Physics and Chemistry of the Earth 66 (2013) 68–74

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Physics and Chemistry of the Earth

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Performance evaluation of chicken, cow and pig manure in theproduction of natural fish food in aquadams stocked with Oreochromismossambicus

1474-7065/$ - see front matter � 2013 Elsevier Ltd. All rights reserved.http://dx.doi.org/10.1016/j.pce.2013.08.009

⇑ Corresponding author. Tel.: +27 15 268 2833.E-mail address: rapatsa.maditshaba13@gmail.com (M.M. Rapatsa).

M.M. Rapatsa ⇑, N.A.G. MoyoAquaculture Research Unit, Faculty of Science and Agriculture, School of Agriculture and Environmental Sciences, University of Limpopo (Turfloop Campus), Private Bag X1106,0727, South Africa

a r t i c l e i n f o a b s t r a c t

Article history:Available online 12 September 2013

Keywords:FishPlanktonManureWaterQuality

The main objective of this study was to characterize the ecological conditions that prevail after the appli-cation of chicken, cow and pig manure. Three treatments, chicken, cow, pig manure and a control wereassigned to aquadams in a completely randomized design and each treatment was replicated three times.The aquadams were fertilized 2 weeks before the fish were stocked. One hundred Oreochromis mossam-bicus (mean weight ±40 g) were stocked in each aquadam. Water physico-chemical parameters (temper-ature, dissolved oxygen, pH, electrical conductivity, salinity, turbidity, ammonia, nitrite, total alkalinity ascalcium carbonate, and phosphorus) were determined once a week for the duration of the experiment.Zooplankton and phytoplankton in the different treatments were enumerated once every 2 weeks. Therelationship between phytoplankton communities and the water physico-chemical parameters wereevaluated using canonical correspondence analysis (CCA). The CCA indicated that the physico-chemicalvariables which best explain the distribution of phytoplankton were carbonate alkalinity, pH, phosphate,potassium, nitrogen and dissolved oxygen. Phytoplankton abundance was highest in chicken manurebecause the optimum nutrient conditions for the growth of phytoplankton were found in this treatment.Zooplankton abundance was also highest in the chicken manure treatment. The control was associatedwith one phytoplankton taxa, Chlorella. The numerical contribution of the different food items in thestomachs of O. mossambicus was determined. The diet of O. mossambicus was dominated by phytoplank-ton particularly Microcystis species. Total coliforms and Escherichia coli were used to assess the microbi-ological quality of the water in the different manure treatments. Chicken manure had the lowest totalcoliform and E. coli count. However, chicken manure had the highest Bacillus count. The implicationsof the microbial load in the chicken, cow and pig manure are discussed.

� 2013 Elsevier Ltd. All rights reserved.

1. Introduction

The use of organic manure in fertilizing fish ponds is an age oldtradition in Asia and it is well established in many parts of theworld to augment primary productivity (Knud-hansen et al.,1991). Organic manure is less expensive than chemical fertilizers.Animal manure has a long history of use as a source of solublephosphorus, nitrogen and carbon for algal growth. It is often usedin earthen ponds to improve primary production and fish growth(Kang’ombe et al., 2006; Terziyski et al., 2007). An increase innutrient content provides favorable conditions for phytoplanktonproduction. Phytoplankton as well as microorganisms responsiblefor mineralization of organic matter, serves as a food source forzooplankton. Moreover, it increases biomass of zooplankton and

benthic organisms which are important as natural fish food. Inorganically manured ponds, the organic matter is degraded by aer-obic bacteria into carbon dioxide and ammonia. Algae will utilizethe carbon dioxide. During photosynthesis, the algae will produceoxygen which will sustain fish, zooplankton and phytoplankton.Algae represent a major food source for fish in ponds.

Chicken, cow and pig manure are some of the most readilyavailable organic manure in South Africa (Prinsloo and Schoonbee,1986). The potential of these organic manures to enhance fish pro-duction has not been fully exploited in South Africa. There appearsto have been some limited interest in using organic manure be-tween 1970 and 1990 (Hopkins and Cruz, 1982; Prinsloo andSchoonbee, 1986; Schroeder, 1974). The results from these studieswere promising. South Africa’s renewed interest in inland aquacul-ture is captured in the Department of Agriculture Forestry andFisheries’ Strategic Plan 2011–2015 and the National AquacultureStrategic Framework. Both these documents highlight the

M.M. Rapatsa, N.A.G. Moyo / Physics and Chemistry of the Earth 66 (2013) 68–74 69

importance of increasing aquaculture productivity, profitabilityand sustainability. South Africa is a water scarce country and useof organic manure in aquadams optimizes the utilization of ascarce resource. Use of organic manure can enhance inland aqua-culture in South Africa if the right type of manure, in correct dos-ages, is applied in ponds stocked with suitable fish species.

Previous studies in South Africa focused more on the growthrate of the fish rather than the food items generated after the appli-cation of the manure. Furthermore, in recent times attention hasfocused on the possibility of fish cultured in ponds fertilized withanimal manure as sources of human pathogenic bacteria (Ampofoand Cleck, 2010; Novotny et al., 2004). It has been reported thathalf of the microorganisms recovered from fish and water of pondsfertilized with animal manure were members of the family Enter-obacteriaceae (Mandal et al., 2009). Reports of the occurrence ofpathogenic strains of E. coli from fishery resources are also on theincrease (Ampofo and Cleck, 2010; Mandal et al., 2009). This studywill investigate the total heterotrophic bacterial count, total coli-form count, E. coli count and Bacillus count in the chicken, cowand pig manure. E. coli is an important water quality indicatorand its presence in water indicates a potential risk to consumers.Fish do not carry E. coli internally since they are not warm blooded.However, the water that covers the fish could contain E. coli. SinceE. coli is found in the faeces of warm blooded animals it is prudentto determine the E. coli count for each manure treatment. Bacillusincludes both free-living and pathogenic species. In organicallymanured ponds Bacillus plays an important role in the breakdownof organic detritus (Ali et al., 2011). A fish pond with good waterquality and low nutrient content results in low fish yields, whilea pond with high nutrient content but poor water quality may re-sult in the production of contaminated fish. The main objective inthis study was therefore to determine the effects of chicken, cowand pig manure on water quality, plankton abundance and selectedmicrobes in aquadams stocked with O. mossambicus.

2. Materials and methods

2.1. Experimental setup

The study was conducted outdoors at the Aquaculture ResearchUnit at the University of Limpopo, South Africa. Twelve aquadams1 m high and 3 m in diameter were used to determine the effect ofchicken, cow and pig manure on water quality parameters, plank-ton and microbial communities. The aquadams were filled with7000 L of aged tap water and left to stand for a week before theapplication of manure. The three treatments together with the con-trol were assigned to aquadams in a completely randomized designand each treatment replicated three times. The aquadams werefertilized 2 weeks before the fish were stocked (to ensure planktonand other organisms’ production such as bacteria), at an applica-tion rate of 0.26 kg/m2/week (Jha et al., 2008). The experimentwas run for 120 days (February 2012–May 2012).

2.2. Proximate analysis of organic manure used

The chicken, cow and pig manure were collected from a smallscale local farm. Proximate analysis of all the three organic manurewas undertaken before the application to the aquadams. All bio-chemical analyses were done on a dry matter basis using standardmethods (AOAC, 2003). The analysis of dry matter was done bydrying pre-weighed samples in an oven at 105 �C for about 16 hto reach a constant weight. Nitrogen was analyzed using the Kje-dahl method and phosphorus and potassium analyzed using spec-trophotometry. Crude fiber, protein and fat were determined usingprocedures stipulated by the Association of Official Analytic

Chemistry (AOAC, 2003). Ash content was determined by burningthe samples in a muffle furnace at 550 �C for 4 h.

2.3. Fish stocking

Oreochromis mossambicus fingerlings with mean weight of 40 gwere collected from the nearby Sand River. They were kept in alarge tank for a 1 week acclimation period to make sure the fishare healthy before stocking. After 1 week in the holding tank, fishwere selected and stocked in each aquadam (100 per dam). Duringthe acclimation period, dead fish were replaced with fish of similarsize.

2.4. Water quality monitoring

Temperature (�C), dissolved oxygen (mg/L), pH, electrical con-ductivity (mS/cm) and salinity (%), turbidity (NTU) were measuredon site using a Horiba U23 multiprope meter (Horiba, Osaka, Ja-pan). Readings were recorded once a week at 10:00 and 16:00 hthroughout the culture period. Water samples from each treatmentwere analyzed for ammonia (mg/L), nitrite (mg/L), total alkalinityas CaCO3 (mg/L), and phosphorus (mg/L) once a week, using stan-dard methods as described by APHA (1985).

2.5. Plankton enumeration

Water samples for primary production were collected once aweek from all treatments in 500 mL glass bottles and determinedusing the light and dark bottle method. The light bottles were ex-posed to light for 24 h and the dark bottles put in a dark place for24 h. Zooplankton and phytoplankton were collected two times aweek using 80 lm and 53 lm mesh size nets, respectively. Thesamples were preserved in 10% formalin. The phytoplankton wasidentified under a light microscope at a magnification of 400� ata volume of 250 mL using a phytoplankton identification manualby Botes (2003). The phytoplankton was identified to genera level.This was done to capture the algal groupings that are tolerant ofhigh organic load. Zooplankton was identified to family level undera light microscope at the magnification between 50� and 400�.Identification of the families was done using manuals from WaterResearch Commission by Day et al. (1999, 2001, 2003) and de Mooret al. (2003a,b). Enumeration of both phytoplankton and zooplank-ton was done using a counting chamber. The counting chamberswere made of Plexiglas and had a polished bottom for besttransparency.

2.6. Stomach content analysis

A sample of twenty fish were collected from each treatmentevery month, dissected, and stomachs removed and fixed in 10%formalin solution. The numerical contribution of the different fooditems was determined by counting the stomach contents in acounting chamber under a stereomicroscope. The counting cham-bers were made of Plexiglas and had a polished bottom for besttransparency. Frequency of occurrence of the different diet itemswas determined according to Hyslop (1980).

2.7. Microbial analysis

Water samples were collected two times a week and analyzedfor total heterotrophic bacterial counts, total coliform counts, Esch-erichia coli and Bacillus spp. count. Total coliforms were incubatedat 37 �C for 24 h. E. coli was incubated at 44 �C for 24 h, while totalbacterial counts were incubated for 48 h at 30 �C. All the bacterialmedia were obtained from Sigma and Aldrich Ltd., Pretoria, SouthAfrica.

70 M.M. Rapatsa, N.A.G. Moyo / Physics and Chemistry of the Earth 66 (2013) 68–74

2.8. Statistical analysis

The water quality parameters, flora and fauna were subjected toone-way analysis of variance (ANOVA) at the significance level(P < 0.05) using the Statistical Package and Service Solutions (IBMSPSS version 20). The data was tested for normality using the Shap-iro–Wilk normality test. Canonical correspondence analysis (CCA)is a direct gradient analysis used to examine the relationships be-tween the measured variables and the distribution of communities(ter Braak and Šmilauer, 2012). It was therefore used to determinethe relationship between water quality parameters with phyto-plankton. The data was log (x+1) transformed to stabilize the vari-ance and the statistical package CANOCO 5 was used. Monte-Carlo permutation tests were used to test the statistical signifi-cance of forward selected variables. The significant contributionof these variables to the ordination was tested at (P < 0.05).

3. Results

Chicken manure had the highest nitrogen, phosphorus, potas-sium, crude protein and ash content (Table 1). Cow manure exhib-ited the lowest nutrient concentrations.

The different nutrient concentrations significantly affectedsome water quality parameters. Nitrogen, phosphorus and potas-sium were significantly higher (P < 0.05, ANOVA) in chicken man-ured aquadams (Table 2). Aquadams fertilized with pig manureand cow manure showed higher levels of nitrogen, phosphorusand potassium in comparison to the control (Table 2). Primary pro-duction was also significantly higher (P < 0.05, ANOVA) in chickenmanure than in the other treatments. Cow manure treatment wasmore turbid than the other treatments. Bicarbonate alkalinity washighest in chicken manure and lowest in the control (Table 2).

There were significant differences in phytoplankton abundancebetween the treatments (P < 0.05, ANOVA). Phytoplankton abun-dance was highest in the chicken manure treatment than other

Table 1Proximate composition (%) of the organic manure applied in aquadams.

Proximate component (%) Organic manure source

Chicken Cow Pig

Nitrogen 2.75 1.31 1.70Phosphorus 3.64 0.14 0.72Potassium 1.81 0.60 0.52Crude fiber 19.90 22.60 20.90Crude protein 27.60 8.13 18.60Fat 8.52 7.50 8.30Ash 36.20 16.8 28.04

Table 2The mean ± SE of major physico-chemical parameters analyzed for water quality of the di

Parameters Treatments

Chicken manure

Temperature (�C) 22.28 ± 1.58Conductivity (mS/cm) 0.07 ± 0.005Salinity (%) 0.03 ± 0.0DO (mg/L) 7.73 ± 0.51Primary production (mg/m2/day) 1.12 ± 0.16pH 8.82 ± 0.22Bicarbonate alkalinity (mg/L) 25.60 ± 1.40Carbonate alkalinity (mg/L) 20.00 ± 0.0Potassium (mg/L) 3.61 ± 0.03Nitrogen (mg/L) 2.00 ± 0.02Phosphate (mg/L) 1.08 ± 0.47Ammonium (mg/L) 0.03 ± 0.01Turbidity (NTU) 173.0 ± 1.63

treatments while the control had the lowest abundance. Microcys-tis was the only taxa that occurred in all the treatments andnumerically dominated the flora (Table 3). Chlorella only occurredin the control (with no manure). Apart from Microcystis, the tenother phytoplankton genera recorded very low abundances(Table 3).

CCA was used to detect patterns of phytoplankton genera distri-bution in relation to water physico-chemical parameters. In theCCA ordination, axes 1 and 2 explained 82.53% in the species envi-ronment plot (Fig. 1, Table 4). Axis 1 represented mainly carbonatealkalinity, primary production, pH and temperature gradient (Ta-ble 5). Axis 2 represented conductivity, DO and phosphorus (Ta-ble 5). Along the phosphorus axis lays the phytoplanktonClosterium spp and this was associated with chicken manure(Fig. 1). Cosmarium spp on the other hand was on the carbonatealkalinity axis. The distribution of Coelospharium and Aphanizome-non were also on the carbonate alkalinity gradient. Cryptomonus,Anabaena and Spirulina were on the ammonium axis and this wasassociated with pig manure (Fig. 1). The ubiquitous and cosmopol-itan Microcystis was found close to the centre of the ordination andits distribution was not defined by any nutrient gradient. This alsoapplies to Oscillatoria (Fig. 1). The distribution of Chlorella was alsonot defined by any nutrient gradient and was associated with thecontrol. Cow manure was not correlated with any of the waterphysico-chemical parameters and phytoplankton communities(Fig. 1). Flagilaria was not correlated to any of the environmentalvariables, although it had a weak correlation with ammoniumand pH which were associated with pig manure.

Five groups of zooplankton were recorded and they occurred inall the treatments, except for Ostracoda which were not found inthe control (Table 6). There was a significant difference in zoo-plankton abundance (P < 0.05) across the treatments. Chickenmanure treatment recorded the highest zooplankton abundancefollowed by pig manure and cow manure while the control re-corded the lowest abundance. The zooplankton fauna was domi-nated by Cladocera and Rotifera in all the treatments (Table 6).Significantly higher Rotifera abundances (P < 0.05) were recordedin the chicken manure treatment. Furthermore, the manure treat-ments had higher zooplankton abundance than the control.

The diet of O. mossambicus was numerically dominated byMicrocystis, Cladocera and Culicidae across all treatments (Fig. 2).Culicidae was not part of the plankton enumerated but it was ob-served in the stomachs of O. mossambicus.

Heterotrophic bacterial counts results varied significantly in thedifferent manure treatments. The average counts were signifi-cantly higher (P < 0.05) in pig and chicken manured aquadams (Ta-ble 7). Pig manure treatment had high total coliform counts andlow Bacillus spp. count and chicken manure treatment had signifi-

fferent treatments.

Cow manure Pig manure Control

22.32 ± 1.50 22.24 ± 2.34 21.56 ± 0.910.06 ± 0.001 0.47 ± 0.35 0.06 ± 0.0070.03 ± 0.0 0.03 ± 0.0 0.03 ± 0.07.21 ± 0.49 6.64 ± 0.29 5.97 ± 0.430.48 ± 0.21 0.88 ± 0.81 0.42 ± 0.428.45 ± 0.05 9.08 ± 0.18 8.49 ± 0.27

23.77 ± 0.03 12.37 ± 0.03 0.01 ± 0.0075.33 ± 0.13 16.77 ± 0.03 0.0 ± 0.01.63 ± 0.02 1.58 ± 0.01 0.01 ± 0.00.70 ± 0.03 0.70 ± 0.03 0.01 ± 0.00.06 ± 0.003 0.07 ± 0.003 0.01 ± 0.00.05 ± 0.01 0.08 ± 0.01 0.01 ± 0.0

180.2 ± 0.54 160.5 ± 1.74 85.3 ± 0.0

Table 3The mean ± SE of phytoplankton abundance (no/mL) in the different treatments.

Phytoplankton Chicken manure Cow manure Pig manure Control

Anabaena 0.67 ± 0.67 0.0 ± 0.0 1.67 ± 1.36 0.0 ± 0.0Aphanizomenon 12.67 ± 0.46 0.0 ± 0.0 7.33 ± 0.58 0.0 ± 0.0Chlorella 0.0 ± 0.0 0.0 ± 0.0 0.0 ± 0.0 4.0 ± 0.58Closterium 2.0 ± 1.62 0.0 ± 0.0 0.0 ± 0.0 0.0 ± 0.0Coelospharium 19.0 ± 4.36 0.0 ± 0.0 15.3 ± 3.61 0.0 ± 0.0Cosmarium 16.67 ± 3.9 0.0 ± 0.0 1.0 ± 1.0 0.0 ± 0.0Cryptomonus 0.0 ± 0.0 0.0 ± 0.0 29.0 ± 5.38 0.0 ± 0.0Flagilaria 24.67 ± 4.83 0.0 ± 0.0 40.3 ± 6.35 0.0 ± 0.0Microcystis 3461.34 ± 4.14 1681.24 ± 8.39 1807.31 ± 0.66 642.56 ± 6.50Oscillatoria 16.00 ± 2.18 8.67 ± 1.13 11.67 ± 2.72 0.0 ± 0.0Spirulina 0.0 ± 0.0 0.0 ± 0.0 1.0 ± 1.0 0.0 ± 0.0

Total 3551.0 ± 22.16 1689.9 ± 9.52 1914.6 ± 22.66 646.6 ± 7.08

1.0-1.0

1.0

-1.0

Temperat

ConductvDO

PrimProd

PH

BicrAlkl

CarbAlkl

Potassiu

NitrogenPhosphat

Ammonium

Turbidit

Anabaena

Aphanizm

Chlorela

Closteri

Coelosph

Cosmariu

Cryptomn

Flagilar Microcys

Oscillat

Spirilin

ChicManr

CowManur

PigManur

Control

Fig. 1. CCA plot of the relationship between water quality parameters andphytoplankton in chicken, cow and pig manure treatments.

Table 4Eigenvalues of the correlation matrix of the species-environment relation.

Phytoplankton and water quality parameters Axis 1 Axis 2 Axis 3

Eigenvalues 0.3484 0.1403 0.1034Explained variation (cumulative) 58.83 82.53 100

Total variation 0.59213

Table 5The correlation matrix of phytoplankton–water quality relation.

Axis 1 Axis 2 Axis 3

Temperature �0.8104 �0.2620 0.5420Conductivity 0.0689 �0.9686 �0.2390Dissolved oxygen �0.5500 �0.8180 0.1684Primary production �0.8445 �0.3650 �0.3919pH �0.8335 0.4844 �0.2657Bicarbonate alkalinity �0.4998 �0.7908 0.3533Carbonate alkalinity �0.9480 �0.2072 �0.2417Potassium �0.6485 �0.7546 �0.1005Nitrogen �0.5845 �0.7889 �0.1899Phosphorus �0.3949 �0.8408 �0.3702Ammonium �0.5730 0.7145 �0.3702Turbidity �0.0280 0.3813 �0.9240

M.M. Rapatsa, N.A.G. Moyo / Physics and Chemistry of the Earth 66 (2013) 68–74 71

cantly lower coliform count and high Bacillus spp. count. Esche-richia coli abundance was low in all the treatments.

4. Discussion

Chicken manure had the best nutrient composition; this is whyit produced higher plankton abundances. Nitrogen, phosphorusand potassium are normally the limiting nutrients and were high-est in chicken manure and these results are consistent with Adew-umi et al. (2011) and Kang’ombe et al. (2006). Cow manure was theworst performing manure in relation to phytoplankton and zoo-plankton abundances. This is because cows are ruminants and

the food ingested is digested more than once, therefore most ofthe nutrients are taken up in the body with little left in the faeces(Edwards et al., 2000; FAO, 1985). Chickens and pigs are monogas-tric animals and the food is digested once. Most of the nutrientcontent of feed given to chicken is voided as faecal waste (FAO,1985; Perkins et al., 1964). These nutrients stimulate plankton pro-duction (Jha et al., 2008; Piasecki et al., 2004).

Microcystis is a blue–green algae and its position near the centreof the ordination plot indicated its low correlation with either ofthe water physico-chemical parameters. This probably shows thatMicrocystis is tolerant of different environmental conditions. Brun-berg and Blomqvist (2006) and Furusato et al. (2004) also notedthat Microcystis are tolerant of adverse environmental conditions.This may explain its dominance in all the treatments. Several stud-ies have also shown that Microcystis dominates the phytoplanktonflora in organically manured ponds (Hossain et al., 2006; Kan-g’ombe et al., 2006; Wade and Stirling, 1999). Oscillatoria whichis also blue–green algae was found at the centre of the ordinationand this also indicates its tolerance of different environmental con-ditions. Microcystis and Oscillatoria were the only two phytoplank-ton groups found in the diet of O. mossambicus in this study. Boththese phytoplankton groups were more abundant in the chickenmanure treatment than the other treatments. The other blue–green algae genera Aphanizomenon and Coelosphaerium were corre-lated to carbonate alkalinity. High carbonate alkalinity results inhigh pH values which are suitable for plankton production(Knud-hansen et al., 1991). Aphanizomenon and Coelosphaeriumwere not important dietary components of O. mossambicus in thisstudy. Cryptomonus, Anabaena and Spirulina were correlated withammonium and were most abundant in the pig manure treatment.Cosmarium is also a blue–green algae that was correlated withbicarbonate alkalinity. Bicarbonate alkalinity was highest in thechicken manure and this may explain the abundance of Cosmarium

Table 6The mean ± SE of zooplankton abundance (no/mL) in the different treatments.

Zooplankton Chicken manure Cow manure Pig manure Control

Cladocera 1347.67 ± 29.98 211.3 ± 11.87 356.3 ± 28.83 0.67 ± 0.67Chironomidae 132.0 ± 2.63 37.29 ± 1.20 76.15 ± 1.79 74.24 ± 2.54Copepoda 312.5 ± 4.92 22.5 ± 1.46 109.5 ± 0.47 1.25 ± 0.0Ostracoda 231.0 ± 15.20 13.67 ± 3.70 98.33 ± 9.91 0.0 ± 0.0Rotifera 1347.45 ± 28.88 212.5 ± 11.47 357.47 ± 29.72 0.75 ± 0.47

Total 3370.62 ± 81.61 497.26 ± 19.7 997.75 ± 70.72 76.91 ± 3.68

Fig. 2. The diet of O. mossambicus in the manured aquadams.

Table 7Abundance of microorganisms and fish mortality in aquadams fertilized with chicken, cow and pig manure.

Treatments

Chicken manure Pig manure Cow manure Control

Total heterotrophic bacterial count (cfu/ml) 11,950 17,800 6750 5250Total coliforms count/100 ml 152 2420 155 54E. coli counts /100 ml + 1 + 1Bacillus spp. count (cfu/ml) 565 25 40 1

+ = <1.

72 M.M. Rapatsa, N.A.G. Moyo / Physics and Chemistry of the Earth 66 (2013) 68–74

in the chicken manured aquadams. None of these phytoplanktongenera were recorded in the diet of O. mossambicus in this study.Wijeyaratne and Perera (2001) recorded Anabaena and Spirulinain the diet of O. mossambicus at a reservoir in Sri Lanka. Closteriumis a diatom and it was correlated with phosphorus and was onlyfound in the chicken manured aquadams. Several studies have re-corded different types of diatoms in the diet of O. mossambicus inthe wild (de Moor et al., 1986; Nyandoto, 2013; Sen and Sonmez,2006). It is, however, noted throughout these studies that O. mos-sambicus feeds on the most available food items in their immediateenvironment. Dependence of feeding habits of tilapias on the avail-

ability of the most abundant food items in the environment is welldocumented by Bowen (1982). It therefore, appears that the abun-dance of Microcystis in the diet of O. mossambicus might be simply afunction of its availability.

The increase in phytoplankton leads to high primary productiv-ity which leads to increased zooplankton abundance (Knud-hansenet al., 1991). The highest zooplankton abundance was obtained inaquadams fertilized with chicken manure. Cladocera and Rotiferadominated the zooplankton community in the present study andwere found in all treatments. They were found in all treatment be-cause they are cosmopolitan zooplanktons that are tolerant of dif-

M.M. Rapatsa, N.A.G. Moyo / Physics and Chemistry of the Earth 66 (2013) 68–74 73

ferent environmental conditions. They are found in most freshwater habitats including lakes, ponds, streams and rivers. Rotiferawere most abundant in aquadams treated with chicken manure.Cattle manure had the second highest abundance and the lowestabundance was in the control due to low abundance in phyto-plankton, since zooplankton feeds on phytoplankton. Copepodswere also found in all the treatments, with the abundance follow-ing the order chicken, pig and cow manure and control. However,Copepod abundance did not differ significantly between the treat-ments. Copepods are usually the dominant zooplankton fauna andare major food organisms for small sized fish. Organic fertilizersstimulate zooplankton production in particular copepods (Kan-g’ombe et al., 2006). Cladocerans and copepods dominated the zoo-plankton component of the diet of O. mossambicus. Theirdominance in the diet might also be a reflection of their abundancein the different treatments.

There was high abundance of heterotrophic bacteria in pig andchicken manured aquadams. When manure is applied to aquad-ams, it is broken down by bacteria to release nutrients which areutilized by other bacteria and phytoplankton. Chicken and pigmanure treatments were more productive which is indicated bysignificantly higher plankton abundances than in the cow manuretreatment and control. Cow manure had lower heterotrophic bac-terial count and this result is consistent with many authors (El Da-kar et al., 2004; Jha et al., 2008; Kumar et al., 2006; Salton and El-Laithy, 2008; Zaki et al., 2011). Although pig manure treatment hadthe highest coliform count, this does not in anyway indicate thepresence of pathogens in the water column treated with pig man-ure. The high coliform count in pig manure suggests that fish cul-tured in pig treated ponds may be a health hazard. More work willneed to be done on this aspect since the pathogenic strains of col-iforms were not identified in this study. Bacillus spp. count washighest in chicken manure and lowest in pig manure. Bacillus isefficient in phosphorus solubilization; this may explain its abun-dance in the chicken manure since chicken manure had high phos-phorus content. Furthermore, it can improve water quality, reduceammonia levels and enhance immune function and anti oxidationactivity (Shalaby, 2011; Qi et al., 2009; Zakaria et al., 2011).

5. Conclusion

Fertilization of the aquadams resulted in the production of amixture of phytoplankton and zooplankton groups. Chicken man-ure treatment produced more natural food for O. mossambicus thancow and pig manure because of its superior nutrient content. O.mossambicus fed on the most abundant food item. Chicken manurealso had the highest Bacillus count and the lowest coliform count.For future studies the key question that must be answered iswhether all the phytoplankton groups that were produced afterapplication of manure are desirable for the production of fish food.There is thus a need to evaluate the phytoplankton that is mostdesirable in fish production. It is recommended that tilapia fishfarmers in South Africa use chicken manure to enhance fish pro-duction in their farms.

Acknowledgements

The authors gratefully acknowledge the financial assistancefrom National Research Foundation (NRF) and the Aquaculture Re-search Unit (ARU). We extend our appreciation to Mr. Gavin Geld-enhuys for all the technical support.

References

Adewumi, A.A., Adewumi, I.K., Olalege, V.F., 2011. Livestock waste-menace: fishwealth-solution. Afr. J. Environ. Sci. Technol. 5, 149–154.

Ali, S.M., Wafa, M.I.A., Abbas, W.T., 2011. Evaluation of Azotobacter and Azospirillumbiofertilizers as a probiotics in Oreochromis niloticus aquaculture. J. Fish. Aquat.Sci. 6, 535–544.

American Public Health Association (APHA), 1985. Standards Methods forExamination of Water and Waste Water, 16th ed. Washington DC, USA.

Ampofo, J.A., Cleck, G.C., 2010. Diversity of bacteria contaminants in tissues of fishcultured in organic waste-fertilized ponds: health implications. Open Fish Sci. J.3, 142–146.

Association of Official Analytical Chemists (AOAC), 2003. Official Methods ofAnalysis of the Association of Official Analytical Chemists, 17th ed. WashingtonDC, USA.

Botes, L., 2003. Phytoplankton Identification Catalogue – Saldanha Bay, South Africa.GloBallast Monograph Series. No. 7. IMO, London, UK, pp. 77.

Bowen, S.H., 1982. Feeding, digestion and growth-qualitative considerations, in:Pullin, R.S.V., Lowe-McConnell, R.H. (Eds.), The Biology and Culture of Tilapias,IC-LARM Conf. Proc. 7, Manila, pp. 141–156.

Brunberg, A., Blomqvist, P., 2006. Benthic overwintering of Microcystis coloniesunder different environmental conditions. J. Plankton Res. 24 (11), 1247–1252.

Day, J.A., Steward, B.A., de Moor, I.J., Louw, A.E., 1999. Crustacea I in: Guides to theFreshwater Invertebrates of Southern Africa. Water Research CommissionReport No. TT 121/00, pp. 126.

Day, J.A., Steward, B.A., de Moor, I.J., Louw, A.E., 2001. Crustacea I in: Guides to theFreshwater Invertebrates of Southern Africa. Water Research CommissionReport No. TT 148/01, pp. 177.

Day, J.A., Harrison, A.D., de Moor, F.C., 2003. Diptera I in: Guides to the FreshwaterInvertebrates of Southern Africa. Water Research Commission Report No. TT201/02, pp. 200.

de Moor, F.C., Wilkson, R.C., Herbst, H.M., 1986. Food and feeding habits ofOreochromis mossambicus (Peters) in hypertrophic Hartbeespoort Dam, SouthAfrica. S. Afr. J. Zool. 21 (2), 170–176.

de Moor, I.J., Day, J.A., de Moor, F.C., 2003a. Insecta I in: Guides to the FreshwaterInvertebrates of Southern Africa. Water Research Commission Report No. TT207/03, pp. 288.

de Moor, I.J., Day, J.A., de Moor, F.C., 2003b. Insecta II in: Guides to the FreshwaterInvertebrates of Southern Africa. Water Research Commission Report No. TT214/03, pp. 209.

Edwards, D.R., Larson, B.T., Lim, T.T., 2000. Runoff nutrient and fecal coliformcontent from cattle manure application to fescue plots. J. Am. Water Resour.Assoc. 36 (4), 711–721.

El Dakar, A.Y., Hassanien, G.D.I., Seham, S., Gad, S.E., Sakr, S., 2004. Use of medicaland aromatic plants in fish diets: I. Effect of dried marjoram leaves onperformance of hybrid tilapia Oreochromis niloticus � Oreochromis aureus,fingerlings. J. Egypt. Acad. Soc. Environ. Dev. (B.Aquaculture) 5 (1), 67–83.

Food and Agricultural Organisation of the United Nations (FAO), 1985. TrainingManual Integrated Fish Farming in China. NACA/TR/85/11. FAO, Bangkok,Thailand, pp. 371.

Furusato, E., Asaeda, T., Manatunge, J., 2004. Tolerance for prolonged darkness ofthree phytoplankton species, Microcystis aeruginosa (Cyanophyceae),Scenedesmus quadricauda (Chlorophyceae) and Melosira ambigua(Bacillariophyceae). Hydrobiologia 527, 153–162.

Hopkins, K.D., Cruz, E.M., 1982. The ICLARM-CLSU Integrated Animal–Fish FarmingProjects: Final report. ICLARM Technical, Report No. 5, pp. 96.

Hossain, Y., Begum, M., Ahmed, Z.F., Hoque, A., Karim, A., Wahab, A., 2006. A studyon the effects of iso-phosphorus fertilizers on plankton in fish ponds. South. Pac.Stud. 26, 101–110.

Hyslop, E.J., 1980. Stomach content analysis – a review of methods and theirapplication. J. Fish. Biol. 17 (4), 411–429.

Jha, P., Barat, S., Nayak, C.R., 2008. Fish production, water quality and bacteriologicalparameters of Koi carp ponds under live-food and manure based managementregimes. Zool. Res. 29 (2), 165–173.

Kang’ombe, J., Brown, J.A., Halfyard, L.C., 2006. Effect of using different types oforganic animal manure on plankton abundance, and on growth and survival ofTilapia rendalli (Boulenger) in ponds. Aqualt. Res. 37, 1360–1371.

Knud-hansen, C.F., Batterson, T.R., McNabb, C.D., Harabat, I.S., Sunantadinata, K.,Eidman, H.M., 1991. Nitrogen input, primary productivity and fish yield infertilized freshwater ponds in Indonesia. Aquaculture 94, 49–63.

Kumar, R., Mukherjee, S.C., Prasad, K.P., Pal, A.K., 2006. Evaluation of Bacillus subtilisas a probiotic to Indian major carp Labeo rohita. Aqualt. Res. 37, 1215–1221.

Mandal, S.C., Hasan, M., Rahman, M.S., Manik, M.H., Mahmud, Z.H., Sirqjul Islam,M.D., 2009. Coliform bacteria in Nile Tilapia, Oreochromis niloticus of shrimp-gher ponds and fish market. World J. Fish Mar. Sci. 1 (3), 160–166.

Novotny, T., Dvorska, L., Lorencova, A., Beran, V., Pavlik, I., 2004. Fish: a potentialsource of bacterial pathogens for human beings. Vet. Med. Czech 49 (9), 343–358.

Nyandoto, J.M., 2013. Food and feeding habits of Mozambique Tilapia Oreochromismossambicus (Peters, 1952) from Hardap Dam, Namibia, Phd Thesis.

Perkins, H.F., Parker, M.B., Walker, M.L., 1964. Chicken manure – its production,composition and use as a fertilizer. Georgia Agricultural Stations. University ofGeorgia, College of Agriculture Bulletin N.S 123, pp. 24.

Piasecki, W., Goodwin, A.E., Eiras, J.C., Nowak, B.F., 2004. Importance of copepoda infreshwater aquaculture. Zool. Stud. 43 (2), 193–205.

Prinsloo, J.F., Schoonbee, H.J., 1986. Summer yield of fish in polyculture in Transkei,South Africa, using pig manure with and without formulated feed. S. Afr. J.Anim. Sci. 16, 65–71.

Qi, Z., Zhang, X., Boon, N., Bossier, P., 2009. Probiotics in aquaculture of China –current state, problems and prospect. Aquaculture 290, 15–21.

74 M.M. Rapatsa, N.A.G. Moyo / Physics and Chemistry of the Earth 66 (2013) 68–74

Salton, M.A., El-Laithy, S.M.M., 2008. Effect of probiotics and some spices as feedadditives on the performance and behaviour of Nile tilapia, Oreochromisniloticus. Egypt. J. Aquat. Biol. Fish. 12 (2), 63–80.

Schroeder, G.L., 1974. Use of fluid cowshed manure in fish ponds. Bamidgeh 26 (3),84.

Sen, B., Sonmez, F., 2006. A study on the algae in fish ponds and their seasonalvariations. Int. J. Sci. Technol. 1, 25–33.

Shalaby, E.A., 2011. Prospects of effective microorganisms technology in wastetreatments in Egypt. Asian. Pac. J. Trop. Biomed. 3, 243–248.

ter Braak, C.J.F., Šmilauer, P., 2012. CANOCO Reference Manual and User’s Guide toCanoco for Windows: Software for Canonical Community Ordination (Version5.0). Microcomputer Power. Ithaca, New York, USA, pp. 496.

Terziyski, D., Grozev, G., Kalcher, R., Stoeva, A., 2007. Effect of organic fertilizer onplankton primary production in fish ponds. Aqualt. Int. 15, 181–190.

Wade, J.W., Stirling, H.P., 1999. Fertilization of earth ponds. II: Effects on planktoncommunities. J. Aquat. Sci. 14, 13–18.

Wijeyaratne, M.J.S., Perera, W.M.D.S.K., 2001. Trophic interrelationships amongexotic and indigenous fish co-occurring in some reservoirs in Sri Lanka. AsianFish. Sci. 14 (3), 333–342.

Zakaria, Z., Gairola, S., Shariff, N.M., 2011. Effective Microorganisms (EM)technology for water quality restoration and potential for sustainable waterresources and management, In: International congress on environmentalmodelling and software modelling for environment’s sake. Fifth Biennalmeeting, Ottawa, Canada, pp. 8.

Zaki, M.A., El-Nakiel, F.A.M., Labib, E.M.H., 2011. Sustainable EnvironmentalDevelopment for Fish Aquaculture by Using Effective Microorganisms (EM) asa Probiotic. EMRO Co., Ltd., Monririh Building, 3F SOi Sailom, Phahonyothin Rd,Bangkok, Thailand, pp. 4.