ABSTRACT
This study evaluated the Physico-Chemical parameters and plankton composition of Wawan-
Rafi Lake in Kazaure, Nigeria. Monthly variation and composition of Physico-Chemical and
biological (plankton) parameters of Wawan-rafi Lake were studied for a period of six months
(July – December 2013). Result showed monthly variations of Physico-Chemical parameters.
Means of monthly values of pH ranges between 6.00-7.12, temperature ranged between 18 –
240C, and electrical conductivity was between 273.33µs/cm – 540.00µs/cm . Dissolve
oxygen (DO), Dissolved solid (DS) and Biological oxygen demand (BOD) Means of
monthly values ranges between 3.53±0.03 mg/l – 6.00±0.31mg/l, 103.67±5.78mg/l -
131.00±12.01mg/l, and 5.10±0.10mg/l – 6.83±0.20mg/l respectively. While Suspended Solid
(SS), sulphate, phosphate, nitrate and chemical oxygen demand (COD) their Means of
monthly values ranges between 2.33±1.95mg/l – 96.00±8.96mg/l, 5.94±3.60mg/l –
14.98±0.09mg/l, 8.33±2.98mg/l – 16.73±0.88mg/l,8.97±0.63mg/l-10.37±0.38mg/l and
1.50±1.01mg/l–6.00±1.16mg/l respectively . Four Phytoplankton phyla were recorded, they
were dominated by Chlorophyta then Cyanophyta followed by Euglenophyta and
Bacillariophyta. The Zooplankton of the lake were made up of Protozoa, Rotifers and
Cladocera. Correlation matrix showed that there were significant correlation between
Phytoplankton, Zooplankton and Physico-Chemical parameters. The composition of plankton
of Wawan-Rafi Lake were affected by seasonal variations and fluctuation of Physico-
Chemical parameters.
TABLE OF CONTENTS
Content Page
Title page………………………………………………………………………………… ii
Dedication………………………………………………………………………………… iii
Declaration………………………………………………………………………… - - iv
Certification……………………………………………………………………………… v
Acknowledgements…………………………………………………………………… - vi
Abstract - ………………………………………………………………………… - - vii
Table of Contents……………………………………………………………………… - viii
List of Tables…… - ……………………………………………………… - ………… xiii
List of Plates……………………………………………………………………… - - xiv
List of Figures…………………………………………………………………………… xv
List of Appendices……………………………………………………………… - …… xvi
10 INTRODUCTION - - - - - - - - - - - - - - - - 1
11 Background of the Study………………………………………………………… 1
12 Statement of the Research Problem…………………………………………… 4
13 Justification…………………………………………………………… - - - 5
14 Aim……………………………………………………………………… - ……… 5
15 Objectives………………………………………………………………… - … - 5
16 Hypotheses……………………………………………………………………… 6
20 LITERATURE REVIEW…………………………………… - ……………… - 7
21 Physico-Chemical Parameters…………………………………………… - … - 7
211 Temperature - - - - - - - - - - - - - - - - - - - 7
212 Turbidity……………………………………………………………………… - 8
213 Water pH - - - - - - - - - - - - - - - - - - - 9
214 Water hardness - - - - - - - - - - - - - - - - - 10
2
15 Dissolved Oxygen (DO) - - - - - - - - - - - - - - - 10
216 Biochemical oxygen demand (BOD) - - - - - - - - - - - 11
217 Electrical conductivity of water - - - - - - - - - - - - - 12
218 Total dissolved solids (TDS) - - - - - - - - - - - - - - 12
219 Phosphate-phosphorus (PO4-P) - - - - - - - - - - - - - 13
2110 Nitrate-nitrogen (NO3-N) - - - - - - - - - - - - - - - 13
22 Biological Parameters - - - - - - - - - - - - - - - - 14
221 Studies on phytoplankton - - - - - - - - - - - - - - - 14
222 Studies on zooplankton - - - - - - - - - - - - - - - - 15
30 MATERIALS AND METHODS……………………………………………… - 17
31 Study Area……………………………………………………………………… - 17
32 Sampling Stations……………………………………………………………… 17
33 Sampling Procedures…………………………………………………………… 17
34 Physico-Chemical Parameters………………………………………………… 20
341 Determination of pH……………………………………………………………… 20
342 Determination of water temperature - - - - - - - - - - - - 20
343 Determination of dissolved oxygen (DO) and
biochemical oxygen demand (BOD) - - - - - - - - - - - - 20
344 Determination of electrical conductivity, dissolved solids (DS)
and Suspended Solid (SS) - - - - - - - - - - - - - - - 20
345 Determination of phosphate-phosphorus - - - - - - - - - - - 22
346 Determination of nitrate-nitrogen - - - - - - - - - - - - - 22
35 Biological Parameters - - - - - - - - - - - - - - - - 23
351 Determination of phytoplankton - - - - - - - - - - - - - 23
352 Determination of zooplanktons - - - - - - - - - - - - - 23
36 Community Structure Analysis………………………………………………… 25
361 Margalef index of species richness… - ……………………………………… - 25
363 Community dominance index (CDI)……………………………………………… 25
37 Statistical Analysis………………………………………………………… - …… 26
40 RESULTS………………………………………………………………………… 27
41 Physico-Chemical Parameters………………………………………………… 27
411 pH………………………………………………………………………………… 27
412 Electrical conductivity (EC)…………………………………………………… 27
413 Temperature………………………………………………………………… - - 27
414 Dissolved oxygen (DO)………………………………………………………… 27
415 Dissolved solid (DS)…………………………………………………………… 29
416 Biological oxygen demand (BOD)…………………………………………… - 29
417 Suspended Solids (SS)…………………………………………………………… 29
418 Sulphate………………………………………………………………………… - 29
419 Phosphate………………………………………………………………………… 31
4110 Chemical oxygen demand (COD)…………………………………………………… 31
4111 Nitrate…………………………………………………………………………………… 31
42 Relationship between Phytoplankton, Zooplankton and
some Physico-chemical Parameters…………………………………………… 34
43 Phytoplankton - - - - - - - - - - - - - - - - - 36
431 Cyanophyta……………………………………………………………………… 36
432 Chlorophyta………………………………………………………………… - … 36
433 Euglenophyta…………………………………………………………………… 43
434 Bacillariophyta…………………………………………………………………………… 43
44 Zooplankton………………………………………………………………… - 43
441 Protozoa………………………………………………………………………… - 47
442 Rotifers - - - - - - - - - - - - - - - - - - - - 47
443 Cladocera……………………………………………………………………… - 47
50 DISCUSSION………………………………………………………………… 50
51 Physico-chemical parameters………………………………………………… 50
52 Plankton composition………………………………………………………… - 55
60 CONCLUSION AND RECOMMENDATION…………… - …………… - 58
61 Conclusion……………………………………………………………………… 58
62 Recommendations……………………………………………………………… 58
REFERENCES…………………………………………………………………………… 60
CHAPTER ONE
10 INTRODUCTION
11 Background of the Study
Global aquatic ecosystem fall into two broad classes defined as Saline or non Saline
in the content, it may be freshwater or saltwater ecosystem Freshwater ecosystem is
aquatic system with low or no percentage of dissolve salt and is subjected to the
influence of a wide array of physical and chemical factors The increase and decrease
of these factors frequently affect the flora and fauna which lead to the altering of their
diversity in addition the factors that affect the biodiversity of aquatic ecosystem
which include pressure, density buoyancy, temperature light, oxygen content,
carbondioxide content, pH or hydrogen ion concentration(Achionye-Nzeh and
Isimaikaiye 2010)
The aquatic habitat of lake remain vertically stratified in relation to light intensity,
wavelength absorption, hydrostatic pressure, temperature etc in lake, for example
there are five well recognized horizontal strata namely
1 Shallow water near the shore forms the littoral zone: It contains upper warm
and oxygen rich circulating water layer which is called epiliminion The
littoral zone includes rooted vegetation
2 Sub-littoral zone: Extend from rooted vegetation to the non-circulating cold
water with poor oxygen content (hypoliminion)
3 Limnetic zone: Is the open water zone away from the shore It is the zone up
to depth of light penetration where rate of photosynthesis is equal to the rate of
respiration
4 Profoundal: Is the deep water area beneath limnetic zone and beyond the depth
of effective light penetration
5 Abyssal zone: Is found only in deep lakes since it begins at about 2,000 meters
from the surface (Verma and Agarwal,2000;Atobatele and Ugwumba 2008)
Furthermore, lentic water of lakes is also classified on the basis of the depth of light
penetration enabling photosynthesis into trophogenic zone (including littoral plus sub-
littoral zones) and a tropholytic zone (upper part of profoundal zone) The former is
often distinguished by abundant plant growth and dependant fauna, while it donates
general absence of vegetation and habours mostly saprobes In between two zones is
the compensation level which forms a boundary between two zones It exhibit perfect
equilibrium between respiration and photosynthesis (Verma and Agarwal, 2000)
Lakes have the tendency to become thermally stratified during hot and cold, dry or
wet, summer or winter to undergo definite seasonal periodicity in depth distribution of
heat and oxygen Light too penetrate only to a certain depth depending upon turbidity
These gradations of oxygen, light and temperature profoundly influence the life in the
lake, its distribution and adaptation (Ibrahim et al, 2009)
Wawan-Rafi Lake is one of the freshwater bodies with a history of existence dated
back over 100 years It was located at Wawan-Rafi village which is 2 kilometers west
of Kazaure town, Kazaure local government area of a Jigawa State(MANR,1992)
Quality of water can be described according to its physico-chemical and plankton
diversity and distribution Planktons by definition are organisms that are unable to
swim against water currents, most plankton are so small they can only be seen with
the aid of a microscope They are very numerous and form an important part of
aquatic ecosystem Phytoplanktons are producers, transforming sunlight into food
energy Producers provide food for many different primary consumers Zooplanktons
are heterotrophic planktonic animals floating in water which constitute an important food source for many species of aquatic organisms In addition, they serve as
indicator organisms of water quality The species composition of the plankton when
observed can provide an indication of environmental health, (Hassan et al, 2004)
The classic example is algal blooms associated with eutrophication, especially during
large phytoplankton blooms known as ―red tidesâ€" During red tides, some organisms
disappear completely as water quality deteriorates, and the number of species and
total overall number of different organisms found in the lake decline, (Hassan et al,
2010)
According to Akomeah et al,( 2010), plankton are usually categorized according to
their feeding mode or life cycle thus, 1) feeding mode: Phytoplankton = autotrophs,
Zooplankton = heterotrophs, or 2) life cycle: holoplankton (entire life cycle in water
column as plankton), meroplankton (part of life cycle as plankton) The amount of
phytoplankton in water depends on light availability, the amount of nutrients
available, and the relative proportions of nutrients available (with nitrogen and
phosphorous usually as limiting nutrients) and the temperature of the water The
amount of zooplankton in water depends generally on the amount of phytoplankton
and detritus available to feed on, detritus can be food for primary consumers, (Hassan
et al, 2010) Phytoplankton in a reservoir is an important biological indicator of water
quality (Yakubu et al, 2000) While phytoplankton are important primary producers
and are at the base of the food chain in open water, some species on the other hand
can be harmful to human and other animals by releasing toxic substances (hepatoxins
or neutrotoxins etc) into the water (Whitton and Potts, 2000) Phytoplankton is
recognized worldwide as bioindicator organisms in the aquatic environment (Yakubu et al, 2000) Many government agencies are interested in the interaction between
water use and water pollution Nevertheless, an increasing number of environmental
protection agencies are being assigned the task of safe guarding the quality of water
for multipurpose uses It was recommended that all immediate and potential interests
in the water basins are considered simultaneously in the management of water for all
purposes It has been observed that only an ecologically healthy fresh water
ecosystem fulfils this global order and this can be measured by the ecology of the
plankton in the water body
Water used by man ranges from purely social needs such as recreation, religious
worship and regional/cultural uses such as drinking, cooking, laundry, bathing, waste
disposal, to economic needs such as irrigation, fisheries, animal production, electric
power generation and navigation For most of these uses, man depends mainly on
fresh water available in inland lakes and rivers, which constitute less than 50% of the
total amount of water in the biosphere (Yakubu et al, 2000)
12 Statement of Research Problem
In recent years, there has been increasing concern about the rate at which inland
waters are polluted through run offs into streams and lakes, as in Wawan-Rafi lake
therefore leading to euthrophication which affect the specific composition of
planktons and variation of physico-chemical parameters as well as changing the
qualities of these water bodies (Chapman and Romberg, 2008)
13 Justification
The quality of a given water is governed by its physical, chemical and biological
parameters status in comparism with international inland and drinking water standard
(Yakubu et al, 2000)
Changes may had happened over a period of time in Wawan-rafi lake because of how
the neighbouring communities use the lake Rainfall, is very critical element in the
area, because of its deficiency in the dry season, the neighbouring communities resort
to the use of lake for agriculture, recreational, livestock and human consumption due
to insufficiency of pipe borne water
These activities of the neighbouring communities of Wawan-rafi lake may affect the
physico-chemical parameters and biological (plankton) composition in relation to
season as well as the quality of the water, which is the focus of the study
14 Aim of the Study
The aim of this study was to determine the physico-chemical parameters and plankton
diversity and distribution of Wawan-Rafi Lake
15 Objectives of the Study
1) To determine the seasonal variation in physico-chemical parameters of the
lake
2) To determine the phytoplankton and zooplankton composition and distribution
of the Lake
3) To determine the relationship between the physico-chemical parameters,
phytoplankton and zooplankton composition and distribution in the Lake
16 Research Hypotheses
1) There is no significant difference in the seasonal variation of physico-chemical
parameters of the Lake
2) There is no significant difference in phytoplankton and zooplankton seasonal
composition and distribution in the Lake
3) There is no significant relationship between physico-chemical parameters,
phytoplankton and zooplankton composition and distribution in the Lake
