الفهرس 
Benefits of liningOnly 14 pages are availabe for public view
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Abstract
The present study was carried out to assess the impacts of the
lining (as a physical mean for water management) on the water quality
and Nile tilapia fish, Oreochromis niloticus as bio-indicator species.
The present study included two approaches (laboratory study and field
investigations).
The obtained results could be summarized in the following points:
I: The results of the Laboratory studies:
1. After maintaining the fish O. niloticus, for 12 weeks, in aquaria
with different substrata (cement, plastic and mud) and control
ones (without lining), it was found that there were no
significant differences (P>0.05) in the growth performance and
the electrophoretic protein banding of the tested fish.
The average initial size of the tested fish, of the different
groups, was 3 g in weight and 5 cm in length and after 12
weeks the average final size of the fish was 15 g weight and
18 cm length; i.e. their growth rate was nearly the same in all
groups.
The electrophoretic technique (SDS-PAGE) of the tissue
soluble proteins revealed that there were slight variations
among the protein banding profiles of the tested fish groups.
The number of bands yielded from the fish samples of
different lining groups was 11, 14, 14 and 12 for cement,
plastic, mud and control fish groups, respectively. The four testing fish groups were sharing 9 bands with each other
which may be structural proteins.
The dendrogram from cluster analysis showed that the fish
of the cement-lined group demonstrate the highest value of
the similarity indices ”S” 0.96 and 0.88 with control and
mud groups, respectively.
2. The biochemical analysis of the serum samples of fish (30-70 g
in weight and 12-17 cm in length) reared in the different
substrata for 6 weeks indicated that there were also no
significant differences (P>0.05) in the blood parameters
(glucose, ALP, ALT, AST, total lipids & total proteins
contents, urea and creatinine) and they were all similar to the
normal values of the control group.
3. The physicochemical parameters of the water (temperature, pH,
dissolved oxygen, electrical conductivity and the total
dissolved solids) of the different groups of aquaria also recoded
no significant differences (P>0.05) among them.
II: The results of the field investigations:
The investigated sites were divided into two areas according to
the degree of pollution; where the area (2) was more polluted
(especially with heavy metals) than the area (1). Area (1) was
including site I (lined) and II (unlined), where the sites III (lined) and
IV (unlined) were at the area (2).
1. The physico-chemical parameters of the water of the
investigated lined and unlined sites in the two areas of study
were measured seasonally. The results indicated that: The water temperature of the two study areas (1 and 2) were
significantly different (P<0.05), as the water temperature
recorded the highest values in the study area (2), especially
at the unlined site (site IV: Ismailia canal at Mostorod)
during summer; it was 33 ºC.
The pH values of the area (1) were neutral at the lined site
(site I: El-Bostan canal) and slightly alkaline at the unlined
site (site II: Nasser canal).
However, the pH values of the area (2) were significantly
acidic (P < 0.05) at the unlined site (site IV: Ismailia canal at
Mostorod) than the lined one (site III: River Nile at Warraq
El-Haddar).
The EC and the TDS were also increased significantly
(P<0.05) in the unlined sites than the lined ones of the both
areas of study.
2. The heavy metal analysis showed that the study area (2) was
polluted with heavy metals (Cu, Pb and Cd) than the area (1).
Also, it was revealed that the lined sites of both areas are less
loaded with heavy metals (if found) than the unlined sites.
3. The performance of fish at the different sites was investigated.
It was noticed that the fish inhabiting the area (1) were
performing well in the both lined and the unlined sites.
However, fish samples collected from the lined site of the area
(2) showed a significant (P<0.05) better performance, by a
greater growth factor, than of the unlined sites. This was related to the high levels of heavy metals pollution in this site that
affected the growth rate.
4. The health of fish represented by the blood analysis of the fish
samples collected from the different lined and the unlined sites
was significantly (P<0.05) affected by the water quality of each
site.
The concentrations of glucose, total lipids, urea and
creatinine of fish samples were significantly (P<0.05) high
in the unlined sites comparing to the lined sites of the both
study areas.
On the same way ALP, ALT and AST enzymes showed a
significant (P<0.05) elevation in the samples of the unlined
sites than those of the lined sites at the two study areas.
On the other hand, the total protein content of the fish
samples of the unlined site at the area (1) showed a
significant (P<0.05) increase than those of the lined site of
the same area. This may indicate an early stage of tissue
damage that allows the proteins to be leaked out of the cells
(especially from the damaged hepatocytes) into the blood
circulation.
On contrast, the fish samples of the unlined site of the area
(2) revealed a significant (P<0.05) decrease in the protein
content comparing to those of the lined site which may be a
result of the late stage of the damaged tissue that no longer
able to produce proteins. The present histological study was carried out on two organs;
gills and liver of the collected fish samples. The manifested
histopathological results of the fish samples collected from the
different lined and unlined sites confirm the previous results of
the blood analysis.
i - The histopathological lesions found in the gills:
The gills of the fish samples collected from different sites
showed some alterations that were more or less similar but differ
in their degree of injury from mild as recorded in the lined site of
the area (1) to sever as observed at the unlined site of the area
(2).
These lesions were including cellular and circulatory changes:
The cellular alterations were including shortening/atrophy and
curling in the lamellae. Lamellar interstitial oedema that led to
epithelial lifting was observed. Hypertrophy of the chloride cells
and epithelial hyperplasia of the gill filament led to fusion of
neighboring lamellae were also seen. There was also
desquamation of the gill lamellae. Necrosis and epithelial
degeneration occasionally occurred.
While the circulatory disturbances were including lamellar
clubbed tips, vasodilation in the gill filament with blood
congestion, telangiectasis and aneurism.ii - The histopathological lesions found in the liver:
The most prominent alterations of the collected liver samples
were cytoplasmic vacuolation, dilation and congestion in the
blood vessels and sinusoids.
In addition to, irregular arrangements of hepatocytes; i.e.; loss of
its characteristic architecture, as a result of the degenerative and
necrotic changes were also observed.
Also, pyknotic nuclei were one of the most frequent and marked
changes observed nearly in all samples.
Widen extracellular spaces and loss of contact between
hepatocytes and pancreocytes was also seen; especially in the
liver samples collected from the unlined site of the area (2); site
IV: Ismailia canal at Mostorod.
Aggregations of inflammatory cells and hemorrhage of the blood
inside the blood vessels were also noticed in liver samples of
Ismailia canal.
Hemosiderin granules were only seen during winter in the fish
samples collected from the El-Bostan canal; the unlined site of
the study area (1).
CONCLUSION
1. The application of lining (whatever the used material) has no
negative effect neither on the physico-chemical parameters of the
water nor the health state of fish.
2. However, it plays a significant role in preserving the water with
good quality. The mechanism is unknown but it is supposed that the soil nature -especially earthen one with the increased
pollution factors today- plays a non negligible role in
maintaining the suitable habitat for bacteria, viruses and
parasites which are harmful to both aquatic life and human who
is the main consumer of the freshwater fish.
3. The histological and biochemical alterations found in the fish
samples were due to many types of pollutants; especially heavy
metals in the surrounding environment. So these bio-markers
with the physico-chemical parameters of the water assist in
monitoring and evaluation the state of the aquatic environment.