Environmental Engineering Reference
In-Depth Information
Table 5.8
Mean cell volume (
ยต
m
3
) in other algae in the selected ponds
S. no.
Species
Pond 1 (0.5 ppm)
Pond 2 (1.5 ppm)
Pond 3 (2.5 ppm)
1
Trichodesmium
sp.
3552.14
4005.29
3914.66
2
Trichodesmium thiebautii
2849.42
2911.68
2899.95
3
Oscillatoria
sp.
698.44
803.28
714.66
4
Oscillatoria limosa
699.49
734.22
710.05
5
Gloeocapsa
sp.
153
178.69
165.25
6
Stigonema
sp.
749.75
813.66
795.28
7
Cylindrospermopsis raciborskii
835.66
892.44
854.1
8
Anabaena
sp.
354.29
496.38
398.72
9
Dictyocha sp.
103.28
211.44
196.71
10
Ditylum sol
1982.44
2004.91
1995.76
11
Chlorella salina
568.44
601
575.75
12
Amphora hyalina
2111.7
2802.55
2644.12
13
Netrium
sp.
456.55
609.82
517.44
14
Draparnaldia sp.
1468.22
1802.1
1717.45
15
Gloeocapsa
sp.
213.11
288.42
265.07
Figures in bracket indicate the applied doses of ferrous sulphate in the pond water
massive geophysical changes does not arise
when iron fertilization is done.
5. In aquaculture pond, the algal bloom can be
converted into animal biomass as the cultured
species feed and phytoplankton and the
question of DO fall does not arise.
6. The HAB species can be detected and managed
as aquaculturists monitor the water quality and
check the pond health almost on an hourly
basis.
7. Hydrogen sulphide gas produced by microbial
activity in the aquaculture ponds can be pre-
cipitated through the application of ferrous
sulphate, which may otherwise be toxic for
the cultured species.
Different doses of iron were mixed in rain-
water-harvested ponds selected in deltaic Sun-
darbans to trigger up the bloom of phytoplankton
(Fig.
5.12
).
The excess phytoplankton was utilized as the
natural food of cultured species (
Macrobrachium
rosenbergii
). The best growth (in terms of bio-
mass) was observed in the pond where 1.5 ppm
ferrous sulphate was applied (Table
5.5
and
Fig.
5.13
). The protein content was also highest
in the pond treated with 1.5 ppm ferrous sul-
phate, which is an effect of growth of more
phytoplankton in the pond treated with 1.5 ppm
ferrous sulphate compared to the other 3 ponds
(Tables
5.6
,
5.7
,
5.8
,
5.9
and
5.10
).
