AASCIT Journal of Environment

2015; 1(3): 41-47

Published online July 20, 2015 (http://www.aascit.org/journal/environment)

Keywords Diversity,

Abundance,

Aquatic Macrophytes,

Physcio-Chemical Parameters,

Ebonyi River

Received: June 30, 2015

Revised: July 6, 2015

Accepted: July 7, 2015

The Aquatic Macrophytes and Physico-Chemical Parameters of Ebonyi River Southeastern Nigeria

Uneke Bilikis Iyabo, Okereke Amarachukwu

Dept. of Applied Biology, Faculty of Biological Sciences, Ebonyi State University, Abakaliki,

Ebonyi State, Nigeria

Email address unekebi@yahoo.com (U. B. Iyabo), unekebij@yahoo.com (U. B. Iyabo)

Citation Uneke Bilikis Iyabo, Okereke Amarachukwu. The Aquatic Macrophytes and Physico-Chemical

Parameters of Ebonyi River Southeastern Nigeria. AASCIT Journal of Environment.

Vol. 1, No. 3, 2015, pp.41-47.

Abstract Aquatic plants contribute to maintaining key functions with its economic importance and

related biodiversity in freshwater ecosystems, and to provide the needs of human societies.

The way the ecological niches of aquatic macrophytes are determined by

physico-chemical parameters which include the dissolved oxygen (mg/dl), water t(°C),

total dissolved solids(mg/dl), flow rate of the river (m/s), conductivity (µs/cm) and the pH

value as the abiotic factors were considered. A simple, broadly applicable model of the

distribution of growth forms according to these physico-chemical parameters was

discovered. The aquatic macrophytes diversity and abundance in Ebonyi River was as

follows with the family of Cyperaceae and Poaceae having the greatest abundance

followed by Onagraceae, while Amaranthaceae, Araceae, Asteraceae, Hydrophyllaceae,

Leguminosae, Polygonaceae and Pontederiaceae were least abundant. The above

mentioned physcio-chemical parameters also varied within period of study their mean

deviations as follows; dissolved oxygen (5mg/l), water temperature (29.17 °C), pH (7.70),

total dissolved solids (18.0mg/dl), conductivity (38.33µs/cm) and flow rate (7.97 m/s).

The pH was discovered to be indirectly proportional to the number of aquatic macrophytes;

lesser pH leading to greater aquatic macrophytes while greater number of aquatic

macrophytes leads to lesser total dissolved solids.

1. Introduction

Aquatic plants are of two types, which are the aquatic microphytes and aquatic

macrophytes. Aquatic microphytes are those that are microscopic in nature and cannot be

easily seen with the naked eyes, example includes; the phytoplanktons, diatoms, etc.

Aquatic plants (macrophytes) are plants that have adapted to living in aquatic

environments (saltwater or freshwater). They are also referred to as hydrophytes or

macrophytes. These plants require special adaptations for living submerged, in or at the

water's surface. The most common adaptation is aerenchyma, but floating leaves and

finely dissected leaves are also common (Agbogidi et al., 2000). Aquatic plants can only

grow in water or in soil that is permanently saturated with water. They are therefore a

common component of wetlands and rivers (Keddy, 2010). The principal factor

controlling the distribution of aquatic plants is the depth and duration of flooding.

However, other factors may also control their distribution, abundance, and growth form,

including nutrients, disturbance from waves, grazing, and salinity. Aquatic vascular plants

have originated on multiple occasions in different plant families; they can be ferns or

angiosperms (including both monocots and dicots). Seaweeds are not vascular plants;

rather they are multicellular marinealgae, and therefore are not typically included among

42 Uneke Bilikis Iyabo and Okereke Amarachukwu: The Aquatic Macrophytes and Physico-Chemical Parameters of

Ebonyi River Southeastern Nigeria

aquatic plants. A few aquatic plants are able to survive in

brackish, saline, and salt water. Examples are found in genera

such as Thalassia and Zostera. Although most aquatic plants

can reproduce by flowering and setting seed, many also have

extensive asexual reproduction by means of rhizomes, turions,

and fragments in general. One of the largest aquatic plants in

the world is the Amazon water lily; one of the smallest is the

minute duckweed. Many small aquatic animals use plants like

duckweed for a home, or for protection from predators (Ezeri

et al., 2003 and Chowdhury et al., 2008). But areas with more

vegetation are likely to have more predators. Some other

familiar examples of aquatic plants might include floating

heart, water lily, lotus and water hyacinth (Keddy, 2010). A

river is a natural flowing watercourse, usually freshwater,

flowing towards an ocean, a lake, a sea, or another river. In

some rare cases a river could flow into the ground and dry up

completely at the end of its course, without reaching another

body of water. At the bank on the river is a wetland which is a

land transitional between terrestrial and aquatic system where

soil is frequently waterlogged and is able to sustain life like

aquatic plant (Bell, 1992; Bornette et al., 2008). Thus this

study is aimed at providing the general knowledge of aquatic

plants, the knowledge of the economic importance of aquatic

macrophytes, the diversity of the aquatic macrophytes present

in Ebonyi River and the physico-chemical characteristics of

the river.

2. Materials and Methods

2.1. Study Area

Ebonyi state is located in the Southeastern Benue trough of

Nigeria. The main study area falls within the climatic region

of Southeastern Nigeria where the rainy season spans from

April to October and the dry season from October to April.

The average annual rainfall of the study area is about 1500mm

with actual surface temperature (seasonal temperature) of

between 24 – 36 °C during dry season and about 18 °C during

rainy season. Ebonyi river is located in Onu-Ebonyi Izzi,

North-Eastern part of Ebonyi State, between latitude of 064`N

and longitude 087`E. The river is a source of water to Izzi

village, utilized for both domestic and agricultural purpose.

The river is about 5km from Abakaliki, the capital of Ebonyi

state (Fig. 1). The river flows throughout the year but flows

heavily during the rainy season.

Fig. 1. Map of Ebonyiriver showing study area.

AASCIT Journal of Environment 2015; 1(3): 41-47 43

2.2. Physico-Chemical Parameters

Water Temperature: Digital thermometer was used to

determine the water temperature in situ each time a trip was

made to the site by dipping thermometer into the water until a

steady value was observed then recorded as the water

temperature in degree Celsius (°C). Flow rate: Flow rate was

determined in situ using cock, stop watch and time. The

distance covered by the flowing cock within a specific period

was recorded and flow rate calculated as d/t

Where d= distance covered in meters (m)

Time= time taken in seconds (s)

Hydrogen Ion Concentration (pH): This was determined in

situ using Hanna pH meter model HI96107. The metre was

calibrated using pH buffer at 8.9 then dipped in the water

sample until steady value was read, then recorded as pH

values.

Dissolved Oxygen (DO): The amount of dissolved oxygen

was determined in situ by winkler’s methods

a. A 300ml glass stopper BOD (Biological Oxygen Demand)

bottle was filled with the water sample ensuring that there

were no air bubbles.

b. 2ml of Manganese (ii) sulphate was added to the

collection by inserting a calibrated pipette just below the

surface of the liquid and the pipette squeezed out slowly

to ensure that bubbles are not introduced into the sample

through the pipette.

c. 2ml of alkaline potassium iodide solution was added into

the sample in the same manner as in b.

d. The bottle was carefully covered with a stop cock

ensuring that air was not introduced and the sample

mixed by inverting the bottle severally. The sample was

checked for air bubbles and if found, the sample was

discarded. The presence of oxygen in the sample was

noticed by the appearance of a brownish-orange cloud of

precipitate.

e. 2ml of concentrated Hydrogen-tetra-oxosulphate (vi)

acid was added to the sample. The bottle was carefully

covered and inverted severally dissolving the precipitate,

thus making the sample to be a ‘fixed’ solution.

f. 2ml of the sample in a glass was titrated with

sodiumthiosulphate until a pale straw colour was

obtained. This was done by slowly dropping the

sodiumthiosulphate solution (A ml) from a calibrated

pipette and swirling the sample.

g. 2ml of freshly prepared starch solution was added to the

sample which gave a dark blue colour.

h. Addition of sodiumthiosulphathe (B ml) continued

slowly until the sample turned clear which marks the end

point of the experiment.

i. The concentration of the Dissolved Oxygen in the sample

was equivalent to the millitres of the sodium hiosulphate

used during the titration as 1ml equal 1mg/l dissolved

oxygen. That is, the concentration of Dissolved Oxygen

= Aml + Bml (knowing that 1ml of sodiumthiosulphate is

equal to 1mg/l of Dissolved Oxygen.

Conductivity: This was determined using Hanna

conductivity metre (model H198801). The meter was inserted

in the water in situ and allowed to attain a steady value and

then recorded in (µS/cm).

Total Dissolved Solids (TDS): This was measured using

Hanna TDS metre (model H198801). The meter was inserted

into the water and allowed to attain a steady value; the value

was recorded at TDS (mg/l) (Anene, 2003).

2.3. Collection and Identification of Aquatic

Macrophytes

Aquatic macrophytes were collected along river bank of

Ebonyi River and on the surface water for the floating

macrophytes once each time the trip to the site were made for

the period of three months; both creeping and standing

macrophytes were collected. The macrophytes collected were

arranged in white paper and covered with brown paper

envelop to avoid drying up. It was quickly transported to

Applied Biology Laboratory for identification. Macrophytes

were identified from family to species level with the use of a

catalogue (Agbogidi et al., 2000).

3. Results

The result of the physico-chemical parameter of Ebonyi

River shown in Table 1 explained the different values

obtained/recorded in the different parameters during the study

period. Dissolved oxygen was highest in the month of

November and lowest in the month of January with a mean of

5 mg/l. The water temperature was recorded highest in the

month of January and lowest in the month of November with

the mean of 29.20C and the pH value was recorded highest in

the month of January and lowest in the month of November,

having a mean of 38.33µS/cm. the flow rate was also recorded

in m/s having its highest speed in the month of December and

lowest speed in the month of January (Fig. 1). The total

dissolved solid (TDS), conductivity, water temperature (WT)

and PH is very high in January, showing that the period is high

in January whereas the Flow rate and the dissolve oxygen (DO)

are very low and the TDS, DO, conductivity and flow rate has

a maximum value in December. The TDS and PH have

minimum value in November (Fig. 1). All through the period

of the study, the family Cyperaceae had the highest number of

species in Ebonyi river seconded by Poaceae and Onagraceae

whereas the Araceae and Hydrophyllaceae had the least

abundance of species (Table 2). Fig. 2 shows the percentage

abundance of each family of the aquatic Macrophytes. This

shows that the families of Poaceae, Cyperceae and

Onagraceae and are favoured in Ebonyi River, whereas the

families of Araceae and Hydrophyllacea are not favoured in

Ebonyi River .

44 Uneke Bilikis Iyabo and Okereke Amarachukwu: The Aquatic Macrophytes and Physico-Chemical Parameters of

Ebonyi River Southeastern Nigeria

Table 1. Mean and Standard Deviation of Physico-chemical parameters of Ebonyi River.

Physico-chemical parameters Max. Min. Mean±Standard deviation

Dissolved oxygen (Mg/L) 5.2 4.8 5.00±0.20

Water temperature (°C) 32.8 26.6 29.17±3.24

pH-value 8.2 7.1 7.70±0.57

Total Dissolved Solids (Mg/L) 21 15 18.00±3.00

Conductivity (µS/Cm) 45 32 38.33±6.51

Flow rate (M/S) 8.3 7.5 7.97±0.42

Table 2. The relative abundance of the species found during the period of study.

FAMILY Species Abundance

AMARANTHACEAE Alteranthera sessilis +

Total 1

ARACEAE Pisia stratiotes +

Total 1

ASTERACEAE Eclipta alba +

Total 1

CYPERACEAE

Cyperus iria

Cyperus haspan

Fimbristylis ferruginea

Fimbristylis littoralis

Fuinea aliaris

Kyllinga balbosa

Kyllinga squamulata

+++

Total 7

HYDROPHYLLACEAE Hydrolea palustris +

Total 1

LEGUMINOSAE Neptonia aleracea +

Total 1

ONAGRACEAE

Ludwigia abyssinica

Ludwigia hyssopifolia

Ludwigi octovalvis

++

Total 3

POACEAE

Acrocera zizaniodes

Echinochloa crus-pavonis

Echinochloa pyramidalis

Elytrophorus spicus

Oryza barthii

Panicum laxum

Panicum subalbidum

+++

Total 7

POLYGONACEAE Polygonium lanigerum +

Total 1

PONTEDERIACEAE Eichhornia natais

Heteranthera callifolia +

Total 2

Key: + = present

++ = abundance

+++ = more abundance

AASCIT Journal of Environment 2015; 1(3): 41-47 45

Fig. 2. The summary of the physic-chemical parameters of the water sample.

Fig. 3. The percentage (%) abundance of aquatic Macrophytes by family in Ebonyiriver.

4. Discussion

The various physico-chemical parameters of Ebonyi River

with Dissolved Oxygen ranging from 5.2 to 4.8, having the

mean value of 5.00 during the study period. Higher percentage

of Dissolved Oxygen was observed in the month of November,

2014 with 34.67% and low in the month of January, 2015 with

32.00%. The water temperature of the river ranged from

32.8°C to 36.6°C with an average of 29.17°C and a standard

deviation of 3.24°C. Lower temperature was observed in the

month of November, 2014. The pH values of the river ranged

from 8.1-7.1 with an average of 7.7; this shows that the river is

slightly alkaline, giving the river its fresh water nature. The

Total dissolved solids ranged from 21-15 (mg/l) with a mean

of 18 and standard deviation of 0.57, having a higher TDS in

the month of January and lower in the month of November.

The conductivity ranged from 45-32 (µS/cm) with a mean of

46 Uneke Bilikis Iyabo and Okereke Amarachukwu: The Aquatic Macrophytes and Physico-Chemical Parameters of

Ebonyi River Southeastern Nigeria

38.33 (µS/cm) and a standard deviation of 6.51. Higher

percentage was observed in the month of January. The flow

rate of the river ranged from 8.3-7.5 with a mean of 7.97 and

standard deviation of 0.42. Higher percentage was observed in

the month of December and lowest in the month of January.

The variation of these parameters may probably be due to the

change in weather condition during the study period (Cooley,

1996). The different species of aquatic macrophytes found

during the study period and its abundance using the number of

species belonging to various families indicates that the species

found are common aquatic macrophytes found around the

wetlands of the South-Eastern part of Nigeria (Ayeniet al.,

1999). A total number of 10 families (Amaranthaceae,

Araceae, Asteraceae, Cyperaceae, Hydrophyllaceae,

Leguminoceae, Onagraceae, Poaceae, Polygonaceae and

Pontederaceae) were identified in the study area with

Cyperaceae and Poaceaehaving highest abundance with +++

and rare abundance was observed in the rest families with +

except Onagraceae which had a sparse abundance of ++. The

percentage abundance of the ten families, highest percentage

abundance was observed with the Cyperaceae family and

lowest was with the Araceae and Hyderophyllaceae. This

statistic shows that the river had more of grass weed

macrophytes than the root knod or leguminous weed

Macrophytes which is in agreement with Ita (1994) who

revealed the abundance of aquatic plants in various parts of

Nigeria. Panicum subalbidumis robust annual or short-lived

perennial with soft herbaceous culms 60-200 cm. high, erect

or decumbent and rooting at the lower nodes, the upper nodes

sharply demarcated. Leaf laminae is 20-50 cm long and 7-15

mm wide, linear, flat, acute or acuminate. Panicle 20-50 cm.

long, ovate or oblong, sparsely to moderately branched, the

tertiary and sometimes the secondary branches appressed at

maturity. Spikelets is (2.7) 3-3.5 mm long, narrowly ovate,

acuminate; inferior glume ¼-1/3 the length of the spikelet,

broadly ovate, 1–3-nerved, obtuse or acute; superior glume

7-9-nerved; inferior lemma similar to the superior glume,

sterile, its palea poorly developed or absent; superior lemma

and palea pallid or dark, glossy (Jackson and Wiehe, 1958).

The plant is found at margins of rivers, lakes and swamps

200-3400 m. It is used as food grain for insects (Jackson and

Wiehe, 1958). Ludwigia hyssopifolia belonging to the family

of Onagraceae also called water primrose, the plant is an erect,

glabrous herb of up to 60cm high that reproduces from seeds.

It is commonly found in lowland rice soil and flood plains of

West Africa. Cyperusiria is a tufted annual sedge up to 75 cm

high that reproduces by seeds and widely spread in many parts

of West Africa belonging to the family of Cyperacea.

Ludwigia abyssinica belonging to the family of Onagraceae,

having a common name of water primrose. It is an erect,

annual or perennial shrub about 1-2m high that reproduces

from seeds. It is commonly found in lowland area. Panicum

subalbidum of the family POACEAE is a tufted swamp grass

up to 2 m high that reproduces from seeds. It occurs in deep

water rice and swamps. It is an erect, tuft, annual grass about

1.5 m high that roots at the nodes and reproduces from the

seeds. The roots are fibrous, well developed, thick and

massive. The stems are rounded and spongy. The leaf blades

are flat, linear, about 40-45 cm long and up to 1.5 cm wide,

rough upper surface and the margins, and taper from the

middle to the fine narrow tip. The inflorescence is dense

panicle about 25 cm long and erect and stiff branches, the

spikelets are flat, oblong, 7-10 mm long, rather deciduous and

with pink awns 4-16 mm long. It is an important weed of

lowland rice, also occurring in swamps and shallow waters

(Ita, 1994). Oryza barthii is a robust, tufted sedge 1-2 m high

that can reproduce from seeds. It has an erect, stout stem

which is triangular in cross-section, thick at the base and

develops numerous fibrous roots. The leaves are large, up to

90 cm long and 2 cm across, taper gradually to the tip and have

broad, overlapping sheaths that clasp the stem below. The

inflorescence is a multi-branched panicle, 25-60 cm long,

subtended by leaf-like bracts which become linear and mjuch

reduced towards the upper part of the plant. The terminal

clusters are larger than the lateral ones and the spikelets are

brown. It is a common weed of swamps often found growing

in rice paddies, irrigation canals and the edges of streams in

the forest zones (Ita, 1994). Rhynchospotra corymbosa (Linn)

Britt.is an erect, branched annual herb up to 60cm high, that

reproduces form seeds. The stem is slightly fleshy but may be

more or less woody at the base. It is often reddish in colour

and root at the nodes. The presence of short stiff hairs makes

the stem feel rough to the touch. The leaves are opposite, ovate

to lanceolate, 2-10cm long and 1-3cm wide pointed at the apex,

rather finely and distantly toothed, and rough on the surfaces.

The upper leaves have no stalks. The inflorescence is made up

of solitary flowers or groups of 2-3 flowers at the tips or in leaf

axils. The flowers are borne on pedicels that are 2-7 cm long.

They are white and hairy with inconspicuous ray florets and

numerous disc florets, each of which is about 1 cm in diameter.

The fruits are pale brown or black achenes, 3 mm long, warty

and wedge-shaped. It can be found in damp and poorly

drained soils, in paddy rice fields, canals and irrigated fields

(Ita, 1994 and Westlake et al., 1998). Eclipta alba is an erect,

glabrous herb of up to 60 cm high, that reproduces from the

seeds. The stem is multi-branched, more or less hollow and is

slightly winged. The leaves are alternate, rather variable in

size, about 2-10 cm long and up to 1.5 cm wide. The flowers

are yellow and in the leaf axils. They are solitary and each has

four sepals and eight stamens. The fruit is a many seeds, linear

capsule that is enlarged at the apical portion where the seeds

are in two rows. The seeds are enclosed in an endocarp. It is a

common weed of lowland rice and flood plains of West Africa

(Sculthrope, 1985 and Sterm, 2000).

5. Conclusion

In conclusion, the physico-chemical parameter study of

Ebonyi River and the identified aquatic macrophytes suggest

that the presence of these macrophytes increases the amount

of Dissolved Oxygen of the river through the exhalation of the

by-product which is oxygen from the photosynthetic process

of the plants. The turbidity of the river which was determined

from measuring the Total Dissolved Solid of the water

AASCIT Journal of Environment 2015; 1(3): 41-47 47

samples is less when the presence of aquatic macrophyteis

high, which indicates that macrophyte has a cleaning effect on

the water. The analysis also suggest that more aquatic

macrophytes are found around the rivers with a slightly

alkaline to neutral pH value river; thus the presence of aquatic

macrophytes in any place depends more on the pH value and

the Total Dissolved Solid of the river.

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