Environmental Engineering Reference
In-Depth Information
5.70
5.65
5.60
5.55
y = 1.0328e
0.1992x
R
2
= 0.1413
5.50
5.45
5.40
5.35
5.30
5.25
8.20
8.22
8.24
8.26
8.28
8.30
8.32
8.34
Aquatic pH
Fig. 6.13
Interrelationship between oyster shell carbon weight and aquatic pH considering all the three sectors of
Indian Sundarbans
Cameron et al.
cant
contribution of organic shell matter to the total
shell weight of unionid bivalves. Their results
indicate that measures of standing stock biomass,
production or energy
(
1979
) showed a signi
basis. Also site-speci
c allometric equations
need to be developed relating the stored car-
bon with easily measurable variables like
shell weight or
esh weight.
2. In climate science, ocean acidi
fl
ow in bivalve populations
can be considerably underestimated unless the
organic material contained within the shells is
included in the estimates.
Jurkiewicz-Karnkowska (
2005
) estimated the
comparison of carbon concentrations in the soft
tissues and shells of molluscan species that is the
main component of malacocoenoses of the Ze-
grzy
fl
cation is a
common terminology for a decreasing trend
of aquatic pH due to uptake of anthropogenic
carbon dioxide (CO
2
) from the atmosphere.
About 30
40 % of the carbon dioxide
released by the human activities into the
atmosphere dissolves into the oceans, rivers
and lakes. To maintain chemical equilibrium,
some of it reacts with the water to form car-
bonic acid. Some of these extra carbonic acid
molecules react with a water molecule to
generate a bicarbonate ion and a hydronium
ion, thus increasing the ocean
-
ski Reservoir. An assessment of carbon
accumulation in molluscs living in the reservoir
and spatial variability of this is also performed.
The mean values of carbon content in the soft
tissues of the investigated molluscs ranged from
about 36 % to about 46 % dry wt., whereas
carbon content in shells was similar in all cases
on average about 13 % dry wt.
The present chapter depicts few interesting
ń
(H
+
'
s
'
acidity
'
ion concentration) as per the expression:
CO
2
ð
aq
Þ
þ
H
2
O
$
H
2
CO
3
$
HCO
3
þ
H
þ
$
CO
2
3
þ
2H
þ
ndings on molluscan carbon, which are sum-
marized in points:
1. From the case study conducted by the authors
on Saccostrea cucullata, a common oyster
species widely available in Indian Sundar-
bans, it is observed that carbon in the oyster
fl
Between 1751 and 1994, surface oceanwater pH is
estimated to have decreased from approximately
8.25
8.14, representing an increase of almost
30 % in H
+
-
s
oceans. In Indian Sundarbans, at the apex of Bay of
Bengal, it is observed that the aquatic pH
decreased by 0.11, 0.10 and 0.06 unit in the
western, central and eastern sectors, respectively,
over a span of 23 years (1990
ion concentration in the world
'
Vide
row 14 in Table
6.1
). Similarly, stored carbon
in the calcareous shell of the oyster species is
directly proportional to shell weight (
esh is a direct function of
fl
esh weight (
row
13 in Table
6.1
). This study is, however,
regional and needs further research on global
Vide
2012), which is
0.0047, 0.0043 and 0.0026 unit/year, respectively
(
-
Vide
Fig.
6.6
).
