Environmental Engineering Reference
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Fig. 2.27 Marine mammals in the kelp bed (diagrammatic)
while approaching from the inshore to the off-
shore waters (Figs. 2.29 , 2.30 , 2.31 , 2.32 , 2.33
and 2.34 ) speaks in favour of severe anthropo-
genic pressure along the nearshore waters.
The coliform groups of bacteria are used as an
indicator to bacterial contamination of water.
These groups of bacteria consisting of 16 fami-
lies and 256 species originate from the intestinal
tracts of human and other warm-blooded animals
and therefore may occur in both terrestrial and
marine environments (Bhattacharyya 1996 ).
Mangrove vegetation is very common in the
coastal and estuarine regions of the tropical
countries. In fact mangroves are woody plants
that grow at the interface between land and
sea in tropical and subtropical latitudes
(Fig. 2.35 ) and are characterized by the presence
of pneumatophores, salt glands, lateral roots and
cryptoviviparous germination.
These plants, and the associated microbes,
fungi, plants and animals constitute the mangrove
forest community or mangal (Kathiresan and
Bingham 2001 ). The mangrove ecosystem pro-
vides a unique ecological environment for diverse
bacterial communities. The bacteria occupy a
number of niches and are fundamental to the
functioning of these habitats. They are particularly
important in controlling the chemical environment
of the mangal. For example, sulphate-reducing
bacteria (e.g.
Desulfovibrio
,
Desulfotomaculu
,
Desulfosarcina
) are the pri-
mary decomposers in anoxic mangrove sediments
(Chandrika et al. 1990 ; Loka-Bharathi et al. 1991 ).
These bacteria largely control iron, phosphorous
and
Desulfococcus
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