136
9.35 ± 0.99 ppm dry wt. (at Bagmara) during premonsoon to 23.86 ± 1.84 ppm dry
wt. (at Kakdwip) in leaf. During premonsoon in 2013, available Pb values in root,
stem and leaf ranged from from 1.13 ± 0.04 ppm dry wt. (at Bagmara) during premonsoon to 15.66  ±  1.03  ppm dry wt. (at Kakdwip) during monsoon in root,
1.18 ± 0.03 ppm dry wt. (at Bagmara) during premonsoon to 9.49 ± 0.16 ppm dry
wt. (at Harinbari) during monsoon in stem and 1.03 ± 0.02 ppm dry wt. (at Bagmara)
during premonsoon to 7.66 ± 0.31 ppm dry wt. (at Kakdwip) in leaf of E. agallocha.
In 2014, for the same species the values ranged from 4.02 ± 0.12 ppm dry wt. (at
Bagmara) during premonsoon to 17.78  ±  1.11  ppm dry wt. (at Kakdwip) during
monsoon in root, 3.72  ±  0.12  ppm dry wt. (at Bagmara) during premonsoon to
Kakdwip
Harinbari
Chemaguri
Sagar south
Lothian island
Jambu island
Frasergunj
Gosaba
Chotomollakhali
Bali island
Sajnekhali
Bagmara
Concentration of Zn (ppm dry wt.)
Root Premonsoon
Stem Premonsoon
Leaf Premonsoon
Leaf Monsoon
Stem Postmonsoon
Leaf Postmonsoon
Stem Monsoon
Root Postmonsoon
Root Monsoon
140
120
100
80
60
40
20
0
Fig. 5.34 Spatio-temporal variations of Zn (in ppm dry wt) in the vegetative parts of Avicennia
officinalis during 2014
Kakdwip
Harinbari
Chemaguri
Sagar south
Lothian island
Jambu island
Frasergunj
Gosaba
Chotomollakhali
Bali island
Sajnekhali
Bagmara
Concentration of Cu (ppm dry wt.)
Root Premonsoon
Stem Premonsoon
Leaf Premonsoon
Leaf Monsoon
Stem Postmonsoon
Leaf Postmonsoon
Stem Monsoon
Root Postmonsoon
Root Monsoon
60
50
40
30
20
10
0
Fig. 5.35 Spatio-temporal variations of Cu (in ppm dry wt) in the vegetative parts of Avicennia
officinalis during 2013
5 Mangroves: A Sink of Heavy Metals