Environmental Engineering Reference
In-Depth Information
Many oil products are highly viscous. In
particular, crude oils and heavy fuel oils can be
deposited on shorelines and shoreline resources
in thick, sticky layers that may either disrupt or
completely prevent normal biological processes
of exchange with the environment. Even if a
petroleum product is not especially toxic in its
own right, when oil physically covers plants and
animals, they may die from suffocation, starva-
tion or other physical interference with normal
physiological function.
F. Construction of Dams and Barrages
The Bangladesh part of the Sundarbans spreads
over the districts of Khulna, Bagerhat and Sat-
khira. It covers almost 62 % of total land cover,
and geographically,
started being affected. The dominant species
Sundari (
H. fomes
) and Goran (
Ceriops decan-
dra
) are affected by top-dying disease. Top dying
of
in the Sundarbans is considered as
the most serious of all the diseases and disorders
in Bangladesh mangrove system (Rahman
2001
;
Islam
2008
).
G. Exploitation of Resources
A heavy dependence on foraging for shell
H. fomes
sh on
the shore was typical of many of the semi-
nomadic indigenous peoples encountered by
Europeans for the
-
eighteenth centuries, for example the bushmen,
called
rst time in the sixteenth
-
by the Dutch at the Cape,
Native Americans and Native Australians (Mee-
han
1982
; Alfredson
1984
). Collecting of shell-
'
strandlopers
'
it
lies between latitudes
21
°
31
′
Nand22
°
30
′
N and between longitudes
sh was, and often still is, an important element
of the activities of peoples with permanent set-
tlements who also
89
E (Katebi
2001
). The rivers
of the Bangladesh Sundarbans are more stable
than the main stream of the Ganges. The erosion
and accretion balance in the Sundarbans have
been estimated to be 146 km
2
for the period
1960
-
1984 (Jabbar
1995
; Siddiqi
2001a
,
b
). The
deltaic swamp of the Sundarbans is
°
18
′
E and 90
°
18
′
shed and farmed, such as the
Polynesian cultures and Native Americans. In
many cases, seashells or their products (e.g.
wampum in north-east America, cowries in
Polynesia) were used as currency. In Europe,
widespread subsistence collecting of shell
at with
micro-topographical exceptions only. It runs
from north to south at a slope of 0.03 m vertically
per km of horizontal distance. Micro-topo-
graphical variation is due to rivers, streams and
tidal
fl
sh
was common from prehistoric times until the late
middle ages.
It has been documented that in Indian coastal
zone, about 3,600 tonnes of molluscs are removed
annually from Kakinada Bay and Coringa mud
ow (Begum
1987
; Ansarul
1995
).
With commissioning of the Farakka Barrage,
the discharge in the downstream was drastically
reduced. As a result, all the components of eco-
systems development on the availability of water
fl
ats
for lime production (Fig.
7.43
). Species of bivalves
(
fl
Placuna placenta
,
Anadara granosa
,
Macoma
sp,
Meretrix
sp.) and gastropods (
Cerithidea cingulata
,
Telescopium telescopium
) are regularly handpicked.
Fig. 7.43
Molluscan shell heaped up for lime production
