Environmental Engineering Reference
In-Depth Information
Results
The result from this site shows trends of drastic changes in various parameters.
Phyto-planktons
The diversity of phyto-planktons was assessed and the summary is presented in
Table 1 . Three prominent class of phyto-planktons: Bacilariophyceae (19 genus),
Chlorophyceae (8 genus) and Myxophyceae (5 genus) were observed. Clear varia-
tion in species can be seen. Before dam, the abundance/presence of almost all the
species was recorded. After dam wall these species are beginning to dwindle but most
of the species are intact/present. A total of 32 genus were observed before dam wall
(Table 1 ) and out of total 32 genus, 10 genus were not observed in site after dam wall.
Zoo-planktons
Eleven species of other fauna were observed (Table 2 ) in total before dam wall site.
Out of total 11, only six species were observed after dam wall. Significant reduction
in overall diversity was observed. Copepod, Diptomus, Kertella, Rotaoria and
Nolthoca were not observed in samples after the dam wall.
Physico-chemical Properties
The results on water temperature show a clear increase in average water temperature
in the regions after the dam wall (Table 3 ). The temperature range before the dam wall
was 14.46 ᄆ 0.99 to 10.46 ᄆ 0.73 ᄚC while after the dam wall the temperature ranged
from 17.00 ᄆ 1.16 ᄚC to 11.00 ᄆ 0.80 ᄚC in the same area. Similar pattern was observed
in case of dissolved CO 2 and DO. Before dam average CO 2 range was 2.71 ᄆ 0.27 mg/L
while after dam it was 3.09 ᄆ 0.32 mg/L. DO before dam wall was 10.02 ᄆ 0.30 mg/L
while after dam it became 8.42 ᄆ 0.30 mg/L. All these values were signiicantly differ-
ent ( p > .001).
Fish Population Estimates
Drastic changes in fish number is observed (Table 4 ). Before dam wall the number
of ishes was 44.14 ᄆ 6.15 and after dam wall 21.7 ᄆ 2.95 ( p > .001).
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