CHAPTER 2: REVIEW OF LITERATURE - Shodhgangashodhganga.inflibnet.ac.in/bitstream/10603/35936/8... · 2018-07-02 · REVIEW OF LITERATURE 10 2.1 Study of Inland Freshwater - Origin

REVIEW OF LITERATURE

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CHAPTER 2: REVIEW OF LITERATURE

2.1 Study of Inland Freshwater - Origin and Development ........................................................ 10

2.2 Studying Tropical Lakes - less ice and more biological complexity ..................................... 12

2.3 Lake Studies in India ................................................................................................................... 13

2.4 Diatom Studies Worldwide ........................................................................................................ 15

2.4.1 Taxonomy ......................................................................................................................... 15

2.4.2 Benthic diatoms and its habitats .................................................................................... 16

2.4.3 Diatoms as Bioindicators ................................................................................................ 17

2.4.4 Development of Diatom Indices ................................................................................... 20

2.5 Temperate v/s Tropical Diatom Research .............................................................................. 24

2.6 Diatom Research in Lakes ......................................................................................................... 25

2.7 Diatom research in India ............................................................................................................ 26


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2.1 Study of Inland Freshwater - Origin and Development

Exploration during 15th through 18th centuries initiated the origin of lake studies-

“Limnology” which also bought tremendous advances in scientific knowledge (National

Research Council, 1996). Early limnological studies conducted by limnologists, perceived

studies mainly related to physical properties of lakes (Hutchinson, 1967); however it was

not earlier than mid-19th century when limnological science combined biology, physics, and

chemistry of inland waters (rivers, streams and lakes). Francois A. Forel (1841-1912)

during one of his earliest observations in Lake Geneva coined the term “Limnology”

(from Greek, limnee = "lake" and logos = “knowledge”) and with his long series of papers

(1892-1904) discusses about lake benthic fauna, their significance to the fish population

with modern concepts of ecosystem ecology (National Research Council, 1996).

Even before the term Limnology was coined, Stephan Forbes (1887) had described lakes

as ‘Microcosms”. He included lake study in various fields: mineral cycling, production and

decomposition of organic matter, food web interactions and the effects of physical

conditions on biological communities. 18th century also had pioneers in limnological

science like William Baird and William Phillip, both possessed extraordinary expert in

microcrustaceans and algal blooms respectively. Lake studies have often been made for

specific region/ community, later it was extended to every geographic region, establishing

many field stations (also called as bio-stations), and information collection on individual

lakes by prominent limnologists, combined at the regional scale. Development in the field

of limnology rapidly expanded in early 1900s when German Zoologist August

Thienemann and Swedish botanist Einar Naumann co-founded “The International Society

of Limnology”. This gave rise to the rich tradition towards limnological studies in

University of Wisconsin, North America that continued over 100 years till to day.

Information on physical, chemical and biological properties of lakes was utilized for

descriptive water quality monitoring studies. Water quality indicators such as physical

measure (transparency), chemical concentrations (of nutrients), and biological

characteristics (species types and abundance and primary production) were used to classify

lakes according to their overall nutritional status and productivity.


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During the second half of 20th century, increased funding for pollution studies of

freshwater bodies has drawn scientists from varied fields to limnological research.

Raymond Lindeman (1942), an aquatic ecologist advanced to ecological principles based

on energy flow through food chains. In 1942, the trophic-dynamic concept emphasized

the importance of short-term nutritional functioning to an understanding of long-term

changes in the lake community dynamics. In 1960s G. Evelyn Hutchinson contributed a

monumental treatise on limnology (in four volumes) that demonstrated concepts in

biogeochemistry of lake ecosystems. Odum in 1970 examined microcosm’s experimental

ecology for understanding diurnal oxygen method for measuring primary production and

several large-scale experiments in tropical rain forests (Odum and Pigeon, 1970). In 1971,

Convention on wetlands known as “Ramsar Convention” an intergovernmental treaty was

introduced to provide a framework for conservation and sustainable use of wetlands

resources. According to Ramsar convention all inland water bodies (lakes, rivers, ponds

and so on) were considered as “Wetlands” that gained worldwide recognition. At the same

time, Clean water Act in 1972 introduced amendments to Federal Water pollution control

Act in United States of America primarily focusing on reducing water pollution from point

sources such as sewage and industrial discharges. As it advanced to 1980s, many lakes and

wetlands were investigated for management aspects and many were recorded as polluted

due to the expansion of human settlements, increased population and increased water use

for various purposes. This led to degradation of water bodies, conditions extending

beyond the pollution sources (primarily direct wastewater discharges into lakes and

wetlands); they include various diffuse pollution sources, as well as a variety of physical

stresses that directly or indirectly affect aquatic habitats. In 1994, National Research

Council of United States of America (USA) appointed an expert committee, the committee

of Inland Aquatic Ecosystems, to recommend ways to strengthen limnological programs

within USA educational institutions. It reviewed the history of limnology, and its role in

solving contemporary water problems and recommends improved ways to educate future

limnologists. Lake studies in 21st century initiated the regular use of biological organisms as

indicators for the water and wetland management with the establishment of United States’

Environmental Protection Agency (EPA) - National water quality and Assessment

programs. Conquering the traditional chemical monitoring approach, biological

monitoring using aquatic organisms such as invertebrates, fish, macrophytes and algae


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gives a better view of ecosystem integrity as they represent result of long term dynamic

processes, degradation and restoration of an ecosystem (Duran and Suicmez, 2006; Solak

and Àcs, 2011).

2.2 Studying Tropical Lakes - warm and complex

Tropical studies lag behind from that of temperate regions, which by 1900 emerged as an

expert study by pioneers in Limnology (Talling and Lemoalle, 1998) and Melack, 1996 and

Talling and Lemoalle, 1998 narrates the brief history of limnological journey in tropical

regions. Limnological studies in Africa and major countries of Asia were based upon the

small expeditions focused on fisheries, with minimum knowledge on biodiversity. The

early freshwater seasonal pattern was investigated at Nyasa lake, Malawi (Fülleborn, 1900)

and Ceylon (Srilanka) lakes (Apstein, 1907), yet, it was in 1920s, when the physical,

chemical and biological components were interrelated and investigated immensely, for

instance, lakes in East Africa and Indonesia (Worthington, 1930). Methods to assess

production rate per unit area was applied to lakes of Central America and Africa (Prowse

and Talling, 1958), which later in 1960-1970 expanded towards diversity measurements of

fish, benthic invertebrates and zooplankton. In 1980, limnological surveys in tropics

captured the phase of temperate limnology followed by Biwako in 1993 (BITEX ’93) was

one among many global experiment on a lake where >70 researchers of various disciplines

(Physicists, biologists, chemists, technicians) from seven countries (Australia, Canada,

China, Israel, Japan, Spain, and the United States), participated in the water management

project (Kumagai and Robarts 1996). Later a new initiative, CRAB (Cyanobacterial Risk

Assessment of Biwako) was continued at Biwako lake basin to control the effects of

Cyanobacterial blooms (Kumagai, 2001). In late 20th century inland ecosystems in Asian

countries were immensely influenced by urbanization and pollution, along with

development of hydro-biological studies, which tend to focus on biological diversity, the

correlation between the distribution of various organisms and degree of water pollution

and the effects of various organic and inorganic pollutants on biota (Dodson et al., 2000).


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2.3 Lake Studies in India

Origin and use of lakes in Indian subcontinent dates back to mythological and monarchs

Era, but studies on the same were originated not prior to late 1900, though rulers

implemented timely maintenance of inlands waterbodies. In India selected lakes, rivers,

and estuaries were surveyed for biodiversity (algae of Himalayas by Dickie, 1882), water

quality and habitat characteristics (Annandale, 1915–24). The Yale North India Expedition

in 1932 provided a detailed limnological survey with the report on eleven high altitude

lakes in the Ladakh-Tibet region and several lakes in Kashmir (Hutchinson, 1933, 1937),

followed by Swedish Expedition to Burma in 1934. However, it was in 1955 by Ganapati,

the first paper published explaining both limnological studies in South India and new algal

taxa records. The first few years i.e., 1961-1965, research was focused on pond chemistry,

taxonomy description and discovery of new algae, fungi and other macroinvertebrate. The

trend of progress in limnology in India during 1960-1970 is evident from the increased

number of publications that appear to be identical to those in other scientific disciplines.

The Government of India enacted Water Act in 1974 (Prevention and Control of

Pollution), which was gradually adopted by the State governments. Soon, a committee for

Prevention and Control of Water Pollution were established in most of the States. Gopal

and Zutshi, (1998) reviews fifty years of hydrobiological research in India summarizes the

history of exploring biological diversity, population ecology and developmental biology

including their responses to varying physical and chemical factors and pollutants in Indian

inlands waters. Hydrobiological studies that were well developed in the beginning of this

century, gained advancement soon after independence as all kinds of aquatic habitats were

investigated for the assessment, conservation and sustainable utilization of inland fishery

resources of the subcontinent. With the opening of the National Environmental and

Engineering Research Institute (NEERI) at Nagpur and its zonal laboratories across

country, limnological research received impetus attention in central India. India became a

signatory to the Ramsar Convention on Internationally Important Wetlands in 1981. This

gradually turned the attention towards waterfowl census, monitoring other aquatic

organisms and appreciating wetland ecosystems. A National Lake Conservation Plan,

launched in 1997 by the Ministry of Environment and Forests of Government of India

identified 11 lakes for special conservation measures.


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The effects of various organic and inorganic toxic substances (herbicides, pesticides,

industrial effluents, heavy metals, and hydrocarbons) on the morphology, physiology,

biochemical composition, enzyme activities, behavior, growth and reproduction of various

aquatic organisms have become key research interest during the past two decades

throughout the country. Taxonomical and biodiversity observations of several aquatic

organisms’ like algae especially diatoms, zooplankton, macroinvertebrates and other

microbial flora predominated ever since the microscopes were introduced in India, though

the update of taxonomy and further exploration stood far behind when compared to other

developing biodiversity rich nations The Indian Council of Agricultural Research has

published a series of volumes on algal flora of India (Desikachary, 1959; Venkataraman,

1961; Philipose, 1967). During 1980s, algae have been the subjects of various intensive

limnological studies in order to record impact of heavy metals, pesticides and fertilizers

and organic pollution on species (Rai et al., 1981; Mallick and Rai, 1990; Rai and Mallick,

1993). Algae as indicators and algal biomonitoring have been effectively implemented in

water monitoring programs because their abundance reflects immediate shifts in

environmental conditions and thus pollution status is predictable (Kolkwitz and Marsson,

1908; Patrick, 1949; Potapova and Charles, 2007). Many studies demonstrated the use of

algae community structure for categorizing impact of pH, conductivity and nutrients (N

and P) in rivers and streams (Pan et al., 1996; Leland and Porter, 2000; Lavoie et al., 2003).

Among algae, diatoms are measured as potential biomonitoring tool, the easy taxonomy

and their sensitive reaction to changing environment being prominent characteristics for

ideal bioindicators. However, diatom based biomonitoring research is scarce in tropical

countries like India that represents wide range of ecosystems and correspondingly higher

biodiversity.

Diatoms of class Bacillariophyceae, accounts for one of the major eukaryotic

photosynthetic algae, recognized world-wide because of their unique silicified cell walls

(frustules), which consist of two overlapping thecae, each in turn consisting of a valve and

a number of hoop-like or segmental girdle bands (Sim et al., 2006). Diatoms are inhabitants

of every habitat on earth where water is present (wet habitats), which marks its origin from

Heterokont algae, since Jurassic period (Round and Crawford, 1981). Today, the ubiquity

and occurrence of diatoms has accomplished its wide use to unravel enormous research


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issues such as global diatom distribution (Kooistra et al., 2008), taxonomical aspects

(Karthick et al., 2011; Karthick et al., 2012a,b), ecological class (van Dam et al., 1994), their

response to environmental conditions (Alakananda et al., 2011) and land use (Walsh and

Wepener, 2009); developing diatom indices for water quality assessments (Taylor et al.,

2007); fossil diatoms in paleolimnological studies (Juggins and Cameron, 1999; Smol, 2010)

and molecular tools (Nguyen et al., 2011). This review briefs the extensive diatom research

in the areas mentioned above and elaborates the aspects of diatom research in India.

2.4 Diatom Studies Worldwide

2.4.1 Taxonomy

The expedition in the field of taxonomy was apparently started with its 1st recorded in

1703 by a fellow of the Royal society and was penned by Antonie van Leeuwenhoek, who

appears to have recorded the existence of diatoms much earlier, during the invent of

microscope itself. Later, various diatoms were described and given binomials by O.F.

Müller (1783 1786), while the advanced and improved microscopic resolution made

possible for important diatom illustrated monographs during 19th century (Grunow, Cleve,

Ehrenberg, Schmidt and Van Heurck) (Hassall, 1845). There was much more emphasis on

the research in obtaining materials for describing new taxa and to observe geographic

distribution of diatoms. It was not until 20th century that diatoms and biogeography began

to receive systematic attention and began remarkable initiative of diatom identification

literatures by Hustedt (1909; 1922; 1930; 1933; 1962; 1966). Helmcke and Krieger (1953-

54) and Krammer and Lange-Bertalot (1985, 1986, 1991) introduced photographs with

more structural details rather than hand drawings for diatom naming and identification

through electron microscopy (EM) (Koppen, 1975; Kreis and Stoermer, 1979). The

diatom research in the latter half of 20th century was diversified to record species optima

and tolerance of diatoms to sustain in various environments and was preceded with the

study of present flora, fossil diatoms and development of diatoms as bioindicators. This

aspect has increased more research in global biodiversity and the proper identification of

given taxa necessary for the effective development of diatom indices. On the other side,

the proliferation of new names has renewed the interest in diatom biogeography and

biodiversity that records autecology of generalized species (cosmopolitan), a few

discontinuities in distribution and stress upon endemism.


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2.4.2 Benthic diatoms and its habitats

The interactions and competition among often hundreds of diatom populations for

nutrient availability further shape the structure and function of the community and that

interaction to varying degree differ significantly among available habitats (Burkholder,

1996). Moeller et al., (1988) and Burkholder et al., (1999) examined phosphorus uptake for

single epiphytic cells of various contrasting attachments to the host plant. This

documented the relative importance of the plant versus the water column as a phosphorus

source. Physical characteristics such as light, substratum type, and water current differ

from one place to another and substratum type and habitat heterogeneity indeed act upon

species composition (Leland 1995; Wunsam et al., 2002; Townsend and Gell, 2005). Hence,

diatom sampling from every available habitat throughout a defined section of the stream

provides an accurate characterization of assemblages in that section (i.e. reach) (Weilhoefer

and Pan, 2007; Peck et al., 2006). Some studies suggest composite sampling approaches to

sample streams and rivers periphyton. Composite samples are performed by sampling a

particular habitat e.g., rocks at many locations randomly along transects and combining the

samples into one composite (e.g. Weilhoefer and Pan, 2007).

Diatoms specific to microhabitat signifies specific optimum conditions for survival and

put together in a community represents the immediate environment. Studies of lakes,

rivers, and other ecosystems document diatoms as powerful indicators that represent

particular habitat such as epipsammic (Krejci and Lowe, 1986; Vilbaste et al., 2000),

epipelon (Palmer and Round, 1967; Round, 1978, 1981), epilithic (Taylor et al., 2005;

Morales et al., 2007), subaerial (Rushforth et al., 1984; Johansen, 1998) and epiphytic

(Cattaneo and Kalff, 1978; Power et al., 2009). Rivers comprising majority of epilithic

habitat (Lobo et al., 2004) while epiphytic habitats dominating lakes (Blanco et al., 2007)

often act as proxies for development of region specific diatom indices. Cejudo-Figueiras et

al., (2010) tested neutral substrate hypothesis and showed significant differences in the

composition of diatom assemblages among nutrient concentrations and host macrophytes.

This supported the use of epiphytic diatoms as biological indicators for shallow lakes.

Diatoms from epipelic/ episammic are common in many ecosystems and known to be

evolved with several adaptations for successfully occupying this microhabitat (Moss, 1977).

Round (1957) has used littoral sediment diatoms to determine trophic preferences in base-


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poor lakes of the English Lake District, and in Spanish shallow lakes they were used to

assess trophic and saprobic conditions (Blanco et al., 2004). Carrick and Lowe (2007)

demonstrated that benthic diatoms in Lake Michigan living on sand (epipsammic) were

able to use sand (SiO2) as a silicon source when Si concentrations appeared to be limiting

in the water column (Si < 0.5 ppm).

Besides, a single habitat sampling such as rocks and hard surfaces are recommended in the

EU and some US programs (Kelly et al., 1998; Moulton et al., 2002; CEN, 2003, 2004). On

the other hand, artificial substratum sampling is precise when high variability in natural

habitat is apparent or when natural habitats are unsuitable/ unavailable. However, it is

expensive because it requires two separate trips to the field and because artificial substrata

are highly susceptible to vandalism and damage from floods (Stevenson et al., 2009).

Nevertheless, the diatom assemblage and its best relationships with environment are

obtained from all the three habitats at polluted and urban ecosystems (Jüttner et al., 1996;

Winter and Duthie, 2000, Alakananda et al., 2011). The subsequent indices applied provide

information on key indicator taxa and conservation of the respective.

2.4.3 Diatoms as Bioindicators

The epoch of diatom research was swerved from taxonomy towards diatom

ecology in later half of 19th century and the value of diatoms as ecological indicators of

water quality became clearer during 20th century. It was through Kolkwitz and Marsson

(1908) and, Ruth Patrick’s early monitoring studies (1949) that the account of diatoms as a

tool for assessment of environmental conditions was initiated in different ecosystems

(rivers, streams, and wetlands). The study of Kolkwitz and Marsson (1908) illustrates water

conditions determining the composition of the diatom flora based on which autecological

indices were developed. Subsequently, Patrick’s work (1949, 1954) followed by

Fjerdingstad, (1964) emphasized diatom community in the characterization of a river

quality. Later, this illustrated diatom assemblages and their worth in pollution studies,

especially in river ecosystems (Sabater and Sabater 1988; Gómez 1998; Sabater 2000;

Gómez and Licursi 2001).


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One of the major problems faced during late 20th century and in recent years was the

urbanization especially in developing countries. With an increase in anthropogenic activities

and improper water management, not only the rivers and streams, but also lakes and

wetlands are subjected to a variety of hydrological alterations more noticeably in arid and

semi-arid regions (Pan et al., 2004). The pollution sources such as sewage, effluents from

industries, agricultural runoff, soil erosion, etc. were considered as the cause for

deteriorated ecosystem health and require appropriate assessment (Steinberg and Wright

1994; Smol, 2002; Welch and Jacoby, 2004). The objective of such ecological assessment

should be to identify the cause for problem and to refine the best possible way to solve it

under given conditions. Diatoms have been frequently used as bioindicators for a large

range of applications in the environmental and earth sciences and explain the stressors

acting upon the continued ecosystem degradation (Stoermer and Smol 1999; Kitner and

Poulícková 2003; Poulícková et al., 2004; Flower, 2005; Simkhada et al., 2006). Monitoring

studies follow analyzing chlorophyll a (chl a) concentrations, ash-free dry mass (AFDM),

chemical composition, functional characteristics and taxonomic/structural composition of

diatom assemblages (listed in Stevenson et al., 2009). The basis for use of diatoms as

bioindicators is the taxonomic composition i.e., their shift in community structure, in

particular to influence of water quality variables such as pH, ionic concentrations,

eutrophication due to high nitrates and phosphates. The optima and tolerance response of

diatoms in a more integrated manner evaluate the ecosystem integrity rather than traditional

water monitoring. Studies on a combination of factors such as physical and chemical-

resolving the issue of distribution of diatom communities was carried out worldwide,

especially in Europe, Africa, Australia, Asia and America (Watanabe et al., 1988; John, 1998;

Prygiel et al., 1999; Chessman et al., 1999; Wu, 1999; Potapova and Charles, 2002; Wu and

Kow, 2002; Taylor et al., 2005) and it was demonstrated that the diatoms are preferred as

biological indicators of river water quality. In order to determine ecological status of lakes

and rivers based on the diatom distribution (as proxies of the entire phytobenthos),

DALES (Diatom Assessment of lake Ecological Status) and DARES (Diatom Assessment

of River Ecological Status) were proposed in Europe. Diatom distribution has been

documented as evidence for neutralization of acid-mine lakes (Brugam and Lusk, 1986),

rehabilitation of sand mines into artificial wetlands (John, 2003) and effect of heavy metals

in a mine tailing on diatoms (Sabater, 2000).


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Diatom community structure at spatial scale attribute to changing land use patterns of the

watershed, that were investigated focusing on increasing population (Cooper, 1995),

nutrient concentration (Potapova and Charles, 2002), riparian disturbance (Hill et al., 2000)

and decreasing species richness, evenness and diversity from agriculture / forest areas to

urban area (Bere and Tundisi, 2011). Walsh and Wepener, 2009 examined the changing

diatom assemblages to different land use of streams where, motile Nitzschia sp. was

dominant at high intensity agriculture; motile Navicula sp. was dominant at low intensity

agriculture sites and urban wetlands being occupied by most pollution tolerant taxa.

Landscape Development Intensity index (LDI) and Diatom index of Wetland Condition

(DIWC) were computed for Florida wetlands to examine landscape human disturbance and

its effect on diatom species (Lane and Brown, 2007).

The hydrated silica in diatom frustules are resistant to deterioration and could be preserved

well in archeological records for decades and hence diatom assemblages within a lake

sediment core are evidence for reconstructing past environments. Fossil diatom flora of

sediment core from lakes were described by Duthie and Rani (1967); Stoermer and Yang

(1968) and Duthie and Srinivasa (1971) and later ensued by Batterbee, 1986; Rautio et al.,

2000 and Moser, 2004. These studies utilize freshwater diatoms preserved in deep cores as

ecological biomarkers to make inferences about resource use and to locate archaeological

structures. Jiang et al., (2001) highlights the uncertainties in reconstructing

paleoenvironments based on diatom records because, present diatom flora and those

preserved in sediments would not be the same. Therefore, relationships of present diatom

flora with those of sedimentary diatoms of the region are necessary before carrying lake

reconstruction using fossil diatoms (Jiang et al., 2001; Nascimento et al., 2010). Diatom

species assemblages, their relationship to specific environmental measures (e.g. pH, salinity)

are used to derive transfer functions and outcome was interpreted by statistical techniques

such as weighted averaging (ter Braak and van Dam, 1989; Birks et al., 1990); linear methods

of Partial Least Squares (PLS) (Wold et al., 1984); Artificial Neural Networks (ANN) (Racca

et al., 2001; Gevrey et al., 2004) and multivariate analysis techniques for instance Canonical

Correspondence Analysis (CCA) (Soininen, 2002), Principle Component Analysis (PCA)

(Wunsam et al., 2002) and Detrended Correspondence Analysis (DCA) (Jüttner et al., 2000).

All these analyses indicate influence of environmental factors such as water depth, salinity


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and pH on diatom assemblage structure and proved to be a robust method for analyzing

data. Correlation of diatom communities with water chemistry was examined (Guzkowska

et al., 1990; Soininen and Eloranta, 2004; Charles et al., 2006; Soininen, 2008) using

TWINSPAN analysis (Two-Way Species Indicator Analysis), which reveals each site with a

specific diatom group as indicator of urbanization, significantly correlated with

environmental variables.

2.4.4 Development of Diatom Indices

Based on the tolerance range of some species in overall community composition, Kolkwitz

and Marsson (1908; 1909) developed first indices, ‘Saprobian system’ for estimating the

degree of organic pollution using several organisms such as fish, green algae etc. in

European freshwaters. During 1970’s, water quality of rivers, lakes and streams was

classified based on the key indicator species, mostly by algal community and algae got

more attention from hydrobiologists due to the utility of algae as indicators of

environmental conditions and their fundamental role in food chain (Trobajo and Sullivan,

2010). Quantitative method such as weighted-averaging method was developed for

determining optima and tolerance of taxa for environmental variability (Pantle and Buck,

1955; Zelinka and Marvan, 1961; ter Braak and Van Dam, 1989). Lange-Bertalot (1978,

1979) developed a more practical method to assess water quality utilizing both the species

identity and relative abundance of constituent diatom species in the assemblages. Keeping

Biological Monitoring Working Party (BMWP) score as benchmark, indicator value was

assigned considering the autecology of each species in an assemblage, which reflects

environmental conditions (Lowe, 1974; van Dam et al., 1994; Kelly and Whitton 1995).

Several indices were developed based on the weighted average equation of Zelinka and

Marvan, (1961) and recently Trophic Diatom Index (TDI) was developed in waters of

Eastern Europe and applied across Europe and elsewhere (Kelly and Whitton, 1995; Wu,

1999; Taylor et al., 2007; Stenger-Kovács, 2007). Further, various diatom indices were

developed using OMNIDIA software (Lecointe et al., 1993), to determine the trophic

status of aquatic ecosystems. Lange-Bertalot (1979) developed tolerance value for each

species based on the empirical observations of effects of organic pollution on diatoms in

European rivers. Table 1 list 17 indices calculated using OMNIDIA software and, list of

sensitivity and indicator values for each taxon is mentioned in Kelly and Whitton, 1995.


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Table 1: Summary of the Diatom indices with significance levels using the OMNIDIA.

Sl. No.

Indices Infers Reference

1 Descy’s pollution metric or DESCY

Pollution level Descy, 1979

2 Saprobity Index (Sládeček’s Index) or SLA

Organic pollution Sládeček, 1986

3 Watanabe index or WAT (Diatom community index)

Pollution level Watanabe et al., 1988

4 Specific pollution sensitivity index

Pollution CEMAGREF, 1982

5 Specific Pollution Sensitivity Metric or IPS

Pollution level Coste, 1987

6 Steinberg and Schiefele trophic metric or SHE

Steinberg and Schiefele, 1988

7 Generic diatom index or GDI Coste and Ayphasshorho, 1991

8 Commission for Economical community Index or CEC

Organic Pollution Descy and Coste, 1991

9 Schiefele and Schreiner’s index or SHE

Schiefele and Schreiner, 1991

10 Trophic diatom Indices Trophic status Hofmann, 1994 11 DAIpo index Trophic status Van Dam et al., 1994 12 Trophic diatom index or TDI Organic pollution Kelly and Whitton, 1995

13 Percent Pollution Tolerant taxa or % PT

Pollution level Kelly and Whitton, 1995

14 Eutrophication/ Pollution index or EPI-D

Saprobic, trophic levels, halobic levels.

Dell’Uomo, 1996

15 Biological diatom index or BDI

Lenoir and Coste, 1994

16 Artoise-picardie Diatom index Prygiel et al., 1999 17 Pampean Diatom Index or

IDP Gómez and Licursi, 2001

18 Watanabe Index (Diatom community Index) or WAT

Pollution metric Lecointe et al., 2003

19 Generic Diatom Metric or IDG

Pollution metric by Genus

Lecointe et al., 2003

20 Indice Diatomique Artois Picardie or IDAP

Lecointe et al., 2003

Alpha diversity indices calculate number of species in the sample (species richness),

evenness in species abundance or the compiled indices characterizing both richness and

evenness (Shannon, 1948; Simpson, 1949). These scores examine the characteristic


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features of communities and the numeric results show not only natural effects (example:

altitude), but also agricultural and organic pollution (Jüttner et al., 1996). Patrick, (1973)

and, Stewart and Robertson, (1992) concluded that many times diversity indices could

differentiate between polluted and unpolluted sites. Furthermore, it has been established

that diatom based indices (TDI, BDI, GDI etc.) offers successful approach for assessing

water quality over diversity indices (Wu, 1999; Blanco et al., 2007; Cejudo-Figueiras et al.,

2010).

The development of diatom indices became more important through the initiation of

Water Framework Directive (WFD European Union, 2000) with the goal of maintaining

‘good ecological status of all water bodies in Europe by 2015’. The implementation of this

innovative legislation offered an opportunity and an urgent need to develop diatom indices

that allow an assessment of the ecological status of rivers and streams. In recent years,

lakes have been studied to assess the applicability of diatom indices in water quality

monitoring, considering different substrata such as periphytic (Stoermer and Smol 1999;

Jüttner et al., 2000), sediment (Dixit et al., 1999), epiphytic (Blanco et al., 2004) and epipelic

(Poulickova et al., 2009) diatoms. Studies showed the composition and seasonal variations

of the epilithic and epiphytic diatoms as more accurate in revealing water quality compared

to other habitats (Bennion and Smith, 2000; Maraslioglu et al., 2007).

Even though, many common diatom indices were developed originally in France, later its

application across globe for assessment of diatom based environment monitoring was

established, resulting in diatom indices as the best suit in monitoring rivers, streams, lakes

and other water bodies. Wu, (1999) tested GDI indices in Keelung River in China where,

diatom assemblages numbers positively correlated with water quality index (WQI). The use

of GDI has the advantage that only identification to generic level is required, while the

majority of conventional indices require identification to species. Water quality is better

explained across continents by several indices such as CEC, SPI and BDI at Spain

(Cejudo-Figueiras et al., 2010); Iran (Atazadeh et al., 2007); South Africa (Taylor et al., 2007;

Walsh and Wepener, 2009) where EPI captured impacts of nutrients, ionic strength and

phosphorous level on diatom taxa and recently TDI, IDG, IPS, CEC applied to urban

wetlands of Tamil Nadu, India (Alakananda et al., 2011) and yield comparable results as


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physical chemical analysis with classifying most of the sites as eutrophicated based on the

nutrient levels.

As most of the studies explain the beneficial use of diatom indices, many studies also

revealed the short come in implementing these to other geographic regions because of

change in sensitivity and tolerance of species from one region to another. Four indices

(GDI, BDI, CEC and GDI) and a predictive model (MoDi) were applied to assess the

sensitivity of all indices to a range of anthropogenic disturbances at streams of Portuguese

(Feio et al., 2009). However, Diatom indices produced different results based on the

sensitivity to various pressures, more accurately was the MoDi model in expressing the

quantitative and qualitative changes in freshwater systems through diatoms. Compared to

the use of trophic indices, the Biological Water Quality Index (BWQI) incorporates an

integrate response of the epilithic diatom community to the eutrophication and organic

contamination processes for Southern Brazilian rivers. Thus, many new indices evolved

offering region specific species autecological studies e.g., tropical diatom Index for lakes

(TDIL) to assess ecological status of Hungarian shallow lakes (Stenger-Kovács et al., 2007);

Eastern Canadian Diatom Index (IDEC) to define ecological threshold biologica integrity

status (Grenier et al., 2010); Diatom species Index for Australian Rivers (Chessman et al.,

2007) was used to observe the effect of catchment land use on water quality (Chessman

and Townsend, 2010); Pampean Diatom Index (IDP) to asses streams of Pampean plains

(Gómez and Licursi, 2001) and many more. The successful use of new indices in state

environmental monitoring programs at each region substantiates the computation of

region specific diatom indices as a valuable tool for classification of poor water types.

However, none of the indices could be applied to tropical lakes and wetlands particular to

Indian subcontinent considering the description of many new species from biodiversity

hotspots of Himalayan and Western Ghats streams and are not been included in any of the

17 indices discussed above. On the contrary, physical and chemical investigation fails

because of insufficient data on aquatic floral diversity. Investigations on diatom genera

including their diversity, distribution, ecology and evolution would aid in understanding

the geographical distribution pattern and influence of human disturbances on diatom

structure in each niche. Formulation of India-specific diatom indices will broaden


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taxonomic and ecological information on optimal and tolerance range of each diatom

species.

2.5 Temperate v/s Tropical Diatom Research

Many factors that differ among temperate and tropic regions are temperature, water

mixing, Coriolis effects and oxygen holding capacity (Lewis, 2000); rainfall (Magallona,

1994); sunlight (Magallona, 1989) etc., exhibiting impacts on primary productivity (Wondie

et al., 2007); nutrient limitation (Matson et al., 1999) and so on, which adds to the ever-

changing ecosystems. Challenges to the ecological integrity and monitoring of aquatic

ecosystem are similar in both tropical and temperate regions. Water bodies have

undergone alterations as a result of increase in population density, changes in land cover

and degradation in water quality. These conditions imply to both temperate and tropical

ecosystems but, the extent to which monitoring regulations of temperate can be applied to

tropics or vice versa is not always clear (Lewis, 2000). Tropical lakes are considered more

sensitive to eutrophication than temperate lakes, i.e., the potential eutrophication to

degrade water quality. Probability of losing biodiversity is high in tropical than in

temperate because many species show restricted distribution (Gibson, 2011). But the use

of diatom as indicators and diatom indices for monitoring environmental quality of rivers,

lakes and streams; and their fundamental role in food webs (Stevenson and Pan, 1999) is

wide spread regardless of temperate or tropical region, however, species differ.

Consequences lie in diatom indices, which were developed in Europe, keeping temperate

taxa in concern, and applied to other regions. As few taxa are region specific and even

ecological optima of several species differ from one region to another, the taxonomic

composition and ecology are poorly studied, especially for tropical and subtropical

ecosystem (Round et al., 1990; Gaiser et al., 2005; Karthick et al., 2011). For example,

Mastogloia species is recorded as predominant and characteristics of epiphytic habitat in

subtropical areas (DeFelice and Lynts, 1978; Montgomery, 1978), who’s autecology, may

also vary. Diatom species belonging to genus Achnanthidium are common in North

American rivers; however, their identification remains difficult and their ecology is

insufficiently studied (Potapova and Ponader, 2004). The species common to particular

region has been described in local flora literatures; but not included in standard diatom


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identification literatures used across globe (Ponader and Potapova, 2007), which mostly

covers only common European flora.

Many studies of temperate area represent diatom as water quality monitoring tool -

moorland pools in the Netherlands and Belgium (Denys and van Straaten 1992, van Dam

and Buskens 1993); littoral diatoms to monitor acidification in alpine lakes (Tolotti, 2001);

heterogeneity in benthic diatoms of Finland (Soininen, 2004); alpine stream ecosystem

(Poulíckova et al., 2004). On the other hand, studies on stream quality in Kathmandu valley

and middle hills of Nepal and India (Jüttner et al., 2003); Australian rivers (Townsend and

Gell, 2005); seasonal variation of primary production in Ethiopia lake (Wondie et al., 2007);

Brazil lakes (Nascimento et al., 2010); diatom communities of eutrophic lake of china

(Gong et al., 2009); water quality of streams of central western Ghats (Karthick, 2010)

represents tropical region. However, there are few studies where region specific new

diatom indices are discussed, which revealed better water quality results than European

indices (refer Diatom indices section). The newly developed indices use wide range of

ecological optima of a particular species as recorded from that region and hence accurate

water quality assessment is achievable. It merely depends on the proper systematic and

taxonomy occurring at tropical latitudes through which its ecology can be defined.

Provided that the common diatom taxa with similar environmental optima found in both

temperate and tropical latitudes are abundant, use of regular diatom indices, using

OMNIDIA software is preferable.

2.6 Diatom Research in Lakes

During the last decades many diatom metrics based on ecology and species relative

abundances have been developed for rivers and streams (Ector and Rimet, 2005; Bere and

Tundisi, 2011). Diatom research of lakes lags behind, although their use as indicators of

trophic and saprobic conditions is evident (Hoffman, 1994). A while later, research on

diatoms of lakes has tend to focus on the dynamics of plankton (e.g. Reynolds, 1984) and

on paleo-ecological studies (Dixit et al., 1992; Alefs et al., 1996; Smol 2002; Meriläinen et al.,

2003). Paleoecology focuses on environmental reconstruction with a strong theoretical basis

for the use of diatom assemblages to reflect pH (Battarbee et al., 1999) and nutrients

(Bennion et al., 1996) for establishing ‘reference conditions’ (Bennion et al., 2003). These


26

studies have been focused on diatom samples collected in sediments. Many studies

monitoring environmental gradients will require additional sampling of live assemblages

from other habitats of lakes such as plants, stones and sediments (King et al., 2000; Lim et

al., 2001; Schönfelder et al., 2002; Kitner and Poulíčková 2003; Blanco et al., 2004; Ács et al.,

2005). Lake diatoms are important contributors of the primary production in shallow

aquatic ecosystems and they can be used as indicators of the present water quality and

trophic status (Stenger-Kovács et al., 2007). They have been used increasingly to assess

water quality and, in particular to monitor eutrophication of lakes in agricultural and urban

areas and other pollution e.g., pollution resulting from the intermittent release of sewage,

shoreline development, road works or salting in urban centered lake (Hawes and Smith,

1993; Passy, 2001).

2.7 Diatom research in India

Diatom study in India strikes long back in 19th century by Ehrenberg’s record on diatoms

of Calcutta (1845) followed by De Toni (1891-94), Cleve (1878) and Leuduger-Fortmorel

(1879). As the work progressed, taxonomy was diversified, many authors focused mainly

towards systematics, distribution and with few ecological notes and growth characters

(Biswas, 1936; Venkataraman, 1939; Iyengar, and Subramanyan, 1944; Subramanyan, 1946;

Gonzalves and Gandhi, 1952; Krishnamurthy, 1954; Desikachary, 1962; Sreenivasan and

Duthie, 1973; Foged, 1976; Karim, 1975; David and Dean, 1977; Sarode and Kamat, 1979;

Ghosh and Gaur, 1998; Nather Khan, 1991; Jüttner et al., 1996; Nautiyal and Nautiyal,

1999). The extended work and contribution in the field of diatom taxonomy was by Gandhi

(1955 – 1970) highlighting the diatom flora from various localities of Western Ghats and

Western India such as Bombay (Mumbai), Salsette Islands, Kolhapur, Ahmedabad,

Lonavala hill station, Hirebhasgar dam, Sagar, Jog falls and Pratabgarh, Rajasthan. Diatom

systematics were also reported by Roy (1954) and Rao (1955) on Chilka Lake; Ahmed

(1966) of Allen forest lake Kanpur and Swarup and Singh, (1979) on Suraha lake; Singh and

Saha (1982) from Bhagalpur ponds and Das and Santre (1982) from Senchal Lake,

Darjeeling. Karthick, 2010 explains taxonomic research on diatoms during 18th to 20th

century (Karthick and Kociolek, 2012 a, b; Karthick et al., 2012).


27

Diatoms as a largest component of algae appeared to be good proxy for environmental

conditions such as change in physical, chemical and biological components of an ecosystem

(Hutchinson, 1967; Venkateswarlu and Reddy 1985; Bhatt, et al., 1999) and were used to

assess organic pollution (Hosmani and Bharati, 1980; Saha et al., 2000; Jafari and Gunale,

2006). During the last decade, investigations progressed further towards predicting

environmental changes using diatom as bioindicators and their association with different

habitats as studied by Hickel, (1973), Gopinathan (1975) in Cochin backwater Simkhada

and Jüttner, (2006) in Kathmandu Valleys, Singh et al., (2010) in Mansagar lake, Rajasthan

and Alakananda et al., (2011) in Coimbatore wetlands. Recently Jüttner et al., (1996, 2003) of

Nepal lakes and Simkhada and Jüttner, (2006) studied diatom diversity and distribution on

different habitats and its relationship with water chemistry at Kathmandu valley ponds.

In India, diatom study and their applicability in diatom indices for river quality in the Nepal

hills and effects of habitat-specific sampling was studied by Jüttner et al., (1996, 2000) and

Simkhada et al., (2006). Assemblage composition of epiphytic diatoms reflect gradients in

water chemistry and habitat character of the pond with respect to pond vegetation and

substratum type and land use in the catchment. Further, Cantonati et al., 2001 and Jüttner et

al., 2003 confirmed that the composition of the diatom flora found in Himalayan streams

was strongly influenced by cations, anions, nutrients and substrate. Studies of lakes and

wetlands are not new in India. However, the application of diatoms in biomonitoring and

ecological importance is largely unexplored to study urban wetlands and pollution causing a

decline in the number of wetlands. Even though, the studies on diatom indices are

standardized for arid regions (Atazadeh et al., 2007) the strength of the relationships

between landscape features and site specific biota is poorly known in South India.

Ecological monitoring programs that include diatom studied for lakes and wetlands are

exceptional and in many cases uncertain. This is mainly due to the lack in exploration of

taxonomical aspects from different regions to update the ecological optima of species and

also inferences about the difficulty in taxonomy. Assessment of more than a few lakes and

wetlands in India and documenting diatoms in unexplored regions can contribute to the

evaluation of diatom diversity status in India.


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Wetlands of rapidly urbanizing region such as Bangalore are disappearing due to the

unplanned urbanization, increased human settlements and so on. There are numerous

studies to state the present water quality conditions of wetlands across the subcontinent,

while with no emphasis on biological component is a major gap, which leads to

mismanagement of wetlands. Recent studies (Ramachandra, 2002, 2005 and Ramachandra

et al., 2012) highlighted the decline in natural resources and loss of wetlands in Bangalore

during the last decade, which has led to increased floods events and loss of biodiversity.

Further agricultural and road runoff that elevated salt content in water and untreated

industrial effluents caused imbalance in water quality and aquatic life in most of the

wetlands (Mahapatra et al., 2011). Ramachandra and Kumar, (2008) recorded formation of

urban head islands with rise of 2oC temperature in Bangalore urban region due to decline of

wetlands and green cover. This temperature rise and related environmental variables could

affect the cell size of algae (diatoms) and its metabolism (Montagnes and Franklin, 2001)

Concomitantly, there is a need to investigate effect of temperature and other global

warming issues on wetland primary producers such as diatoms and other phytoplankton in

severely polluted water bodies. Ramachandra et al., (2011) also showed that the economic

value of urban wetlands has accounted for <1,00,000 Rs./220 ha/year. Low economic

value could be logical to decreased fish production and water availability because of

increased sewage inflow and water degradation.

In order to recommend diatom biomonitoring in urban wetlands, a pilot scale wetland

investigation using different bioindicators (diatoms and macroinvertebrates) was explored

(Alakananda et al., 2011, Alakananda et al., 2012). Results explained the potential use of

diatoms as bioindicators when compared to other biotic groups and the cost effective

technique to assess accurate water pollution status. Ramachandra and Aithal, (2012) showed

increase in built-up and decreasing vegetation cover in highly urbanized cities of India that

also suggested local government and urban planners to relook the biotic component in

urban management plans. Therefore, diatom based biomonitoring should be incorporated

along with regular monitoring surveys for urban wetlands. The knowledge on diatom

distributional pattern, impact of environmental variables on habitat availability, diatom

composition and other microbial community is essential. Based on their sensitivity and

tolerance ranges and taxa composition, diatoms would results in easy biomonitoring and


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thus novel conservation plans can be designed. In this regard, there is a need for ecological

and biomonitoring studies of diatoms to evolve appropriate management and restoration

strategies of urban wetlands, which in turn aid in protecting flora, fauna and habitats.

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CHAPTER 2: REVIEW OF LITERATURE - Shodhgangashodhganga.inflibnet.ac.in/bitstream/10603/35936/8... · 2018-07-02 · REVIEW OF LITERATURE 10 2.1 Study of Inland Freshwater - Origin