131
wt. (at Kakdwip) during monsoon in root, 0.02 ± 0.009 ppm dry wt. (at Bagmara)
during premonsoon to 0.08 ± 0.009 ppm dry wt. (at Kakdwip) during monsoon in
stem and 0.02  ±  0.009  ppm dry wt. (at Bagmara) during premonsoon to
0.07 ± 0.001 ppm dry wt. (at Kakdwip) in leaf respectively (Figs. 5.25, 5.26, 5.27,
5.28, 5.29, 5.30, 5.31 and 5.32).
During 2013, concentration of Zn values ranged from 32.57 ± 3.04 ppm dry wt.
(at Bagmara) during premonsoon to 107.09 ± 6.31 ppm dry wt. (at Kakdwip) during
monsoon in root, 25.05  ±  0.93  ppm dry wt. (at Bagmara) during premonsoon to
95.31 ± 6.38 ppm dry wt. (at Kakdwip) during monsoon in stem and 19.99 ± 1.27 ppm
dry wt. (at Bagmara) during premonsoon to 57.12 ± 3.07 ppm dry wt. (at Chemaguri)
in leaf of A. officinalis. In 2014, for the same species the values ranged from
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
120
100
80
60
40
20
0
Fig. 5.25 Spatio-temporal variations of Zn (in ppm dry wt) in the vegetative parts of Avicennia
marina during 2013
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
120
100
80
60
40
20
0
Fig. 5.26 Spatio-temporal variations of Zn (in ppm dry wt) in the vegetative parts of Avicennia
marina during 2014
5 Mangroves: A Sink of Heavy Metals