127
dry wt. (at Kakdwip) during monsoon in stem and 0.02 ± 0.008 ppm dry wt. (at
Bagmara) during premonsoon to 0.06  ±  0.005  ppm dry wt. (at Kakdwip) in leaf
respectively (Figs. 5.17, 5.18, 5.19, 5.20, 5.21, 5.22, 5.23, and 5.24).
In case of A. marina, during 2013, concentration of Zn ranged from
20.57 ± 1.06 ppm dry wt. (at Bagmara) during premonsoon to 99.21 ± 6.14 ppm dry
wt. (at Kakdwip) during monsoon in root, 15.00 ± 0.81 ppm dry wt. (at Bagmara)
during premonsoon to 91.55 ± 3.11 ppm dry wt. (at Kakdwip) during monsoon in
stem and 13.43  ±  1.99  ppm dry wt. (at Bagmara) during premonsoon to
56.85 ± 3.97 ppm dry wt. (at Chemaguri) in leaf of A. marina. In 2014, for the same
species the values ranged from 26.61 ± 1.99 ppm dry wt. (at Bagmara) during preKakdwip
Harinbari
Chemaguri
Sagar south
Lothian island
Jambu island
Frasergunj
Gosaba
Chotomollakhali
Bali island
Sajnekhali
Bagmara
Concentration of Zn (ppm dry wt.)
100
Root Premonsoon
Stem Premonsoon
Leaf Premonsoon
Leaf Monsoon
Stem Postmonsoon
Leaf Postmonsoon
Stem Monsoon
Root Postmonsoon
Root Monsoon
90
80
70
60
50
40
30
20
10
0
Fig. 5.17 Spatio-temporal variations of Zn (in ppm dry wt) in the vegetative parts of Avicennia
alba during 2013
Kakdwip
Harinbari
Chemaguri
Sagar south
Lothian island
Jambu island
Frasergunj
Gosaba
Chotomollakhali
Bali island
Sajnekhali
Bagmara
100
120
80
60
40
20
0
Root Premonsoon
Stem Premonsoon
Leaf Premonsoon
Leaf Monsoon
Stem Postmonsoon
Leaf Postmonsoon
Stem Monsoon
Root Postmonsoon
Root Monsoon
Concentration of Zn (ppm dry wt.)
Fig. 5.18 Spatio-temporal variations of Zn (in ppm dry wt) in the vegetative parts of Avicennia
alba during 2014
5 Mangroves: A Sink of Heavy Metals