Effects of the Macro-Invertebrates Community Structure on the Quality of Surface Water in Enugu Urban, Enugu State, Nigeria

Journal of Interior Designing and Regional Planning Volume 4 Issue 1

Effects of the Macro-Invertebrates Community structure On the Quality of Surface Water in Enugu Urban, Enugu State, Nigeria

1Mr. Nnachi Michael Ama, 2Prof. Essaghah .A, 3Dr. Virginia Delunzu-Okwu, 4Dr. Ubani Obinna. J 1Lecturer Department of Urban & Regional Planning, Enugu State University of Science &Technology, Enugu 2Professor Department of Urban & Regional Plannin, Enugu State University of Science &Technology, Enugu 3Ph.D holder Department of Urban & Regional Planning, Enugu State University of Science &Technology, Enugu 4Lecturer Department of Urban & Regional Planning, University of Nigeria, Enugu Campus, Enugu Email: [email protected]

Abstract The need for a robust understanding of macro invertebrates’ diversity can lead to specific management of surface water. This is essential due to frequent threats to aquatic ecosystem. The thrust of this study was to examine the water quality assessment using macro- invertebrates in surface waters in Enugu urban. In this study, 12 surface water samples were collected from the six major rivers in Enugu urban. Macro invertebrates were collected using semi-quantitative sampling techniques.The study spanned both the dry (February –early April) and the wet seasons, (late April to September). Nine (9) taxa comprising of 33 species belonging to Arthropod, Annelida and Mollusca were identified accounted for 1163 individuals. Increasing dominance of Macro-invertebrates followed the order: Mollusca (35%), Coeloptera (28%), Diptera (12.7%), Annelida (11.4%), Trichoptera (4.96%), Placoptera (2.78%), Ephemeroptera (3%), Hemiptera (0.85%) and Odonata (0.08%). The low number of macro-invertebrates and the dominant species (Melanoides, tuberculataandChironomussp.) being pollution tolerant suggest that the rivers especially Ekulu and Asata is relatively under stress. Species diversity indices showed a variation in the community structure in the rivers. Therefore, there is a need to regularly monitor and control the source of pollutants to the water bodies.

Keywords: Macro-invertebrates, physicochemical parameters, Pollution, Water quality

INTRODUCTION natural pressures encountered by aquatic In Nigeria, most cities contain a number of and terrestrial organisms in their habitats, water bodies together with a small network human activities do generate other more of streams. Enugu urban is among the environmental pressures. However, in cities that is have many surface water; order to understand the status of surface these rivers are linked to one another water quality and reduce pollution rate in across neighborhood’s. Among the surface surface waters, the knowledge about the water bodies are Ekulu River, Asata River, health status of aquatic environment New Haven River, Agangwu (around Coal including their biodiversity is important. Camp area), Okwuosa River, Idaw River This is robust when assessed along the and Ogbete River. [1]. Most of these seasonal and spatial variability of the freshwater ecosystems are prone to water body [2]. This can be done, aside the pollution loads from different pollution physico-chemical parameters, by using points. Though there are many sources of various established bio indicators of water

Journal of Interior Designing and Regional Planning Volume 4 Issue 1

quality. Many developed countries such as monitoring of water quality. Eliasl et al., in Europe, Canada and United States have [4] have posited that macro invertebrate grossly used macro invertebrates as bio may be suitable for assessment of severity indicators in technical standards of water of contamination of water pollution and quality monitoring [3]. In developing that these families are very diverse, countries such as Nigeria, their use is still sensitive, population to pollution of a very limited. Unfortunately, studies in water body. The study equally asserted surface water pollution have not paid that the variation in the number of these sufficient attention to the relationship macro invertebrate populations in water between spatial and temporal variation and body indicates pollution, presence of stress the diversity of macro-invertebrates in factors and damage to the ecosystem. rivers have been lacking in Nigeria at large Several studies have found the and Enugu in particular. Assessment of discrepancies of data between chemical surface water quality in Nigeria even in and biological measures [5, 6]. Studies Enugu urban was mainly done by have submitted that the assessment of the analyzing physico-chemical parameters. relative impact of water pollution on living Unlike the physico-chemical variables organisms inhabiting in surface water can which provide information about water be extensively done by bio-monitoring of quality at the time of measurement, the streams. Freshwater organisms live monitoring of living organisms (bio continuously in the water and sensitive to monitoring) can provide information about all environmental stressors [7]. However, past and/or episodic pollution and the physical and chemical assessment is not cumulative effects of a suite of watershed enough to explain the quality of water impacts. This type of comprehensive because physical and chemical parameters assessment of water quality is lacking in cannot provide long-term pollution [8]. the body of academic knowledge in

Nigeria let alone in Enugu. There is no Biological monitoring has advantages over information on the structure and functioning of macro invertebrate’s chemical monitoring because it integrates species and taxa in surface water in Enugu responses to a range of pollutants urban, also no assessment of water quality occurring over different times [9]. A using macro invertebrates has been done in macro invertebrate serves a pivotal role to these rivers in Enugu urban. Against this understand ecological status of water body background, the purpose of this study is using biological indicator as a tool and assessing the macro-invertebrates provide accurate measures of stream parameters of the surface water in Enugu health. Studies have shown that out of the urban. Enugu State, Nigeria. The outcome various organisms that are prevalently of the study to give a better understanding used as biological indicators, benthic of the ecology of the surface water to macro invertebrates have always been ensure proper management and used. This is due to: the relatively low conservation of freshwater mobility and long life cycles, secondly, benthic macro invertebrates always reflect LITERATURE REVIEW temporal patterns and local conditions. It Macro invertebrates are organisms which has been posited also that invertebrates are are large enough to be seen with the subsets an aquatic environment and they unaided eye and without vertebral column, are of ecological and aquatic importance most abundant and diverse group of as they maintain various levels of inter- animals found in freshwater which include action between the community and the flies, Snails, mussels, worms, nematodes environment [10]. and crustaceans are used for bio

Journal of Interior Designing and Regional Planning Volume 4 Issue 1

They are significant within the food chain depicts the map of Enugu showing the as larger animals such as fish and birds various neighborhoods and Core Rivers in the rely on them as a food source. Macro study area. A small portion of Enugu water invertebrates are sensitive to different supply currently comes from boreholes of the th chemical and physical conditions. 9 Mile Corner water scheme. In the study area, the borehole specific capacity of 410 STUDY AREA liters/hour/meter of draw down can be The Enugu Urban area is bounded to the expected. The depths of an average borehole West by Ngwosettlement in Udi Local are generally about 110 meters. It lies in Government Area, in the East by Nkanu East transitional-savanna region; and this is Local Government Area, in the North by derived from prolonged cultivation. It is Enugu East Local Government Area and in important to know that rivers in the study the South by Nkanu West Local Government area are linked to one another across some Area. Enugu urban is located at the neighbourhoods. In other words, some of transitional-savanna region. The 2006 them are tributaries of others as they move National Population Census of Enugu was along neighbourhoods. From the geological 722, 644, according to (National Population map of Enugu, Ekulu River is the largest Commission, (NPC), 2007). Using 2.8% river that cuts across the study area; other annual rate of increase, the populations’ rivers in the study area include Asata River, projections of people that consume water in Aria River, Ikiriki River, Idaw River and the sample areas is about 873, 043. Figure 1 Ogbete River.

Figure 1: Map of Enugu Enugu Urban Source: produced from Geographical Information system GIS (Quick bird Satellite imagery 2018)

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METHODS AND MATERIALS they are Ekulu river, Asata river, Aria This study adopted the experimental river, Ikiriki river, Idaw River and research method. The surface water Ogbete river. Their locations, depths, sampled in the study were all the six stations and reach was shown in table 1 major surface water in Enugu urban and below

Table 1: Description of the sample location s/n Station Sample Locations Latitude Longitude Depth (m) Reach 1. S1 Ekulu River at New market fly over 331160 15126 1.67 Upper 2. S2 Ekulu River at Ujodo development centre 332483 715284 1.83 Lower Asata River at Enugu Port-Harcourt 3. S3 338568 71323 0.98 Upper Express Way, New Artisan 4. S4 Asata River at Amigo Lane CIC. 335499 713803 1.32 Lower 5. S5 Aria River at Works Road 332125 713009 1.55 Upper Aria River at Access Bank, Garden 6. S6 333501 713578 0.91 Lower Avenue 7. S7 Idaw River at Maryland, Timber Shed 334454 709239 2.10 Upper 8. S8 Idaw River at Abalukwu Street 33335 709384 2.34 Lower Ikiriki River at Enugu Port-Harcourt 9. S9 337584 708958 1.98 Upper Express Way, Ugwuaji Bridge 10. S10 Ikiriki River at Amechi Road 333999` 707648 2.09 Lower 11. S11 Ogbete River at Old UNTH 331781 711408 1.77 Upper 12. S12 Ogbete River at Holy Ghost Cathedral 332946 71132 2.65 Lower Source: field work, 2018

Two sampling locations were assigned in the small and the large mobile each of the river, one at the Upper section invertebrates were collected. This is (upstream) of each river, another at the actually to ensure internal validity of the Lower section (downstream) of the river. study. Since this is an experimental Thus, a total of 12 sampling location was research, samples were identified in the used in the study been examination laboratory and segregated into families contacts since there are 6 water bodies in with the use of microscopes and hand lens. use. Each of the 12 locations was sampled Collected samples were equally preserved between February and November 2018 on with ethanol and formaldehyde in the a bi-monthly basis in the early hours (7.00 laboratory for avoids loss and decay. a.m. to 9.00 a.m.) of the day during first Macro invertebrate species were identified week of every two months. The sampling using available keys and keys from Merritt period covered both the dry (February– and Cummins method (1996) as well as early April) and the wet seasons. (late assistance from macro invertebrate April to September). This was used to taxonomist/ specialists and their toxicity determine seasonal variations of the water assessed. quality during the two seasons. A semi- quantitative sampling technique was used Furthermore, in other to appreciate the to collect samples from 12 sites from the 6 abundance and distribution of these selected water bodies. Representative samples, these indices- Shannon- Wiener aquatic macro invertebrates’ samples were (H’), Maraglef’s index, and Equitability targeted in the collection of the samples. index parameters were adopted. However, At each site, aquatic macro invertebrates evenness is calculated as defined by Pielou were collected using Surber net samplers index (E). Mathematically, the Margalef’s (475 μm mesh, area of base 0.09 m2) and Index (d) was used to calculate for species a bottom kick net (500 μm mesh) and or taxa richness using this formula below. manually using hands. In the study, both

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d = 푆−1/In푁 S = Number of species Where, S = Number of species Evenness/Equitability Index (S) was N = Total number of individuals used to calculate the degree of uniformity In = Natural logarithm in the distribution of individuals of each taxon collected. Shanon-Weinner’s Index (H) was used E = 퐻\ 퐻푚푎푥 to calculate the general diversity. This Where, index is a function of the relative H = General diversity abundance of the species in the Hmax or logs = Maximum expected macrobenthic community. diversity H = N log N−Σ f1logf1 ------RESULTS AND DISCUSSION N The data obtained on the investigated Where, macro invertebrates Species Composition, N = Total number of individuals Abundance and Distribution in Rivers F1 = Number of individuals in species Enugu Urban are given in Tables 2, and 3.

Table 2: Macro invertebrates Species Composition, Abundance and Distribution in rivers in Enugu Urban Species identified Ekulu Asata Aria Idaw Ikiriki Ogbete Total % Annelida Eclipidrilussp. 5 2 4 1 5 2 19 1.6 Stylodrilussp. -3 0 3 3 1 3 10 0.8 Isochaetidefreyi. 0 1 3 2 6 5 17 1.4 Limnodrilussp. 3 0 4 2 1 1 11 0.9 Potamothrixsp. 14 0 12 5 0 0 31 2.6 Tubifexsp. 10 6 4 1 5 5 31 2.6 Chaetogastersp. 1 0 0 0 0 0 1 0.08 Pristina sp. 0 0 1 4 6 2 13 1.1 11.40% Mollusca Valvatasp. 2 3 3 0 0 0 8 0.7 Bulinussp. 10 6 13 20 8 3 60 5.1 Biomphalariasp. 10 10 150 37 10 7 224 19.2 Ammicolasp. 11 13 10 0 4 0 38 3.2 Pisidium sp. 4 17 38 11 5 4 79 6.9 35.00% Arthropoda Ephemeroptera (may flies) Callibaeticsp. 0 0 15 10 11 0 36 3.00%

Odonata (dragon flies) Ischnurasp. 0 0 0 1 1 0 2 0.08%

Hemiptera (waterbugs) Hesperocorixasp. 6 3 2 0 5 5 21 0.85%

Plecoptera (stone flies) Ostrocercasp. 0 0 1 0 0 0 1 0.08 Leuctra sp. 0 0 18 11 1 0 30 2.7 2.78% Coeloptera (beetles) Hydrobiussp. 32 10 101 30 103 20 296 25.3 Agabetessp. 1 1 5 15 2 5 29 2.4

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28.00% Trichoptera Macrostermum sp. 0 0 28 20 10 0 58 4.96%

Diptera (true flies) Chaobrussp. 10 7 10 1 3 2 33 2.9 Simuliumsp. 1 1 45 21 0 1 69 5.9 Chironomussp. 34 4 3 1 2 2 46 3.9 12.70% Total Sample collected 154 84 472 196 189 67 1163 100 Percentage 13.1 7.2 40.5 16.8 16.2 5.7 100 100

The study also presented the summary of the various rivers. Table 3 shows the the abundance of these invertebrates in the summary of the diversity pattern of these study area. The equitability index shows invertebrates. Asata River has 0.293 while that the invertebrates were not equitable in Aria has 0.274.

Table 3: Summary of the abundance and distribution of macro invertebrates at the Rivers in Enugu Urban Description (Indices) Ekulu Asata Aria Idaw Ikiriki Ogbete Number of Taxa 9 9 9 9 9 9 No of species per site 16 14 22 19 19 15 No of individuals 154 84 472 196 189 67 Margalef’s index 2.276 2.405 2.679 1.391 2.918 2.054 Shannon-weinner 0.683 0.340 0.617 0.412 0.623 0.342 Equitability 0.126 0.292 0.274 0.104 0.268 0.287

The study shows that the Aria River had apply fertilizers in their farms, hence the the highest number of species followed by constant traces of fertilizer components Idaw River, then Ikiriki and Ekulu Rivers, inside the rivers becomes eminent. The use while Ogbete River recorded the lowest in of fertilizers increases the amount of terms of species diversity (table 2). Wide nutrients entering the water and this may fluctuations were observed in the lead to a corresponding increase in abundance of taxa from river to river. The ammonia, nitrate-nitrogen levels and a non-presence of ephemeroptera, reduction in dissolved oxygen. However, plecoptera, stone flies and Trichoptera Mollusca were found in all the streams and especially at Ekulu River can be traced to this suggests that there was tolerance to increase in farming and car washing some levels of pollution. The Tubifex and activities around the bank of the rivers. It potamonthrix were the only Annelid has become a common site in these rivers observed in large quantity in the streams. for artisans and car owners to wash their Its presence has been linked with an cars after the day’s duty in these rivers. affinity for phosphate concentrations and This action is traceable to the incessant the organism is known to bio-accumulate nature of the public water supply system. high phosphate concentrations without Enugu urban does not have regular water signs of poisoning. In the study, the low supply and this had made some drivers number of these macro invertebrates in the mostly commercial car drivers to resort to study area could be due to some the use of the river banks to wash their imbalances/ this according to a similar dirty cars. Furthermore, Ekulu river and study by Andem [11] could arise from Ikiriki river has their banks host many alterations of some important factors [11]. agricultural activities. And it has been the However, their abundance at Ekulu River tradition of farmers in the study area to may be linked to their high tolerance to

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anoxic conditions. The presence of these sampling period. Again, the presence of the Tubifex species in the studied rivers Trichoptera species in some of the rivers could be due to the flow of the water actually suggests that those rivers have current from the other tributary of the river high level of Dissolved Oxygen. The and being tolerant to the alkaline and relative abundance of Diptera species anoxic condition of the sample site may (12.7%) recorded in this study might be proliferate at the expense of resident taxa. favored by the conditions of the immediate Furthermore, the study recorded the substrates which include the alkalinity of dominance of pollution tolerant species the study area [15]. In summary, the (Chironomus) in the study area. This absence of these pollutant tolerant species clearly suggests the deterioration of water (Ephemeroptera, trichoptera and quality. Study has shown that Chironomus Placoptera) in Ekulu and Aria rivers and is normally sustained in polluted the presence of abundance of environment due to possession of Chironomoussp in them indicate that these hemoglobin a pigment that helps them to two rivers are seriously polluted and always store dissolved oxygen [12]. highly dangerous for both aquatic and Disturbing in the study was the presence of human dependence. This serves as a wake- Chrinomussp, Tubifexsp, and up call to public health officers and public Limnodrilussp in all the sampling sites, services providers in Enugu. This this actually was an indication of the information, haven empirically proven the presence of pollution in a localized state, water quality status of these rivers which can have a devastating effect in both especially Ekulu and Aria Rivers, should the aquatic and terrestrial environment in call for immediate remedial attention to be the study area and even in the entire taking by the water management ecosystem including humans [13]. The authorities in Enugu urban presence of Chironomoussp (3.9%) in this study corroborates with that of [14] who SPECIES DIVERSITY AND recorded 3.42% of Chironomoussp. in his EQUITABILITY work on macro-invertebrates community The species diversity of the overall mean diversity in relation to water quality status abundance of macro-invertebrates in all of River Kunda India. Since this the sampling stations was shown in table Chironomoussp species is in great 3. The table shows that there were no abundance in the rivers in the study area, marked changes in species diversity in all this suggests that organic pollution in the the sampling stations. The highest Shanon- stream was from anthropogenic source. Wiener index calculated was in station Ekulu river (0.683) while the lowest index The study shows that the highest species was recorded in Ogbete river (0.340) - diversity was Arthropod which was 53.3%, (table 3). The Margalef’s value was this was followed by Mollusca (35.0%) highest (2.918) at Ikiriki River and lowest and the Annelida accounted for 11.4% of value was recorded in Idaw River (Table the species observed. These indicate that 3). The study shows that the highest there was no habitat destruction as all equitability value in Asata River was these taxa were recovered in all the six 0.292. The Shanon-Wiener diversity rivers that were used during the study. The indices in the locations of the rivers fell abundance of these species is an indication between 0.30 - 0.68. These values of good quality and may be due to habitat according to the classification of [16] are preference, dilution during rains and indicative of not so much polluted water availability of food. Similarly, the study conditions. They were however closer to recorded that they were only (2) species of the lower ending of the range which means Coeloptera in the studied rivers during the they may be tending towards moderately

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polluted conditions. Equitability values REFERENCES were low, ranging from 0.10 - 0.29 and 1 Ubani O, Mba E & Ozougwu M this indicated the uneven distribution of (2014), An Assessment of the individual numbers among the species. Pollution Levels of Rivers in Enugu These low values indicated that the Urban Nigeria and their Environmental location status in terms of benthic fauna, Implication, Journal of Environment ranged from not polluted to moderately and Earth Science, 18(4),No 3 pollute. The varying degrees of species www.iiste.org composition in these rivers also denoted 2 Mophin-Kani, K., and Murugesan, the instability of the environments which A.G. (2014) Assessment of River suggests a certain degree of pollution. The Water Quality Using Macro lower abundance of sensitive species and invertebrate Organisms as Pollution higher abundance of tolerant species in the Indicators of Tamirabarani River rivers indicated homogeneous habitat Basin, Tamil Nadu, India. International structure and reflected poor water Journal of Environmental Protection. 4 conditions. The few macro invertebrate (1)1-14. communities indicated polluted 3 Faulkner, H., Edmons Brown, V. and environment reflecting poor and unstable Green, A. (2000). Problems of Quality ecosystem with soiled nature in Diffusely Polluted Ur-ban Streams the Case of Pymme’s Brook, North CONCLUSION London. Environmental Pollution 109, The macro-invertebrates at the rivers in 91-107. Enugu urban during the study period were 4. Elias, J.D., Ijumba, J.S., and Florence dominated by three phyla Annelida, A. Mamboya, F.A. (2014) Mollusca and Arthropod. The occurrence Effectiveness and Compatibility of of pollution tolerant species and pollution Non-Tropical Bio-Monitoring Indices sensitive species in the water body is an for Assessing Pollution in Tropical indication of increase in environmental Rivers - A Review. International stress through anthropogenic activities, Journal of Ecosystem. 4(3): 128-134. which may in turn facilitate the DOI: 10.5923/j.ije.20140403.05. biodegradation of the rivers. The status of 5. Dickens, C. W. S. and Grahm, P. M. water quality in the rivers is not clean (2002) The South African Scoring because it is moderately polluted. The low System (SASS) Version 5 Rapid bio- number of benthic macro invertebrates and assessment method for rivers. African the dominant species being pollution Journal of Aquatic Science. 27: 1-10. tolerant suggest that the river especially 6. Baker, A., Inverarity, R., Charlton, M. Ekulu and Asata is relatively under stress. and Richmond, S. (2003). Detecting Maximum density and lowest density of River Pollution Using Fluores- cence macro invertebrate was observed during Spectrophotometry: Studies from the wet and dry seasons respectively. Species Ouse-burn, NE England. diversity indices showed a variation in the Environmental Pollution, 124:57- 70 community structure in the rivers. 7. Morse, J.C., Bae, Y.J., Munkhjargal, Therefore, there is a need to regularly G., Sangpradub, N., Tanida, K., monitor and control the source of Vshivkova, T.S., Wang, B., Yang, L. pollutants to the water bodies. The varying and Yule, C.M., (2007). Freshwater degrees of species composition in the Bio-monitoring with Macro water bodies also denoted the instability of invertebrates in East Asia. Frontiers in the environments which suggests a certain Ecology and the Environment 5, 33-42 degree of pollution. 8. Bedoya, D., Novotny, V. and Manolakos, E.S. (2009). Instream and

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offstream Environmental Conditions Dambatta, Kano State, Nigeria, UJMR, and Stream Biotic Integrity: Volume 2 Number 4 Importance of Scale and Site 13. Tyokumbur, ET; Okorie, ET; Similarities for Learning and Ugwumba, OA. (2002). Limnological Prediction. Ecol Model 220: 2393- assessment of the effluent on macro 2406. invertebrate fauna in Awba stream and 9. Andem, BA; OkoraforEyo, KA; Ekpo, Reservoir, Ibadan, Nigeria. The PB (2012).Ecological Impact Zoologist 1: 59 –62. Assessment and Limnological 14. Sharma KK and Chowdhary S (2011). Characterization in the Intertidal Macroinvertebrate assemblages as Region of Calabar River Using Benthic biological indicators of pollution in a Macro invertebrates as Bio-indicator Central Himalayan River, Tawi (J&K). Organisms. Int. J. Fishe IJBC. 3(5): 167-174. .Aqua.Studies1(2): 8-14 15. Wallace, R. B and Hynes, H. B. N. 10. Anderson, N.H. and Sedell, J.R. (1981). The effect of chemical (1979). Detritus processing by Macro treatment against black fly larvae on invertebrates in Some Ecosystems. the fauna of running waters. In: Laird Ann. Rev. Entomol24:357-377. M(Eds.), Black Flies, The Future For 11. Jüttner, I., Sharma S., Dahal B.M. and Biological Methods In Integrated Ormerod, S.J. (2003). Diatoms as Control, Academic Press, London, pp. Indicators of Stream Quality in the 327 – 358. Kathmandu Valley and Middle Hills of 16. Wilhm, J. L. and Dorris, T. C. (1966). Nepal and India. Freshwater Biology Species diversity receiving domestic 48: 2065–2084. and oil refinery effluents. A. M. 12. Ibrahim, S. and Nafi’u, S.A. (2017), Midland Nat., 76: 427-449. Macro invertebrates as Indicators of Water Quality in Thomas Dam,