629
of awareness in appreciating the full economic
benefi ts on the part of policymakers have led to
its market failure. At policy level, wetlands are
too often taken for granted and are considered as
wastelands. A survey conducted by WWF–IUCN
covering some of the important wetlands in India
identifi ed wildlife poaching (38 %), pollution
(37 %), grazing pressure, alteration to other land
uses, overfi shing and siltation as some of the
major threats. The developmental policies of the
government encourage large-scale aquaculture,
pisciculture and salt manufacturing as in Chilka
Lake and west coast mangroves or pisciculture in
Kolleru Lake. Such matters are to be taken care
of in order to conserve the wetlands.
29.2.4.7 Anthropogenic Effects
In many wetlands, human infl uence has caused
signifi cant changes in the chemical cycling.
These changes have been occurring as a result of
clearing of land and subsequent erosion and
hydrological modifi cations, such as stream channelisation and dams and pollution. It may be
noted here that increased erosion in uplands leads
to increased deposition of sediments in the lowland wetlands, such as forested swamps. This, in
turn, may cause increased biochemical oxygen
demand (BOD) and may alter the hydrological
regime of the wetlands in a relatively short period
of time. Concomitantly, stream channelisation
and dams may lead to changes in the fl ooding frequency in many wetlands. This may alter the
inputs of nutrients. It may be noted here that
dams generally serve as ‘nutrient traps’. They
retain materials which would otherwise nourish
downstream wetlands. Further, in some cases,
stream channelisation has led to stream downcutting which ultimately drains wetlands.
29.2.5 Wetland Problems
Exemplifi ed
29.2.5.1 Problems Exemplifi ed
Through Sone Beel in Assam
(a) Inlet(s) diversifi cation
(b) Outlet(s) diversifi cation
(c) Outlet(s) blockade(s)
(d) Siltation
(e) Maha jal (enormous encircling gear)
operation
(f) Paddy cultivation
(g) Big size carnivorous fi shes
(h) Availability of exotic fi shes
(i) Day-in and day-out fi shing operations
(j) Fish disease, particularly Epizootic Ulcerative Syndrome (EUS) (Fig. 29.2 )
Further, an account of potentials and problems
of the wetlands in some of the provinces of India
is given below.
29.2.5.2 In Assam
Potentials
1. Assam has 0.12 × 10
6 ha of wetlands coverage, refl ecting its tremendous amount of lentic
potential.
2. The wetlands provide fi sh as protein, habitat
for biota, fi sh catching as livelihood, water for
navigation, vast area for fl ood management (in
this fl ood-prone area), etc.
Problems
(a) c 35,000 ha in Assam is in derelict condition
out of 70,000 ha of registered wetlands coverage. This is an alarming situation with regard
to conservation of wetlands.
(b) In general, the wetlands of Assam are victims
of soil erosion, siltation, encroachment, infestation with weeds, unsustained utilisation of
bioresources, lack of proper legal and administrative procedures, lack of proper education
both in the schools and in the rural society
and so on.
29.2.5.3 In Manipur
Potentials
1. The province of Manipur has been famous by
having the Loktak Lake and the National Park
containing the ‘Sangai’.
2. Besides providing with fi shes for nutrition,
habitat for biota, etc., the lake also provides
hydroelectricity and navigational facility and
helps in fl ood management and livelihood
opportunities to many people.
29.2 Problems
of awareness in appreciating the full economic
benefi ts on the part of policymakers have led to
its market failure. At policy level, wetlands are
too often taken for granted and are considered as
wastelands. A survey conducted by WWF–IUCN
covering some of the important wetlands in India
identifi ed wildlife poaching (38 %), pollution
(37 %), grazing pressure, alteration to other land
uses, overfi shing and siltation as some of the
major threats. The developmental policies of the
government encourage large-scale aquaculture,
pisciculture and salt manufacturing as in Chilka
Lake and west coast mangroves or pisciculture in
Kolleru Lake. Such matters are to be taken care
of in order to conserve the wetlands.
29.2.4.7 Anthropogenic Effects
In many wetlands, human infl uence has caused
signifi cant changes in the chemical cycling.
These changes have been occurring as a result of
clearing of land and subsequent erosion and
hydrological modifi cations, such as stream channelisation and dams and pollution. It may be
noted here that increased erosion in uplands leads
to increased deposition of sediments in the lowland wetlands, such as forested swamps. This, in
turn, may cause increased biochemical oxygen
demand (BOD) and may alter the hydrological
regime of the wetlands in a relatively short period
of time. Concomitantly, stream channelisation
and dams may lead to changes in the fl ooding frequency in many wetlands. This may alter the
inputs of nutrients. It may be noted here that
dams generally serve as ‘nutrient traps’. They
retain materials which would otherwise nourish
downstream wetlands. Further, in some cases,
stream channelisation has led to stream downcutting which ultimately drains wetlands.
29.2.5 Wetland Problems
Exemplifi ed
29.2.5.1 Problems Exemplifi ed
Through Sone Beel in Assam
(a) Inlet(s) diversifi cation
(b) Outlet(s) diversifi cation
(c) Outlet(s) blockade(s)
(d) Siltation
(e) Maha jal (enormous encircling gear)
operation
(f) Paddy cultivation
(g) Big size carnivorous fi shes
(h) Availability of exotic fi shes
(i) Day-in and day-out fi shing operations
(j) Fish disease, particularly Epizootic Ulcerative Syndrome (EUS) (Fig. 29.2 )
Further, an account of potentials and problems
of the wetlands in some of the provinces of India
is given below.
29.2.5.2 In Assam
Potentials
1. Assam has 0.12 × 10
6 ha of wetlands coverage, refl ecting its tremendous amount of lentic
potential.
2. The wetlands provide fi sh as protein, habitat
for biota, fi sh catching as livelihood, water for
navigation, vast area for fl ood management (in
this fl ood-prone area), etc.
Problems
(a) c 35,000 ha in Assam is in derelict condition
out of 70,000 ha of registered wetlands coverage. This is an alarming situation with regard
to conservation of wetlands.
(b) In general, the wetlands of Assam are victims
of soil erosion, siltation, encroachment, infestation with weeds, unsustained utilisation of
bioresources, lack of proper legal and administrative procedures, lack of proper education
both in the schools and in the rural society
and so on.
29.2.5.3 In Manipur
Potentials
1. The province of Manipur has been famous by
having the Loktak Lake and the National Park
containing the ‘Sangai’.
2. Besides providing with fi shes for nutrition,
habitat for biota, etc., the lake also provides
hydroelectricity and navigational facility and
helps in fl ood management and livelihood
opportunities to many people.
29.2 Problems