Page
TABLE OF CONTENTS:
1
Abstract.
2
1.0 Introduction
4
2.0 Materials and Method
8
2.1 Study Area
8
2.2 Some Physical/Chemical Sample determinations
9
2.2.1 Total Dissolved Solid (TDS)
9
2.2.2 Total Suspended Solid (TSS)
9
2.2.3 Iron
10
2.2.4 Reactive Nitrogen
11
2.3 Collection of Samples
11
2.4 Chlorophyll-a Determination
12
2.5 Community structure Analysis
12
2.5.1 Margelef Index
12
2.5.2 Species Equitability or Evenness
13
2.5.3 Similarity/Dissimilarity Index
13
3.0 Results
14
3.1 Hydro climate Properties
14
1
3.2 Diatom Community
22
3.3 Community Structure Indices
37
4.0 Discussion
39
5.0 Conclusion
43
Acknowledgement
43
References
43-49
A Comparative Study of the Epiphyton and Phytoplankton Biomass in
Yewa Lagoon at Iragbo in Relation to Environmental Characteristics.
Effiong, K. S1,. and Inyang, A. I2.
1 Department of marine Sciences, Faculty of Natural and Applied Sciences, Akwa Ibom State
University, Ikot Akpden, Nigeria.
2 Department of marine Sciences, Faculty of Natural and Applied Sciences, Akwa Ibom State
University, Ikot Akpden, Nigeria.
Email address:
kokoetteeffiong@gmail.com
(Effiong,
Kokoette
Sunday),
aniefiokinyang@yahoo.com
(Inyang, A. I).
Abstract
A comparative study of the phytoplankton and epiphyton biomass in relation to environmental
characteristics at the Iragbo part of Yewa Lagoon were undertaken for six months (December,
2012- May, 2013). Water temperature (≤32.20C), air temperature (≤ 48.50C), transparency (≤
48.5cm), pH (≤ 8.16), were higher in dry months while in the wet months total suspended solids (≤
2
1.3mg/L) and total dissolved solids (≤ 49.0mg/L) values were higher. Dissolved oxygen values (≥
2.8mg/L ≤ 7.6mg/L) were moderate in the Lagoon while biochemical oxygen demand varied
between 7.0mg/L and 16.0mg/L, chemical oxygen demand also varied between 21.0mg/L and
40.0mg/L. Reactive silicates ranged between 0.002mg/L and 0.004mg/L throughout the sampling
months. The heavy metal values; Copper (≤0.03mg/L), Lead (≤ 0.017mg/L), Zinc (≤ 0.62mg/L)
and Iron (≤ 0.34mg/L) remained low throughout the sampling period.. Both the phytoplankton and
epiphyton biomass were higher in the dry months. Phytoplankton chlorophyll-a values were
highest in January while epiphyton chlorophyll-a value was highest in February. The pinnate
diatoms dominated the epiphyton community while the centrales diatoms dominated the
phytpplankton community. A total of 4885 individuals of 76 phytoplankton species belonging to 6
divisions were identified while a total of 2505 individuals of 39 epiphyton species belonging to 4
divisions were identified. For the phytoplankton community, a total of 1565 individuals (31.80%)
represent bacillariophyta division while 635 (12.90%), 2535 (51.52%), 115 (2.33%), 15 (0.5%),
and 20 (0.85%) represent chlorophyta, euglenophyta, chrysophyta and pyrophyta respectively. For
the epiphyton community, a total of 2525 individuals (87.37%) represents bacillariophyta division
while 105 (3.69%), 195(6.74%), and 65(2.24%) individuals represent chlorophyta, cyanophyta and
euglenophyta respectively. Species used elsewhere for biomonitoring were observed in the lagoon,
they include (Euglenoid) Euglena and Phacus species, Trachelomonas hispida, (Diatoms)
Gomphonema parvulum, Synedra ovate, Pinnularia major and (Green algae) Chlorella sp.
Keywords: Chlorophyll-a, Similarity, Bioindicator, Phytoplankton, Epiphyton.
3
INTRODUCTION:
Planktonic algae are free-floating microscopic plants, which obtain chlorophyll and
grow by photosynthesis in the presence of sunlight and lacks roots, stems and leaves
(Lee, 1999; Nwankwo, 2004a). Phytoplankton are the plant components of plankton
that photosynthesize, release oxygen to the environment and serve as food producers
in aquatic ecosystems (Mader, 2001). Freely suspended microscopic plant forms are
termed phytoplankton; they are photosynthetic organisms that float near the surface
water. Whereas forms attached to aquatic macrophytes are termed epiphyton
(Nwankwo 2004b). They absorb nutrients from the water or sediments, add oxygen
to the water as a by-product and are usually the major source of organic matter at the
base of food web in the aquatic environment (Lawson and John, 1987; Lee, 1999).
Algae are almost ubiquitous throughout the world, being most common in aquatic
habitats. They can be categorized ecologically by their habitats. Planktonic
microscopic algae grow suspended in the water, whereas neustonic algae grow on
the water surface. Cryophilic algae occur in snow and ice; thermophilic algae live in
hot springs; edaphic algae live on or in soil; epizoic algae grow on animals, such as
turtles and sloths; epiphytic algae grow on fungi, land plants, aquatic plants or other
algae; corticolous algae grow on the bark of trees; epilithic algae live on rocks;
endolithic algae live in porous rocks; and chasmolithic algae grow in rock fissures.
Some algae live inside other organisms, and in a general sense these are called
endosymbionts. Specifically, endozoic endosymbionts live in protozoa or other,
larger animals, whereas endophytic endosymbionts live in fungi, plants, or other
algae.
There are quite a handful of records on the algal flora of south-western Nigeria.
Adesalu and Nwankwo (2005), reported a prominent role played by phytoplankton
in Ogbe creek.
4
Nwankwo (1984) observed seasonal changes of phytoplankton of Lagos Lagoon
and adjacent sea in relation to environmental factors. Onyema and Nwankwo (2008)
studied the epiphytic assemblage of a polluted estuarine creek in Lagos. Nwankwo
et al. (2008) observed the hydrochemistry and plankton dynamics of Kuramo
Lagoon in Nigeria. Plankton studies in the Lagoon also include those of Olaniyan
(1957) who investigated the zooplankton, Inyang et al (2015a) who studied the
composition of periphyton community on water hyacinth at Ejirin part of Epe
Lagoon , Hendey (1964) who studied the phytoplankton and Inyang et al (2015b)
who did a comparative study of periphyton on Eichhornia crassipes and
Phytoplankton communities at Ejirin part of Epe Lagoon,
The coastal area of south western Nigeria, more specifically is a meandering
network of lagoons that angle approximately 45 0 to the prevailing south westerlies
(Hill and Webb, 1958; Ibe,1988). Of these Lagos Lagoon complex stretches for
257km from Benin Republic to the west in the Niger Delta to the east and consist of
nine lagoons. According to Nwankwo, 1993, the lagoons and creeks of south
western Nigeria are linked to the sea through Lagos harbour which remains open all
through the year. A well defined salinity gradient, linked with the rainfall pattern,
extends far inland westwards and eastwards. This area therefore shows major
floristic changes along salinity gradient (Nwankwo, 1988). Furthermore, the texture
of the bottom sediment maybe described as muddy sand, sandy mud, muddy or
coarse with shell material.
Since the incursion of water hyacinth (Eichhonia crassipes) into Nigerian coastal
waters in September 1984 from the Porto Novo creek (Benin Republic), it has
continued to flourish especially in Yewa lagoon that has a direct influence from the
Yewa River being fresh water. Some of the immediate problems created by this
infestation include blockage of drainages, increase in breeding sites of mosquitoes
5
and snails, interference with fishing and even impairment of navigation (Nwankwo,
1993).
Epiphyton is a complex mixture of algae, heterotrophic microbes, and detritus that
are attached to submerged surfaces in most aquatic ecosystems. It serves as an
important food source for invertebrates (Kadiri, 1992) tadpole and some fishes. It
can also absorb contaminants removing them from the water column and limiting
their movement through the environment.
According to Nwankwo and Amuda (1993), the creeks of south-western Nigeria
form part of numerous ecological niches associated with the Nigerian coastal
environment. These creeks are of two types; the first is the tidal creek surrounded
partly by fresh water swamp from places beyond the rich of tidal influence. The
other is the non-tidal fresh water creek surrounded by fresh water swamps and
infested with aquatic macrophytes all through the year.
Epiphyton algal communities are important components of aquatic ecosystem. Their
contribution to primary production varies from 0.2% to 41% in lakes (Laugaste and
Reumanen, 2005). Furthermore, the epiphyton algae with macrophyte are employed
as the buffering zone of lakes lagoons (Lakatos et al, 1999). They are important
components of food webs (Michael et al, 2006). Epiphyton algae are good indicator
of water quality and environmental changes due to their sensitivity to external
sources of fertilization (Lowe, 1996).
Epiphyton is also an indicator of water quality; response to this community to
pollutants can be measured at a variety of scales representing physiological to
community-level changes. For this reason, epiphyton has often been used as an
experimental system in, example pollution induced community tolerant studies
(Sladeckova, 1962; Patrick, 1965, 1967 1975; Wilkinson et al, 1976). The
6
importance of aquatics in providing suitable foci for epiphyton algae is well known
(Odum, 1957; Saszka, 1975; Cattaneo and Kalff, 1978). Similarly reports by Zoebell
and Allen (1933), Wilson (Barbour et al, 1999), Erth (1971) have shown relevance
of artificial surfaces in the trapping and study of attached algae. Epiphyton algal
communities are important components of aquatic ecosystem. Their contribution to
primary production varies from 0.2% to 41% in lakes (Laugaste and Reumanen,
2005). Furthermore, the epiphyton algae with macrophyte are employed as the
buffering zone of lakes lagoons (Lakatos et al, 1999). They are important
components of food webs (Michael et al, 2006). Epiphyton algae are good indicator
of water quality and environmental changes due to their sensitivity to external
sources of fertilization (Lowe, 1996). The aim of the study is to carry out the
comparative study of epiphyton and phytoplankton biomass of Yewa Lagoon at the
Iragbo in relation to environmental characteristics.
7
2. MATERIALS AND METHODS
2.1 Study Area
Fig 1. Map of Yewa Lagoon showing Sampling Site.
Yewa lagoon is about 17km from the Nigeria-Benin Republic boarder (Egborge, 1988). It
lies along the boundary between Ogun and Lagos states, and is perpendicular to Badagry
Lagoon (Fig. 1). It lies approximately 6.21km upstream of River Yewa (Egborge, 1988). It
experiences the characteristics seasonal rainfall that determines environmental gradients in
South-Western Nigeria. River Yewa which is the major river emptying into the lagoos has
8
Ere and Iragbo as tributaries, (Effiong and Inyang, 2015). Mangrove vegetations such as the
red mangrove (Rhyzophora sp) and black mangrove (Avicenia sp) are abundant. Some other
species of other aquatic floral species also found in abundance include; Paspalum
orbiculare, Acrostichum aureum, Phoenix rachinata and Nypa fructicans. Manatees,
migratory birds, periwinkle aquatic crab, fishes of various species and snakes make the
fauna of Yewa lagoon. Artisanal fishing and sand mining is the major economic activities of
the indigenes.
2.2 Some Physical/Chemical samples determination
2.2.1 Total Dissolved Solids (TDS)
This was carried out using the Gravimetric method 2540C (APHA, 1998). A wellmixed portion of the sample was filtered and evaporated to dryness (180 oC) in a
weighed dish, dried to constant weight.
The increase in weight of this dish
determined the Total Dissolved Solid (TDS).
Calculation
mg Total Dissolved Solids (TDS)/L =
(𝐴−𝐵)𝑥 1,000,000
𝑆𝑎𝑚𝑝𝑙𝑒 𝑣𝑜𝑙𝑢𝑚𝑒(𝑚𝑙)
Where:
A
=
Dish + Dry Sample (g)
B
=
Dish before use (g)
2.2.2 Total Suspended Solids (TSS)
This method was carried out using the Gravimetric method 2540D (APHA, 1998). A
filter dish was dried at 103 ± 2oC, in an oven for 1hr. The filter was removed and
9
allowed to cool in a desiccator, before being weighed. 50ml of a well-mixed sample
was filtered through the filter unit and allowed to drain. The filter dish was removed
and dried at 103 ± 2oC in an oven for 1hr. The dish was removed and allowed to
cool in a desiccator, and then re-weighed. The increase in weight represented the
TSS, and was calculated as follows:
TSS (mg/L) =
(𝐴−𝐵)(106 )
𝑉𝑜𝑙𝑢𝑚𝑒 𝑜𝑓 𝑠𝑎𝑚𝑝𝑙𝑒 𝑡𝑎𝑘𝑒𝑛 (𝑚𝑙)
Where:
A = weight (g) of dish + residue
B = weight (g) of dish before use.
2.2.3 Iron
This was carried out using the Perkin Elmer 5000 atomic absorption
spectrophotometer. 100ml of thoroughly well mixed water sample was transferred
into a beaker and 5ml concentrated nitric acid was added. The beaker was placed on
a hot plate and evaporated to dryness. The beaker was then cooled and another 5ml
concentrated nitric acid was added. Heating was continued until a light – coloured
residue was observed. Then, 1ml concentrated nitric acid was added and the beaker
was warmed slightly to dissolve the residue. The walls of the beaker were then
washed with distilled water. The volume was adjusted to 50ml. Iron was determined
in the digested samples.
Calculation:
Concentration of iron (mg/L) =
𝐶𝑜𝑛𝑐𝑒𝑛𝑡𝑟𝑎𝑡𝑖𝑜𝑛 𝑜𝑓 𝑠𝑡𝑎𝑛𝑑𝑎𝑟𝑑 𝑥 𝐴𝑏𝑠𝑜𝑟𝑏𝑎𝑛𝑐𝑒 𝑜𝑓 𝑠𝑎𝑚𝑝𝑙𝑒
𝐴𝑏𝑠𝑜𝑟𝑏𝑎𝑛𝑐𝑒 𝑜𝑓 𝑠𝑡𝑎𝑛𝑑𝑎𝑟𝑑
10
2.2.4 Reactive Nitrogen (NO3 - N)
This method was carried out using the Colorimetric Cadmium Reduction Method.
The pH was adjusted to acidic range by adding 2 drops of HCl to 25ml of filtered
sample. A speck (or a drop) of NED reagent was added to the mixture. The mixture
was allowed to stand for 5-10min., before being determined for NO2 at 520nm, using
a calorimeter or at 543nm using HACH DR 2010 colorimeter.
The difference between this result and that from NO2 (without reduction) indicated
the concentration of NO3. The calorimeter simply displayed the result of NO3,
having performed the computation.
2.3 Collection of Samples.
Collection of water and phytoplankton samples for analyses were carried out
between 9:00hrs and 12:30hrs monthly for six months (December, 2012- May,
2013). Water samples were collected 20cm below the surface water with 250ml
screw capped plastic bottles for physical and chemical analysis. Chlorophyll-a
sample, DO and BOD samples were collected in three 250ml amber bottles.
Phytoplankton samples were collected using plankton net of 55µm mesh size towed
for 7mins at low speed (< 4 knots) and was preserved in 4% unbuffered formalin.
For the epiphyton community, the attached algae of interest were collected along
Iragbo area of Yewa lagoon. Water hyacinth was harvested monthly from the central
part of the lagoon away from the water edges including the fringes of "acadja"
(artificial vegetation for fishing). Healthy plants were carefully selected to ensure
uniformity in size before putting each into plastic containers with 500ml of fresh
water. The attached algae were removed mechanically by shaking vigorously in
water as suggested by Forester and Schlichting (1965), and was preserved in a well
11
labelled plastic container and 4% formalin added as a preservative. Another 500ml
container was filled with an unfixed sample for chlorophyll-a determination.
2.4. Chlorophyll-a Determination
Chlorophyll-a was determined using method described by Holm-Harsen (1978).
250ml of water sample was filtered and the chlorophyll-a was extracted by
methanol. The extraction was centrifuged at 320rpm for 10mins and absorbance was
measured at different wave length, the chlorophyll-a concentration was measured
using the formula below.
Chlorophyll-a (µg/L) =
(𝐴𝑏𝑠[66𝑠𝑛𝑚]−𝐴𝑏𝑠[750𝑛𝑚])𝑥 𝐴 𝑥 𝑉𝑚
𝑣𝑓 𝑥 𝐿
(1)
Where; A = Absorbance coefficient of chlorophyll-a in methanol Vm= Volume of
methanol used for extraction Vf = Volume of sample filtered L = Path length of
cuvette.
2.5. Community Structure Analysis
Community structure analysis were determined by four indices
2.5.1. Margelef index (d): This is a diversity of species richness, which does not
take into account dominant diversity, but is largely dependent on the species
richness, that is, the more the species present in a sample the greater the diversity
[Margelef, 1957].
d=
𝑠−1
𝑙𝑜𝑔𝑒𝑁
(2)
Where: d = Diversity Index S = Number of Species N = Number of Individuals log =
Natural logarithm
H=
𝑁𝑙𝑜𝑔𝑁−∑𝑓𝑖𝑙𝑜𝑔𝑓𝑖
𝑁
(3)
12
Where: H = Shannon-Wiener Information Index ∑= Summation fi = Observed
proportion of individuals that belong to the ith species loge = Natural logarithm.
2.5.2. Species Equitability or Evenness (j) Jaccard.
This is a measure of how evenly the individuals are distributed among the species
present in a sample. It ranges between 0 and 1, the maximum value. One represents a
situation where individuals are spread evenly among the species present [Jaccard,
1912]. It was calculated as follows:
j=
𝐻
𝐻𝑚𝑎𝑥
or
𝐻
(4)
𝑙𝑜𝑔𝑠
Where: j = Equitability measure H = Shannon-Wiener Information Index S =
Number of species in the sample.
2.5.3. Similarity /Dissimilarity Index (Bray Curtis 1957)
In a similarity index, a value of 1 means that the two communities you are
comparing share all their species, while a value of 0 means they share none.
Whereas, in a dissimilarity index the interpretation is the opposite.
The Similarity Index (BC) between two samples is given by the equation:
S=
2𝐶
𝐴+𝐵
(5)
Where: S= Similarity index
C= Number of species common to both samples
A= Number of species in sample A
B= Number of species in sample B,
Dissimilarity = 1- Similarity.
13
3. Results
3.1. Hydro Climate Properties
Data on some hydroclimatic features of the sample site at Yewa Lagoon is presented in table
1. The highest surface water temperature (32.2°C) was recorded in February while the
lowest (30.2°C) was recorded in December. Similarly, higher pH, conductivity, DO and
transparency values were recorded in the dry months than in the wet months (Table 1). On
the other hand, Total Dissolved Solids (TSS), nutrients and Biochemical Oxygen Demand
(BOD) values were higher in the wet months than during the dry months.
Table 1. Variations in some physical and chemical parameters in Iragbo part of Yewa
Lagoon (December, 2012-May 2013).
MONTHS
PARAMETERS
JAN. FEB. MAR.
APR.
MAY.
30.2
30.8
32.2
31.8
31.3
30.5
Transparency (cm)
37.5
48.5
35
34
30.3
28
Ph
8.0
7.6
8.2
7.5
7.3
7.0
Conductivity (µS/cm)
94.0
97.0
99.0
83.0
80.0
78.0
Rainfall (mm)
13.2
0.0
28.0
50.1
165.3
340.8
49.0
46.0
37.0
45.0
56.0
0.53
0.67
0.53
6.8
10.1
6.9
0.1
0.2
3.1
16.8
18.1
33.0
Surface Water
temperature (ºC)
Total Suspended
Solids (mg/L)
Reactive Phosphate
(mg/L)
Reactive Nitrate
DEC.
14
68.0
(mg/L)
Sulphate (mg/L)
0.01
0.02
ND
7.0
8.0
7.82
Iron (mg/L)
0.072
0.07
0.07
0.34
0.208
0.068
Silicate (mg/L)
0.003
0.004
ND
0.003
0.002
0.003
2.8
7.6
5.1
4.1
5.5
4.5
7
10
10
16
13
13
32
38
21
37
38
40
Dissolved Oxygen
(mg/L)
Biochemical Oxygen
Demand (mg/L)
Chemical Oxygen
Demand (mg/L)
Chlorophyll a
(phytoplankton)
Chlorophyll a
(Epiphyton)
0.001
0.004 0.001 0.001
0.003
0.003
0.002
0.005 0.014 0.012
0.003
0.002
ND =Not Detected
Higher sicche disc readings in the dry months coincided with periods of drop in TSS values.
Phosphates-phosphorus recorded a progressive increase into the wet months (≥0.5; ≤ 10.1)
and nitrate level increases steadily and were very high during the wet months. Silicate values
rose steadily in December and January, but fluctuated slightly in other months.
15
Rainfall (mm)
Chlorophyll-a (Water sample) (µg/L)
Chlorophyll-a (Epiphyton) (µg/L)
400
0.007
350
300
0.005
250
0.004
200
0.003
Rainfall (mm)
Chlorophyll a (phytoplankton)(µg/L)/ Chlorophyll a
(epiphyton)(µg/L)
0.006
150
0.002
100
0.001
50
0
0
DEC
JAN
FEB
MAR
APR
MAY
Months
Fig. 2: Monthly variation in chlorophyll a (phytoplankton), chlorophyll a
(epiphyton) and Rainfall at the Iragbo part of Yewa Lagoon (Deccember, 2012May, 2013).
16
Chlorophyll-a (Water sample) (µg/L)
Chlorophyll-a (Epiphyton) (µg/L)
Silicate (mg/L)
0.0045
0.004
0.006
0.0035
0.005
0.003
0.004
0.0025
0.003
0.002
Silicate (mg/L)
chlorophyll a (phytoplankton)/ Chlorophyll a
(epiphyton)
0.007
0.0015
0.002
0.001
0.001
0.0005
0
0
DEC
JAN
FEB
MAR
APR
MAY
Months
Fig. 3: Monthly variation in chlorophyll a (phytoplankton), chlorophyll a (epiphyton) and
Silicate at the Iragbo part of Yewa Lagoon (Deccember, 2012- May, 2013).
17
Chlorophyll-a (Water sample) (µg/L)
Chlorophyll-a (Epiphyton) (µg/L)
Conductivity (µS/cm)
120
0.007
100
0.005
80
0.004
60
0.003
40
Conductivity(µS/cm)
Chlorophyll a (phytoplankton) (µg/L)/
Chlorophyll a (epiphyton)(µg/L)
0.006
0.002
20
0.001
0
0
DEC
JAN
FEB
MAR
APR
MAY
Months
Fig. 4: Monthly variation in chlorophyll a (phytoplankton), chlorophyll a
(epiphyton) and Conductivity at the Iragbo part of Yewa Lagoon (Deccember, 2012May, 2013).
18
Rainfall (mm)
Chlorophyll-a (Water sample) (µg/L)
Chlorophyll-a (Epiphyton) (µg/L)
400
0.007
350
300
0.005
250
0.004
200
0.003
Rainfall (mm)
Chlorophyll a (phytoplankton)(µg/L)/ Chlorophyll a
(epiphyton)(µg/L)
0.006
150
0.002
100
0.001
50
0
0
DEC
JAN
FEB
MAR
APR
MAY
Months
Fig. 21: Monthly variation in chlorophyll a (phytoplankton), chlorophyll a
(epiphyton) and Rainfall at the Iragbo part of Yewa Lagoon (Deccember, 2012May, 2013).
19
Chlorophyll-a (Water sample) (µg/L)
Chlorophyll-a (Epiphyton) (µg/L)
Transparency (cm)
60.0
0.006
50.0
0.005
40.0
0.004
30.0
0.003
20.0
Transparency (cm)
chlorophyll a (phytoplankton)/ Chlorophyll
a (epiphyton)
0.007
0.002
10.0
0.001
0
0.0
DEC
JAN
FEB
MAR
APR
MAY
Months
Fig. 15: Monthly variation in chlorophyll a (phytoplankton), chlorophyll a
(epiphyton) and Transparency at the Iragbo part of Yewa Lagoon (Deccember,
2012- May, 2013).
20
Calcium (mg/L)
pH
Magnesium (mg/L)
Potassium (mg/L)
16
0.12
Magnesium (mg/L)/Calcium (mg/L)/pH
14
0.1
12
Potassium (mg/L)
0.08
10
0.06
8
6
0.04
4
0.02
2
0
0
DEC
JAN
FEB
MAR
APR
MAY
Months
Fig. 8: Monthly variation in levels of Calcium, pH, Magnesium and Potassium in the
Iragbo part of Yewa Lagoon (December, 2012 – May, 2013).
21
3.2 Diatom Community
The phytoplankton of the Iragbo part of Yewa Lagoon belonged to seven main
divisions: Bacillariophyta (32%), Chlorophyta (13%), Cyanophyta (51%),
Euglenophyta (2%), Crysophyta (0.2%), and Pyrophyta (1%). A total of 55 species
belonging to 35 genera were observed. Throughout the sampling period, the highest
(2450 individuals per ml) (53%) phytoplankton occurrence was recorded in January,
the least (414 individuals per ml) (9%)) was recorded in May. Thirteen
phytoplankton orders were also recorded throughout the sampling months, namely;
Centrales, Pennales, Chlorococcales, Volvocales, Zygnematales (Conjugales),
Ulotricales,
Chroococcales,
Hormogonales,
Euglenales,
Mischoccocales,
Dinokontae, Gonyaulacales and Nocticulales. The highest individual species
(biomass) was Oscillatoria sp. which indicated a bloom in January. It is represented
in the table 1below.
Table 2: Species Abundance of Phytoplankton Species that occurred from
December 2012 to May, 2013 at the Iragbo part of Yewa Lagoon
DEC.
JAN. FEB. MAR. APR. MAY
Division:
BACILLARIOPHYTA
(DIATOMACEAE)
Class:
BACILLARIOPHYCEAE
Order I: CENTRALES
Family:
COSCINODISCACEAE
22
Aulacoseira granulata
5
50
95
80
75
90
5
20
60
55
95
65
-
5
70
55
85
65
-
5
-
-
-
Bacteriosira fragilis
-
-
30
-
25
10
Coscinodiscus concinnus
-
-
-
5
5
-
5
-
-
-
-
-
5
5
-
-
-
-
Coscinodiscus nitidus
-
-
15
10
-
-
Cyclotella comta
-
5
10
15
10
-
Cyclotella stelligera
-
-
5
-
5
10
Melosira islandica
-
-
-
10
5
-
-
5
-
-
-
-
5
10
70
35
-
20
Ehrenberg
Aulacoseira granulata var.
angustissima (Ehr.) Ralfs
Aulacoseira granulata var.
angustissima f. spiralis
Muller
Aulacoseira italica var.
subarctica O. Muller
Coscinodiscus lineatus
Ehrenberg
Coscinodiscus marginatus
Ehrenberg
Stephanodiscus astraea
Grunow
Family:
LEPTOCYLINDRACEAE
Leptocylindrus daniscus
Family:
RHIZOSOLENIACEAE
23
Rhizoselenia stolterfothii
5
-
-
-
-
-
Diatoma vulgaris
5
-
-
-
-
-
Synedra acus
-
15
-
-
-
-
5
-
-
-
-
-
5
-
-
-
-
-
-
5
25
20
-
10
-
-
15
5
-
10
-
5
-
-
-
-
5
5
-
-
-
-
Navicula elliptica
5
-
-
-
-
-
Pinnularia major
5
-
-
-
-
-
5
-
-
-
-
-
Order II: PENNALES
Family:
FRAGILARIACEAE
Synedra ulna (Nitzsch)
Ehrenberg
Tabellaria flocculosa (Roth)
Kutzing
Thalassiothrix nitzschioides
Grun.
Thalassiothrix spattulata
Family:
GOMPHONEMACEAE
Gomphonema parvulum var.
lagenula
Family:
ACHNANTHACEAE
Cocconeis placentula
Family: NAVICULACEAE
Stauroneis phoenicentron f.
gracilis
Family: NITZSCHIACEAE
24
Nitzschia longissima
5
-
-
40
30
15
-
5
-
-
-
-
-
-
45
10
15
30
Chlorella vulgaris
150
5
-
-
-
-
Oocystis lacustris
-
5
-
-
-
-
25
-
-
-
-
-
-
-
5
-
5
-
-
5
25
-
10
15
-
5
-
-
-
-
-
5
-
10
15
5
-
-
15
-
5
-
Nitzschia tryblionella var.
victoriae
Division: CHLOROPHYTA
Class:
CHLOROPHYCEAE
Order I:
CHLOROCOCCALES
Family:
CHLOROCOCCACEAE
Chlorella sp. Butcher
Palmellococcus minutus
Kutz.
Tetraëdron regulare var.incus
Family:
HYDRODICTYACEAE
Hydrodictyon reticulatum
Pediastrum biradiatum
Meyen
Pediastrum clathratum (A.
Brawn) Lengerth
Pediastrum duplex
Family:
SCENEDESMACEAE
25
Actinastrum hantzchii
-
-
-
10
15
5
-
-
10
15
10
-
Crucigena minima
-
5
-
-
-
-
Tetrastrum sp.
-
-
-
5
5
-
Pandorina morum
5
-
-
-
-
-
Volvox globator
-
-
-
-
5
-
Closterium arcuarium
5
-
-
-
-
-
Closterium arcutum
5
-
-
-
-
-
5
-
10
5
-
10
5
-
-
-
-
-
-
10
35
15
-
10
Golenkinia radiata Chodat
-
-
10
5
-
5
Gonatozygon kinahanii
5
-
-
-
-
-
Actinastrum hantzchii var.
fluviatile
Order II: VOLVOCALES
Family: VOLVOCACEAE
Order III:
ZYGNEMATALES
(CONJUGALES)
Family: DESMIDIACEAE
Closterium cornu var.
javanicum
Hyalotheca dissiliens
Order IV: Ulotrichales
Family: Ulotrichaceae
Stichococcus bacillaris
Family:
MESOTAENIACEAE
Family:
26
ZYGNEMATACEAE
Spirogyra africana Fritsch
5
-
-
-
-
-
Chroococcus disperses
-
10
-
-
-
-
Chroococcus pallidus Nageli
5
-
-
-
-
-
-
5
-
-
-
-
175
375
-
-
-
-
-
-
15
-
10
20
-
-
25
15
5
10
Oscillatoria sp.
-
1850
-
-
-
-
Oscillatoria tenius Agardh
5
-
-
-
-
-
Cruda
Division: CYANOPHYTA
Order I:
CHROOCOCCALES
Family:
CHROOCOCCACEAE
Microcystis aeruginosa f.
flos-aquae
Microcystis aeruginosa
Kutzing
Order II: NOSTOCALES
Family: NOSTOCACEAE
Anabaena spiroides Klebahn
var. minima Nygaard
Anabaena spiroides Klebahn
var. tumida Nygaard
Order III:
OSCILLATORIALES
Family:
OSCILLATORIACEAE
27
Division:
EUGLENOPHYTA
Order: EUGLENALES
Family: EUGLENACEAE
Euglena ehrenbergii
-
-
15
10
5
-
Phacus caudatus
5
-
-
-
-
-
Phacus longicauda
5
-
-
-
-
-
-
-
15
10
5
-
5
-
-
-
-
-
Phacus sp.
5
-
-
-
-
-
Trachelomonas conica
5
5
-
-
-
-
Trachelomonas nigerica
-
5
-
-
-
-
Trachelomonas robusta
-
5
-
-
-
-
Trachelomonas volvocina
5
-
-
-
-
-
Trachelomonas volvocinopsis
5
5
-
-
-
-
Centritractus belonophorus
-
5
-
-
-
-
Ophiocytium capitatum Wolle
5
-
-
-
-
-
Tetrasporopsis perforate
5
-
-
-
-
-
Phacus longicauda var.
rotundus
Phacus oblonga var.
planctonica
Division: CHRYSOPHYTA
Order:
MISCHOCCOCALES
Family: SCIADACEAE
Division: PYRRHOPHYTA
Class: DINOPHYCEAE
28
Order: DINOKONTAE
Family: PERIDINIACEAE
Peridinium cinctum
5
-
-
-
-
-
-
5
-
-
-
-
5
-
-
-
-
-
Noctiluca scintillans
5
-
-
-
-
-
Total species diversity (S)
38
30
23
22
23
19
Total abundance (N)
525
2450
630
440
460
415
Family:
GYMNODINIACEAE
Gymnodinium excavatum
Order:
GONYAULACALES
Family:
GONIODOMATACEAE
Alexandrium catenella
ORDER:
NOCTILUCALES
Family:
NOCTILUCACEAE
The epiphyton of the Iragbo part of Yewa Lagoon belonged to four main divisions:
Bacillariophyta (87%), Chlorophyta (4%), Cyanophyta (8%), and Euglenophyta
(3%). A total of 39 species belonging to 26 genera (535 individuals per ml) (35%)
epiphyton occurrence was recorded in February, the least (265 individuals per ml
(17%)) was recorded in April. Seven epiphyton orders were recorded throughout the
sampling months, namely: Centrales, Pennales, Tetrasporales, Dismidiales,
Volvocales, Hormogonales and Euglenales. The highest individual species of the
29
epiphyton algae is Aulacoseira granulate Var. angustissima. It is represented by
table 2 below.
Table 3: Species Abundance of Epiphyton Species that occurred from February to
May, 2013 at the Iragbo part of Yewa Lagoon
EPIPHYTON TAXA
DEC. JAN.
FEB.
MAR. APR.
MAY
Division:
BACILLARIOPHYTA
Class:
BACILLARIOPHYCEAE
Order: CENTRALES
Family:
COSCINODISCACAEA
Aulacoseira granulata var.
185
180
200
175
80
95
190
160
185
145
110
75
50
75
85
70
45
55
55
50
40
25
20
30
Coscinodiscus granii
10
-
5
-
-
5
Coscinodiscus nitidus
15
20
15
10
-
5
Cyclotella comta Kutzing
10
15
15
10
5
-
augustissima
Aulacoseira granulata var.
muzzanensis
Aulacoseira italica var.
supsp. Subarctica
Aulacoseira granulata
Ehrenberg
Order: PENNALES
30
Family:
FRAGILARIACAEA
Diatoma elongatum
5
-
-
-
10
15
Fragilaria virescens
-
-
10
15
-
-
Gyrosigma scalproides
10
-
5
5
-
-
Pediastrum chlathratum
-
10
10
-
10
5
10
15
20
10
-
5
Surirella ovate
15
20
15
-
5
-
Surirella robusta
15
10
15
5
-
10
-
15
-
15
-
10
15
10
25
40
15
5
Synedra acus
15
10
30
25
5
20
Leptocylindrus daniscus
25
-
45
20
-
10
Leptocylindrus sp.
10
20
30
15
20
-
Dentonula schroderi
20
30
20
10
15
5
20
15
25
10
15
5
20
15
20
25
-
15
10
10
30
20
15
20
Melosira islandica
55
70
45
75
50
35
Pinnularia divergens
10
-
10
25
-
15
-
15
10
-
10
5
Pediastrum duplex var.
subgranulatum
Surirella robusta var.
armata
Surirella robusta var.
splendid
Stephanodiscus astraea
Grunow
Stephanodiscus minutulus
Tabellaria fenestrata
var.intermediata
Gomphonema dubravicense
31
Division:
CHLOROPHYTA
Class:
CHLOROPHYCEAE
Order:
TETRASPORALES
Family:
TETRASPORACAEA
Asterococcus superbus
10
20
25
-
-
10
Desmidium sp.
5
-
5
5
-
-
Desmidium swartzii
20
10
-
5
10
5
-
5
5
-
15
5
Pandorina morum
-
10
-
-
5
-
Volvox globator
5
-
5
-
-
5
Order: DESMIDIALES
Family:
DESMIDIACAEA
Hyalotheca dissiliens
Order: VOLVOCALES
Family:
VOLVOCACAEA
Division: CYANOPHYTA
Class:
CYANOPHYCEAE
Order: NOSTOCALES
Family:
NOSTOCACAEA
32
Anabaena affinis
20
20
30
20
5
10
10
20
25
35
15
5
5
-
-
5
-
-
-
5
-
5
-
-
Euglena ehrenberghii
10
-
15
-
10
5
Phacus longicauda
10
5
-
10
-
15
-
10
-
-
5
5
Total species diversity (S)
31
29
26
23
20
25
Total abundance (N)
895
885
880
705
465
455
Anabaena spiroides
var.tumida
Calothrix pariatina
Tetraëdron regulare
var.incus
Division: EUPHYTA
Class: EUPHYCEAE
Order: EUGLENALES
Family:
EUGLENACAEA
Trachelomonas hispida
33
115, 2%
20, 1%
Bacillariophyta
15, 0%
Chlorophyta
Cyanophyta
Euphyta
Chrysophyta
Pyrhophyta
1565, 32%
2535, 52%
635, 13%
Fig. 4: Relative abundance of phytoplankton divisions that occurred at the Iragbo
part of Yewa Lagoon from December, 2012 to May, 2013.
34
105, 4%
195, 7%
65, 2%
Bacillariophyta
Chlorophyta
Cyanophyta
Euphyta
2525, 87%
Fig. 5: Relative abundance of Epiphyton divisions that occurred at the Iragbo part of
Yewa Lagoon from December, 2012 to May, 2013.
35
Phyto-taxa
Epi-Taxa
40
35
30
25
20
15
10
Variation in Taxa
5
0
Dec.
Epi-Taxa
Jan.
Feb.
March
Phyto-taxa
April
May
Months
Fig. 6 Variations in taxa for Phytoplankton and Epiphyton communities from Dec.
2012- May 2013 at Irabgo part of Yewa Lagoon.
36
3.3 Community Structure Indices
The indices of species richness (d), Shannon-Wiener diversity (Hs), Evenness or Equitibility
(J), Bray Curtis similarity/dissimilarity index (BC) were calculated to estimated the monthly
variation in phytoplankton and epiphyton diversity.
Table 4: Variations in species richness (d), Shannon-Wiener index(H), Bray Curtis
index(BC) and Equitibility index(J) in phytoplankton community across months Iragbo part
Yewa Lagoon.
MONTHS
INDICES
DEC.
JAN. FEB. MAR. APR. MAY
Shannon-Wiener Index (Hs)
1.05
0.43
1.22
1.18
1.10
1.09
Margalef Index (d)
5.91
3.72
3.41
3.45
3.59
2.99
Bray Cutis Index
0.45
0.58
0.49
0.55
0.60
0.54
Equitability Index (j)
0.67
0.29
0.90
0.88
0.81
0.85
37
Table 5: Variations in species richness (d), Shannon-Wiener index(H), Bray Curtis
index(BC) and Equitibility index(J) in epiphyton community across months Iragbo
part Yewa Lagoon.
MONTHS
INDICES
Shannon-Wiener Index
DEC. JAN.
FEB.
MAR.
APR.
MAY
1.40
1.36
1.34
1.25
1.21
1.30
Margalef’s Index (d)
4.02
4.00
3.98
3.62
3.41
4.27
Bray Cutis Index
0.49
0.50
0.52
0.48
0.51
0.47
Equitability Index (j)
0.91
0.94
0.95
0.92
0.93
0.93
(Hs)
All through the sampling period, both species richness (d) and Shannon-Wiener index (H)
decreased as wet months approached in both phytoplankton and epiphyton communities.
Generally, diversity was low between April and May in both communities, a pattern possibly
related to low light penetration caused by high turbidity.
38
4. Discussion
The physical and chemical changes observed in the Lagoon may have been as a
result of hydroclimatic changes linked to the seasons. For instance, the dry months
concentrated between December and April was accompanied by higher conductivity,
higher temperature and higher transparency. On the other hand, changes may be
linked to impact of leacheates into the Lagoon from Yewa River, associated creeks
and wetlands in the wet months. Similar observations have been reported by
Nwankwo (1993,1996) in the Lagos Lagoon. The higher surface water temperature
observed in the dry months maybe due to less cloud cover and high insulation.
Nwankwo et al. (2008) made similar observations. The decrease in total dissolved
solids, total suspended solids and turbidity during the dry months may be attributed
to decrease in the influx of flood waters from the rivers, creeks and wetlands. This
observation supports the view of Egborge (1988) in Yewa Lagoon.
Conductivity was relatively stable all through the sampling months possibly due to
lack of any intrusion of sea water. Lagoons of South West Nigeria are known to be
of two types, some like the Lagos and Iyagbe Lagoons directly influenced by tidal
sea water are said to be physical while others like Epe, Kuramo, Lekki, Yewa,
Badagry are said to be biologically controlled Onyenekan (1987). Though the
concentration of oil pollution here is very minimal there are still some traces of
effects that it has especially on phytoplankton biomass. The effect of this oil
pollution of the coastal waters is more noticeable during rainy season when spilled
products are washed from drains and drainage channels into the water bodies
(Odiete, 1999)
The pH range of between 6.95-8.16 maybe due to the influence of high carbonate
leacheates draining part of Ewekoro cement factory in Ogun state into the Yewa
river that empties into the Yewa Lagoon. The buffering effect of carbonate in coastal
39
waters of south western Nigeria is well known (Nwankwo et al 2008). The higher
COD values throughout the sampling months and low BOD could be an indication
of some levels of pollution. The BOD values recorded for the Lagoon during the
sampling period lie below the acceptable limits set by WHO for international water
quality standard in coastal waters (15.9-37.5mg/L) with warning levels from (18.934.5mg/L). The Lagoon could be said to be slightly organically polluted. According
to Hynes (1960) working in a river, biochmical oxygen demand values less than 2.0
mg/L indicate clean water, 2.0 to 4.0mg/L indicates moderate pollution while above
8.0 mg/L indicates severe stress. However, Yewa Lagoon is not a river and Hynes
criterium may not be relevant. Since Yewa Lagoon is fresh and lotic and since there
is no direct connection to the sea, it is still possible that standards higher than
8.0mg/L but lower than 16.5mg/L may point towards pollution stress.
The rising values of micro nutrients between February and April maybe due to
reduction of water inflow from the creeks and rivers, it may also be as a result of an
increase in water temperature and possible increase in bacterial oxidation. Similar
observations were made by Thomas (1966) in a small man-made Lake in Ghana.
Reactive silicate all through the sampling months remained comparatively stable
possibly due to non influence from sea water, although reactive silicate values was
less in months where there is high diatom biomass, this may be due to the fact that
diatoms use reactive silicate to build its (frustules). The higher values of nitratenitrogen recorded in the study may account for the relatively higher phytoplankton
abundance. Similar report was found in Nwankwo et al (2013) working in temporal
variations in water chemistry and chlorophyll-a at Tomaro creek.
The impacts of Copper, Lead and Zinc on the growth of both phytoplankton and
epiphyton algae were not specifically felt, the reason maybe that their presence did
not exceed 0.62mg/L in all the sampling months. Bilgrami and Kumar (1997),
40
studying the effect of Copper, Lead and Zinc on phytoplankton growth found out
that at concentrations 0.1mg/L, these metals were not toxic. However, at
concentrations 10.0mg/L, the growth of phytoplankton was inhibited, Cu was the
most toxic, followed by Pb and Zn. The rising values of Iron between March and
April showed an increase in plankton biomas, this may confirm the fact that algae
especially diatoms require Iron for growth. Similar observations were also made by
Bilgrami and Kumar (1997).
The abundance of aquatic machrophytes like Ipomoea aquatic Forsk, Eichhornia
crassipis and Pistia stratiotes by the Yewa Lagoon side as well as the water surface
is an indication of the eutrophic level of the Lagoon. Nwankwo and Akinsoji (1988)
made similar observations while working on benthic algal community on water
hyacinth in south western Nigeria. With the nutrient loads mainly from domestic and
industrial which drains into the Lagoon through creeks, rivers and wetlands, it would
be expected that the algae present would be pollution-tolerant and hence indicator
species.
Diatoms dominated the water hyacinth epiphyton community possibly because of
their ability to develop rapidly on newly submerged surfaces or due to their ability to
successfully adapt to fresh water habitat. According to Shevchenco (2000), it has
been found that the most favorable condition for epiphyton development are formed
on submerged plants, where the number of algal species and their intraspecific taxa
is higher than that on plants of other ecological groups. Nwankwo and Onitiri
(1992), while working on periphyton community on submerged aquatic macrophytes
(Horn-wort and Bladder-wort) in Epe Lagoon reported the dominance of diatoms.
Chlorophyll-a (phytoplankton) abundance showed positive correlation with COD
and DO although not significant while chlorophyll-a (epiphyton) showed significant
positive relationship with P,N and S. The phytoplankton community has a higher
41
species richness than the epiphyton but the epiphyton has a better spread across the
months. A higher population of central diatoms are found in the phytoplankton
community whereas the epiphyton community has a higher population of pinnate
diatoms, this maybe as a result of the ability of the pinnate diatoms to attach easily
to aquatic machrophytes. The similarity between phytoplankton and epiphyton is
0.49. this may mean that about half of the species found in the phytoplankton
community may also be found in the epiphyton community. The dissimilarity index
also indicates that half of the species in the two communities may not be found in
both.
Since many of the species observed were found in almost all the months regardless
of the water status, their presence may not make them satisfactory indicators of any
particular pollution. However, it may be possible to relate the abundance of some
species with changes in water quality. For instance the presence of species like
Gomphonema parvulum (diatom), Synedra acus (diatom), trachelomonas hispida
(Euglenoid), Phacus longicauda (Euglenoid), surivella ovata (Diatom), Pinnularia
major(Diatom),Chlorella vulgaris(green algae), Actinastrum hintzschii(green algae),
Pandorina morum(green algae) are known to be indicators of organic pollution
(Butcher 1947, Palmer, 1969), this may be a pointer that the Iragbo part of Yewa`
Lagoon is gradually being enriched probably due to several tributaries connected to
it. Nwankwo and Amuda (1993), while working on periphytic diatom on three
floating aquatic macrophytes in a polluted south-west Nigerian creek also made
similar observations. Some algal species like Actinastrum hantzzchii(Green algae),
Pediastrum clathratum(Green algae), Pinnularia divergens( Diatom), Euglena
ehrenbergii(Euglena) and Golenkinia radiate (Green algae) are threatened by the
pollution status of the Lagoon.
42
5.0 Conclusion
Both phytoplankton and epiphyton biomass were higher in the dry months due to
relative stability of the lagoon water and higher light penetration, this may imply that
during wet months the lagoon receives substantial amount of inland waters through
its many tributaries, resulting to light penetration, high turbidity and high TSS
thereby resulting to paucity of diatoms in the lagoon. Naturally the pH of fresh water
like the Yewa Lagoon is well known to be more acidic but in this work it is seen to
be more alkaline due to lechaets from Ewekoro cement factory. Almost half of the
species identified during the investigation belong to both plankton communities.
Phytoplankton algal species that could be used as indicator of organic pollution
identified include: Diatoms- Gomphonema parvulum, Synedra acus, Pinnularia
major. Green algae- Chlorella vulgaris, Actinastrum hantzschii. Euglenoids- Phacus
longicauda while Epiphyton species that could be used as indicator of organic
pollution identified include: Diatoms- Synedra acus, surivella ovata, Green algaePandorina morum, Euglenoids- Trachelomonas hispida, Phacus longicauda.
Acknowledgement
The authors are grateful to the staff of Marine Biology Laboratory, University of
Lagos for field assistance and sample analysis. Special thanks go to Prof. Nwankwo,
D. I. for this expertise advice and meticulous assessment of the work.
43
References
Adesalu, T. A. and Nwankwo, D. I. (2005). Studies on the phytoplanktonof Olero Creek and
parts of Benin River, Nigeria. The Ecologia. 3(2): 21-30.
APHA (1998). Standard Methods for the Examination Water and Sewage, 16th ed. American
Public Health Association incorporated. Washington. D.C. 1268pp
Barbour, M.T, Gerritson, J, Synder, D.B, Sterling, J.B (1999). Rapid bioassessment protocols
for use in streams and wadeable rivers: Epiphyton, benthic macroinvertebrates and fish.
United State Environmental Protection Agency; Washington.
Bilgrami, K. S. and Kumar, S. (1997). Effects of Copper, Lead and Zinc on phytoplankton.
Biologia plantatum. 39(2): 315-317.
Bray, J. R. And J. T. Curtis (1956). An ordination of Upland forest Communities of Southern
Wisconsin. Ecological Monographs. 27:325-349
Butcher, R. W. (1947). The biological detection of pollution. Institute of sewage purification
journal, 2: 92-97.
Cattaneo, A, Kalff, J. (1978). Seasonal cxhanges in the epiphyte community of natural and
artificial macrophyte in Lake memphremagog (QUE and VT). Hydrobiologia. 60(2) : 133144.
Effiong, K. S. and Inyang, A. I. (2015). Epiphytic Algae on Aquatic Macrophyte(Water Hyacinth)
in a Tropical Lagoon and their Possible Use as Bioindicator. International Journal of
Environmental Monitoring and Analysis 2015; 3(6):404-410.
Egborge, A.B.N(1988). Water hyacinth- Biological Musuem. Proceedings of International
Workshop on Water Hyacinth, Lagos 7-12 August 1988. 52-70.
Ertl, M. (1971). A qualitative method of sampling epiphyton from substratum. Limnology and
oceanography. 16: 576-579.
Forester, J. and H. Schlichting (1965). Phyco-periphyton in an oligotrophic lake. Transactions of
American Microscopic Society, 84: 485-502.
Hendey, N. I. (1958). Marine diatoms from some West Africa ports, J.M. Micro Soc. 77:22-53.
44
Hill, M.B and Webb, J.E. (1958). The Ecology of the Lagos Lagoon II. The topography and
physical features of Lagos Harbour and Lagos Lagoon. Physiological transactions of the
Royal Society London. 421-447.
Holm-Hansen, O. (1978). Chlorophyll-a determonation improvements in methodology OIKOS,
30: 438-447.
Hynes, H. B. N. (1960). The Biology of polluted waters, Liverpool University Press, Liverpool.
202pp.
Ibe, A.C. (1988). Coastline Erosion in Nigeria. University Press, Ibadan. 217pp.
Inyang AI, Effiong KS, Dan MU. A Comparative study of the periphyton on Eichhornia crassipes
and phytoplankton communities: An Overview of Environmental Conditions at Ejirin Part
of Epe Lagoon, South Western Nigeria. British Journal of Applied Science & Technology.
2015;10:1-23
Inyang AI, Sunday KE, Nwankwo, DI. (2015). Composition of Periphyton Community on Water
Hyacinth (Eichhornia crassipes): In Analysis of Environmental Characteristics at Ejirin
Part of Epe Lagoon in Southwestern Nigeria. Journal of Marine Biology. 2015; 1–9
Jaccard, P. (1912). “The distribution of the flora in the alpine zone”. New Phytologist. 11: 37-50.
Kadiri, M.O. (1992). Seasonal changes in the phytoplankton biomass of a shallow tropical
reservoir. Nigerian Journal of Botany. 12:167-175.
Lakatos, G, Kiss, M. Mezaros, I. (1999). Heavy metals contents of common red (Phragmites
australis/cav./Trini Ex Steudel) and its epiphyton in Hungarian shallow standing waters.
Hydrobiologia. Vol.37 (4).S. 437-445.
Laugeste, R. and Reumamen, M. (2005). The composition and density of epiphyton on some
macrophyte species in the partly meromictic lake Verevi. Hydrobiologia. Vol. 547.(5).
137-150.
Lawson, G. W. and John, D. M. (1987). The marine algae and coastal environment of tropical
West Africa (second edition). Gegruder Borntraeger, Berlin 415pp.
45
Lee, R. E. (1999). Phycology. Cambridge University Press, New York. 614pp.
Lowe, R.L. (1996). Periphty ton patterns in lakes. In: Stevenson R.J, Bothwell, M.L, Lowe, R.L.
(Eds). Algal Ecology: Freshwater Benthic Ecosystems. 57-76.
Marder, S. S. (2001). Biology. In: Diversity of the protests. Kane, K. T., Reiddy, P. E. Melde, A.
and Love, D. (Eds.). 7th edition. The McGraw-Hill Companies, Inc., New York. 528-540pp.
Margalef, R. (1957). Diversidad de especies en comunidales naturals. Publ. inst. Biol. Apl.
(Barcelona). 9:5-27.
Michael, E.S. Michael, E.M., Douglas, A.J (2006). Benthos as the basis for arctic lake food
webs. Aquatic Ecology. Vol.37(4).S.437-445.
Nwankwo, D. I and Onitire, A.O (1992). Periphyton community on submerged aquatic
macrophytes (Hornwort and Bladderwort) in Epe Lagoon, Nigeria. Agric. sci. Technol.
2(2):135-141.
Nwankwo, D. I. (1993). Cyanobacteria bloom species in coastal waters South-West Nigeria.
Archive fur hydrobiology. 90: 543-553.
Nwankwo, D. I. (2004a). The microalgae: our indispensable allies in aquatic monitoring and
biodiversity sustainability. An inaugural lecture delivered at the university of Lagos Main
Auditorium on Wednesday, June, 16, 2004, University of Lagos Press. 44pp.
Nwankwo, D. I. (2004b). Studies in the environmental preferences of blue green algae
(Cyanophyta) in Nigerian coastal waters. Journal of Nigeria Environmental Society. 2(1):
44-51.
Nwankwo, D. I. and Akinsoji, A. (1988). The benthic algal community on water hyacinth
Eichhornia crassipes (Mart) Solms in coastal waters of South Western Nigeria. Archive
Hydrobiologie. 124(4): 501-511.
Nwankwo, D.I and Amuda, S. A. (1993). Periphytic diatoms of three floating aquatic
macrophytes in a polluted south-western creek. International Journal Ecology
Environmental Science. 19:1-10.
46
Nwankwo, D.I, Adesalu, T.A, Amako, C.C, Akagha, S.C, Keyede, J.D. (2013). Temporal
variations in water chemistry and chlorophyll-a at the tomaro creek, Lagos, Nigeria.
Journal of Ecology and the Natural Environment. 5(7): 144-151.
Nwankwo, D.I. (1988). A preliminary checklist of planktonic algae in Lagos Lagoon Nigeria.
Nigerian Journal of Botanical Applied Sciences. 2 (2): 73-85.
Nwankwo, D.I. (1996). Phytoplankton diversity and succession in Lagos Lagoon, Nigeria. Archiv
Fur Hydrobiologie. 135 (4): 529-542.
Nwankwo, D.I., Owoseni, T.I., Usilo, D.I., Obiyan, A.C., and Onyema, I.C. (2008).
Hydrochemistry and plankton dynamics of kuramo Lagoon. Life Science Journal. 5 (1): 8388.
Odoiete, W. O. (1999). Environmental Physiology of Animals and Pollution. Diversified
Resources Ltd., Lagos. 261pp.
Odum, H.T (1957). Trophic structure and productivity of silver springs, Florida, Ecological
Monograph.27:122.
Onyema, I.C, Nwankwo, D.I (2006). The epiphytic assemblage of a polluted estuarine creek in
Lagos, Nig. Pol. Res. 25: 459-468.
Oyenekan, J.A (1987). Benthic macrofauna communities of Lagos Lagoon Nigeria. Nigerian
journal of Sciences.21 (182):45-51.
Palmer, C.M. (1969). A composite rating of algae tolerating organic pollution. Journal of
Phacology.2 (1):79-82.
Patrick, R. (1965). Algae a s indicator of pollution. In: Biological problems in water pollution.
U.S Department H.E.W.P.H.S Public health service publication 999-wp-2j.
Patrick, R. (1967). The effect of varying amount and ratios of nitrogen and Phosphate on algal
bloom. Proceedings of the 21st Annual Industrial Waste Conference, Purdue University,
Indiana, 208pp.
Patrick, R. and Riemer, C.W (1975). The diatom of the United State. Monograph of the
Academy of Natural Science. Philadelphia. 13:1-213.
47
Shevchenko, R. L. (2000). Selective uptake of mineral ions and their concentration factors in
aquatic higher plants. - Folia Geobotanica, 14(3): 267-325.
Sladeckova, A. (1962). Limnology method for the epiphyton (Aufwuchs) community. Botanical
Review. 28: 286-350.
Sozska, G. K. (1975). Ecological relations between invertebrates and submerged macrophytes in
the lake lithoral. Ekologya.polski. 23:393-415.
Thomas, J.D. (1966). Some preliminary observations on the fauna and flora of a small man-made
Lake in the West African Savanna. Bulletin de de L’Institut Foundamental D’Afrique
Noire: TXXVIII ser A (2): 542-562.
Wilkinson, M .A .R, Henderson and C, Wilkenson (1976). Distribution of attached algae in
estuaries, marine pollution bulletin, 7: 183-831.
Zoebel, C. E. and Allen, C. E. (1933). The significant of marine bacteria in the fouling of
submerged faces. Journal of Bacteriology, 29: 239-251.
48
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