arimoro 2007 water quanlity

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Water quality changes in relation to Diptera communitypatterns and diversity measured at an organic effluent

impacted stream in the Niger Delta, Nigeria

Francis O. Arimoro a,*, Robert B. Ikomi a, Chukwujindu M.A. Iwegbue b

a

Department of Zoology, Delta State University, P.M.B. 1 Abraka, Nigeriab Department of Chemistry, Delta State University, P.M.B. 1 Abraka, Nigeria

Received 20 February 2006; received in revised form 18 June 2006; accepted 21 June 2006

Abstract

Impact of abattoir effluents (characterized by intestinal and stomach contents of slaughtered animals, ashes from roasted

animals and blood stains) on water quality, distribution and abundance of Diptera were investigated in an urban stream, River

Orogodo, Southern Nigeria, from July 2003 to June 2004. Water quality changes indicated significant differences (p < 0.05) in

conductivity, dissolved oxygen, BOD5, COD, total hardness, nitrate-nitrogen and phosphate-phosphorus between the three

stations sampled. Higher values of these parameters were observed at the impacted station. The abundance and community

structure of Diptera patterns, especially Chironomidae, Culicidae and Syrphidae families (all indicative of poor water quality)showed strong evidence of impact from the abattoir effluents. Comparisons of abundance values demonstrated high significance

(p < 0.05) between the impacted station and the upstream (station 1) and downstream station (station 3). Shannon index and

BergerParker dominance were greater at the impacted station (station 2). Analysis of faunal similarities showed that upstream

station 1(unpolluted site) was significantly different from stations 2 and 3. The distinct taxa found in station 2 (the impacted

station) suggest that the organic input from the abattoir favoured their abundance as most of them were opportunistic species.

# 2006 Elsevier Ltd. All rights reserved.

Keywords: Diptera; Impact; Water quality; Orogodo stream; Nigeria

1. Introduction

The use of aquatic Diptera to assess water quality is

commonly a part of water assessment programmes. In

pollution-oriented studies, identification of taxa which

are tolerant or intolerant of pollution is important in

designating water quality (Nelson, 1994). Organic

pollution by domestic sewage and abattoir effluent areprominent factors threatening the quality of Nigerian

streams. Small streams in developing areas are not

only strongly affected by these regular organic inputs

but also by episodic inputs from farmland, non-point

sources, which are more difficult to control (Victor and

Ogbeibu, 1985; Brown, 1996). However, the rate of

dilution in these streams is great, as rainfall is high

This article is also available online at:www.elsevier.com/locate/ecolind

Ecological Indicators 7 (2007) 541552

* Corresponding author. Tel.: +234 8035615424.

E-mail address: [email protected] (F.O. Arimoro).

1470-160X/$ see front matter # 2006 Elsevier Ltd. All rights reserved.

doi:10.1016/j.ecolind.2006.06.002
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during most part of the year (Matagi, 1996; Edokpayi

et al., 2000; Zabbey and Hart, 2006) and streams tend

to recover quickly from such impacts.

The Orogodo River flows through the town of Agborwith a population of 100,000 people in southern Nigeria

and is the main source of portable water for the riparian

communities. It is also the main drainage system of the

town accounting for most of the total runoff (Ikomi and

Owabor, 1997). The river at the middle reaches is

subjected to organic pollution arising from effluent

from an abattoir. The effluent of this abattoir comprises

of stomach and intestinal contents of slaughtered

animals as well as ashes of burnt animal parts and

associated bloodstains which are discharged regularly

into the river without treatment.

There have been several recent studies of Diptera

composition and structure in tropical freshwater

bodies (Victor and Dickson, 1985; Ogbeibu and

Egborge, 1995; Ogbeibu, 2001; Ndarunga et al.,

2004). However, there have been few studies on the

effects of abattoir effluents and livestock impacts on

the abundance and distribution of Diptera (Solimini

et al., 2000; Mathooko, 2001). Therefore, this research

was undertaken to investigate water quality and to

identify the groups of diptera that are present in the

organically polluted section of the river, in addition to

comparing the ecological characteristics upstream anddownstream of the abattoir effluent impacted area.

Here we aim to identify significant changes in the

composition, density and distribution of Diptera which

are attributed to this effluent.

2. Materials and methods

2.1. Description of the study area

The Orogodo River is a short stream (about 50 kmlength) located in the Delta State Nigeria. It lies

between latitude 580068200N and longitude 68100

68260E (Fig. 1). The stream is fed principally by

ground seepage from an aquifer in the thick rainforest

zone of Mbiri and also by precipitation, municipal

effluent and surface run off from the riparian

communities. It flows through the main town of

Agbor, Owa-Ofie, Ekuma-Abavo, Oyoko in Delta

State and ends in a swamp between Obazagbon-Nugu

and the oil rich town of Oben in Edo State, southern

Nigeria. Samples of Diptera were collected monthly

from July 2003 to June 2004 at three sampling

stations: the point of discharge of abattoir effluents

(station 2), upstream (station 1) and downstream(station 3) of the impacted station.

Station 1 is located about 15 km upstream from the

source. The marginal vegetation consists of few trees,

mainly oil palm Elaeis guineensis and Cocos nucifera

L., emergent vegetation, namely Pycreus lanceolatus

Poi and submerged vegetation, Ceratophyllum sub-

mersum L. The streambed consists predominantly of

clay and silt. Human activities here include sub-

sistence fishing and bathing. Mean water depth is

0.7 m and width 3.5 m.

Station 2 is the impacted station located behind the

Agbor town abattoir, where effluents are emptied into

the stream. The abattoir effluent is composed of

animal faeces from slaughtered animals, blood and

ashes from burning and roasting of animals, which

constitute an organic pollutant. Some of the water at

this station is eutrophicated with heavy algal growth.

The dominant macrophytes are Nymphae lotus, Azolla

sp., Utricularia sp. and Salvinia sp. Floating duck-

weed (Lemna minor) is also observed close to the river

banks. Mean water depth is 0.5 m and width 5.8 m.

Station 3 is located downstream of the impacted

area, 5 km from the Abattoir close to Abavo by Owa-fie town. The substratum is predominantly clay and

silt. It is flanked by Indian bamboo trees (Bambusa sp.)

and palm trees (E. guineensis). Abundant emergent

macrophytes, Pandanus sp. and Mitragyna ciliata.

Human activities here include bathing, fishing,

sacrifices by superstitious believers, etc. The average

water depth is 1.0 m and width 3.7 m.

2.2. Water quality analysis

Sampling for water quality parameters and Dipterawere carried out in the three study stations at monthly

intervals between July 2003 and June 2004, covering

dry and rainy seasons. Air and water temperatures

were recorded with a thermometer; conductivity, pH,

total alkalinity, dissolved oxygen (DO) and biochem-

ical oxygen demand (BOD5), total hardness were

determined according to APHA (1985) methods.

Monthly rainfall data were obtained from the

meteorological station in Agbor. Other parameters

measured included water velocity determined using

F.O. Arimoro et al. / Ecological Indicators 7 (2007) 541552542
http://dx.doi.org/10.1016/j.ecolind.2006.06.002


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the Ping Pong flotation technique; nitrate-nitrogen

(NO3-N) and phosphate-phosphorus (PO4-P) weremeasured spectrophotometrically after reduction with

appropriate solutions (APHA, 1985). Chemical oxy-

gen demand (COD) was determined after oxidation of

organic matter in strong tetraoxosulphate VI acid

medium by K2Cr2O7 at 148 8C, with back titration.

2.3. Sampling for Diptera

Samples of Diptera larvae were collected with

Surber net (30 cm 30 cm, mesh size 250 mm). Care

was taken to include all possible microhabitats over

representative sections of the stream. At each station,10 sampling units were taken and pooled for analysis.

Samples were fixed with 4% formalin in the field and

preserved with 70% ethanol in the laboratory.

Taxonomic identifications of most Diptera were made

to the generic level. Some members of the subfamily

chronominae were identified to the species level using

the larval head capsules, antennae and labial plates

(Pennak, 1978; Cranston, 2000). Diptera abundance

was obtained by counting all individuals in a taxon and

expressing the results as number m2.

F.O. Arimoro et al. / Ecological Indicators 7 (2007) 541552 543

Fig. 1. Map of River Orogodo showing the study stations.


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All statistical methods used in analyzing the water

quality parameters and diptera community were

adapted from Zar (1984) and Magurran (1988),

including taxa richness, diversity and evennessindices, using the Computer Basic Programme SP

DIVERS (Ludwig and Reynolds, 1988).

Jaccards similarity (Ravera, 2001) was used to

compare the sampling locations and to determine

which ones were similar in taxa composition.

sJ

C

A B C

where Cis the number of species found at both stations

being compared; A is the number of species found at

station 1; B is the number of species found at station 2.

BergerParker dominance index adopted from

(Ravera, 2001), dBP = Nmax/N, where Nmax is the

number of individuals in the most abundant taxon;Nis

the total number of individuals.

3. Results

3.1. Physical and chemical characteristics of the

water body

Table 1 summarizes the mean values of the various

parameters monitored at the three selected stations

over a 12 month time span (July 2003June 2004)

along the River.

Air and water temperatures were in the range of

2431 8C in the three stations sampled and were not

significantly different (p > 0.05) (Fig. 2A and B).

Mean water depth was also similar in all thestations (p > 0.05). Except that orthogonal compar-

ison using Duncans multiple range test revealed that

station 3 (down stream) of the impacted site showed

considerable higher depth 1.20 0.24 m as compared

with the other stations. Generally, water depth

(Fig. 2C) was considerably higher in the rainy season

than the dry season months.

Current velocity variation was also not significant

among the stations sampled (p > 0.05). Station 2,

however recorded high values of current velocity

especially in the rainy season months (Fig. 2D) as a

result of the runoff of storm water from the town which

empties a few kilometres from this station.

Conductivity values were significantly different

among the stations sampled (p < 0.05). The impacted

station (station 2) recorded higher conductivity values

throughout the study period (Fig. 2E).

Most of the chemical variables, that is dissolved

oxygen (Fig. 2F), biochemical oxygen demand

(BOD5), chemical oxygen demand (COD) (Fig. 2G

and H), nitrate-nitrogen (Fig. 2I), phosphate-phos-

phorus (Fig. 2J) and total hardness (Fig. 2K) were

significantly different among the various stationssampled (p < 0.05). Orthogonal comparison using

Duncans multiple range test showed that station 2 was

the cause of the observed differences in these

parameters.


Table 1

Summary of some physical and chemical characteristics of the sampling stations of River Orogodo (values are mean S.E) from July 2003 to

June 2004

Variable Station 1 Station 2 Station 2 ANOVA F-value Probability (p)

1 Air temperature (8C) 26.2 0.38 27.4 0.44 26.4 0.32 1.42 >0.05

2 Water temperature (8C) 26.6 0.54 24.2 0.61 23.4 0.62 0.84 >0.05

3 Water depth (m) 0.7 0.12 0.54 0.08 1.02 0.24 2.49 >0.054 Current velocity (ms1) 0.36 0.02 0.48 0.09 0.38 0.05 2.62 >0.05

5 Conductivity (ms cm1) 121.06 41.66 426.8 96.11 91.02 11.10 21.46*


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Most of the water samples (from station 13) had a

pH value of between 7 and 8. Although slightly higher

values were observed at station 2, this was however

not significant (p > 0.05) between the stations

sampled (Fig. 2L).

Total alkalinity in mg L1 did not vary significantly

among the stations sampled. However orthogonal

comparison using Duncan multiple range showed that

station 2 was the cause of the difference in total

alkalinity among the stations sampled.


Fig. 2. (AL) Physical and chemical characteristics of River Orogodo from July 2003 to June 2004.


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3.2. Diptera composition, abundance and

distribution

The taxa composition, density and distribution

of Diptera in the study area are shown in

Table 2. The assemblage fall into eight families,

namely Chironomidae, Culicidae, Dixidae, Simu-

liidae, Ceratopogonidae, Tabanidae, Syrphidae and

Muscidae. The distribution of these organisms

varied from stations 13 as might be expected in

view of the different abiotic characteristics of the

stations.


Fig. 2. (Continued).


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Twenty-four (24) taxa of Diptera comprising

10,047 individuals were recorded during the entire

study. The total number of taxa and individuals presentat stations 1, 2 and 3 were 13 (1845), 19 (5866), and 18

(2336), respectively.

The most abundant Diptera collected from the three

stations distributed along the Orogodo stream belong

to the following families: Chironomidae, Ceratopo-

gonidae and Culicidae. Less frequent were the

families Syrphidae and Tabanidae, with Muscidae,

Dixidae and Simuliidae sporadically present.

Of all the individuals collected, stations 1, 2 and 3

accounted for 18.2, 58.4 and 23.3%, respectively

(Fig. 3). The overall density of Diptera was

significantly different at the three stations sampled

(ANOVA, p < 0.05). An a posteriori test for multiple

comparison showed that the density at station 2 was

significantly higher than those at stations 1 and 3

(p < 0.05), which were not different from each other

(p > 0.05).

The family Chironomidae contributed 78.3% of

the total diptera density. The dominant taxon in this

family was Chironomus transvaalensis, others

included Chironomus fractilobus, absent in station

1, Tanypus sp., and Pentaneura, cricotopus sp. 1,

Tanytarsus sp. and Corynoneura sp. were completelyabsent in station 2. Pentaneura sp. 2 was limited to

station 2 only. Polypedilum sp. was more abundant in

stations 1 and 3, occurring only sporadically in

station 2.

The family Ceratopogonidae contributed 14.9% of

the total Diptera density. It was most important in

station 2 accounting for 53.2% of the total ceratopo-

gonid density. The dominant taxon in the family was

Allaudomyia sp. which was fairly distributed in all the

stations sampled.

The family Culicidae accounted for 3.6% of thetotal Diptera density. Station 1 recorded the least

Culicidae abundance. Culex pipiens, Anopheles sp.

and Chaoborus anomalus were completely absent in

station 1. C. anomalus was the dominant culicid,

closely followed by C. pipiens.

The family Simuliidae was represented by one

genus, Simulium sp. (0.08%), which was restricted to

station 1 alone. The same applied to the family

Dixidae (0.11%), represented by Dixa sp. and

restricted to station 3 alone.


Table 2

Distribution and abundance (individuals per m2) of Diptera in River

Orogodo study stations, July 2003June 2004

Diptera Stations

1 2 3

Family Chironomidae

Chironomus transvaalensis 21 3658 38

Chironomus fractilobus 498 71

Tanypus sp 28 182 17

Pentaneura sp. 1 4 62 12

Pentaneura sp. 2 21

Cricotopus sp. 1 43 72

Cricotopus sp. 2 11 4 14

Polypedilum sp. 862 71 1456

Tanytarsus sp. 565 104

Corynoneura sp. 16 6

Family Culicidae

Theobaldia sp. 26 8 39

Culex pipiens 98 5

Anopheles sp. 62 6

Mansonia sp. 4 14

Chaoborus anomalus 96 8

Family Dixidae

Dixa sp. 11 17

Family Simuliidae

Simulium sp. 8

Family Ceratopogondae

Palpomyia sp. 16 28 11

Allaudomyia sp. 241 592 427

Forcipomyia sp. 176 4

Family TabanidaeChrysops sp. 27

Tabanus sp. 48 5

Family Syrphidae

Eristalis sp. 203

Family Muscidae

Musca sp. 18

Number of individuals 1845 5866 2336

Number of taxa 18 13 19

Fig. 3. Percentage distribution in density of Diptera in the study

stations.


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Tabanidae (0.8%) was represented by two genera

Chrysops, and Tabanus sp. and restricted to stations 2

and 3. Station 2 accounted for 93.8% of the total

Tabanid density.Family Syrphidae and family Muscidae occurred

sporadically with overall percentages of 2.0 and 0.2%,

respectively. They were represented by Eristalis sp.

and Musca sp., respectively. These species were

restricted to station 2 alone.

Analysis of variance (ANOVA) showed that the

density of Chironomidae was significantly higher

(p < 0.05) than those of other families. Also analysis

of variance revealed that there were differences in the

abundance of Diptera among the stations sampled

(p < 0.05) and orthogonal comparison using Duncan

multiple range test showed that station 2 means was

quite different from the means of stations 1 and 3.

3.3. Spatialtemporal dynamics in population

density

The spatialtemporal distribution in abundance of

Diptera in the study stations is shown in Fig. 4. In the

three stations sampled, the highest densities were

recorded during the dry season months, January in

station 1, February in stations 2 and 3. Lower densities

were recorded in July and October for station 1 and in

August for stations 2 and 3. These were periods of high

water level. Analysis of variance however reveals that

Diptera abundance with season was not significant

(p > 0.05).The Ecological relationship between mean abun-

dance and water quality variables at each station using

Pearsons correlation coefficient (Table 3) revealed

that in station 1, water depth, current velocity, and

dissolved oxygen were negatively correlated with the

mean abundance of Diptera, whereas conductivity and

total hardness were positively correlated with the

mean abundance of Diptera. In station 2, water depth,

current velocity, dissolved oxygen were negatively

correlated with the mean abundance of Diptera,

whereas BOD, COD, NO3-N, PO4-P, total hardness

and pH were positively correlated with the mean

abundance of Diptera. Station 3 was similar to station

1; however water depth was negatively correlated with

the mean abundance of Diptera.

3.4. Diversity, dominance and similarity indices

Table 4 shows the summary of the diversity and

dominance indices calculated for the three stations.

The taxon richness calculated as Margalef index (d)

was highest in station 3 (2.190), closely followed by

station 2 (2.074) and station 1 accounted for the least


Fig. 4. Spatial temporal distribution of Diptera density in the study area of River Orogodo, Southern Nigeria.


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(1.595). Shannon diversity (H) and maximum possible

diversity were higher in station 2 although this was

statistically not significant (p > 0.05). Evenness

values were closely similar in all the three sampling

stations. BergerParker dominance value was lowest

in station 1 and similar in both stations 2 and 3.Faunal similarities between sampling stations

evaluated by Jaccards coefficient are given in

Table 5. This test showed that the pair of stations 2

and 3 (0.61), were more similar than other pairs of

sampling stations. Stations 1 and 2 were dissimilar

(0.39), while stations 1 and 3 were fairly similar

(0.55).

4. Discussion

The water quality changes observed especially the

high BOD5 levels, Conductivity, COD, and low

dissolved oxygen values obtained in station 2 portends

the abnormality of the water at this station as a result

of the impact arising from the untreated abattoir

effluents. Nitrate-nitrogen and phosphate-phosphorus

levels of the water obtained from the abattoir

discharge indicate a substantial amount of organic

input coming from the abattoir. These values were

significantly higher than the levels of the control

stations, upstream and downstream of the impacted

sites. The values of nutrients obtained for this study

were very high compared with low titre value reported

for similar natural unimpacted stream within southern

Nigeria (Ogbeibu and Oribhabor, 2002; Edema et al.,2002).

The relatively high velocity reported in station 2,

especially during the rainy season months is attributed

to surface runoff and storm water especially when it

rains.

The pH of an aquatic system although not definitive

is an indicator of the water quality and the extent of

pollution in the watershed (Jonnalagadda and Mhere,

2001). Unpolluted streams normally show a near

neutral or slightly alkaline pH. Most of the water

samples had a pH of about 7 and 8. Station 2, hadslightly higher values of pH which again could be

traced to the nature of the effluent which is slightly

alkaline.

BOD5 values indicate the extent of organic

pollution in aquatic systems, which adversely affect

the water quality (Jonnalagadda and Mhere, 2001). In

all the water samples BOD5 was less than 4 mg L1

except in station 2 where BOD was in the range of 8

14 mg L1, indicating that the effluent from the

abattoir was organic in nature. This high BOD5 value


Table 3

Pearson correlation coefficients between mean abundance and some

physicochemical parameters at each station

S/N Parameter Stations

1 2 3

1 Air temperature (8C) 0.50* 0.12 0.31

2 Water temperature (8C) 0.59* 0.20 0.43

3 Water depth (m) 0.88* 0.89* 0.85*

4 Current velocity (m s1) 0.66* 0.69* 0.72*

5 Conductivity (ms cm1) 0.87* 0.40 0.77*

6 Dissolved oxygen (mg l1) 0.53* 0.74* 0.28

7 BOD5 (mg L1) 0.05 0.85* 0.03

8 COD (mg L1) 0.65* 0.79* 0.09

9 Nitrate-nitrogen (mg L1) 0.64* 0.62* 0.10

10 Phosphate-phosphorus

(mg L1)

0.62* 0.54 0.54*

11 Total hardness

(mg L1 CaCo3)

0.85* 0.60* 0.16

12 pH 0.23 0.63* 0.02

13 Total alkalinity (mg L1) s 0.45 0.05 0.11

* Significant difference at probability level (p < 0.05).

Table 4

Diversity of Diptera in the study stations of River Orogodo, 2003

2004

Station 1 Station 2 Station 3

Number of samples 12 12 12

Number of taxa 13 19 18

Number of individuals 1845 5866 2336

Margalef index (d)

(taxa richness)

1.595 2.074 2.190

Shannon diversity (H) 0.611 0.654 0.631

Maximum possible

diversity (Hmax)

1.114 1.279 1.255

Evenness (E) 0.548 0.511 0.503

BergerParker dominance 0.467 0.624 0.623

Table 5

Jaccards similarity Index for pairs of sampling stations in River

Orogodo, July 2003June 2004

Stations

1 2 3

Stations

1 0.39 0.55

3 0.61


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recorded in station 2 reflect high burden of organic

pollution.

Water hardness reported for stations 1 and 2 were in

the range of 62.496.45 mg L1

CaCO3 which is inthe range of soft waters by Lind (1979) classification.

Station 2 with an average hardness of 146

7.39 mg L1 CaCO3 is classified as hard water.

The total number of Diptera taxa reported in the

study (24) is high when compared with earlier studies

by Ogbeibu and Victor (1989), Edokpayi et al. (2000)

and Adakole and Anunne (2003), which reported 19,

13 and 18, respectively, in Nigerian freshwater

streams. The probable reason for this high number

of taxa in this report may be due to the organic

materials from the abattoir effluents, whose substrate

is mostly covered by bacteria and sewage fungi which

are the main food source for most diptera (Rueda et al.,

2002). Again, the shallow nature of the stream at this

station must have favoured the growth of pollution

tolerant species such as Eristalis, which extends its

breathing tube outside the water surface. Related

studies elsewhere include those ofMiserendino (2001)

which reported 27 taxa in Andean Patagonian Rivers

and Ogbeibu (2001) recorded 26 taxa in Okomu forest

ponds in southern Nigeria. The principal taxa, in the

present study, Chironomus sp., Polypedilum sp.,

Allaudomyia sp., Culex and Tanytarsus sp. haveearlier been reported in Nigerian waters (Ogbeibu and

Victor, 1989; Edokpayi et al., 2000; Adakole and

Anunne, 2003; Zabbey and Hart, 2006).

Station 2 recorded high abundance of individual

Diptera as compared to the upstream and downstream

stations. Probably this high abundance could be as a

result of the opportunistic species monopolizing the

available resources or further exhibiting certain

adaptations to survive these conditions (Mason,

1991). Again, it is possible that the organic pollutant

has been directly or indirectly used as a food resource,and probably there could have been a reduction in

competition and predation for the remaining species.

Similar studies elsewhere Solimini et al., 2000;

Brown, 1996; Ravera, 2001; Rueda et al., 2002)

revealed that Diptera abundance is due to considerable

load of organic particles from untreated sewage and

livestock effluents.

The overall composition and density of fauna

varied both spatially and temporarily in response to

physical, chemical and biological factors of the

environment. The family Chironomidae especially

C. transvaalensis, C. fractilobus, Tanypus sp. and

Pentaneura sp. 1 and Pentaneura sp. 2 were abundant

taxa especially in station 2. The long reproductiveperiod, the absence of growth synchronization of egg

or larval diapause and a better adaptation to low

oxygen conditions are probably the reasons for the

preponderance of these species. Furthermore, Chir-

onomids are known to build up large populations

quickly and can tolerate sudden changes in habitat

conditions (Solimini et al., 2003). Tanytarsus sp.,

Cricotopus and Corynoneura sp. were completely

absent in station 2. This is an indication that these taxa

are representative of pollution intolerant species and

could not survive the very low oxygen concentration

of that station. Ogbeibu (2001) was of the opinion that

Tanytarus and Cricotopus species are prominent in

stations of permanently high oxygen saturation. These

species are therefore incapable of resisting the harsh

environmental changes and are recommended as

indicator species for freshwater streams in southern

Nigeria.

C. pipiens, Mansonia sp., Anopheles sp., Theobal-

dia sp. and Chaoborus anomalous all belonging to the

family Culicidae were more abundant in station 2.

These organisms are characteristic of polluted waters.

They have been reported in grossly polluted shallowwaters (Hynes, 1978). They are known to exist in

waters in high density that is depleted of oxygen

(Hellawell, 1986). Their abundance is also presum-

ably favoured by the rich supply of particulate organic

matter on which they feed.

The family Ceratopogonidae was represented in all

stations. The larvae of this family are common among

aquatic plants (Ogbeibu, 2001).

Tabanus sp. and Chrysops sp. were the representa-

tive genera of the family Tabanidae. They were more

abundant in the impacted site. Their dominance in thisstation is also traceable to their ability to tolerate and

survive adverse environmental conditions and low

oxygen concentration.

The family Syrphidae was represented by Eristalis

sp. alone and was recorded in station 2 only. This

organism has been implicated in sewage polluted

streams (Ravera, 2001; Rueda et al., 2002). Their

ability to survive is their possession of delicate

retractile anal skills for respiration, and the presence

of decaying organic matter which they feed on



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(Pennak, 1978). They are also known to thrive well in

shallow waters; this is to permit the tip of the extended

caudal respiratory tube to be projected just above the

surface.Dixidae was represented by one genus, Dixa. These

midges are found resting on vegetation (Pennak,

1978). In consonance with our study they were more

abundant in station 3, the site with abundant

vegetation.

The diversity and evenness of species calculated by

Shannon function were similar among the stations

however, station 2 recorded slightly higher Shannon

diversity, maximum possible diversity and dominance

than the upstream and down stream stations. This may

be a reflection of the state of pollution, which was

favourable for the abundance of opportunistic species.

The relatively low number in taxa richness (Margalef

index) in stations 1 and 3 was due to the relatively low

number of representative individuals. This is not a

consequence of environmental degradation but of the

natural selection of Diptera by scarce organic matter

input in these stations.

Jaccard similarity index revealed that stations 2 and

3 were similar. Probably, the discharge of organic

matter/particles at station 2 must have affected the

faunal characteristics downstream with minor changes

as a result of dilution and recovery. Stations 1 and 2were dissimilar, whereas stations 1 and 3 were fairly

similar, indicating that the latter were unimpacted sites.

From the results obtained in this study, there was

restoration downstream of pollution intolerant Dip-

tera. This is evidenced by the natural depuration

process. According to Miserendino and Pizzolon

(2000) organic load dilution is known to occur

downstream generating a species composition and

abundance similar to upstream station.

In conclusion, the perceived effects of the abattoir

waste discharges on the aquatic water body can bemitigated, if these wastes are properly channeled and

treated before discharge into the water surface.

Acknowledgements

We are grateful to Drs. A.E. Ogbeibu and O.J.

Olomokoro who gave their expertise and assistance in

identifying most of the diptera larvae and the

Department of Zoology, Delta State University,

Abraka, Nigeria, for providing some of the materials

used in this study.

References

Adakole, J.A., Anunne, P.A., 2003. Benthic macroinvertebrates as

indicators of environmental quality of an urban stream, Zaria,

Northern Nigeria. J. Aquat. Sci. 18 (2), 8592.

APHA (American Public Health Association), 1985. Standard

Methods for Examination of Water and Waste Water, 15th

ed. American Public Health Association, Washington DC, pp.

1134.

Brown, C.A., 1996. Macroinvertebrate community patterns in rela-

tion to physicochemical parameters measured at land-based

trout farms affecting streams in the South-Western Cape, South

Africa. Arch. Hydrobiol. 138, 5776.Cranston, P.S., 2000.Electronic guide to the Chironomidae of Aus-

tralia. http://entomology.UC davis.edu/Chiro page.

Edema,C.U.,Ayeni,J.O.,Aruoture, A.,2002. Some observationson

the zooplankton and macrobenthos of the Okhuo River, Nigeria.

J. Aquat. Sci. 17 (2), 145149.

Edokpayi, C.A., Okenyi, J.C., Ogbeibu, A.E., Osimen, E.C., 2000.

The effect of human activities on the macrobenthic invertebrates

of Ibiekuma stream, Ekpoma, Nigeria. Biosci. Res. Commun. 12

(11), 7987.

Hellawell, J.M., 1986. Biological Indicators of Freshwater Pollution

and Environmental Management. Elsevier, New York, pp. 546.

Hynes, H.B.N., 1978. The Biology of Polluted Waters Liverpool.

University Press, Cambridge, UK, pp. 202.

Ikomi, R.B., Owabor, N., 1997. Hydrology of Orogodo River atAgbor. Bull. Sci. Assoc. Niger. 21, 167175.

Jonnalagadda, S.B., Mhere, G., 2001. Water quality of the Odzi

River in the Eastern Highlands of Zimbabwe. Water Res. 35,

23712376.

Lind, O.T., 1979. A Handbook of Common Methods of Water

Analysis for Limnology C.V. Moshy Publishers, St. Louis,

USA, pp. 69.

Ludwig, J.A., Reynolds, J.F., 1988. Statistical Ecology. A Primer on

Methods and Computing. Wiley Interscience, Wiley, New York,

pp. 337.

Magurran, A.E., 1988. Ecological Diversity and its Measurement.

Croom Helm Ltd., London, pp. 176.

Mason, C.F., 1991. Biology of Freshwater Pollution. LongmanScientific and Technical, New York, USA, pp. 350.

Matagi, S.V., 1996. The effects of pollution on benthic macroinverte-

brate in a Ugandan stream. Arch. Hydrobiol. 137 (4), 537549.

Mathooko, J.M., 2001. Disturbance of a Kenya rift valley stream by

daily activities of local people and livestock. Hydrobiologia 458

(13), 131139.

Miserendino, M., Pizzolon, L.A., 2000. Macroinvertebrates of a

fluvial system Patagonia: altitudinal zonation and functional

structure. Arch. Hydrobiol. 150 (1), 5583.

Miserendino, M.L., 2001. Macroinvertebrates assemblages in

Andean Patagonian rivers and streams: environmental relation-

ships. Hydrobiologia 444, 147158.

http://entomology.uc%20davis.edu/Chiro%20pagehttp://entomology.uc%20davis.edu/Chiro%20page


12/12

Ndarunga, A.M., Ndirritu, G.G., Gichuki, N.M., Wamicha, W.N.,

2004. Impact of water quality on the macroinvertebrates assem-

blages alonga tropical streamin Kenya. Afr. J. Ecol.42, 208216.

Nelson, S.M., 1994. Observed field tolerance of caddisfly larvae

(Hesperophylax sp.) to high metal concentration and low pH. J.Freshwater Ecol. 9 (2), 169170.

Ogbeibu, A.E., Victor, R., 1989. The effects of road and bridge

construction on the bank root macrobenthic invertebrates of a

southern Nigerian stream. Environ. Pollut. 56, 85100.

Ogbeibu, A.E., Egborge, A.B.M., 1995. Hydrobiological studies of

water bodies in the Okomu Forest Reserve (Sanctuary) in

Southern Nigeria. 1. Distribution and diversity of the inverte-

brate fauna. Trop. Freshwater Biol. 4, 127.

Ogbeibu, A.E., 2001. Composition and diversity of Diptera in a

temporary pond in Southern Nigeria. Trop. Ecol. 42 (2), 259268.

Ogbeibu, A.E., Oribhabor, B.J., 2002. Ecological impact of river

impoundment using benthic macroinvertebrates as indicators.

Water Res. 36, 24272436.

Pennak, R.W., 1978. Freshwater invertebrates of the United States.

John Wiley, New York, pp. 801.

Ravera, O., 2001. A comparison between diversity, similarity and

biotic indices applied to the macroinvertebrate community of a

small stream: the Ravera river (Como Province, Northern Italy).

Aquat. Ecol. 33, 97107.

Rueda, J., Camacho, A., Mezquita, F., Hernandez, R., Roca, J.R.,

2002. Effect of episodic and regular sewage discharges n the

water chemistry and macroinvertebrate faunaof a Mediterranean

stream. Water Air Soil Pollut. 140, 425444.

Solimini, A.G., Ruggiero, A., Anello, M., Mutschlechner, A.,Cachini, G.,2000. The benthic communitystructure in mountain

ponds affected by livestock watering in nature reserves of central

Italy. Proc. Int. Assoc. Theor. Appl. Limnol. 27, 15.

Solimini, A.G., Ruggiero, A., Bernardini, V., Carchini, G., 2003.

Temporal pattern of macroinvertebrate diversity and production

in a new man-made shallow lake. Hydrobiologia 506509, 373

379.

Victor, R., Ogbeibu, A.E., 1985. Macrobenthic invertebrates of a

stream flowing through farmlands in Southern Nigeria. Environ.

Pollut. Ser. A 39, 337349.

Victor, R., Dickson, T., 1985. Macrobenthic invertebrates of a

perturbed stream in Southern Nigeria. Environ. Pollut. Ser. A

38, S99S107.

Zar, J.H., 1984. Biostatistical Analysis, second ed. Prentice Hall,

New Jersey, pp. 717.

Zabbey, N., Hart, A.I., 2006. Influence of some physico-chemical

parameters on the composition and distribution of benthic fauna

in Woji creek, Niger Delta, Nigeria. Global J. Pure Appl. Sci. 12

(1), 15.


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