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MACROPHTIC DIVERSITY IN CERTAIN WETLANDS OF BARAK VALLEY REGION IN ASSAM
Debashish Kar &
Monjurul Hoque Barbhuiya
Aquatic macrophytic diversity and its role in understanding the
wetland ecosystem dynamics is of significance tremendously. Species
composition of the Aquatic macrophytes (AM), their succession and
phytosociological status in four wetlands of the Barak Valley, viz.,
Barak-Nadi Salchapra Anua Beel, Satkarakandi Anua Beel, Ram Nagar
Anua Beel and the Chatla Haor were studied during the 1998-99. 25
different species of AM were recorded from the studied wetlands,
which included 5 free floating, 6 rooted floating, 3 submerged and
11 emergent species of AM. Significantly, six AM species have been
found to occur throughout the year. While Jussiaea repens showed
flowering during April, Nymphaea nouchali bloomed during June-Aug
followed by Nymphoides cristatum and N. indicum which exhibited
profuse flowering during Sep - Oct. Ipomoea aquatica depicted
significant growth of population during July-August. Hydrilla
verticillata , Vallisneria spiralis, Noechamendra alternifolia,
Eleocharis acutangula, Sagittaria trifolia, Scirpus eriophorum were
found to be dominant during the dry season. The floating varieties,
viz., Eichhornia crassipes, Salvinia cucullata and Azolla pinnate
were recorded throughout the year and were found to be associated
with each other. Further, H. verticillata, V. spiralis and T.
bispinosa were found to be associated. Phytosocial association have
also been observed among Nymphaea sp and Nymphodides spp, as well
as, among E.acutangula, S.eriophorum and Echinochloa stagnina.
Species composition and succession along with significance of the
phytosocial association have been discussed in the paper.
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STATUS OF BENTHIC AND LOTTORAL FAUNA OF A LENTIC WETLAND HABITAT IN THE BANGALORE URBAN
REGION WITH ASSOCIATIVE ECOLOGICAL MANAGEMENT STRATEGIES SUGGESTED
B.K. Chakrapani and S. Ravichandra Reddy
The Benthos and Littoral fauna of an aquatic habitat especially in
the context of inland freshwater wetlands can be more effectively
reflective of the operative environmental conditions than the
physico-chemical indices as is more commonly used. The benthos and
littoral fauna may provide for use as possible rapid overall
ecological bioindices to gauge the ecological as well as the
biodiversity status of wetland ecosystems.
The littoral fauna especially , could also provide important
information in understanding and possibly gauging the potentialities
of fishery development from the point of view of socioeconomic
aspects.
An assessment of these faunal aspects can definitely provide
important cues and start-up ideas for shore management strategies.
Such strategies are a key to the maintenance and effective
conservation of wetlands in a sustainable manner considering a wide
range of aspects concerning wetland ecosystems. In the present
scenario, sustenance of biodiversity would be the most important of
these aspects and this would indirectly be linked to the enhancement
of ecological and socioeconomic considerations.
In this light, the benthic and littoral fauna of fresh water lentic
habitat(tank in local parlance-also referred to as lake)was assessed
over a 15-month period in the early eighties. The population density
and the biomass were estimated. The Madivala tank which was in the
urban fringe area till about the early 1980’s, has presently come
much within the urban limits of the rapidly developing and expanding
Bangalore city since about the mid 1980’s.
The benthic fauna was seen to be represented by annelids, insects,
crustaceans, mollusca and the pisces of which the insects dominated.
The littoral fauna was seen to be represented by the nematodes,
annelids, insects, crustaceans, molluscs and the pisces. Of these,
the crustaceans were seen to dominate.
Some interesting ecologically significant observations were made.
For example,though on the whole a fairly good number of fish species
were found in this habitat, it was interesting to find the dominance
of considerable numbers of only two of them, being largely supported
in the littoral region. This was observed to be more so in the
regions associated with the water hyacinth Eichornia crassipes which
also supported profuse numbers of the mosquito larvae.
On similar considerations, a general idea is also gathered for a
number of habitats with respect to shore ecological features and the
biota supported. The diversity of littoral aquatic vegetation as
being a very important component of the wetlands is also to be
brought in this paper.
Further, considering these aspects the possibilities of evolving
habitat related ecologically suitable management strategies
involving shore regions of wetlands would also be discussed in this
paper.
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AIR QUALITY MONITORING AND MODELING FOR COIMBATORE CITY
P. Meenakshi and R. Elangovan
The air environment, unlike water can not be purified at a central
location and reused. As a nonrenewable resource, extreme care must
be exercised to maintain good air quality, inspite of rapid
industrialization and urbanization. The Coimbatore City has cool
climate and locked almost on all sides by hills. Hence dispersion
of air pollutants is limited and the air quality gets deteriorated.
Regular monitoring of air quality is very important in such a case.
Since regular air quality monitoring is time consuming and involves
heavy utilization of funds and manpower, this tedious procedure can
be eliminated if a suitable model can be developed and used for air
quality prediction. As a case study, air quality monitoring was
done at five selected survey stations in this city. The major air
pollutants like SPM, SO2, NOX were monitored in each of these
survey stations once in a week . Along with these polluting
parameters meteorological parameters such as wind speed and
direction, wind temperature and pressure , humidity were also
monitored. A statistical regressive model was developed relating
the polluting parameters with the meteorological parameters, which
can be used in the future for predicting the air pollution.
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THE BIODIVERSITY STATUS OF PLANKTON IN TANKS AS WETLAND HABITATS OF THE BANGALORE
REGION, KARNATAKA, INDIA
B.K. Chakrapani
The Bangalore region, in the past, in view of its undulating
topography and the historical developments in terms of its growth
as well as the needs of its people has supported the creation of a
large number of tanks - about 389 as per records. These tanks which
served to store or harvest the rainwater, in the ecological terms,
are lentic water impoundments created by building of man-made bunds
across mainly seasonal streams/minor rivers flowing through the
valleys in the region. Initially the tanks served to cater mainly
the agricultural (irrigation) needs and others like water for
drinking and other domestic utilities. Economic value in terms of
fish and other minor aquatic procedure resources were also served.
Here it is significant to note that from the time of establishment
of Bangalore in the early 15th century by Magadi Kempegowda and
developments during Hyder Ali’s period during mid 18th century and
later as an important military town by the British from 19th
century and later after the independence, it saw a steady growth in
the initial stages. The pace was faster since about the 1940’s and
very rapid since around the mid 1970’s.
During the above changes,Bangalore’s urban area has seen tremendous
ecological changes in terms of its water resources of streams/minor
rivers and therefore the tanks fed by these sources. The streams/
minor rivers steadily changed over to make way as the smaller and
bigger storm water drains which drained the city’s waste water
into the tanks. Thus the scenario has changed the status of many of
the tanks ecologically over time especially in the urban areas.
The ecological importance of tanks(wetlands)being wide ranging and
multifarious is both scientifically as well as socio-economically
well established. In fresh water lentic ecosystem like these, the
plankton community both as producers (phytoplankton) and primary
consumers (zooplankton), trigger off the initial biosynthetic steps.
They also form important links between the basal abiotic and non-
living (organic) matter and the living matter. Many foodchains are
thus triggered, eventually leading to the support of larger groups
like the molluscs, insects, fish and in turn, the waterfowl.
India being a signatory since 1982 to the ‘Ramsar Convention on
Wetlands of 1971’, is bound to protect, conserve and improve at
least its important wetland resources.
In light of the above, plankton surveys were conducted during 1989
and 1995 of such wetland habitats (tanks) mainly during January to
coincide with the Midwinter Annual Asian waterfowl censuses in the
Indian region.
Nearly eightyeight wetlands were surveyed during the two years. The
result of these survey are provided in terms of the phytoplankton
and zooplankton biodiversities from these habitats and the
significant ecological inferences which could be drawn would also
be discussed in this paper.
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POPULATION DYNAMICS OF AQUATIC INSECTS IN FRESHWATER
BODIES OF GULBARGA
K.Vijay Kumar, S.Gayatri
and K.Shailaja
Population dynamics of aquatic insects was studied in freshwater
bodies of Gulbarga. Eutrophication, high turbidity, low dissolved
oxygen, high alkalinity, free carbondioxide and total hardness were
the abiotic factors preventing the diversification and abundance of
aquatic entomofauna in the Jagath tank. A few aquatic insects have
been regarded as biological indicators of pollution.
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BIOCHEMICAL ASPECTS OF WATER POLUTION IN TWO LAKES OF MYSORE CITY
Hosmani S.P. and L.Vasanth Kumar
A detailed study of the physico - chemical and bio-chemical
parameters in Kukkarahalli lake and Dalvoi lake indicates that the
gross percentage of chemical parameters in Kukkarahalli lake is
27.90% and the percent of total plankton is low (43%). The activity
of chemicals lead to the liberation of extra cellular products,
thereby increasing their quantity (53.19%). The death and decay of
plankton may add to the activity of bacteria in this lake, the
quantity of bacterial colonies also increases(57.5%). In Dalvoi
lake the percentage of chemical is very high (72.09%) and plankton
is also relatively high (56.80%). The percentage of bio-chemical
parameters is correspondingly low (46.80%).
Both lakes seem to be highly productive, one on the basis of
bio-chemical products (Kukkarahalli Lake) and other on the basis of
plankton productivity(Dalvoi Lake). Death and decay of algal blooms
in these waters add to the bio-chemical concentration. These waters
have comparatively high electrolytes, the dissolved oxygen is low
while phosphate and nitrogen content are relatively high and show a
quantitative abundance of plankton blooms and are highly eutrophic.
Exploitation of polluted waters rich in algal biomass for
biotechnological products can be established. Phycobiliproteins
from algae can be used as sensitive fluorescent dyes,immunochemical
reagents and can be used as efficient flurochromes in multiple
colour analysis.
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TEMPORARY PONDS - A NEGLECTED ECOSYSTEM
M.N. Madhyastha,
K.C.Shashi
Kumar and P.D.Rekha
Temporary ponds and puddles are by and large neglected ecosystems
and generally undervalued till recently. But their contribution to
the ecosystem function is significant. They support wide variety of
organisms including varieties of higher plants requiring different
stages of water level, supporting some rare plants, various
amphibians and their tadpoles and many microorganisms. In addition
provide nesting and perching habitats for birds to rear their young
and provide resting areas. Many migratory birds also stop and rest
in these areas. Despite their temporary nature, they support these
biota both during wet and dry seasons. They contribute immensely to
the village population, meeting its immediate water demands.
These small ponds are utilized for a variety of human activities
like drinking and small scale agricultural water supply, recreation,
fishing as well as for dumping agricultural and domestic wastes.
Inspite of their importance towards supporting diversity of life,
they are amongst the vulnerable and easily damaged of the aquatic
ecosystems. The anthropogenic activities filling the shallow water
bodies exert a stress on these systems. These fragile ecosystems
are being destroyed completely because of inappropriate management
practices. The temple tanks are not exceptions to this. The organic
loading results in the complete coverage of these waters by algae
and floating macrophytes like Salvinia, pistia, and Eichhornia spp.
Further it leads to the eutrophication process increasing the
biochemical oxygen demand and decreases the oxygen level when
decomposed by microorganisms, which in turn exhibits shift in the
natural, healthy flora and fauna leading to ecological succession.
Hence there is an urgent need to examine their status and role in
the biodiversity conservation and action as well. Proper management
plans involving the local people’s participation will help to
restore the health of these wetland ecosystems.