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INTRODUCTION
Water is the most valuable natural resource on the earth and it forms an
integral part of the earth’s environment. The very existence of life forms on the
planet earth is essentially depended on this most precious vital solvent. Most of our
great civilizations were established on the banks of rivers to ensure reliable and
clean supply of water. The Nile, the Tigris and Euphrates were where man began to
establish themselves on the earth. In all parts of the world, the major rivers played a
major part in the evolution of man. In ancient cultures water represented the very
essence of life. The Romans were the first to pipe water into their growing cities,
especially with their aqueducts. They also realized that sewage water could cause
damage to their people, and needed to be removed from large areas of people.
Thales of Miletus (624-546), a famous Greek philosopher has stated that the origin
of all matter is water. Water is an integral part of Hindu beliefs and customs and it is
always given a sacred position in the centuries-old civilization of India.The
civilization originated and flourished on the banks of the sacred rivers and the
influence of the rivers is reflected in all aspects of life. In the hymns of the Vedas,
the Puranas, the Upanishads, the epics and the great works of Vedic scholars, the
importance of water is often highlighted (K.Shadananan Nair, 2004).
The safe and stable supply of water is important to all socio economic
development of a country. Water is essential for natural habitat – for drinking,
cleaning, agriculture, aquaculture, transportation, industry, recreation, animal
husbandry, providing electricity for domestic, industrial and commercial use. The
quantity and quality of water not only has an impact on human society, but also on
the aquatic and terrestrial environments. Increased human activities have greatly
influenced the water cycle, resulting in growing number of global water problems.
In recent times, due to increase in population, industrialization and indiscriminate
use of chemicals in agriculture, there is an ever increasing threat to the quality of
water resource base, resulting in decrease of fresh water availability.
The lakes hold more than 90 percent of all the liquid freshwater on our
planet’s surface (World Lake Vision Action Report-2007). Many of the world’s
most important lakes are in crisis, beset by a great variety of problems that affect the
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quantity and quality of the water they contain, the organisms they support, and their
ability to meet the water needs of the surrounding human populations. Some suffer
from excessive water withdrawals and diversions, while others have witnessed
deteriorating water quality because of polluting human activities on the surrounding
lands. Lakes are not only a significant source of precious water, but often provide
valuable habitats to a variety of flora and fauna. They moderate the extreme
hydrological events such as drought and floods. They influence microclimate,
enhance the aesthetic beauty of the landscape and extend many recreational
opportunities. Lakes are an inherent part of the society in Indian culture and serve a
variety of purposes. Lakes and tanks play an important role in helping irrigation as
well as recharging ground water in the surrounding areas. It is estimated that up to
1980, about 4000 large reservoirs and about 8,00,000 small reservoirs worldwide are
serving mankind. The total catchment area of lakes and tanks in India is about
2.9m.ha. According to Infrastructure Development Corporation of Karnataka
(IDeCK), there are 36,508 inland water bodies in Karnataka, of these about 965
water bodies are located in Mandya district. These are used mainly for the purpose
of irrigation. As per the U.N produced Global Biodiversity out look report (2010),
shallow water wetlands such as marshes, swamps and shallow lakes have declined
significantly in many parts of the world.
The main problems encountered in lakes include excessive influx of
sediments from the lake catchment, discharge of untreated or partially treated
sewage and industrial waste waters, solid waste disposal, entry of diffused source
nutrients from agricultural fields, over-exploitation of lake for activities like
recreation, fishing, encroachments, land reclamation resulting in lake shrinkage,
shoreline erosion and impact on lake hydrology, deterioration in water quality and
impact on bio diversity and climate change. Trophic status refers to the overall level
of biological production in a lake. It is usually based on the total mass of algae. The
degree of biological production within a lake is a key biological component of water
quality. Lakes with low levels of biological production are often clean and clear,
supporting small fish populations. As biological productivity increases, algal blooms
may occur and the water can become murky. Decomposition of plant material can
use up oxygen and pose stress on the aquatic fauna including the fish population.
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Table 1.1
District wise number of Lakes and tanks in Karnataka State
Sl.No Name of the district No of Lakes and Tanks 1 Bidar 86 2 Gulbarga 507 3 Bijapur 125 4 Bagalkot 73 5 Belgaum 811 6 Raichur 450 7 Dharwad 8 Gadag 3080* 9 Koppal 213 10 Uttar Kannada 3270 11 Haveri 1438 12 Bellary 233 13 Shimoga 4890 14 Chitradurga 15 Davangere 371* 16 Udupi 247 17 Chikmaglur 2866 18 Tumkur 1998 19 Kolar 20 Chikka Ballapura 4263* 20 Hassan 5599 21 Dakshin Kannada 432 22 Kodagu 1146 23 Mandya 965 24 Bengaluru (Urban) 25 Bengaluru (Rural) 27 Ramanagar
2076*
28 Mysore 29 Chamrajanagar
1369*
TOTAL 36508
Courtesy : IDeCK, Bangalore
*The number of lakes is the total number in the erstwhile undivided district
The study of inland waters is called limnology. It includes physical, chemical
and biological study of lakes, ponds, rivers, springs, streams and wetlands.
Limnology classifies lakes and other water bodies on the basis of trophic state
index. "Trophic" means nutrition or growth. A eutrophic ("well-nourished") lake has
high nutrients and high plant growth. An oligotrophic lake has low nutrient
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concentrations and low plant growth. Mesotrophic lakes fall somewhere in between
eutrophic and oligotrophic lakes. The main factors reulates the trophic status of lakes
are, the rate of nutrient supply by water shed, soils, vegetation and anthropogenic
activities; the climatic factors such as sunlight, temperature, precipitation, inflow
and out flow of water of the lake. The lakes may be culturally eutrophied by
accelerating their natural rate of nutrient inflow. This will happens due to the poor
management of the watershed and inflow of the sewage from human settlements.
Such changes may occur over a period of time and are reversible if anthropogenic
nutrient loading can be controlled. The water quality indices are usefull to assess the
trophic status of the water body, so that the regulatory authorities can take
appropriate remedial measures for the management of the water quality. Forel
(1841-1912), a Swiss scientist, established the field of limnology with his studies of
Lake Geneva. Forel is considered as the "founder of modern limnology." His
investigations of biology, chemistry, water circulation, and sedimentation, and most
importantly their interactions, established the foundation of a new discipline. He
discovered the phenomenon of density currents in lakes, and explained seiches, the
rhythmic oscillations observed in enclosed waters. Thienemann (1922), a German
zoologist and Naumann, a Swedish botanist co-founded the International Society of
Limnology. With the work of prominent early American limnologists like
Hutchinson, Ed Deevey, Birge, and Juday, limnology flourished well in both
Europe and America. Limnological studies on lakes, rivers, and streams have been
emphasized owing to deterioration of water quality due to eutrophication (Suxena et
al.,1988).
The name plankton was first used by a German biologist Hensen (1887).
This term is derived from the Greek adjective planktos, meaning "errant",
"wanderer" or "drifter. Plankton of fresh water includes several groups of bacteria,
algae and animals. Plankton are microscopic organisms that live suspended in
aquatic ecosystems and they constitute a very important part of fresh water
communities. As they are smaller in size, they occupy large area on water bodies
and multiply at an exponential rate. The plankton move in the water bodies by
convection or wind induced current.
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Phytoplankton are microscopic plants and they photosynthesize their food in
the water bodies. They are important in aquatic ecosystems as they form a part of
primary producers and assist in recycling of elements such as Carbon, Nitrogen and
Phosphorus. Phytoplankton growth depends on the availability of carbon dioxide,
sunlight and other nutrients. The zooplankton are relatively larger than their
phytoplankton counterparts and consists of smaller protozoan’s and metazoans such
as crustaceans, rotifers and other animals. Many environmental factors can affect
phytoplankton and zooplankton communities in lake systems. Increased nutrient and
light availability result in rapid phytoplankton growth. These plankton are consumed
by zooplankton, which become the dominant plankton taxa. When the water is clear
the phytoplankton populations become depleted due to increased predation by
growing numbers of zooplankton. Zooplankton abundance declines as a result of
decreased phytoplankton prey and increased predation by juvenile fishes. With
increased nutrient availability and decreased predation from zooplankton, a diverse
phytoplankton community will flourish in the water body. It is assumed that
phytoplankton are more abundant in areas with high intensity of light while higher
temperature influences on the growth and multiplication of both phytoplankton and
zooplankton.
When a water body is barren and unoccupied, the newly colonizing
organisms rely on favourable environmental conditions called the abiotic factors for
their successful growth and survival. When a variety of plankton are already present
in the ecosystem, the growth activities of these species can affect the lives of the
fellow species and these factors are the biotic factors. The angle of incidence of
sunlight on water surface, temperature of water, clouds and season greatly affects
the planktonic succession in water bodies. The availability of inorganic phosphate
and nitrate may influence on the phytoplankton biomass. When the phytoplankton
productivity is high, the nutrient concentration may be reduced due to their
utilization by the phytoplanktons and subsequently the phytoplankton population
may become dwindled due to grazing by zooplanktons and juvenile fishes.
A lentic water body may be disturbed by various factors such as wind,
temperature, dissolved oxygen, carbon dioxide and pH. Wind is considered to be an
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important factor for disturbing water, though temperatures also produce convection
currents, it is even across the body of water. Human intervention such as recreation
and fishing activities can also cause water movement. As many chemical reactions
and cellular processes are depended on oxygen, the concentration of oxygen may
also alter the ecosystem. The same thing may happen in case of carbon dioxide
which can change the pH of water. Hence the physico chemical characteristics of
water will determine which type of organisms has to survive in that particular fresh
water ecosystem. In total these factors will actively manipulate and bring ecological
changes in the waterbody. They also partially play an important role in planktonic
succession of the ecosystem.
Lentic water bodies can vary greatly in appearance from small temporary
puddles to large lake capable of supporting diversified life communities. The biotic
and abiotic factors of the water body will determine the type of plant and animal
communities of the ecosystem. Plankton requires a range of macro elements viz.,
nitrogen, phosphorus, magnesium and potassium. Carbon dioxide is essential for
metabolic activities of the aquatic vegetation including the phytoplankton.The
increased Co2 level may be due to respiratory activity of plankton, vegetation and
also due to decomposition of organic matter by aerobic bacteria. The plankton grows
and reproduces in a rapid manner. The productivity and survival of plankton is
greatly influenced by the environmental factors. Different plankton communities are
capable of growing in different trophic levels of the water bodies and hence there
will be competition for niches in the fresh water environment. These results in the
occupation of one type of planktonic communities in a particular area at one specific
time and it will be succeeded by another group under favourable conditions.
Like any other ecosystem human activities have affected the fresh water
ecosystems also to a considerable extent. This has altered many of our aquatic
ecosystems both physically and chemically. Encroachment of lakes, sedimentation,
entry of untreated sewage, surface run off from farm lands can affect the aquatic
environment by reducing the water storage level, enrichment of nutrients and
addition of new chemicals like detergents and pesticides. Zutschi et al.(1988) and
Pandit (1999) have reported that disposal of sewage to water bodies from adjoining
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settlements is not only causing deterioration of water quality, but also shrinkage in
their size. According to Gulati and Van Donk (2002) the addition of farm land
drained nutrients such as nitrate and phosphorus from canals and rivers is the major
cause for eutrophication of shallow lakes.
The extention of human habitations and public effluent sources are the chief
factors for the degradation of lakes. It has been reported that lakes receives about
70% of their pollutants from domestic sewage. This has resulted in the periodic out
break of water borne diseases and communicable diseases as such water nourishes
larvae of vectors like mosquitoes. This also affects the flora and fauna of the lake as
the water become enriched with the nitrate and phosphate present in the sewage. The
organic matter of the sewage undergoes microbial degradation and increases the
biological oxygen demand and reduces the dissolved oxygen required for aquatic
life. Johnson et al. (2001) speculated that population increase and rapid economic
development in next 25 years will substantially increase the demand for freshwater
resources. The availability of freshwater for human consumption will be one of the
great issues of the twenty-first century. Eutrophication has become a major cause for
concern in the developing world, including South American, African, and South
Asian countries. Scientific interest in eutrophication has consistently been
significant during the last 25 years. Emphasis on this area of research has risen
suddenly in recent years. Brönmark and Hansson (2002) predicted that
eutrophication, acidification, and contamination by toxic substances are likely to
increase as threats to freshwater resources and ecosystems.
A number of research publications have appeared in this field. Many of the
papers have dealt with physical and chemical factors operating in the water bodies,
while others have discussed the distribution of planktons and influence of
phytoplankton on the growth of zooplanktons. The occurrence of algal blooms in the
water bodies, the causes for such a phenomenon and their effect on the growth of
other phytoplankton have been studied in recent years. With all these efforts on the
management of lakes, the lakes differ from each other in physical structure, degree
of pollution, physicochemical nature of water, geographical conditions and aquatic
vegetation.
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Any change in the natural quality of water is best reflected in the change in
natural flora and fauna of the aquatic ecosystem (Kulshreshtha et al. 1989). Hence
biological indicators show the degree of ecological imbalance that has been caused
to the lake, while chemical methods assess the concentration of pollutants
responsible for such kind of imbalance. As lakes are influenced by both abiotic and
biotic factors, both types of assessments are necessary for an effective monitoring of
pollution and proper management of lakes. Plankton, particularly phytoplankton, has
long been used as indicators of water quality. Because of their short life spans,
planktons respond quickly to environmental changes. They flourish both in highly
eutrophic waters while a few others are very sensitive to organic and/or chemical
wastes. Some species have also been associated with noxious blooms sometimes
creating offensive tastes and odours or toxic conditions. Because of their short life
cycles planktons respond quickly to environmental changes, and hence the standing
crop and species composition indicate the quality of the water in which they are
found. Most algal taxa can be identified to species level by experienced biologists,
and the tolerance or sensitivity to specific changes in environmental conditions is
known for many species (Rott 1991, Dixit et al. 1992).
Assessment of eutrophication is also an important criterion to understand the
extent of nutrient concentration and how it has adversely altered the ecological
balance of the aquatic communities. Extension of human habitation and
indiscriminate application of chemicals in the crop fields has caused decline in the
plankton growth and some have became extinct. On the other hand in the course of
plankton succession some species have enormously increased in their number
making the water bodies unfit for drinking, recreation and other domestic purposes.
Although extensive research work has been carried out on physicochemical aspects
and phytoplankton independently, information on planktonic diversity and their
influences on other biotic communities in Mandya lakes are lacking.
In view of this the present investigation has been undertaken with the
following objectives, assessment of the factors controlling the chemistry and quality
of water in the lakes
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1. Assessment of variations in the biotic conditions of the lakes
a) Determination of water quality indices; Carlson’s trophic state index (1949),
Dominance index, Shannon and Weiner diversity index (1949), Simpson’s
diversity (1949), Pielou’s evenness index (1975), Menhinick’s index (1977),
Margalef’s index (1968), Shannon’s equitability index (1964), Fisher’s ά
index, Berger and Parker index, CCME water quality index, NSF water
quality index, Diatoms as water quality indices.
b) Statistical analysis
(i) Primitive component Index
(ii) Bray Curtis similarity indices
(iii) Canonical correspondence analysis
2. Protecting the biodiversity of the lakes
3. Suggesting the methods of conservation of the lakes.
As per the CCME water quality index, the water quality parameters are
deviated from the objective values in both the lakes and the deviation was in
between 40 to 48%. The dominance of Bacillariophyceae, Chlorococcales and
Euglenaceae also indicated the polluted status of these water bodies. The
physicochemical investigation has showed that the important limiting nutrients for
planktonic growth, phosphate and nitrate are with in the permissible limits of the
standard values. This may be due to the absorption of these nutrients by
phytoplankton and macrophytes present in the lake. The number of phytoplankton
may also decreased due to their consumption by zooplanktons and they in turn
became prey for other faunal population including fishes. Since both lakes are being
used for pisciculture, the movement of boats during fishing and manual removal of
algal bio mass and macrophytes also contributed to a great extent in controlling
enrichment of the lakes by the organic nutrients.
Based on these findings suggestions have been made regarding the probable
conservative methodologies that can be adopted by the community and regulatory
bodies for the protection and conservation of the biodiversity of the studied lakes.
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REVIEW OF LITERATURE
Since the early part of the 20th century, lakes have been classified according
to their trophic state. Different organizations of different countries around the world
which are involved in water resources control are using a regular form of Physico-
Chemical indices for water quality assessment. These indices have been the product
of efforts and research development from governmental agencies and academic
institutions. Among the first prominent comparisons of water quality indices were
Landwehr & Deininger (1976), followed by Ott (1978), who revised water quality
indices used in the USA, besides publishing a detailed discussion about the practices
and theories of environmental indices. In Europe contributions have come from van
Helmond and Breukel (1997), who demonstrated that at least 30 water quality
indices are of common use around the world.
The broader and generally accepted conception of limnology involves the
study of all inland aquatic ecosystems including the biological aspects (Brezonik
1996; Strom 1929; Wetzel 2003). Forbes (1887) described the physicochemical and
biological composition of lentic water bodies and called such standing water bodies
as microcosms. The discovery of plankton by Victor Henson (1887) was a mile
stone in the field of limnology. Birge and Judey (1911) studied the physicochemical
and biological characteristics of lake Mendotta and they concluded that
eutrophication of lakes is due to increased human interference by discharging waste
water in to aquatic ecosystem. West and West (1912) studied the periodicity of
phytoplankton on account of variation in physicochemical characteristics for the first
time in some British lakes. Fritsch (1913) established the first mobile biological
research station in United Kingdom for the survey and study of aquatic ecosystems
for their physicochemical and biological characteristics. Pearsall (1921), Storm
(1924), Howland and Lucy (1931), Hutchinson and Pickford (1932) and Yoshimura
(1932) conducted studies on fresh water lakes. Prescott (1938) recorded the
objectionable algae and their control in lakes and reservoirs. Bailey (1938) studied
the ecology of phytoplankton of lake Michigan in United States of America. Thresh
et al. (1944) studied the chloride content of surface waters and concluded that
higher level of chloride content is due to higher pollution. Prescott (1952), after
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studying fish mortality rate in lakes concluded that the toxic substances released
during death and decay of plankton was the cause for increased fish mortality.
Gerloff and Skoog (1957) studied the ecological aspects of Lake Wisconsin in
United States of America. Shannon and Brenzoic (1972) developed a trophic state
criterion using multivariate approach. The important contribution to hydrobiology in
India include those of Gonzalves and Joshi (1946) who studied the seasonal
occurrence of algae in a tank at Bandra, Mumbai; Patrick(1948) observed the factors
affecting the distribution of diatoms and Rao (1955) discussed on the distribution of
algae in six small ponds of Hyderabad. Krishnamurthy (1954) studied the diatomic
flora of south India. Gandhi (1955) worked on the fresh water diatoms of Pratapgad,
Rajasthan. Philipose (1960) worked on fresh water phytoplankton of inland
fisheries; Singh (1960) recorded the phytoplankton ecology of inland water of Uttar
Pradesh. Munnawar and Zafar (1967) studied the distribution pattern of
phytoplankton of polluted and unpolluted lakes of Hyderabad. From these studies
they pointed out the impact of physicochemical parameters on algal growth.
Hydrobiological studies of a temple tank, Devikund in Deoband by Verma and
Shukla (1968) was a break through in the study of limnology. This has encouraged
Vyas (1968) to do phytoplankton study in Picchola Lake and Zaffar (1969) to study
ecology of algae in the ponds of Hyderabad.
Hydrobiological studies in India were geared up during 1970 to1980.
Venkateswarulu (1970) conducted the ecological study of algae in river Moosi,
Hyderabad with special reference to water pollution and periodicity of some
common algal species. Seenayya (1971) studied the plankton composition in fresh
water lakes, while Munnawar (1972) was the first person to report Euglenoids as
indicators of organic pollution. The significant contribution to limnology has been
made by Bharathi and Hosmani (1973) who conducted hydrobiological studies in
ponds and lakes of Dharwar. They observed gradual decrease in total production
towards summer in polluted ponds and blooming of different species of algae
causing the water unfit for drinking. Bharathi and Hosmani (1974) studied the
slightly polluted ponds disturbed by animal and human population and found
increase in total algal production with the increase in number of species. Dillon and
Rigler (1975) showed total nitrogen and phosphorus ratio as growth limiting factor
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for algae. They pointed out that a ratio of 12 indicates that phosphorus is the limiting
factor, while a ratio less than 12 indicates that nitrogen becomes limiting factor.
Hosmani (1976) reported the increased phosphates, calcium, oxidisable organic
matter, albuminoid ammonia, low pH and high degree of organic pollution causes
the death and decay of Myxophyceae and this will accelerates the bloom of Franceia
ovalis. Bharathi and Hosmani (1977) studied the ionic composition of 16 lakes of
Hassan and Chitradurga districts. Santini and Savatore (1979) studied the
distribution of phytoplankton in three lentic water bodies of Brasilica(Italy) and
reported profound effects of the levels of phosphorus on chlorophyll content of
algae. The significant contribution to fresh water ecology has been made by Bharathi
Singh and Swarup (1979) who made limnological studies of Surah lake (Ballia) with
special reference to periodicity of phytoplankton. The other noteworthy publications
in the field of Indian limnology were those of Goel et al. (1980) who studied the
impact of sewage on fresh water ecosystem and Hosmani and Bharathi (1980) using
Palmer pollution indices reported algae may be used as polluton indicators in fresh
water bodies. Rekha Purohit and Singh (1981) studied on the physicochemical
aspects of Nainithal Lake.
Significant quantum of research work was done in this field during 1981 to
1990. Archibald and Lee (1981) established the fact that the ratio of inorganic
nitrogen to orthophosphate is indicative of algal growth limiting factor. Rai and Hill
(1982) classified the central Amazon lakes using the physicochemical and
microbiological parameters. They classified the lakes as oligotrophic and eutrophic
based on electrical conductivity, pH, dissolved oxygen, silica, phospahte content and
bacterial density. Barroin et al. (1982) investigated the physicochemical aspects of a
eutrophic water body, the lake Lemen, France. Hosmani and Bharathi (1982)
classified the water bodies using various algal populations. Prasad and Yashpal
Singh (1982) studied the indicator organisms of water pollution. Mohanty (1983)
also reported algae as indicators of pollution. Other important publications on lentic
water bodies include the investigative works on Lalpuri Talab at Rajkot by Kaul and
Siddarth (1983); the works on desmids of Karnataka and Goa states by Bharathi and
Hegde (1983). Schroeder et al. (1983) recorded the biogenic calcium carbonate
production in an oligotrophic lake in Austria. Forsyth et al. (1983) studied on
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limnological aspects of Roangaio Lake of Newzealand. Koshel et al. (1983) reported
that calicite precipitation decreases the phytoplankton population, dissolved oxygen
and total phosphate in the lake of Breiber, Lucin, Germany. Raina et al. (1984) made
a detailed study of water quality and reported that biological oxygen demand values
indicated that the water was not heavily polluted, but nutrient elements play an
important role in determining the trophic status of the water bodies. Bhatnagar
(1984) studied the limnology of lower lakes of Bhopal with reference to sewage
pollution and eutrophication. Zutshi et al. (1984 and 1988) worked on eutrophic
gradient in Dal Lake and concluded that the low dissolved oxygen may be due to
increased rate in the decomposition of organic matter by microbes and low pH
during summer may be due to conversion of carbon dioxide in to carbonic acid.
Chandra et al. (1984) reported the total absence of plankton occurred due to acute
toxicity of the combined effluents having toxic constituents of chlorine and mercury.
Dakshini and Gupta (1984) made an ecological survey of three lakes of Delhi. Chan
(1985) studied the effects of water pollution on the flora and fauna of a fresh water
pond at Aligarh. He reported that chlorophycean members were dependent on
nitrates, diatoms were controlled by phosphates while the excess growth of
Microcystis aeruginosa, which is an indicator of eutrophic nature of pond stimulated
the growth of Euglenaceae and Bacillariophyceae. Hosmani and Mallesha (1985)
reported algal species as indicators of water pollution. Kanungo et al. (1985) made
observations on the physico chemical characteristics of some ponds of Raipur city.
Khan (1985) published algal flora of Sultanpur and reported 79 species of aquatic
algal taxa comprising Cyanophyata, Rhodophyata, Xanthophyta, Chlorophyta and
Euglenophyta. Puttaiah and Somashekar (1985) studied the limnological aspects of
Mysore city ponds. Sharma et al. (1985) reported 2 species of Pediastrum from
Gwalior. Chaturvedi (1985) published the diatom flora of Bareilly district and
reported 53 species of diatoms and 46 taxa of desmids.Chaturvedi (1985), Sharma et
al., (1985), Hegde and Bharathi (1986) while studying fresh water ecosystems
reported the presence of various species of algae. Sharma et al.,(1986),Chitranshi
and Bilgrami (1986) have studied the lentic water ecosystems and discussed on the
importance of physicochemical characteristics of water in relation to the distribution
pattern of phytoplankton. Hegde and Bharathi (1986) investigated the euglenoid
blooms in relation to physicochemical characters in ponds and lakes of Dharwar.
14
Srivastava and Sen (1987) while studying fresh water algae of Narmada River near
Jabalpur reported 64 new forms. These studies reported new algae from different
parts of India.
Singh (1987) during his investigations on Ox-bow lake found that high
temperature coupled with higher concentrations of phosphorus enhances the rate of
reproduction of Microcystis aeruginosa. Puttaiah and Somashekar (1987) reported
that high concentrations of carbon dioxide and low concentrations of oxygen are the
causes for abundance of Euglenoids in fresh waters of Mysore. Singh and Mahajan
(1987) discussed the role of temperature, nitrate and phosphorus on plankton
variations in lakes of Himachal Pradesh. Similarly Kurata et al., (1987) studied
seasonal changes of various physicochemical parameters in lake Notoro Hokkaido,
Japan. Other publications include June and Fred (1987) who studied
physicochemical and biological characteristics of lake Sharpe, South Dakota, USA.
Zusti and Khan(1988); Anand (1988); Bhattacharya (1988); Saifulla et al.,(1988)
who did a lot of work on chemical composition of standing water bodies. They
concluded that physicochemical characterization of water significantly affect the
algal population and they emphasized the importance of PH, total alkalinity, Co2
content of water on the sucession of phytoplankton leading to eutrophication.
Hosmani (1988) studied seasonal changes in phytoplankton community in fresh
waters and found that blooms of Franceia ovalis, Euglena elastica, Euglena gracilis
and Trachelomonas charkoweinsis had a significant effect in reducing the number of
species in ponds. Tripathy (1989) recorded maximum diatom population during
summer and monsoon.
Khatavar et al. (1989) established the relationship between phytoplankton
and some nutrients especially during summer months. They reported the
concentration of chloride, sulphate and organic carbon plays a vital role in
accelerating the blooms and they also showed that phosphorus concentration has a
profound effect on bloom formations. Similar observations were made by Ahluwalia
(1989), Srivastava et al., (1989), Gosh and George (1989) and Varadaraj and
Ayyappan (1989). Though many studies have been conducted on fresh water
ecosystems during 1990-91, most of them were concentrated on algal systematics.
15
Some of the reports were those of Naik and Hegde (1990) at estuary of the river
Sharavathi, Mathur and Pathak (1990) on rock shelters, Srivastava and Othawani
(1990) from semi arid region of Rajasthan. Ashok kumar and Patel (1990) studied
desmids of Gujarath and reported 32 taxa of Cosmarium from different fresh water
habitats. Ibrahim Banat (1990) studied productivity of algae in waste water
treatment plants. Ikonnikov(1990) pointed out the problem of toxic pollution of
Ladoge lake in Russia and suggested that increased discharge of toxic substances in
to the lake has caused water quality deterioration, changes in species composition
and other deterious effects on the aquatic ecosystems. Various scales for
determination of trophic state of water on the basis of phytoplankton biomass and
chlorophyll levels has been presented by Trifonova (1990).Naganandini and
Hosmani(1990) studied certain inland waters of Mysore district and found that the
cyanophycean bloom was dominated by Microcystis aeruginosa. They reported the
influence of dissolved organic matter, carbon dioxide, phosphorus, calcium,
dissolved oxygen coupled with death and decay of Spirulina nordestedtii. These
observations were supported by Swarnalatha and Narasing Rao (1991) who were in
the opinion that cyanophycean blooms are indicators of pollution. Surendra kumar
and Sharma (1991) in their studies on Picchola Lake pointed out that the trophic
level of water rises due to high electrical conductivity, pH, total alkalinity and
nitrates. Molot and Dillon (1991) discussed nitrogen phosphorus ratio in relation to
chlorophyll production in the lakes of central Ontario. Some of the works of this
kind include study of the distribution of phytoplankton and water chemistry of fresh
water bodies near Srinagar by Sarwar and Wazir (1991); investigation on periodicity
of planktonic algae by Kaushik et al., (1991); functional interaction between
phytoplankton and zooplankton in Green Bay lake by Sagar and Richman; study of
seasonal diversity of desmids in lakes of Denmark by Nyagard (1991).
Nirmalakumari (1991) did biochemical studies on river Moosi, Hydearabad
and reported glycolic acid and total carbohydrates was maximum during summer
when the Chlorella vulgaris dominated in the water. Choudary (1991) noticed that
optimum diversion rates of pH and temperature had a profound influence on
diatoms. Jyothi et al., (1992) studied Cyclotella bloom and found higher
concentration of chlorides, phosphates and organic matter during the bloom. The
16
succeeding contributions to the field of limnology were, Vaisya and Adoni (1992)
who studied Sagar Lake and inferred that lake had become hyper eutrophic due to
unbalanced physical and chemical parameters. The other similar researches carried
out includes the study on cyanophycean bloom by Swarnalatha and Rao (1992);
study of lake near Marma Goa by Borker et al., (1992). Adhikari and Sahu (1992)
studied the Chilka Lake and concluded that temperature above 20oc along with
alkaline pH was responsible for Trichodesmium bloom during summer months.
Belsare et al., (1992) studied on numerical and volumetric variation in plankton
population of a polymictic trophical lake in Bhopal; Biswas (1992) recorded
phytoplankton periodicity in Ogelube Lake, Nigeria and reported maximum density
of desmids during summer. Dixit et al.,(1992) conducted extensive studies on
diatoms and revealed that they can be used as bio indicators for a variety of aquatic
issues including lake acidification, eutrophication as well as climate changes.
Mohapara and Mohanty (1992) determined the water quality of two water bodies
using algal bioassay method and reported that Chlorella was found more efficient
than Anabaena in reducing nutrient load and pollution. Jones et al., (1993) studied
water chemistry and trophic status of 8 lakes in Costa Rica. Parvateesham and
Mishra (1993) studied algae of Pushkar Lake including the pollution indicating
forms. Rao et al., (1993) classified Ooty Lake as eutrophic based on the nutrient
status and phytoplankton production. Swarnalatha and Narasing Rao (1993) studied
Banjara Lake, Hyderabad and described the various factors responsible for the
appearance of the bloom Microcystis aeruginosa. Heckey (1993) concluded that
nutrient loads to lakes are mainly due to atmospheric deposition and land run off
which accounts for 90% of phosphorus and 94% nitrogen input in to the lake.
Shaji and Patel (1994) studied phytoplankton ecology of a polluted pond at
Anand, Gujarat and reported that temperature, total alkalinity, dissolved oxygen,
calcium, chlorides, nitrates, phosphorus and silicon have profound effect on algal
flora. Khan and chowdhary (1994) investigated the physical and chemical limnology
of Lake Katpai, Bangla Desh; Uman and Jimeaney (1994) studied basic limnology
of a lake at Costa Rica.Changes in physico chemical environment of water causes
significant changes in the phytoplankton community structure. Flores and Barone
(1994), Uku and Mavuti (1994) showed that this process results in the domination of
17
zooplankton communities such as rotifers and small bodied cladocerons. Lehman et
al., (1994) observed increase in chlorophyll.a concentration of algal blooms during
rainy season. Bratli (1994) studied the lake Froylandsvatn, Norway and pointed out
that phosphorus input results in frequent blooms of blue green algae which in turn
produce toxins. Mc Cormic and Cairns (1994) studied water bodies of Florida and
showed that algae can respond rapidly and predict the presence of wide range of
pollutants that can be used as warning signals in water quality determination.
Miyajima et al., (1994) reported higher diatom population and biogenic composition
of silica in an eutrophic water body, the lake Biwa, Japan. Swarnalatha and Narasing
Rao (1994) while investigating two ponds observed that the pond which experiences
continuous bloom of cyanophyceae was more polluted and the pond that supported
more desmids was less polluted. Bairagi and Goswamy (1994) also reported the
similar observations. Goel et al.,(1994) reported the dependance of blue green algal
dominance on phosphorus and nitrogen ratio.
There were few publications in this field during 1995, which include the
works of Agbeti and Smol (1995) who studied physicochemical and biological
characteristics of high mountain lakes. Pandey et al., (1995) studied the seasonal
abundance of phytoplankton in relation to ecological conditions in the stretch of
Cosi River. Das and Verma (1996) studied algal flora of Chitwan and Nawalpoosi
districts of Nepal. Anna-lisa Holopainen et al., (1996) studied the trophic state of
Lake Ladoga and their relation to phytoplankton. Boris et al., (1996) surveyed the
toxicity of cyanophycean blooms in the same lake and found that Anabaena
circinalis, Anabaena flos-aquas, Anabaena lemmermani, Gloeotrichia cichimilata,
Microcystis aeruginosa and Oscillatoria species are the causative species for such
toxic blooms. Ravikumar and Puttaiah (1996) studied ecology of lakes of Hassan
district. James and Havens (1996) investigated the occurence of algal blooms in
lakes of Okeeccobes, Florida and they found that the occurrence of these blooms is
strongly and positively related to nitrogen and total phosphorus concentrations.
Hosmani and Vasanthkumar (1996) studied biochemical aspects of water pollution
and inferred that Kukkarahalli Lake is highly productive in terms of biochemical
products whereas Dalvoi Lake is productive in terms of plankton.
18
The seasonal variations in the physicochemical parameters like dissolved
oxygen, chloride, salinity and planktonic composition of Kurichi pond were studied
by Arivozhagan et al.,(1997). Takano and Hino (1997) from their studies on an
hypertrophic lake Barato, Japan concluded that high temperature promotes the
growth of diatoms. Iqbal Habib and Chaturvedi (1997) made a systematic study of
chlorococcales at Ramanagar, Kumaun Himalayas. They reported 18 taxa of
chlorococcales. Hosmani et al., (1997) studied the occurrence of Euglena sanguina
and reported that temperature above 26o C, high pH, carbon dioxide, albuminoid
ammonia, phosphate with low concentrations of carbonates, nitrates and free
ammonia accelerated the bloom. Other such reports were those of Swarnalatha and
Narasing Rao (1998), Pandey et al., (1998) who are of the opinion that inflow of
nutrients and consequent algal growth deteriorates the water quality. Correl (1998)
discussed the role of phosphorus in the eutrophication of lake, which results
in the excessive production of autotrophs mainly cyanophycean members.
Arvind et al., (1998) studied correlation coefficients of some physicochemical
parameters of river Thungabhadra, Karnataka. Singh et al., (1998) investigated the
hydrobiology of some eutrophic ponds of Rohtas, Bihar. Taar et al., (1998) made
ecological studies in water bodies of Nagapur. Wani (1998) studied the seasonal
dynamics of phytoplankton in Himalayan lakes and reported that the diatoms were
the most represented species. Seema et al., (1999) studied eutrophic status of some
lakes in Amaravathi district. Chidambaram (1999) conducted biochemical
evaluation of coastal aquaculture using marine cyanobacteria and observed the
continuous bloom as an indication of pollution and eutrophication of coastal water.
Borse and Bhave (2000) studied the influence of temperature on dissolved
Co2 and pH. They reported higher level of Co2 in summer and lower level during
winter and it was depended on carbonates and bicarbonates in water. Nandan et
al.,(2001) worked on Hartala lake of Jalgaon district of Maharastra and inferred the
abundance of blue green algae was due to higher concentration of dissolved Co2,
carbonates, total alkalinity, chlorides and phosphates. Noor Alam (2001)
physicochemical parameters of a pond at Hatwah, Bihar and recorded variations in
free Co2, dissolved oxygen, pH and alkalinity and suggested measures to prevent
deterioration. Rajkumar (2001) studied the seasonal distribution of plankton in a
19
fresh water pond of Pollachi, Tamil Nadu. He reported the minimum numer of
phytoplankton during the winter months. Anilkumar et al., (2001) studied the
important factors of organic pollution which affect primary productivity in wet lands
of Jarkhand. Variations in the level of phosphorus and Co2 in Ambegosale lake was
studied by Madhuri Pejavar et al., (2002). Nagarathna and Hosmani (2002) studied
the factors influencing the bloom of Nitzschia obtusa in a polluted lake. Correlation
matrix and cluster analysis indicated that most of the physicochemical parameters
were inversely proportional to the growth of diatoms. Karthikeyan et al., (2002)
studied the physicochemical, biological and bacteriological study of Kadathur canal
water of Amaravathi River, Tamil Nadu and concluded that all the parameters are in
high level and the water is unsuitable for drinking and irrigation purposes. Mamatha
Rawath and Jakhoy (2002) conducted limnobiological study of a few reservoirs of
Jodhapur, Rajasthan and reported that they had low DO and the quality of water was
poor.
Carvalho and Kirika (2003) reported a decline in inflow of nutrients reduces
phosphorus concentration in lakes which in turn reduces phytoplankton biomass.
Xie et al., (2003) reported persistent coincidence between the occurrence of
microcystis bloom and that of phosphorus in an enclosure experiment in a Chinese
lake. Bozena Bogaczewicz-Admczak et al., (2003) have used the OMNIDIA
softwatre to calculate diatom indices to assess water pollution in the Puck bay of
Southern Baltic Sea. Jutner et al., (2003) used diatom indices to assess water quality
in Kathmandu valley and middle hills of Nepal and India. Poulickova (2003) has
studied the indicator role of diatoms in the littoral regions of eutrophic shallow lakes
in the Czech Republic. Maria José Dellamano-Oliveira et al., (2003) studied
limnological characteristics and seasonal changes in density and diversity of the
phytoplanktonic community at the Caco pond, Maranhao state, Brazil. They
recorded highest number of cyanophyceae and chlorophyceae groups during rainy
and dry seasons. Ariyadej et al., (2004) studied phytoplankton diversity and its
relationships to the physico-chemical environment in the Banglang reservoir, Yala
province. They found that light limitation by high turbidity is another factor that
frequently controls phytoplankton growth either during the whole year or seasonally.
Indicator role of diatoms is studied by Poulickova et al., (2004) in Austrian Alpine
20
lakes and Blanco et al., (2004) in the Spanish lakes. Mahadev and Hosmani (2005)
made an extensive study of Langlier’s index and its relation to fresh waters. They
found that phytoplankton growth in saturated waters had a tendency of changing the
pH of the water. Nandan and Aher (2005) studied algal communities for the
assessment of water quality of Haranbaree dam and Mosam river of Maharashtra
and recorded 22 pollution tolerant genera of phytoplankton. Algal biodiversity in
fresh water and the related physicochemical parameters were studied by
Veereshkumar and Hosmaini (2006). They inferred that occurrence of desmids in
fairly good numbers is an indication that the lakes are oligotrophic and are tending
to become eutrophic and they were also depended on high temperature, pH and
bicarbonates.Moreno-Ostos et al., (2006) studied spatial distribution of
phytoplankton in thermally stratified Andalusian reservoirs, Spain. They showed
that thermally stratified reservoirs are dynamic, complex and heterogeneus
ecosystems.
Anithadevi and Singaracharya (2007) studied the phytoplankton of lower
Maniar Dam and Kakathiya canal, Karimnagar, A.P. They concluded that
chlorophyceae and bacillariophyceae are the indicators of a healthy ecosystem while
cyanophycean members indicate the bad quality of water. Ranjani et al., (2007)
made hydrobiological studies on physicochemical parameters of Ghariyarwara pond
of Birganj, Nepal. They found the dominance of chlorophyceae throughout the year
and seasonal occurrence of other phytoplankton. Bhuian and Gupta (2007)
conducted comparative hydrobiological study of few ponds of Barak Valley, Assam.
They inferred that quality of an aquatic ecosystem is dependent on physicochemical
qualities of water and also on the biological diversity of the water body. They
reported the highest dissolved oxygen and nearly neutral pH in the water body was
due to the diversified plankton population. Tas and Gorulol (2007) studied the lake
Cemek, Turkey. They observed the lake supported about 104 taxa of cyanophyceae,
bacillariophyceae, chlorophyceae, cryptophyceae, dinoflagellates and
xanthophycean members among which bacillariophyceae and chlorophyceae were
dominant. Tiwari and Shukla (2007) while studying temporary water bodies of
Kanpur observed high values of alkalinity, phosphate, ammonia and chloride which
indicate the eutrophic nature of these water bodies. Mathivanan et al., (2007)
21
conducted pollution assessment of Cauvery River with reference to pollution in
Annamalainagar, Tamil Nadu. They observed fluctuations in the occurrence of
phytoplankton and their productivity was high during June and low during
December. They further noticed that the productivity was depended on temperature,
turbidity and nutrients. Manikya Reddy (2007) studied on algae as ecological
indicators for the assessment of water quality in Hyderabad. He observed that
benthic algae will serve as indicators in lotic waters and bacillariophyceae dominates
the benthic group. Jose John and Francis (2007) investigated on the algal flora of
Thoduouzha taluk, Kerala, India. Yogendra and Puttaaiah (2007) reported that BOD
and COD demand decreases with the increased nitrogen due to nitrification process
of water. Dhembare (2007) studied physicochemical parameters of Mula Dam water
in Ahmadnagar and observed the role of calcium on the aquatic flora. He also noted
phosphates causes eutrophication of water bodies. Venkata Subramani et al., (2007)
while studying lakes of Bodham, reported chloride as indicator of pollution and also
opined that increase in sulphate in water was due to discharge of sewage. Khare et
al., (2007) have studied water quality at Komph-Niwari Lake at Chhatarpur, Madya
Pradesh. They observed that dissolved oxygen level of water constantly changes due
to organic matter. Smitha et al., (2007) reported that the high sodium levels
contribute to salinity problems and can interfere with mg++ and ca++ availability.
Taylor et al., (2007) conducted diatom studies of Vaal river, South Africa. They
opines that diatom communities, when analysed, provide an accurate assessment of
water quality, but these diatom communities also provide an integrated reflection of
past water quality. Ewelina Szczepocka (2007) while studying diatoms of Bzura
River, Poland observed the appearance of pollution sensitive diatoms which were
not found earlier and concluded that the regeneration process of this aquatic body
started with the liquidation of local industry, primarily textiles and the construction
of several dozen sewage treatment facilities in major towns and at larger industrial
plants located along the course of the river.
Shamsul Islam M (2008) studied phytoplanktonic diversity index with
reference to Mucalinda Sarovar, Bodh Gaya and classified it as mildly polluted
based on Shannon and Weaver’s diversity index. Sivakumar K and R. Karuppasamy
(2008) made the study on physicochemical parameters and their effects on plankton
22
productivity with reference to increase in fish productivity in the selected areas of
Cuddalore district, Tamil Nadu. They observed the decrease in nutrients after high
productivity of phytoplankton. Hosmani (2008) studied the ecology of Euglenaceae
from Dharwar and reported that they responded to high temperature, oxidisable
organic matter and low concentration of dissolved oxygen. Taweesak Khuantrairong
and Siripen Traichaiyaporn (2008) studied diversity and seasonal succession of the
phytoplankton community in Doi Tao Lake, Chiang Mai Province, and Northern
Thailand. They found phytoplankton communities had the highest and lowest
Shannon-Weaver diversity indices in the winter and summer seasons respectively.
Pramila Kumari et al., (2008) conducted bio monitoring of plankton to assess quality
of water in the lakes of Nagpur city.
Basavarajappa et al.(2009) studied the water quality parameters of four fresh
water lakes of Mysore based on CCME WQI. Arvind Kumar and Varma (2009)
studied the spectrum of plalnkton abundance in certain lotic eco systems of
Jarkhand, India. Ayoade et al., (2009) studied two regulated high altitude rivers of
Garhwal, Himalaya, India and reported higher planktonic population density and
fauna diversity in lentic portion of Tehri dam reservoir area is due to favourable
environment unlike the riverine zones where fast current and higher turbidity affect
the growth. The least fauna diversity and density below the dam (downstream) may
be due to wide fluctuation in the water level brought about by flow regime of water
from reservoir as regulated by authority. Hasan Kalyoncu et al., (2009) used diatoms
for the assessment of water quality in two streams of South Turkey. They reported
that Darıoren stream was not polluted while the sampling sites on Isparta stream was
polluted. They concluded that diatom assemblages were useful for assessing the
stream ecological status. Joanna Żelazna-Wieczorek and Maciej Ziułkiewicz (2009)
have used benthic diatoms for the assessment of spring water quality in suburban
areas of Poland and they found that the selected diatom indices for determination of
the quality of the spring water does not reflect changes in the quality of the studied
springs. Devi Prasad et al., (2009) studied the fish diversity in major wet lands of
Mysore. Rajashekhar et al., (2009) studied zooplankton diversity of three
freshwater lakes with relation to trophic status in Gulbarga district, North-East
Karnataka. Chaiwat Prakirake et al.,(2009) attempted to develop a specific water
23
quality index for water supply in Thailand. Silvia Tavernini et al., (2009) studied
trophic state and seasonal dynamics of phytoplankton communities in two sand-pit
lakes of Italy.Ma Roselia et al., (2009) by studying phytoplankton diversity and
strategies in regard to physical disturbances in a shallow, oligotrophic, tropical
reservoir in Southeast Brazil, concluded that Intermediate Disturbance Hypothesis
(IDH) is a powerful mechanism towards understanding the complex phytoplankton
structural changes under spatial and temporal scales and thus to proceed towards
predictability.
Sawanth et al., (2010) made limnological study of Atyal pond in Kolhapur,
Maharatra and reported the pond is rich in nutrients and has become eutrophic.
Aiyaz et al., (2010) studied the biodiversity index of algal flora in Wular Lake,
Kashmir and reported significant correlation between diversity, conductivity, carbon
dioxide, total hardness and nitrate. Shinde et al., (2010) studied seasonal variations
in physicochemical characteristics of Morsool Savangi Dam, Aurangabad district,
India. They reported that water is fit only for fish culture. Hosmani (2010) made an
extensive study on phytoplankton diversity in lakes of Mysore district and reported
the uniform distribution of algal species and low in diversity with in the population.
Bhosale et al., (2010) dealt with the diversity of plankton in water bodies of Miraj
Tahsil, Maharastra. There were great variations in the physicochemical complexes
as well as the phytoplankton population. Elif Neyran Soylu and Arif Gonulol (2010)
studied seasonal succession and diversity of phytoplankton in a eutrophic lagoon
(Liman Lake). Edokpayi et al., (2010) attempted to assess temporal fluctuations in
water quality of the coastal waters of Training Mole, Tarkwa Bay, Nigeria. They
observed the distribution of dissolved inorganic nutrients may be very much
influenced by factors like tidal and physical stirring by currents and benthic
invertebrates as well as drainage discharged from industries and human settlement
around the Training Mole. Ingole et al., (2010) studied phytoplankton of Fresh
water reservoir at Majalgaon. Mukherjee et al., (2010) studied plankton diversity
and dynamics in a polluted eutrophic lake of Ranchi. They observed no limiting
nutrient as such in the lake to control the growth of organisms. One of the reasons to
define such dynamics is the low availability of free carbon dioxide. Siddaraju et al.,
(2010) assessed the water quality of Arakere and Thaggahalli lakes of Mandya
24
district, Karnataka using NSFWQI. They categorized water of both the lakes as bad
to medium. Sharma et al., (2010) used Carlson’s trophic state index for the
assessment of trophic state of Mansi Ganga Lake at Mathura and classified the lake
as eutrophic.
Ravikumar and Puttaiah (2011) studied the physio-chemical status of four
fresh water bodies of Hassan District, Karnataka. Siddaraju and Devi Prasad (2011)
have used the epiphytic diatoms as ecological indicators to assess the water quality
of two lakes of Mandya. As per the diatom indicators the water of the lakes were
classified as hyphoeutrophic. Offem et al., (2011) studied the influence of seasons
on water quality, abundance of fish and plankton species of Ikwori Lake, South-
Eastern Nigeria. They recorded more number of species during dry season than the
wet. Sharma Riddhi et al., (2011) carried out studies on limnological characteristics,
planktonic diversity and fishes in Lake Pichhola, Udaipur, Rajasthan (India). They
observed a high rate of primary production, diversity of phytoplankton, zooplankton
and fish species. Shaaban et al., (2011) studied the relationships between total
chlorophyll and phytoplankton individuals of Rosetta branch of river Nile, Egypt.
They found positive relationship between the fluctuations of total chlorophyll
contents of the phytoplankton and those of total number of individuals.
Umamaheshwari (2011) studied algal biodiversity in a group of fifteen small lakes
of T. Narasipur taluk, Mysore district. Bere & Tundisi (2011) conducted diatom
based water quality assessment in streams influenced by urban pollution using
natural and two selected artificial substrates. They found that the use of a natural
substrate is better compared to artificial substrate.
Hosmani and Mruthyunjaya (2012) studied the distribution of phytoplankton
in four lakes of Tirumakudal Narasipura of Mysore District. They found abundance
and blooms of cyanophyceae and bacillariophyceae indicating their tendency of
Lakes becoming eutrophic. Shivanna et al., (2012) conducted water quality
assessment of six selected tank waters for irrigation in Tiptur taluk, Karanataka and
found that no water sample in the study area is ideal for irrigation. Vijayvergia
(2012) studied Udaisagar lake of Udaipur city with reference to its physicochemical
environment. Sana Akhtar and Mohammad Nawaz (2012) studied Impact of Water
25
Quality on Aquatic Life in River Ravi, Pakistan. Divya and Rakhi (2012) conducted
Assessment of Water Quality in Terms of Total Hardness and Iron of Some
Freshwater Resources of Kanpur and its Suburbs. Siddaraju and Devi Prasad (2012)
assessed the water quality of two lakes of Mandya using CCME water quality index
and categorized the water of both the lakes as poor quality. Krishna et al., (2012)
studied physico chemical and bacteriological parameters of Kaveri river at
Talakaveri region and recorded maximum of 21 MPN count per 100ml during
summer. Akshatha (2012) has assessed the water quality of a polluted pond at
Mysore using NSF water quality index. Siddaraju and Devi Prasad (2012) recorded
the increased diversity of phytoplankton in two lakes of Mandya during summer and
inferred that it may be due to increased nutrients level in water. Sarma and Dutta
(2012) studied the two riverine wetlands of Goalpara district, Assam. Alaka et al.,
(2012) studied the phytoplankton diversity in perennial reservoirs of dry tahsils of
Sangli district, Maharashtra. They found that the phytoplankton diversity is mainly
influenced by seasonal conditions and anthropogenic activities in the reservoir.
Hosmani (2012) studied the ionic composition of and its implications on aquaculture
in Hadinaru Lake and concluded that the lake water is not suitable for aquaculture.
Sitre (2012) studied the biodiversity of rotifers in Ambazari lake of Nagpur city with
respect to water quality. He observed the seasonal rotifer biodiversity which showed
peak in density and diversity during summer season, while lower values were
recorded during rainy season.
Although more than 400 references have been made during this study some
of the literature review pertaining to sub chapters has been discussed at the
respective topics to avoid redundancy and references have been quoted at the end of
the thesis. As limnology comprises physical, chemical and biological aspects of
aquatic water bodies comprehensive research papers on fresh water biota have been
published occasionally. Some researchers have gave more emphasis on physico
chemical factors of the water body, some have concentrated on unicellular and
colonial phytoplankton while others have discussed about the causes of pollution,
interrelationship between the nutrient concentration and the occurrence of algal
blooms in the water bodies. In recent years statistical approach and multivariate
analysis have been done and precise conclusions have been drawn.
26
Nowadays a vast number of research journals have been published both at
national and international levels. Based on the records that could be procured
through various agencies as well as referring to various literatures available in the
subject, it has been possible to obtain the present data. It has provided sufficiently
high percent of references to constitute the review of literature. But avoiding too
early data and taking in to account the references available from (1900) to the
present day (2012); the review has been done.
Figure 2.1 References during 1901 to 2012 (% Values)