134
21.56 ± 2.03 ppm dry wt. (at Kakdwip) in leaf of A. officinalis. In 2014, for the same
species the values ranged from 10.01 ± 0.85 ppm dry wt. (at Bagmara) during premonsoon to 30.43  ±  2.03  ppm dry wt. (at Kakdwip) during monsoon in root,
8.34 ± 0.39 ppm dry wt. (at Bagmara) during premonsoon to 28.25 ± 2.16 ppm dry
wt. (at Kakdwip) during monsoon in stem and 6.46 ± 0.12 ppm dry wt. (at Bagmara)
during premonsoon to 23.95 ± 1.99 ppm dry wt. (at Kakdwip) in leaf respectively.
During premonsoon in 2013, available Hg values in root, stem and leaf ranged from
from 0.03 ± 0.009 ppm dry wt. (at Bagmara) during premonsoon to 0.09 ± 0.003 ppm
dry wt. (at Kakdwip) during monsoon in root, 0.03 ± 0.006 ppm dry wt. (at Bagmara)
during premonsoon to 0.08 ± 0.009 ppm dry wt. (at Kakdwip) during monsoon in
Kakdwip
Harinbari
Chemaguri
Sagar south
Lothian island
Jambu island
Frasergunj
Gosaba
Chotomollakhali
Bali island
Sajnekhali
Bagmara
Concentration of Hg (ppm dry wt.)
Root Premonsoon
Stem Premonsoon
Leaf Premonsoon
Leaf Monsoon
Stem Postmonsoon
Leaf Postmonsoon
Stem Monsoon
Root Postmonsoon
Root Monsoon
0.1
0.09
0.08
0.07
0.06
0.05
0.04
0.03
0.02
0.01
0
Fig. 5.31 Spatio-temporal variations of Hg (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
Root Premonsoon
Stem Premonsoon
Leaf Premonsoon
Leaf Monsoon
Stem Postmonsoon
Leaf Postmonsoon
Stem Monsoon
Root Postmonsoon
Root Monsoon
Concentration of Hg (ppm dry wt.)
0.1
0.09
0.08
0.07
0.06
0.05
0.04
0.03
0.02
0.01
0
Fig. 5.32 Spatio-temporal variations of Hg (in ppm dry wt) in the vegetative parts of Avicennia
marina during 2014
5 Mangroves: A Sink of Heavy Metals