Journal of Environmental Treatment Techniques 2015, Volume 3, Issue 2, Pages: 71-75
71
Assessment of Elemental and Microbial Quality of Lake Efi in
Bayelsa State, Central Niger Delta, Nigeria
Tariwari C.N. Angaye
1
* and Cosboy E. Mieyepa
2
1- Toxicity Research Group, Department of Biological Sciences, Niger Delta University, Bayelsa State, Nigeria.
2- Department of Environmental Resource Management, Faculty of Environmental Engineering, Imo State University, Nigeria.
Received: 19/04/2015 Accepted: 08/06/2015 Published: 30/06/2015
Abstract
Efi lake of Bayelsa state, Nigeria, is emerging as a resource in the Niger Delta. It holds a great mythological significance, as
well as a means of livelihood. This study assessed the Elemental and Microbial quality of the lake. Water Samples of the lake
were collected upstream, midstream and downstream in March 2015, and similarly analyzed following standard protocol. Results
showed that, compared to iron which ranged from 0.034 - 0.74 mg/l, copper, mercury and lead were below detection limits, while
Cadmium (0.00 - 0.057 mg/l), Chromium (0.00 - 0.137 mg/l) and Zinc (0.00 - 0.231 mg/l) occurred in very low concentrations
(P < 0.05). The physicochemical parameters showed that temperature, pH, conductivity and TDS ranges as; 28.36 - 30.10
o
C, 6.55
- 7.20, 48.13 - 68.93 μS/cm, 54.25 - 102.92 mg/l respectively; while turbidity, DO and Nitrate ranges as 7.87 - 17.29 NTU, 9.07 -
19.52 mg/l and 1.34 - 2.82 mg/l respectively (P < 0.05). Total heterotrophic bacteria and fungi were 0.44 - 1.159 X 10
6
and 0.46 -
0.86 X 10
4
Cfu/ml respectively. Furthermore, the total and feacal coliforms were 76.72 - 260.23 and 53.67-157.02 MPN/100 ml
MPN/100 ml respectively. The results generally indicate mild anthropogenic activities in the lack. Hence, robust government and
communal laws should be enforce to protect this potential eco-tourist area.
Keywords: Niger Delta, Efi Lake, microorganisms, physico-chemistry, Heavy metals
1 Introduction
1
A delta is could be defined as that portion of a
country’s land mass through which its rivers systems are
discharged to the ocean. The Niger Delta is a wetland
characterized by high level of precipitation and multiple
flooding. Its river system are deltaic with three basic
tributaries [1]. These tributaries are River-Forcados to the
west in Delta state, River-Orashi located eastward and
River-Nun (central i.e. between orashi and forcardos), in
Bayelsa state. These three rivers form a triangular delta
originating from a major parent tributary at Ebueto. The
Niger delta has four ecological zones (coastal barrier
island, mangrove swamp forest, freshwater swamp and
lowland rainforest). Core States in the Niger Delta
includes; Delta, Bayelsa, Rivers and Akwa Ibom. It is a
geopolitical region located on the southern part of the
Nigerian map. With more than 40 different ethnic groups,
its population is estimated to be over 20 million.
Lake Efi is emerging as one of the potential eco-tourist
zone of bayelsa state, Nigeria. Located in a community
called Kalama, in Sabagreia town of Kolokuma/Opokuma
Corresponding Author: Tariwari C.N. Angaye, Toxicity
Research Group, Department of Biological Sciences, Niger
Delta University, Wilberforce Island, Bayelsa State,
Nigeria. E-mail: maktarry@yahoo.com;
Tel: +234-703-7889-063.
Local Government Area. The origin of the lake holds a
basking mythological history, which originated over three
centuries ago. After a fierce argument between two
fishermen (from Kalama and Gbarain communities), on the
ownership of the lake. They both agreed on a competitive
(win and claim) venture doctored by the Kalama man. The
terms agreed was that the first between the two to make fire
around the lake will solely retain owner the lake. The terms
agreed made the Gbaraun man to quickly dash home to
fetch fire from his community which is closer to the lake.
The Gbaraun man was outsmarted that prior to his arrival,
the Kalama man made fire from sticks around the lake,
with the aid of his gun powder. The lake is pristine due to
its self-purifying mechanism, and it host diverse species
ranging from fish, turtle and crocodile. The lake is
surrounded by forest and is about 2km square area in size.
It has been managed by a conditional fishing festival only
observed every decade [2].
The quality of water in communities aligning coastal
settlement is essential to their relative health and
sustenance. In Bayelsa state, the river of some riverine
communities unfortunately act as a waste dump sites [3].
The wastes streams discharged into the water bodies may
include organic and inorganic waste such as; heavy metals,
elemental ions, oil and grease and other wastes of organic
origin [3, 4], originating from point and non-point sources
as leachates swept by runoffs [4]. Although the
contamination of a river may be determined by its flow
intensity and dilution capacity [3], however the persistent
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J. Environ. Treat. Tech.
ISSN: 2309-1185
Journal of Environmental Treatment Techniques 2015, Volume 3, Issue 2, Pages: 71-75
72
anthropogenic activities over a period of time may
influence the contamination rate.
The viability of microbes linked to water-borne
diseases is made possible by persistence sewage discharged
into water bodies. Significant level of heterotrophic
bacteria have been reported in surface water of the Niger
Delta. They include [3]. They species includes;
Staphylococcus aureus, Escherichia coli, Bacillus,
Pseudomonas, Proteus, Enterobacter, Streptococcus,
Salmonella, Shigella, Vibrio species [5]. Also microbes like
the Salmonella Typhi [6, 7], as well as the Pseudomonas
and Escherichia genera have been reported on the
Wilberforce axis of River Nun [8]. Notwithstanding, Efi
Lake is a means of livelihood and potential eco-tourist zone
of Bayelsa state; as such it has become necessary to assess
the Elemental and Microbial quality of Lake so as to
circumspect it envisaged sustainability.
2 Materials and Methods
2.1 Study area
Sampling was carried out in Efi Lake located in
Kalama community of Sabagreia town in
Kolokuma/Opokuma LGA, Bayelsa State Nigeria. It is
located on latitude and longitude N05
o
02
∣
49.1
∣∣
and E006
o
14
∣
40.3
∣∣
respectively. The major occupation of the
sabagreia people is farming and petty trading. Efi Lake is a
resource, which holds a great mythological history, and
diverse aquatic macrophytes, and some endangered species.
The study area has a tropical humid warm climate with two
prevailing seasons. They are the rainy season (March to
October), with an annual precipitation of over 2000mm and
the dry and dusty seasons (November to February).
2.2 Sample collection
A total of six sample was collected in the month of
February 2015, two from each sampling points (i.e.
upstream, midstream and downstream). The water sample
were collected aseptically with sterile microbiological
bottles and preserved in ice packs. Other physicochemical
parameters were determined in-situ using potable meters.
The samples were immediately digested with few drops of
nitric acid and stored in ice pack where applicable, and
transported to the laboratory for the analysis of ex-situ
parameters (i.e. heavy metals).
2.3 Laboratory analysis
2.3.1 Microbial Quality Assessment
The enumeration of total heterotrophic bacteria (THB)
and fungi (TF) were carried out using serial dilution and
aerobic pour plate technique as described by several
authors [3, 9, 10]. Serially diluted aliquots of the water
samples were ascetically plated into Nutrient Agar and
Sabouraud dextrose agar respectively for THB and TF
respectively. The plates were maintained for an incubation
period of 24-48 at 37°C for THB, while the TF was
maintained at 48-72 at 37°C. The viable colonies were
enumerated and expressed as colony forming units per
millilitres (i.e. cfu/ml). Total coliform (TF) and fecal
coliforms (FC) were assessed using Multiple Tube
Fermentation Technique expressed as MPN (Most Probable
Number) APHA 9222C.
2.3.2 Elemental Assessment
All analysis were carried out following standard
protocol [11]. The pH, temperature, dissolved oxygen and
conductivity were measured using EXTECH Multi- probe
meter (DO700). Total dissolved solid was measured using
TDS meter. Nitrate was analysed using Colorimetric
method. The heavy metals were analysed using Perkin
Elmer 5100 PC AA Spectrometer Atomic Absorption
Spectrophotometer (AAS).
2.4 Statistical analysis
All statistical analysis for the purpose of this research
were carried out using SPSS software (SPSS Inc, Chicago;
version 16). A one-way analysis of variance was carried out
at P = 0.05, and Duncan’s multiple range test (DMR) was
used to discern the source of the observed differences.
3 Results and Discussion
Table 1 presents the level of endemic microbes in the
lake which includes; Total Heterotrophic Bacteria (THB),
Total Fungi (TF), Total Coliform (TC) and Feacal Coliform
(FC). The density of THB and TF ranged from 0.441-1.159
X 10
6
and 0.459-0.848 X 10
4
Log cfu/ml (P<0.05). The
level of coliform, according to WHO should be zero for
potable water, although result of Efi lake indicated
significant level of total (76.72-260.23 MPN/100 ml), and
faecal (53.67-157.02 MPN/100 ml) coliforms. THB levels
of with mean densities of 6.434±0.039 and
6.387±0.055Log cfu/ml have been reported in lower and
upper Nun River of the Niger delta, as well as Ogobiri
(6.414±0.078Log cfu/ml) and Akaibiri (6.394±0.070Log
cfu/ml) axis of river Nun [3]. Due to the detected level of
microbes in the lake the water is, direct consumption of
water is discouraged. On the other hand, depending on the
endemic biota, mild and tolerable level of microbes might
sustain aquatic life, provided the threshold limit of
pathogenic microbes is not exceeded. For instance,
bacterial, viral and fungal diseases have been reported in
fish as a result of exceeding level of water contamination
[12, 13].
Table 2 presents the physicochemical properties of Efi
Lake of Sabagreia, a potential tourist centre and means of
livelihood of the Kolokuma clan in Bayelsa state Nigeria.
Result showed that the temperature of the water ranged
from 28.36-30.10
o
C. Standard temperature that sustain life
should be ambient. Extreme temperatures might aid
exotic/alien species invasion, or even synergicidel with
regards to other elemental or physicochemical activities.
The pH from all sampling points (i.e. upstream, midstream
and downstream), which ranged from, 6.55-7.20 complied
with WHO and Standard Organisation of Nigeria (SON)
permissible limits (6.5 – 8.5), with significant difference
upstream, midstream and downstream (P<0.05). Several
authors have reported the pH of surface water as; 7.4 – 7.57
and 6.9 – 7.33 in dry and wet season respectively for Epie
creek [14], 6.95 – 7.50 for lower Kolo creek [15], 7.17 for
upper river Nun [16], 6.8 – 8.5 for Nkoro River [17] as well
as 6.5-7.11 and 6.5-6.73 for Rivers igedi and Nun
respectively [3].
Journal of Environmental Treatment Techniques 2015, Volume 3, Issue 2, Pages: 71-75
73
Table 1: Microbiological Quality assessment of Efi Lake
Sample Code
THB, X 10
6
(Cfu/ml)
TF, X 10
4
(Cfu/ ml)
TC (MPN/100 ml)
FC (MPN/100ml)
USI
1.159±0.449c
0.742±0.173c
260.232±5.629d
157.032±3.280c
US2
0.698±0.442b
0.585±0.517b
167.122±11.871b
200.302±5.582d
MS1
0.749±0.112b
0.559. ±0.414ab
76.717±8.787a
140.312±10.111a
MS2
0.794±0.110b
0.549±0.299ab
90.050±0.032a
140.152±9.905a
DS1
0.648±0.109b
0.459±0.328a
205.222±2.882c
85.903±3.377b
DS2
0.441±0.252a
0.848±0.192d
250.362±23.005d
53.667±6.498a
WHO
-
-
0
0
SON
-
-
0
0
Each value is expressed as mean ± standard error (n = 3). Different letters in each column indicate significant differences at P<
0.05 according to the Duncan Statistics. Keys: Upstream (US), Midstream (MS), Downstream (DS).
The conductivity of Efi lake ranged from 48.13 - 68.93
μS/cm with significant difference (P<0.05), upstream,
midstream and downstream. The values reported in this
study, complied with WHO and SON permissible limits of
1000 μS/cm. This value corroborates the range of values
reported by other authors who studied surface water of
Bayelsa like; Amassoma and Agudama-Ekpetima rivers,
which are downstream and upstream river Nun with
conductivity values of 56.075±0.591 and
64.950±0.681μS/cm respectively [3], 82.30 – 102.0 μS/cm
for Kolo creek [15], 76.23 umhos/cm for Igbedi creek [18],
87 – 95 umhos/cm during the construction of Tombia
bridge [18]. Puyate and Rim-Rukeh [19], also reported
conductivity with values in the range of 18.9 – 156.4
μS/cm.
The Dissolved oxygen (DO) ranged from 9.07-
19.52mg/l with significant difference upstream, midstream
and downstream (P<0.05). Although DO level was not
specified by WHO and SON, however low level of DO
may be toxic to some aquatic organism [20], especially if
lower than 2.0mg/l [12]. Agedah et al [3] reported DO
levels of 10.200±0.283 and 14.225±0.263mg/l for Igbedi
and Ogobiri which are along the river Nun axis. Some other
rivers in Bayelsa had DO in the ranges of 4.8mg/l – 7.2mg/l
[18], 5.0 – 7.92 mg/l for Kolo creek [15], 1.38 – 9.06 and
1.76 – 5.68 mg/l for dry and wet seasons of Epie creek
respectively [14].
The level of total dissolved solid (TDS) ranged in the
lake ranged from 54.25 - 102.92 mg/l with significant
difference (P<0.05) amongst the sampling points.
Notwithstanding, our values are comparable to previous
studies of surface water in Bayelsa state. Aghoghovwia and
Ohimain [15] reported TDS value of 41.5 – 51.0 mg/l in
Lower Kolo creek. The TDS values of Amassoma and
Igbedi were also reported as 28.180±0.048 and
32.550±0.666mg/l respectively [3]. Epie creek TDS values
were 55 - 62 and 33 – 37.33 mg/l in dry and wet seasons
respectively [14], and 62.1 – 67.9 mg/l for Tombia axis of
the river Nun [21].
Table 2: General physicochemical parameters of Efi Lake
Sample Code
pH
EC (μS/cm)
TDS (mg/L)
DO (mg/L)
Nitrate (mg/L)
USI
6.780±0.042b
64.527±0.955e
92.753±0.723d
11.063±0.145d
1.343±0.081a
US2
6.853±0.060b
68.903±0.478f
102.922±0.365e
9.490±0.091b
2.820±0.115d
MS1
6.557±0.018a
61.413±0.120d
660.500±1.415b
17.187±0.124e
1.907±0.052b
MS2
6.690±0.029ab
59.336±0.191c
54.253±0.764a
19.523±0.125f
2.253±0.179c
DS1
7.460±0.078d
50.127±0.043b
64.250±0.171b
9.077±0.186a
1.377±0.033a
DS2
7.200±0.100c
48.130±0.026a
76.827±0.022c
10.203±0.133c
1.630±0.125ab
WHO
6.5 – 8.5
1000
500
-
50
SON
-
-
-
-
-
The turbidity of the water sample under study from Efi
Lake ranged from 7.87-17.29NTU, with significant
difference (P<0.05), amongst the sampling points. The
highest turbidity value was indicated upstream
(17.293±0.219), while the lowest was downstream
(7.877±0.052). This study is comparable to a recent study,
which reported turbidity values of 103.752±2.062 NTU
upstream the river Nun axis of Agudama-Ekpetima, and
117.002±2.160NTU downstream river Nun [3]. Other
authors who studied surface water in the Niger delta
reported turbidity values 62.54 NTU in Igbedi creek [16], 5
– 64 NTU around Tombia bride Agudama Ikpetiama [21],
11.67 – 19.67 and 16.67 – 28.00 NTU, along the Epie creek
in dry and wet seasons respectively [14], 35.0 – 40.5 NTU
in Kolo creek [15]. The turbidity values of Efi Lake
exceeds WHO and SON permissible limit (5NTU). The
mild variation in turbidity values might be a reflection of
anthropogenic activities of the inhabitants aligning the
coastal settlement or abrasion effect on the bank of the lake
[1, 3].
The Nitrate level in Efi Lake ranged from 1.34-
2.82mg/l with significant difference (P<0.05), amongst the
sampling points (i.e. upstream, midstream and
downstream). The level of nitrate is higher compared to
values of Epie creek with 0.02 – 0.27 mg/l for dry season
and 0.14 – 0.28 for wet season [14]; Akaibiri River of
0.330±0.014mg/l and Igbedi River with 0.813±0.562mg/l
[3], as well as the lower Kolo creek with values in the
range of 0.1 – 0.24mg/l [15]. On the other hand, higher
Nitrate levels within the range of 1.48 – 4.33 mg/l have
been reported in some rivers of the Niger delta [19].
Notwithstanding, it was noteworthy that the Nitrate level of
Efi Lake complied with the allowable limits of WHO and
SON.
Results of the selected heavy metals assayed are
presented in Table 3. Copper, mercury and lead were not
detected in the lake; however, the level of cadmium varies
as; 0.037-0.033 mg/l upstream, 0.00-0.014 mg/l midstream
and not detected downstream. While chromium (0.017-
0.023mg/l) and zinc (0.021-0.091mg/l) were only detected
Journal of Environmental Treatment Techniques 2015, Volume 3, Issue 2, Pages: 71-75
74
upstream, the level of iron was highest amongst all tested
metals (0.393-0.740 upstream, 0.101-0.204mg/l midstream
and 0.094-0.143mg/l downstream). From the foregoing
high level of iron has been detected in both surface and
groundwater of Bayelsa state [22, 23]. Cadmium could be
leaching can result from agricultural activities like fertilizer
and pesticide application [24-26].
Table 3: Heavy metal analysis of Efi Lake
Sample Code
Cadmium (mg/L)
Chromium (mg/L)
Copper (mg/L)
Iron (mg/L)
Mercury (mg/L)
Lead (mg/L)
Zinc (mg/L)
USI
0.037±0.009b
0.017±0.032a
BDL
0.740±0.058b
BDL
BDL
0.021±0.009a
US2
0.033±0.033b
0.023±0.023a
BDL
0.393±0.293a
BDL
BDL
0.091±0.091a
MS1
BDL
BDL
BDL
0.204±0.204a
BDL
BDL
BDL
MS2
0.014±0.00a
BDL
BDL
0.101±0.101a
BDL
BDL
BDL
DS1
BDL
BDL
BDL
0.094±0.034a
BDL
BDL
BDL
DS2
BDL
BDL
BDL
0.143±0.143a
BDL
BDL
BDL
WHO Limit
NS
0.005
1.5
1.0
0.001
0.01
1.5
SON
-
-
1.0
1.0
-
-
-
Each value is expressed as mean ± standard error (n = 3). Different letters in each column indicate significant differences at P<
0.05 according to the Duncan Statistics; BDL= below detection limit
Intolerant dose of cadmium is toxic metal which can
result to neurological, carcinogenic, mutagenic and renal
dysfunction [24]. It results to severe consequences to
aquatic which include instant mortality or other systemic
dysfunction. [27]. Chromium contaminants may originate
from paint pigments, cement, rubber, metal plating, leather
tanning, and textile pigments [26]. The toxic impacts of
chromium includes; dermal allergy, pulmonary, liver and
kidney dysfunction [28-30]. Zinc could be a component
arising from precarious or anthropogenic discharged of
waste from mining activities, wood preservatives or the
manufacture of paint, fertilizer, dye, rubber and ointments
[31]. The accidental consumption of zinc results to adverse
health effects [32].
Although the lake showed significant level of
contaminants from microbiological origin. On the other
hand, elemental analysis indicated that all detected heavy
metals complied with their respective stated limits.
Furthermore, the selected assayed metals in Efi Lake were
observed to be either present in low concentration or below
detection limit. Although iron which ranks highest amongst
assessed heavy metals is due to the geology of the area
[Angaye and oHimain]. Generally, the spatial variation of
is attributed to the nature of the catchment area, industrial
effluents, runoffs, leachates of agricultural activities or
hydrogeological of the area [33]. Notwithstanding, it is
likely that the pH of the lake, is a reflection of the levels of
metals [34]. Also petroleum exploration activities in the
Niger delta can also emit natural gases (carbon dioxide,
oxygen, sulphur dioxide and nitrogen), with some
envisaged elemental leachates to the environment. The
communal monitoring of Efi Lake through time-gap fishing
activities might have been responsible for the low level of
contamination.
4 Conclusions
The communal time-gap exploitation festival Imposed
by the people of the Sabagreia people reflects the mild
anthropogenic incidence of the lake. Unfortunately,
significant level of endemic microbial count makes the lake
water unfit for drinking. Also the higher but compliant
level of Iron amongst tested heavy metals is attributed to
the hydrogeology of the area. The findings of this research
will assist the people of Sabagreia on Potential hazard and
aid relevant agencies on the need for developing the lake.
Although anthropogenic activities on is limited, however
our findings indicates that the level of contaminants could
arise. As such were recommend further development of the
lake as a tourist center as well as constant microbial and
element quality assessment of the lake.
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