameters caused by anthropogenic activities, stress to the aquatic life and pollution. Shannon wieners diversity index H = 2.24 was higher in Station 2, while Simpson’s dominance index D= 8.5 was also high at Station 2.
Temperature, Depth, BOD and TSS correlated positively and favoured the abundance and of Synodontis spp. Temperature, BOD, Turbidity and TSS were also positively correlated and favoured the abundance of C. nigrodigitatus and C. armatum.
Negative correlation was recorded in P. serratus in all parameters and in all seasons and stations C. nigrodigitatus was the most abundant species recorded in the present study (32.65%) while the least abundance species was P. serratus (1.25%) and both were found only in Station 3.
The pH, BOD, TDS, hardness, turbidity, DO, BOD, COD and temperature ranges fall within WHO recommendations. Government should make laws restricting dredging and sand mine activities in the sampled area.
TABLE OF CONTENTS
Title Page – – – – – – – – – – – – i
Approval Page – – – – – – – – – – – ii
Dedication – – – – – – – – – – – – iii
Acknowledgements – – – – – – – – – – – iv
Table of Content – – – – – – – – – – – v
List of Tables – – – – – – – – – – – viii
List of Figures – – – – – – – – – – – ix
Abstract – – – – – – – – – – – – xi
CHAPTER ONE: INTRODUCTION AND LITERATURE REVIEW
1.1 Introduction – – – – – – – – – – – 1
1.2 Justification of the Study – – – – – – – – – 4
1.3 Objective of the Study – – – – – – – – – 5
1.4 Literature Review – – – – – – – – – – 5
1.4.1 Water quality parameters – – – – – – – – – 5
1.4.1.1Temperature – – – – – – – – – – – 6
1.4.1.2 Turbidity – – – – – – – – – – – 6
1.4.1.3 pH – – – – – – – – – – – – 7
1.4.1.4 Dissolved oxygen – – – – – – – – – – 7
1.4.1.5 Total hardness – – – – – – – – – – 8
1.4.1.6 Alkalinity – – – – – – – – – – – 8
1.4.1.7 Total dissolved solids – – – – – – – – – 9
1.4.1.8 Total suspended solids – – – – – – – – – 9
1.4.1.9 Conductivity – – – – – – – – – – – 9
1.4.1.10 Chloride – – – – – – – – – – – 10
1.4.1.11 Sulphate – – – – – – – – – – – 10
1.4.1.12 Total phosphorus – – – – – – – – – – 11
1.4.1.13 Orthophosphate – – – – – – – – – – 11
1.4.1.14 Total nitrogen – – – – – – – – – – 11
1.4.2 Benthic fauna – – – – – – – – – – 12
1.4.2.1 Subdivisions of fauna – – – – – – – – – 14
1.4.3 Relationship between water quality and benthic fauna – – – – – 15
CHAPTER TWO: MATERIALS AND METHODS
2.1 Study Area – – – – – – – – – – – 17
2.2 Sampling Method- – – – – – – – – – 19
2.3 Collection of Samples – – – – – – – – – – 19
2.4 Collection of Water Sample for Physico-chemical Analysis – – – – – 19
2.5 Collection of Vertebrate Samples – – – – – – – – 23
2.6 Collection of Macro-invertebrate Samples – – – – – – – 23
2.7 Statistical Analysis – – – – – – – – – – 24
CHAPTER THREE: RESULTS
3.1 Species Diversity of the Vertebrates and Macro-Invertebrates of Otamiri River- – 25
3.2 Physico-chemical Parameters of Otamiri River – – – – – – – 28
3.2.1 Temperature – – – – – – – – – – – 28
3.2.2 Depth – – – – – – – – – – – – 30
3.2.3 Chemical oxygen demand – – – – – – – – – 32
3.2.4 Biological oxygen demand – – – – – – – – – 34
3.2.5 Dissolved oxygen – – – – – – – – – – 36
3.2.6 Total alkalinity – – – – – – – – – – 38
3.2.7 pH – – – – – – – – – – – – 40
3.2.8 Total dissolved solids – – – – – – – – – – 42
3.2.9 Total hardness – – – – – – – – – – – 44
3.2.10 Turbidity – – – – – – – – – – – 46
3.2.11 Total suspended solids – – – – – – – – – 48
3.3 Correlation of Species Abundance of Benthic Organisms with Physico-chemical Parameters 50
3.4 Effect of Season on Physico-chemical Parameters and Composition of Benthic Fauna– 66
CHAPTER FOUR: DISCUSSION AND CONCLUSION
4.1 Species Diversity and Composition- – – – – – – – 68
4.2 Water Quality Parameters of Otamiri River – – – – – – – 69
4.3 The Relationship between Water quality Parameters and Composition of Benthic Fauna 73
4.4 The Effect of Season on Physico-chemical Parameters of Water and Composition of Benthic
Organisms – – – – – – – – – – – – 74
4.5 Conclusion – – – – – – – – – – – 74
4.6 Recommendation – – – – – – – – – – 74
REFERENCES – – – – – – – – – – – 75
APPENDICES
INTRODUCTION
The benthic macro fauna are those organisms that live at the bottom of a water body and are used to detect changes in the natural environment (Idowu and Ugwumba, 2005; Akaahan et al., 2015).
Studies of aquatic bodies have established the existence of relationships between water quality and macro and micro-invertebrate diversity (Teferi et al., 2013). They serve as monitor for the presence of pollutants, their effects on the ecosystem and the progress of environmental clean-up process (Nkwoji et al., 2010).
The assessment of the biotic condition compliments the physico-chemical parameters in aquatic environment condition determination (Madhushankha et al., 2014).
Macro-invertebrate organisms form an integral part of an aquatic environment and are of ecological and economic importance as they maintain various levels of interaction between the community and the environment (Sharma et al., 2013).
According to Marques et al., 2003), knowledge of the structure of the benthic macro-invertebrate community provides precise and local information on recent events, which can be seen in their structuring.
The use of invertebrates and fish as bioindicators of water quality has been advocated by several researchers (Adakole and Annune, 2003). The use of macro-invertebrate diversity for bio-assessment provides a simpler approach compared to other environmental quality assessment procedures.
This is because, macro-invertebrates can be sampled quantitatively and the relative sensitivity or tolerance of some of them to contamination is known (Adakole and Annune, 2003).
REFERENCE
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Adeogun, A. O. and Oyebamiji, O. F. (2011). Impact of effluents on water quality and benthic macroinvertebrate fauna of Awba Stream and Reservoir. Journal of Applied Science and Environmental Management, 15(1): 105 – 113.
Adeyemi, S. O., Adikwu, I. A., Akombu, P. M. and Iyua, J. T. (2009). Survey of zooplanktons and macro-invertebrates of Gbedikere Lake, Bassa Kogi State, Nigeria. International Journal of Lake and Rivers, 2(1): 37 – 44.
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