90
The artificial sources of nutrients in the mangrove ecosystem are (i) fertilizer
run-off from the adjacent agricultural fields (a considerable portion of nitrate and
phosphate originate from the fertilizers used to boost up agricultural production),
(ii) aquacultural wastes, which contain nutrients released from unused feed, excreta
of the culture species etc.
In many pockets of Indian Sundarbans, agriculture and aquaculture occur simultaneously, which is one of the root causes behind the generation of nitrate and phosphate in the ambient environment (Fig. 4.6).
The fish feed used in the aquaculture sector are rich in protein. They are of different sizes depending on the age of the culture species (Fig. 4.7). The unused
protein- rich feed in the aquaculture farm generate considerable load of ammonia
and nitrogenous wastes when they are discharged to the adjacent aquatic system
during water exchange or pond preparation.
Fish landing stations, tourism units are also the major artificial sources of nutrients in the mangrove ecosystem (Figs. 4.8 and 4.9).
The major sources of nutrients in the mangrove ecosystem are highlighted in
Fig. 4.10.
It is interesting to note that nutrients in the mangrove ecosystem exhibit marked
seasonal oscillation with high values during monsoon followed by postmonsoon
and premonsoon. A case study conducted in an around the mangrove dominated
Indian Sundarbans for three decades (1984–2014) confirms these significant seasonal variations (Figs. 4.11, 4.12, 4.13, 4.14, 4.15, 4.16, 4.17, 4.18, and 4.19). In
this present case study, three stations namely Diamond Harbour (just outside the
border of mangrove dominated Indian Sundarbans), Namkhana (in western Indian
Sundarbans) and Ajmalmari (in central Indian Sundarbans) have been considered.
At Diamond Harbour, dissolved nitrate concentration ranged from 20.84 ppm
(during premonsoon in 1984) to 48.15 ppm (during premonsoon in 2009) (Fig. 4.11).
Fig. 4.4 Mangrove litter in the estuarine water – a source of nutrients for plankton
4 Mangroves: A Nutrient Retention Box
The artificial sources of nutrients in the mangrove ecosystem are (i) fertilizer
run-off from the adjacent agricultural fields (a considerable portion of nitrate and
phosphate originate from the fertilizers used to boost up agricultural production),
(ii) aquacultural wastes, which contain nutrients released from unused feed, excreta
of the culture species etc.
In many pockets of Indian Sundarbans, agriculture and aquaculture occur simultaneously, which is one of the root causes behind the generation of nitrate and phosphate in the ambient environment (Fig. 4.6).
The fish feed used in the aquaculture sector are rich in protein. They are of different sizes depending on the age of the culture species (Fig. 4.7). The unused
protein- rich feed in the aquaculture farm generate considerable load of ammonia
and nitrogenous wastes when they are discharged to the adjacent aquatic system
during water exchange or pond preparation.
Fish landing stations, tourism units are also the major artificial sources of nutrients in the mangrove ecosystem (Figs. 4.8 and 4.9).
The major sources of nutrients in the mangrove ecosystem are highlighted in
Fig. 4.10.
It is interesting to note that nutrients in the mangrove ecosystem exhibit marked
seasonal oscillation with high values during monsoon followed by postmonsoon
and premonsoon. A case study conducted in an around the mangrove dominated
Indian Sundarbans for three decades (1984–2014) confirms these significant seasonal variations (Figs. 4.11, 4.12, 4.13, 4.14, 4.15, 4.16, 4.17, 4.18, and 4.19). In
this present case study, three stations namely Diamond Harbour (just outside the
border of mangrove dominated Indian Sundarbans), Namkhana (in western Indian
Sundarbans) and Ajmalmari (in central Indian Sundarbans) have been considered.
At Diamond Harbour, dissolved nitrate concentration ranged from 20.84 ppm
(during premonsoon in 1984) to 48.15 ppm (during premonsoon in 2009) (Fig. 4.11).
Fig. 4.4 Mangrove litter in the estuarine water – a source of nutrients for plankton
4 Mangroves: A Nutrient Retention Box