Environmental Engineering Reference
In-Depth Information
the river, widespread anthropogenic activities were
noted such as channelization and lift irrigation
(at many places) of the river water for agriculture
(particularly around the banks of the river), illegal
fi shing, mining of rocks, and sand. The presence
of over 200 irrigation projects and 4 major dams
on the Chambal River has severely reduced water
levels, and the river does not fl ow below the Kota
Barrage (left), for most of the year. The Chambal
on average is 400 m wide, but several sections
shrink to less than 20 m. This situation has
increased anthropogenic threats to the river
several fold, and such areas are no longer viable
fi sh habitat. Low water fl ow induces habitat
fragmentation and changes in the assemblage
structure of river fi shes. Isolated pools are also
resulted due to low water fl ows which are vulner-
able to anthropogenic activities, e.g., netting and
dynamiting. Hence, it is very important to main-
tain minimum critical water level particularly
during the breeding period of the fi shes. Besides,
regular monitoring and frequent ecological studies
related to this reservoir is required. Dams obstruct
the dispersal and migration of organisms, and
these and other effects have been directly linked
to loss of populations and entire species of fresh-
water fi sh (Nilsson et al.
2005
). This fact is
accounting for decrease in number of those fi sh
species which migrate upstream, i.e., Deccan
Mahseer (
Tor khudree
). Chambal River provides
a large number of fi sh fi ngerlings and fries to
other parts of the Chambal River where fi shing is
allowed. Besides, numerous endangered animals
are also dependent on fi shes as food. Therefore, it
is necessary to increase security of this riverine
ecosystem (Figs.
15.6
,
15.7
, and
15.8
).
Cpriniformes
Siluriformes
Perciformes
Others
Fig. 15.4
Composition of different orders of fi shes in
Chambal River
Order
:
Clupeiformes
Family: Clupeidae
Genus:
Gonialosa
Regan
53.
Gonialosa manmina
(Hamilton, 1822)
Order: Mugiliformes
Family: Mugilidae
Genus:
Rhinomugil Gill
54.
Rhinomugil corsula
(Hamilton, 1822)
(Figs.
15.4
and
15.5
)
Threats to the Fish Diversity
and Other Fauna
Human impacts have now elevated the natural
rate of species extinction by at least a thousand
times (Pimm et al.
1995
). Human beings pres-
ence near to the waterbodies severely affects their
biota. Main threat for most of the terrestrial and
freshwater species is the destruction of their habi-
tats (Baillie et al.
2004
).
Protected areas have become world's most
important areas from biodiversity conservation
perspective (Burner et al.
2001
).
The Chambal is very important from conser-
vation point of view due to presence of diverse
biota (Hussain and Badola
2001
). However, this
river is affected severely from hydrological
modifi cations due to dams and from the diversion
of river water for irrigation and from anthro-
pogenic activities like sand mining, fi shing, and
human presence (Hussain
2009
; Nair
2010
).
Aforementioned fi ndings are in conformity of the
present fi ndings as almost in entire stretch of
Recommendations
1. It is necessary to increase security to this
riverine ecosystem in general and its biota
in particular.
2. Illegal fi shing must be stopped particularly
during breeding period of fi shes.
3. The adverse effects of dam construction on a
river can be surmounted by providing timber
chute and fi sh ladders or lifts.
Search WWH ::
Custom Search