Arsenic in Mangrove ecosystem

Biogeochemical controls of arsenic occurrence and mobility in the
Indian Sundarban mangrove ecosystem
S.K. Mandal a, Mitali Dey b, D. Ganguly b, S. Sen c, T.K. Jana b,*
a Sundarban Hazi Desarat College, Pathankhali, 24 Pgs (South), India
b Department of Marine Science, Calcutta University, 35, B.C. Road, Kolkata, Kolkata 700019,
India, c Department of Chemist ry, 92, A.P.C. Road, Kolkata 700009, India
This study aims to invest igate the cont rol of arsenic dist ribut ion by biogeochemical processes in
the Indian Sundarban mangrove ecosystem and the importance of this ecosystem as an arsenic
source for surrounding coastal water. The As(V)/As(III) rat io was found to be significant ly lower
in both surface and pore waters compared to sea water, which could be at t ributed to
biogeochemical interconversion of these arsenic forms. The biological uptake of arsenic due to
primary and benthic product ion occurs during the post -monsoon season, and is followed by the
release of arsenic during the biochemical degradat ion and dissolut ion of plankton in the premonsoon
season. These results suggest that arsenic is immobilized during incorporat ion into the
arsenic-bearing init ial phase, and unlikely to be released into pore water unt il the complete
microbial degradat ion of arsenic-bearing organic compounds.
_ 2009 Elsevier Ltd. All rights reserved.
Citation: Mandal, S.K., et al. (2009) Biogeochemical controls of arsenic occurrence and mobility in
the ... Mar. Pollut. Bulldoi:10.1016/j.marpolbul.2009.01.010