BIOMARKERS AS INDICATOR FOR WATER
POLLUTION
WITH HEAVY METALS IN RIVERS, SEAS AND
OCEANS
M.NAGEEB
RASHED
Faculty of Science, 81528 Aswan, South Valley University,
Egypt
E-mail m n r a s h e d @h o t m a il. co m Fax 002 097 480
449
Water is one of our most important natural resources, and there are many conflicting
demands upon it. Skilful management of our water bodies is required if they are to be
used for such diverse purpose as domestic and industrial supply, crop irrigation,
transport, recreation , sport and commercial fisheries, power generation and waste
disposal. Water pollution is most commonly associated with the discharge of effluents
from sewers or sewage treatment plants, drains and factories to the water body of rivers,
seas and marines. In the attempt to define and measure the presence and effects of
pollutants epically the metals in rivers and oceans, the biological markers have attracted
a great deal of interest. The principle behind the biomarker approach is the analysis of
an organism metal content and compared the metal concentration with the background
metal levels. In this review, the data were collected from different literatures around the
world in using the aquatic organisms as biological indicator for metal pollution in
aquatic system.
INTRODUCATION
Water Pollution with metals
The aquatic environment with its water quality is considered the main factor controlling
the state of health and disease in both man and animal. Nowadays, the increasing use of
the waste chemical and agricultural drainage systems represents the most dangerous
chemical pollution. The most important heavy metals from the point of view of water
pollution are Zn, Cu, Pb, Cd, Hg, Ni and Cr. Some of these metals (e.g. Cu, Ni, Cr and
Zn) are essential trace metals to living organisms, but become toxic at higher

Fish have been used for many years to indicate whether water are clean or polluted. Fish
are excellent biological markers of metals in water.
Fish from Lakes: Nasser Lake
Tilapia nilotica is one of the aquatic organisms affected by heavy metals, so in many
cases, Tilapia nilotica was used as metal biological marker in toxicological studies in
which it was substantiated with the highest sensitivity to toxic effect (Patin, 1984).
Rashed (2001a, b) studied Co, Cr, Cu, Fe, Mn, Ni, Sr, Pb, Cd and Zn in different tissues
of fish (Tilapia nilotica) from Nasser lake to assess both the water pollution with these
metals and the lethal level of these metals in fish. Fish samples were collected from two
Kohrs in Nasser Lake ( Kohr Kalabsha and Kohr El-Ramel) .The fish tissues includes
muscle, gill, stomach, intestine , liver, veritable column and scales .The fish ages were 1,
1.5 , 2, 2.5 and 3 years. This study resulted in that fish scales exhibited the highest
concentrations of Cd, Pb, Co,Cr,Ni and Sr (0.088,0.95,0.29,0.30,0.25 and 3.21 µg/g DW
respectively). Whole fish contains the higher concentrations of the studied metals
compared to the previous study by Awadallah et al.(1985) in the same fish from Nasser
Lake, and this mean the increase in metal pollution in Lake water as the results of man
activities (Table 1). This increasing in metal concentration was as the result of increasing
pollution loads to the Lake from agricultural wastes, which include chemical pesticide
and fertilizers. These agricultural wastes reached the Lake body from the agricultural
farms on the beach of the Lake. The source of Pb in the Lake water and fish was resulted
3
from gasoline contains Pb from the fishery boats and tour ships travels from Aswan to
Sudan (Mohamed et al.1990).
Table 1. Metal concentrations in Tilapia nilotica and water from Nasser Lake in years
1980 to 2000
Metals Lake Water (µg//l)
1985* 2000***
Fish (µg/g)
1985** 2000***
Difference

6.45
0.33
2 --
43 0.155
73 0.108
11 0.171
67 6.35
0.004 0.235
* Sherief et al. (1980) ** Awadallah et al. (1985) *** Rashed (
2001a,b)
Lake Mariut and Lake Edku
Adham et al. (1999) used fish as bioindicator for assessing metal pollution in Delta
Lakes (Lake Maryut and Lake Edku ). Lake Edku is grouped 25 the site highest in metal
concentrations. Compared to Lakes Maryut and Edku, the Nile water displayed lower
levels of metal contamination. Lillo (1976) reported that bolti from Mariut Lake
contained less Fe content compared to Nile bolti fish and concluded that the source was
from the factories discharge. El- Nabwi et al. (1987) studied the concentration of Pb in
fish, Tilapia nilotica, from Maryut Lake and found that Pb concentration was 0.42 ppm.
Fish from River Nile
River Nile is the main source for potable water and as the result of man activities in and
on the river body it become loaded by metal pollution. Fish in the River Nile was used as
biological marker for the River pollution by metals . Mohamed et al. (1990 ) used
Tilapia nilotica fish as a biomarker for the Nile water pollution with metals at the
discharge. Point of fertilizer factory with the Nile. Ag,Au,Ca, Cr,Cu,
Fe,K,Mg,Mn,Na,Ni,Pb,Sr and Zn were determined in tilapia nilotica fish collected from
the Nile area at the point of fertilizer discharge to the Nile and south and north this
point. The results revealed that fish near the point of the factory discharge possess the
highest levels of metals as the result of pollution with metals.
Other study for using fish as biomarker for water pollution with metals was
conducted (Khallaf et al., 1994). Two species of fresh water fish (Tilapia nilotica ,named

2.09
0.04
3.38
2.69
0.03
0.05
0.14
0.22
54.7
4.90
3.43
0.047
0.17
Kafer-El-
Zayat(Nile)
Water
Bolti
Karmout
0.16
0.87
1.13
0.15
3.80
1.32
0.16
4.04
0.92
0.07
0.12
0.13

Bolti
Karmout
0.24
0.34
0.61
0.12
1.79
0.46
0.13
2.35
4.20
0.06
0.06
0.13
0.27
5.90
4.30
3.81
0.048
0.20
Permissible level*
Water
Fish
1
20
5
40
0.01
10
0.01

gradual increase in their concentration in relation to the water and fish ( Table 3 )
Table 3. Heavy metal concentrations in water, aquatic plants, fish and organisms from
Ioannina Lake
Items/
Metal conc.
Fe Zn Cu Pb
Water (mg/l)
Aquatic plant
(µg/g)
Fish
(µg/g)
Organisms
(µg/g)
6.1
8.0
0.61
0.40
0.0
ND*
0.63
0.58
0.01
ND
41
25
0.2
ND
3.0
2.13
*ND, Not