Study of Water Quality and Distribution of Phytoplankton in Hebbal Lake, Krishnarajanagara

Abstract

Life on earth depends on fresh water. Phytoplanktons are free floating, photosynthetic, aquatic microorganisms, which moves from one place to another. Phytoplanktons which are present in Hebbal Lake, Krishnarajanagara, and Mysore were studied with respect to their species diversity and distribution. The phytoplankton community is mainly represented by algal representatives including both prokaryotes and eukaryotic genera. Studies on phytoplankton and water quality of Hebbal Lake, Krishnarajanagar, Mysore Karnataka were undertaken for 5months from May 2023 to September 2023. The quantitative analysis of phytoplankton was done by Lackey’s drop method modified by saxena (1987).Diversity indices have been discussed by using PASTA Software Program. Physical and Chemical parameters were analysed using the standard methods of APHA (2025) and Trivedi and Gael (1984). Among the total 60 species recorded, 33species of Bacillariophyceae, 7species of Chlorophyceae, 8species of Cyanophyceae, 8 species of Desmidiaceae, 3species of Euglenophyceae are reported. Bacillariophyceae was the most dominant group followed by Chlorophyceae, Cyanophyceae, Desmidiaceae and Euglenophyceae. The result of physico- chemical and biological parameters along with statistical method and biodiversity indices indicated that the Hebbal Lake is threatened ecologically due to various anthropogenic activities which lead organic pollution and eutrophication status of the lake. Statistical program Bray – Curtis similarity index explained, the cluster of EC, Total hardness and Total alkalinity is highly correlated with the clusters of phytoplanktons. Shannon and Weiner index showed that the lake was heavily polluted in the month of May due to increased temperature.

Introduction

I. INTRODUCTION

Water is an essential component of the environment and it sustains life on the Earth. Water is also a raw material for photosynthesis and therefore is important for crop production. Obviously an optimum agriculture depends on water and soil quality. The 2/3rd mass of our body is water and 70% surface of the Earth is covered by water. It is nature’s most Wonderful, abundant and most useful chemical gifted with physico- chemical properties with unique characteristics.[1]

 Limnology is an interdisciplinary science which involves a great deal of detailed field as well as laboratory studies to understand the structural and functional aspects and problems associated with the fresh water environment from a holistic Point of view. Better quality of water is described by its physical, chemical and biological characteristics .[2] The physico- chemical methods are used to detect the effects of pollution on the water quality. Changes in water quality are reflecting in the biotic community structure. Water pollution occurs when water body is adversely affected due to the addition of undesirable materials to the water. The phytoplankton community is mainly represented by algal representatives including both prokaryotes and eukaryotic genera. Plankton populations are mostly represented by members of Cyanobacteria, Chlorophyta, Dinophyta, Euglenophyta, Haptophyta, Chrysophyta, Cryptophyta and Bacillariophyta.[3]

The planktonic studies are very useful tool for assessment of water quality and the productivity of any type of Water body and also contribute to understanding of water bodies.Algae are the main primary producers in all kinds of water bodies and they are involved in water pollution in a number of significant ways.[2]

Present study refers to the study of water quality of Hebbal Lake of Mysore which was assessed using both phytoplanktons and physico-chemical parameters. From  May 2023 to September 2023.

A. Objectives

Investigations are undertaken in the selected Hebbal lake of Mysore district with the following objectives.

1. To study the relationship between physico-chemical parameters with phytoplankton population.
2. Evaluation of phytoplankton diversity of Hebbal Lake.

II. MATERIALS AND METHODS

1. Topography of Hebbal Lake

Hebbal Lake is also called as Dodda Lake. It is located at 10° 02' 02" North longitudes 74° 43'36* East latitude at an altitude of 788 meters above the sea level. It is situated away from Mysore. Lake is located in Krishnarajanagara Taluk, which is 5 kms away from Krishnarajanagara town. The area was surrounded by 852.79 hectares. It’s a small village and It comes under Hebbal panchayath, Krishnarajanagara.

B. Physico-Chemical Parameters

Surface water samples were collected every month in different spots of a lake for a period of five months from Hebbal Lake in Mysore district and 14 physico- chemical parameters have been analyzed by standard methods  [4], [5].

C. Statistical analysis

To get a precise explanation on physico- chemical parameters and phytoplankton population various statistical analysis was performed. All data obtained  were subjected to multivariate analysis. The statistical analysis was carried out by using following methods[ 1]

1. PCA by PASTA Software
2. Bray- Curtis Similarity index by PASTA Software
3. Biodiversity indices by PASTA Software

D. Phytoplankton analysis

Phytoplankton was collected by filtering 10 litres of water sample with the help of plankton net of mesh size 63 µm and 30cm diameter. The final volume of filtered sample was 50ml. The sample was transferred to 100ml sterile plastic bottle and labelled mentioning the time, date and place of sampling. The collected sample was preserved by using 2ml of 4% formaldehyde and 2 drops of lugol’s iodine solution.

The preserved samples were taken to laboratory for further analysis.

Phytoplankton count was done by Lackey’s Drop Method (1939) as mentioned in APHA (1985)  and  modified by Saxena (1987). In Lackey’s drop method, the coverslip was placed over one drop of water sample in the slide, permanent slide is done by using DPX and whole coverslip were examined under Labomedtrinocular microscope (LX400) with image transferor (DCM 35 USB 2.0) and photographs was captured by the software minisee and species identification was done by using standard monographs like Sudipta Kumar Das and Siba Prasad Adhikary[13],  research articles and research personnel. After that organisms were counted in each drop [1]. This procedure was repeated three times for each samples and number of organism was measured as organism per liter.

Formula used for the calculation of phytoplankton as units/L is

N = No. of phytoplankton counted in 0.1ml concentrate.

C = total volume of concentrate in ml.

V = total volume of water filtered through net

III. RESULT AND DISCUSSION

1. Physical-chemical parameters

The water was analysed for its physical and chemical properties and the results have been discussed and presented in the following sections [4],[5] and presented in Table 3 which shows the values obtained in all samples collected from May 2023 to September 2023.

1. Temperature: It is one of the critical physical parameter which controls most the biological activities in the aquatic environment. The water temperature of lake during study period ranges from 26°C to 29°C.
2. Electrical conductivity: Electric conductivity is a parameter used to ascertain the purity of water and is the measure of capability of water to transmit electric current. The Electric conductance ranges from 614µS to 670µS. A minimum value of 614µS was recorded in May and maximum of 670µS in July. It has been mentioned that increase in EC is due to dissolved salts content.
3. pH: pH is a term used universally to express the intensity of the acid or alkaline condition of a solution. The pH value ranges from 7.2 to 7.8. The minimum value of 7.2 was recorded in July and maximum of 7.8 in August. It has been mentioned that the increase in pH value appears to be associated with increased use of alkaline detergents in residential areas & alkaline material from wastewater is from agricultural areas.
4. Total Alkalinity: Total alkalinity is the measure of capacity of water to neutralize a strong acid. The minimum value 350 mg/L was recorded in May and maximum value of 540 mg/L in September. The alkalinity in the waters is generally imparted by the salts of carbonates and bicarbonates, phosphates, nitrates, borates, silicates, etc, together with the hydroxyl ions in Free State. The high value of total alkalinity in the lake may be due to cattle bathing, Fishering and laundering of clothes.
5. Salinity: Salinity of the water is its capacity to neutralize a strong base to a fixed pH. It is caused by the presence of strong mineral acids, weak acids and hydrolysing salts of strong acids. Salinity low which ranges from 0mg/L to 15mg/L.
6. Total Hardness: The regular addition of large quantities of sewage and detergent into the lake from nearby residential localities is responsible for higher level of hardness. Hardness ranges from 182 mg/L as CaCO3 to 260 mg/l as CaCO3.The minimum of 182 mg/L as CaCO3 was recorded in May and maximum of 260 mg/l as CaCO3 in August. The hardness will be more where the concentration of calcium and magnesium is more.
7. Calcium: Hardness is caused by compounds of calcium and magnesium, and by a variety of other metals. Calcium ranges from 21 mg/L to 30 mg/L. The minimum of 21 mg/L was recorded in May and maximum of 30mg/L in September.
8. Magnesium: Hardness is caused by compounds of calcium and magnesium, and by a variety of other metals. Magnesium ranges from 32.6 mg/L to 62.3mg/L. The minimum of magnesium 32.6 mg/L was recorded in May and maximum of 62.3 mg/L in September.
9. Chloride: Chloride is not utilized directly or indirectly for aquatic plant growth and hence its existence in the aquatic system is regarded as pollution. Chloride ranges from 36.8 mg/L to 55.2mg/L in the lake. A Minimum of 36.80 mg/L was observed in July  and maximum value of 55.2 mg/L in September. High chloride concentration in the lake water may be due to high rate of evaporation or due to organic waste of animal origin and also agricultural forming.
10. Total Dissolved Solids: Total dissolved solids represent the amount of soluble inorganic substance in water. Total dissolved solids observed in the lake ranges from 5 mg/L to 15 mg/L. Minimum value of 5 mg/L was recorded in June and maximum of 15 mg/L in September. The entry of sewage, urban runoff, industrial wastewater influence the increase in the concentration of Total dissolved solids.
11. Free CO2: Free Carbon-di-oxide (CO2) recorded in Hebbal lake ranges from 2.6 mg/L to 5 mg/L and it is found to be maximum in the month of August.
12. Dissolved Oxygen: Dissolved oxygen values ranges from 7.2 mg/L to 20 mg/L. The minimum value of 7.2 mg/L was recorded in May and maximum value 20 mg/L in July. The increase in DO is influenced by the moderate temperature. Lower DO indicates the pollution of the lake by algae is unwanted things in lake.
13. Biochemical Oxygen Demand (BOD): Biochemical oxygen demand (BOD) refers to the oxygen used by the micro-organisms in aerobic oxidation of organic matter, therefore with the increase in the amount of organic matter in the water BOD increases. BOD values ranges from 1.8mg/L to 6.67 mg/L. A minimum value of 1.8 mg/L was observed in September and maximum of 6.67 mg/L in August. Higher contents of organic load as well as high proliferation of microorganism are the causative factors for maximum BOD levels.
14. Chemical Oxygen Demand (COD): Chemical oxygen demand (COD) is commonly used to indirectly measure the amount of organic compounds in water. This makes COD as a useful indicator of organic pollution in surface water. COD values ranges from 52.8 mg/L to 90.2 mg/L. A minimum of 52.8 mg/L was observed in June and maximum of 90.2 mg/L in September. Higher value of COD pointing to deterioration of water quality was likely caused by the discharge of municipal waste water.

B.  Analysis of Phytoplankton Population:

The phytoplankton community is a heterogeneous group of tiny plants adapted to float in the sea and fresh waters. The analysis of phytoplankton population was done in selected Hebbal lake in Krishnarajanagara. Phytoplankton population analysis was done by using standard methods and identification was done by consulting taxonomic guides and monographs [4],[5],[13].

In the present study total of 60 species of phytoplanktons were identified in the Hebbal lake Krishnarajanagara during the period from May -2023 to September -2023 which is represented in the fig 7 Bacillariophyceae was high (50%) followed by Chlorophyceae (17%) and Cyanophyceae (15%), Desmidiaceae (8%), Euglenophyceae (6%) .

Among all the phytoplankton, Navicula tripunctata(9800 O/L) was found in large number followed by Ulnaria ulna (9800 O/L), Gomphonema dichotomum (8400 O/L) .

Table 6:Phytoplanktons of Hebbal Lake from May 2023-September 2023

IV.  ACKNOWLEDGMENT

The authors gratefully acknowledge faculty of Post Graduate department of Botany, Yuvaraja’s College Mysore, University of Mysore, for providing their support and laboratory facility to conduct this research work.

Conclusion

The result of physico- chemical and biological parameters along with statistical method and biodiversity indices indicated that the lake in the present study is threatened ecologically due to various anthropogenic activities which lead organic pollution and eutrophication status of the lake. As wetlands are rich in life, reservoirs find utility for sewage disposal, maintenance of local ground water levels and as a refuge for local and migratory wildlife, therefore it’s our responsibility to conserve the lakes in sustainable manner. Knowing the ecological status of the lake, will be helpful for carrying out restoring practices of the same.

References

[1] Mahesh Kumar, M.K. and Mahesh, M.K. (2019). Freshwater plankton ecology in four lakes of Mysore District, Karnataka. University of Mysore, 1-236. [2] Shashank .S.N. and Mahesh .M.K.(2022).Study of Dynamics of Phytoplanktons and Water quality of Hadinaru Lake, of Mysore District, Karnataka India. International Journal For Research In Applied Science and Engineering Technology,(1-77).2321-9653 [3] SumitaSrivastava, Pramod Kumar and Anil Kumar. 2010. Comparative study of water characteristics and algal biodiversity in river Gomati and Varuna. Plant Archives. Vol. 10. No. 2: 725-728. [4] APHA, AWWA, WCPF. (1995). Standard methods of examination of water and waste water. 19th Ed. [5] Trivedy, T.K. and Goel, P.K. (1984). Chemical and biological methods for water pollution studies. Environmental publications, Karad. [6] Simpson, E. H. 1949. Measurement of Diversity. Nature. 163: 686 [7] Fisher, R. A., Corbert, A. S. and Williams, C. B. 1943. The relation between the numbers of Species and the number of individuals in a random sample of an animal population. J. Anim. Ecol. 12: 42-58 [8] Margalef, D. R. 1968. Perspectives in Eclogical Theory. The Univrsity of Chicago Press Chicago. p. 111. [9] Menhinick’s Index as Described by Whittaker, R. H. 1977. Evolution of species diversity In land communities. In Evolutionary biology eds. Heeht M. K., W. C. Steee and B Wallace Plenum, NY. [10] Pielou, E. C. 1975. Ecological Diversity. John Wiley and Sons New York. p. 165. Shannon, C. E. and Weiner, V. 1949. A mathematical Theory of Communication. University Press, Illinois Urban 101- 107 [11] Berger, W. H. and Parker, F. L. 1970. Diversity of planktonic Foraminifer in deep sea Sediments Sci. 168:1345-7 [12] Shannon, C. E. and Weiner, V. 1949. A mathematical Theory of Communication. University Press, Illinois Urban 101- 107 [13] Sudipta Kumar Das and Siba Prasad Adhikary. (2014). Freshwater Algae of Eastern India. Daya Publishing House, New Delhi.

Copyright

Copyright © 2023 H. N. Punyashree, M. K. Mahesh Kumar, Dr. M. K. Mahesh. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.