Rapp. Comm. int. Mer Médit., 36,2001
139
Introduction
Izmir Bay is located in the western part of Tu
r
key and surrounded by a
densely populated community. This bay has been divided into three sections
(
O
u
t
e
r, Middle and Inner) according to its physical characteristics as they
relate to the different water masses. Monitoring of Hg, Cd and Pb levels in
edible fishes (Mullus barbatus, Pagellus erythrinus, Merluccius merluccius,
Diplodus annularis, Solea vulgaris) was conducted in Izmir Bay during 1996-
1998. A number of studies have been carried out on the concentrations of
trace metals in the Bay during a year with a few different species (1-3) but no
long-term data are available on trace metal concentrations in the Bay during
a 3 year period. The main aim of this study was to monitor levels, temporal
variability and distribution of trace metals in edible fishes of Izmir Bay.
Material and Methods
The locations of sampling areas are given in Figure 1. Biota samples were
collected by trawling and approximately 5-7g of fish muscle was digested
with HNO
3
:
H
C
l
O
4
in microwave digestion system (4). All the analyses were
performed by Varian AAS. Hg concentration was measured by cold va
p
o
r
technique and Cd, Pb were determined by graphite furnace and background
corrections were used as required. The detection limits were Hg:0.05 µgl
-
1
,
Cd:0.10 µgl
-
1
, Pb:0.10 µgl
-
1
. Intercalibration fish homogenate samples (from
IAEA, Monaco) were used as a control for the analytical methods. The va
l-
ues obtained (in µg g
-
1
dry wt.) for the analysis of six replicates of this sam-
ple were as follows: Hg (certified 2.69±0.17; measured 2.77), Cd (certifie
d
0.015±0.012; measured 0.018), Pb (certified 0.074±0.015; measured 0.064)
.
Results and discussion
The concentrations of trace metals found in biota varied, with Hg ranging
from 12-829 and 5-315, Cd from 0.10-10 and 0.44-3.1 and Pb from 14-918
and 7-713 µg kg
-1
fresh weight in the Outer and Middle Bays, respectively
(Table 1). High levels of trace metals were measured in Pagellus erythrinus
for Hg and Cd, and in Mullus barbatusfor Pb in the outer part of the Bay.
Minimum values were found in Merluccius merluccius(Hg),Mullus barba-
tus(Cd) and Diplodus annularis(Pb) in the Outer Bay.The levels were sig-
nificantly lower in Solea vulgaristhan the other species from the Middle and
Inner Bays. There was no significant seasonal variation in trace metal con-
centrations. The relationship between Hg concentration and fork length was
significant in Mullus barbatus(R=0.491),Pagellus erythrinus (R=0.673) and
Merluccius merluccius(0.440). Cd and Pb concentrations in muscle tissue
showed no relation to fork length. A person consuming 2, 150 and 10 meals
per week of edible fishes in the human diet would reach the tolerable week-
ly intake of Hg, Cd and Pb, respectively (5,6). As a general conclusion, the
values are higher than the reported mean concentration of trace metals in
marine organisms from the Aegean and Mediterranean Sea (7-9). However,
the levels of trace metals determined in the different fish from Izmir Bay are
considerably lower than those in polluted areas of the Mediterranean Sea
(10).
References
1. Uysal H. and Tuncer S., 1982. Levels of heavy metals on some commercial food
species in the Bay of Izmir. C.I.E.S.M (VIes Journées Etud. Pollution, Cannes), 323-327.
2. Demirkurt E., Uysal H., Parlak H., 1990. The levels of heavy metals accumulation in
some benthic organisms living in Izmir Bay.Rapp. Comm. Mer. Medit., 32, 1:170.
3. Parlak H. and Demirkurt E., 1990. Levels of heavy metals in two demersal fishes,
Arnoglossus laterna(RISSO, 1810) and Buglossidium luteum (WALBAUM, 1972) in
Izmir Bay.Rapp. Com. int. Mer Medit., 32, 1:274
Table 1. Trace metal concentrations in fish from Izmir Bay (mg
kg-1 fresh wt.)
SamplingOrganismLengthNumberHgCdPb
location
(mm)of sample
06/96Mullus barbatus125-153202592.4918
OuterPagellus erythrinus250-28048292.683
Merluccius merluccius260-2952651.9155
Diplodus annularis130-170102202.114
Solea vulgaris159-23041591.6203
MiddleMerluccius merluccius190-3862922.4713
Diplodus annularis105-14283151.97.1
Solea vulgaris199-2103681.8388
InnerSolea vulgaris156-1713172.297
10/96 OuterMullus barbatus118-153101820.13125
Diplodus annularis118-129101620.16205
Solea vulgaris158-1823170.4146
MiddleSolea vulgaris157-1884220.44115
01/97 OuterMullus barbatus110-15019940.93209
Mullus barbatus150-1656770.5339
Pagellus erythrinus150-23062630.21150
Merluccius merluccius260-2952530.2517
Diplodus annularis135-170103701.030
04/97 OuterMullus barbatus144-1754661.929
Pagellus erythrinus141-19761813.2146
Merluccius merluccius3871964.0455
Diplodus annularis126-16010914.5175
InnerSolea vulgaris170-20537.72.3270
07/97 OuterMullus barbatus111-14310873.5780
Mullus barbatus20613995.7943
Pagellus erythrinus245-270231610376
Merluccius merluccius365-3844271.5431
Diplodus annularis118-14520921.7697
MiddleDiplodus annularis101-1439741.9169
Solea vulgaris161-246125.21.2364
10/97 OuterMullus barbatus163-184103451.5120
Mullus barbatus128-1628752.0349
Pagellus erythrinus151-21863691.258
Merluccius merluccius346-4445532.0120
Merluccius merluccius221-28510121.6315
Diplodus annularis106-143102851.0428
MiddleSolea vulgaris157-17345.21.3110
InnerSolea vulgaris159-22449.51.1217
01/98 OuterMullus barbatus150-16010840.9316
Pagellus erythrinus12711445.489
Pagellus erythrinus20714190.6628
Merluccius merluccius313-3619170.48240
Diplodus annularis109-134201640.90175
Solea vulgaris2201461.278
InnerSolea vulgaris130-1402113.2341
04/98 OuterMullus barbatus130-1618831.2359
Mullus barbatus114-13910270.53256
Pagellus erythrinus26811750.7788
Merluccius merluccius284-3203371.1375
Diplodus annularis127-153101840.58326
10/98 OuterMullus barbatus140-15710410.1044
Mullus barbatus168-18692850.88478
Pagellus erythrinus147-15232792.2203
Pagellus erythrinus186-20123420.6148
Merluccius merluccius251-2732340.58116
Diplodus annularis117-144101741.2594
Solea vulgaris25012125.2220
4. Bernhard, M., 1976. Manual Methods in the aquatic environment (Part 3). Sampling
and analyses of biological material. FAO Fisheries Technical PaperNo:158.
5. FAO/WHO, 1972. Evaluation of certain food activities and the contaminants mercury,
lead, cadmium. Sixteenth report of the Joint FAO/WHO Expert Committee on Food
Additives, Geneva,World health Organization (Technical Report Series No.505).
6. UNEP, 1989. State of Mediterranean Marine Environment. MAP Technical reports
Series No.28, UNEP,Athens.
7.AydogduT., Balkas T., Bingel F., Salihoglu I. and Tugrul S., 1982. Mercury in some
fish of the North +Levantine (Eastern Mediterranean). VIes Journées
Etud. Pollutions,
CIESM, 261-269.
8. IMST, 1997. D.E.U. Inst. of Marine Science&Technology,Tech. Final Reports, Izmir.
9. Kucuksezgin F., Altay O., Uluturhan E. and Kontas A., 2001. Trace Metal and
Organochlorine Residue Levels in Red Mullet (Mullus barbatus) from the Eastern Aegean,
Turkey.Water Research(In Press).
10. Barghigiani C., De Ranieri S. 1992. Mercury content in different size classes of important
TRACE METAL CONCENTRATIONS IN EDIBLE FISHES FROM IZMIR BAY, EASTERN AEGEAN
F. Kucuksezgin*, A. Kontas, O. Altay, E. Uluturhan
Dokuz Eylul University, Institute of Marine Sciences and Technology.Inciralti, Izmir,Turkey - kucuksez@imst.deu.edu.tr
Abstract
The levels of Hg, Cd, Pb were determined in edible fish of Izmir Bay in the framework of a 'Izmir Bay Marine Research Project' during
1996-1998 supported by Izmir Metropolitan Municipality.The concentrations of trace metals found in fish varied for Hg: 5.2-829, Cd:
0.10-10 and Pb: 7.1-918 µg kg
-1
fresh weight in Izmir Bay.There was no significant seasonal variation in trace metal concentrations. The
relationships between Hg concentration and fork length were significant in Mullus barbatus, Pagellus erythrinusandMerluccius
merlucciusin the Bay.Trace metal levels were lower than the results in fish tissues reported from polluted areas of the Mediterranean Sea.
Key words: Mercury, cadmium, lead, fish, Eastern Aegean
Fig.1. The location of sampling sites.
