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Heavy metal levels in characteristic benthic flora and fauna in the Central Aegean Sea
Marine Pollution Bulletin
Edited by D. J. H. Phillips The objective of BASELINE is to publish short communications for the concentration and distribution of elements and compounds in the marine environment. Only those papers which clearly identify the quality of the data will be considered for publication. Contributors to Baseline should refer to 'Baseline--A Record of Contamination Levels' (Mar. Pollut. Bull. 13,217-218). Marine Pollution Bulh'titt, Volume 22, N()I I I, pp. 566 56,9, lgtll. Printed in Greal Britain
0(125-326X/91 $5.l)0+0.1)(I © 1991 Pergamon Press pie
Heavy Metal Levels in Characteristic Benthic Flora and Fauna in the Central Aegean Sea Few areas in Greece are considered to be polluted by heavy metals, and in most of them studies have been made in order to define the level of metal accumulation in the soft tissues of different organisms (VoutsinouTaliadouri 1982; Vasilikiotis et al., 1983; Catsiki et al., 1986; Satsmatzis et al., 1988). Few papers deal with unpolluted areas. The aim of the present work was to provide information about heavy metals content in benthic organisms in an area which is considered to be unpolluted, Milos island in the Central Aegean Sea. Benthic samples were collected in October 1988 from five areas along the coast of Milos island, by SCUBA at a depth of about 12 m (Fig. 1): reference areas (stations 1, 2, 4), the electricity plant area (station 3) and the semi-enclosed gulf including the port of Milos island (station 5). Species examined were the sea urchin Paracentrotus lividus L., the limpet Patella aspera (Lam.) and the two species of algae Cystoseira sp. and Padina pavonica (L.).
tsl.
MILOS
I
5kin
Immediately after collection, individual samples containing the whole body or one tissue--where appropriate-were studied. The gonads of E lividus, the soft tissues of P. aspera and leaves of P. pavonica and Cystoseira were analysed for metals. The epiphyta from the leaves were removed using a small P.V.C. knife. Great care was taken to clean samples of sediments and any other substance (organic material etc.) from every part of the specimen to avoid contamination (Bernhard, 1976). For the animal tissue the gut contents were not depurated or removed. All samples were transported to the laboratory at -10°C, until analysis. The tissue samples were dried by lyophilization and homogenized; approx. 0.5 g of tissue was digested with 5 ml of nitric acid into special Teflon vessels under pressure at 120°C for 12 h (UNEP, 1982). Determination of nickel, copper, cadmium, chromium, manganese and zinc was made using an air-acetylene flame spectrophotometer. A Varian AA 157 atomic absorption spectrophotometer was used for all measurements; the settings of the spectrophotometer are shown in Table l. The accuracy and precision of the methodology were tested during the UNEP Intercalibration Testing Exercise of 1984 and 1989 (Table 2). The detection limits of the spectrophotometric method were about 0.05 ~tg 1-1. Statistical treatment of the results include the Two Way Analysis of Variance (ANOVA) and the Least Significant Range Test (LSR) were used using the software package STATGRAPHICS. The mean concentration values are shown in Table 3. The brown algae Cystoseira sp. had the lower bioaccumulation rates for all metals with the exception of manganese and nickel. This is in agreement with results cited by Bryan (1976). Low values for most of the metals were also observed for P. lividus. The limpet P. aspera, seemed generally to accumulate heavy metals
I
N t
Aegean
Fig. 1 Location of the sampling stations in Milos island.
566
Sea
Volume 22/Number I l/November 1991
more than the other species. This is particularly evident for cadmium; limpets are good indicators of metal contamination--especially for Cd and usually contain high concentrations under normal conditions (Bryan,
1976). P. aspera also shows high manganese concentrations. However, higher values (average manganese levels) are found in the two algae, Cystoseira and P. pavonica and these two species may be considered as biological indicators for manganese (Table 3). Shellfish and algae concentrate manganese many times more than their surrounding seawater (Mero, 1965). For manganese it should be noted that for each one of the selected species four different bioaccumulation levels were determined: sea urchins < limpets < Cystoseira < Padina. The higher concentrations of this metal in algae, when compared with limpets, is in agreement with the findings of Bryan (1976) and F6rstner & Wittmann (1979). For all cases two-way ANOVA revealed statistically significant differences in metal content between the different species tested (Table 4). Levels of heavy metals in marine organisms of Milos island are generally low. In comparison with those of other areas in the Aegean Sea the concentration ranges of all metals are very similar to those found in clean waters (Grimanis et al., 1976; Voutsinou-Taliadouri, 1982; Catsiki et al., 1987).
TABLE l Settings of atomic absorption spectrophotometer. Metal
Wavelength
Slit
Current (mA)
Flame
228.8 357.9 324.8 232.0 279.5 213.9
0.5 0.2 0.5 0.2 0.2 1
4 7 3.5 11.5 12 5
oxidizing reducing oxidizing oxidizing oxidizing oxidizing
Cd Cr Cu Ni Mn Zn
TABLE 2 Analysis of MA-A-2 (fish flesh) standard reference material (llg g-K dry wt). UNEP lntercalibration 1984. Metal Cu Cd Zn
Certified
N
Found
c%
4.5 5:0.3 0.175:0.3 335:1
6 6 6
4.23 5:0.27 0.405:0.27 34.1 5:0.56
6.9 7.4 1.8
TABLE 3 Mean values 5: Standard Deviation values (std) of bioaccumulation of the six metals at the 5 stations in the four species, sp.l: P lividus, sp.2: P. aspem, sp.3: Cystoseira sp., sp.4: P. pavonica. Ni
Cu
Cd
Mn
Cr
Zn
Station 1
sp.l sp.2 sp.3 sp.4
9.30+5.58 28.60+14.69 21.90_+6.33 28.40+8.32
4.00+ 1.40 10.10+2.30 5.20+ 1.70 5.90+2.60
2.40+0.80 8.30+2.30 2.40+0.70 3.20+0.90
2.20+ 1.04 16.30+11.80 27.20_+35.70 46.50+5.20
3.10+ 1.90 6.17+4.60 2.10-1-2.20 4.40+ 1.50
123.60+69.30 56.50+36.90 24.40_+8.10 21.80-1- 12.3(I
Station 2
sp.l sp.2 sp.3
8.74+5.25 26.905:12.66 17.60+4.99
4.29+2.10 7.60-+2.68 4.205:1.04
2.49+0.90 3.70+ 1.50 1.80+ 1.10
10.75+9.70 32.10+44.50 61.705:24.20
2.48+1.20 5.125:2.30 2.50+2.30
120.025:67.80 31.85_+ 18.00 25.905:7.50
Station 3
sp.l sp.2 sp.3 sp.4
14.10_+19.37 25.505:38.54 10.20+7.37 27.305:2.54
6.305:3.30 12.00+4.30 4.605:0.40 6~70 + 0.80
3.00+ 1.70 7.90+2.20 3.505:0.90 3.105:0.40
2.405:0.80 6.30+2.50 18.605:3.00 75.20_+18.90
3.605:2.80 15.305:31.30 1.60+0.80 4.105:1.50
117.605:22.50 42.605:5.40 47.305:10.60 30.105:2.60
Station 4
sp.1 sp.2 sp.3 sp.4
7.105:2.34 19.10_+13.04 8.905:5.91 19.00_+9.19
3.70+_0.70 12.305:3.70 3.605:0.50 6.705:0.40
1.90_+0.20 11.405:3.90 2.205:0.20 3.205:0.30
1.20_+0.30 11.30+3.50 16.705:1.80 74.005:25.80
1.90+ 1.40 5.805:4.20 1.505:1.10 3.505:1.20
75.805:41.10 50.90-+8.70 22.005:3.90 37.30-+4.40
Station 5
sp.l sp.2 sp.3 sp.4
34.90_+ 19.37 16.00_+11.80 17.70+5.30 22.00+6.90
5.50+2.80 7.905:2.80 4.10_+3.30 5.30+ 1.00
3.40_+ 1.20 5.005:1.70 1.60-+0.70 2.705:0.30
6.30-+4.00 23.005:22.80 65.405:68.40 121.305:9.60
18.205:14.70 5.205:4.50 5.30+3.60 4.10+ 1.00
127.30+ 102.70 43.205:11.8(I 59.t0+41.80 32.205:4.80
TABLE 4 Statistical analysis of the metal bioaccumulation data (two-way ANOVA). Metals
Cu
Main effects (a) Station F (b) Species
P F P
Zn
Ni
Cr
Cd
Mn
4.40 0.002* 69.36 < 0.001 *
1.51 0.202 41.55 < 0.001 *
4.24 (I.003" 11.58 < 0.001 *
6.36 < 0.001" 15.42 < 0.001 *
16.55 < 0.001 * 158.22 < 0.001 *
26.11 < 0.001" 251.15 < 0.001"
2.77 0.002*
3.44 < 0.001 *
3.25 < 0.001 *
4.62 < 0.001"
9.80 < 0.001 *
2.47 0.006*
22.579 199
11.419 198
2.001 195
Interactions "station' by ~species" F P
Residual Sum of squares Degrees of freedom
3.121 197
11.753 201
12.004 202
*Statistical significant difference.
567
Marine Pollution Bulletin
In order to establish any differences between stations or an indication of local natural metal contamination, statistical analysis of the data had been applied. A further reason for this inter-station comparison was the fact that a recent installation of an electricity plant discharges its thermal effluents into the area of station 2. For all metals, except zinc, the two-way ANOVA showed significant differences among samples of the same species collected at the five stations (Table 4, Figs 2-4). Generally the results of the statistical analysis demonstrate a trend of higher concentrations from samples collected at station 5. This could be attributed to the fact that this station, located in the internal part of the main gulf of the island, has limited water circulation (Papageorgiou, personal communication). In addition the neighbouring station has domestic areas and two harbour activities (the main port located northeast of the gulf (Fig. 1) and a secondary harbour facility for barite cargoes in the south of the gulf) which
may also contribute to the elevated levels of heavy metal accumulation). Sediment samples from the stations 1, 2, 3 taken during 1988 showed higher concentrations of nickel in station 2 and relatively higher values of copper and chromium (Voutsinou-Taliadouri, 1989). However, this is not reflected in marine organisms, apart from nickel content in P aspera. The effluents of the electricity plant, discharged near station 2, were high in zinc and lead and slightly enriched in copper and arsenic, but did not affect the sediments (Voutsinou-Taliadouri, 1989) or the biota of the area of station 2. The latter presented relatively high values of zinc and copper at this station. Manganese levels in benthic species tested reach their maximum values at this station and are not related to the concentrations of manganese observed in the sediments (Vout sinou-Taliadouri, 1989). In this study the species was the more important
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568
St :5
St 4
St 5
s t a t i o n by species
Fig. 3 Plot of the means and the 95% of the Least Significance Range Intervals for the station by species interactions, showing the differences between species and stations. A: Nickel, B: Chromium. a ~ Cystoseira sp., b ~ / ~ p a v o n i c a , c = P. fividus, d = P aspera.
Volume 22/Number I 1/November 1991
factor which influenced metal bioaccumulation by the tested biota. This could explain the high significant level (P=0.0002) observed at the interactions between station and species (Table 4, Figs 2-4).
m
2.4
We would like to thank Mrs. K. Sapsali for the help she gave us during the sampling.
16-
I/. A. CATSIKI E. PAPATHANASSIOU E BEI National Centre for Marine Research, Agios Kosmas, Hellinikon, Athens 16604, Greece
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In conclusion, although a differentiation between samples from the different localities around Milos island were evident, the levels of metals in marine flora and fauna were low and similar to other clean areas. On the other hand P. aspera was found to be good indicator for most metals (copper, cadmium, chromium, zinc, nickel), while the brown algae for manganese. The existing data could act as reference information for unpolluted areas in the East Mediterranean.
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Fig. 4 Plot of the means and the 95% of the Least Significance Range Intervals for the station by species interactions, showing the differences between species and stations. A: zinc, B: Manganese. a - Cystoseira sp., b - P pavonica, c " P lividus, d - P aspera.
Bernhard, M. (1976). Manual of methods in aquatic environmental research. Per 3. Sampling and analysis of biological material. EA.O. Fish Techn. Rap., No. 158. Bryan, G. W. (1976). Heavy metal contamination in the sea. In Marine Pollution (R. Johnston, ed.), pp. 185-305. Academic Press, New York. Catsiki, A. V., Panayofidis, P. & Papathanassiou, E. (1986). Impact of tannery wastes to the benthic communities in Geras Gulf (Lesvos isi., Greece). In Environmental Quality and Ecosystem Stability, Vol. IIl A/B (Z. Dubinsky & Y. Steinberger, eds), pp. 883-890. Bar-llan University Press, Ramat-Gan, Israel. Catsiki, A. V., Panayotidis, E & Papathanassiou, E. (1987). Bioaccumulation of heavy metal ions by seagrasses in Greek coastal waters. Posid. Newsletter 1(2), 21-30. F6rstner, U. & Wittman, G. T. W. (1979). Metal pollution. In Aquatic Environment. Springer-Verlag, Berlin. Grimanis, A. E, Zafiropoulos, D. & Vassilaki-Grimani, M. (1976). Trace elements in Sargus annularis and Gobius niger from polluted and unpolluted areas of the Aegean sea. Joumees Etud. Pollutions, Cannes, C.I.E.S.M. 6, 319-322. Mero, J. L. (1965). In Mineral Resources of the Sea (J. L. Mero, ed.), p. 312. Elsevier, New York. Satsmatjis, J., Catsiki, V. A. & Georgakopoulos-Gregoriades, E. (1988). Levels of chlorinated hydrocarbons and metals in demersal fishes. Rapp. Comm. Int. Mer. Medit., Athens, C.LE.S.M. 31, 150. UNEP (1982). Determination of total Cd, Zn, Pb and Cu in selected marine organisms by atomic absorption spectrophotometry. Ref. Meth. for Mar. Pollut. Studies. No. 11. Vasilikiotis, G., Fytianos, K. & Zotou, A. (1983). Heavy metals in marine organisms of the North Aegean Sea, Greece. Chemosphere 12, 75-81. Voutsinou-Taliadouri, E (1982). Monitoring of some metals in some marine organisms from Saronikos Gulf. Joumees ,Etud. Pollutions, Cannes, C.LE.S.M. 6, 329-333. Voutsinou-Taliadouri, F. (1989). Geochemical survey of marine sediments in Milos Island in Preliminary Report "Oceanographic survey in Milos Island", National Center of Marine Research (in Greek).
Whilst every effort is made by the publishers and editorial board to see that no inaccurate or misleading data, opinions or statements appear in this journal, they wish to make it clear that the data and opinions appearing in the articles and advertisements herein are the sole responsibility of the contributor or advertiser concerned. Accordingly, the publishers, the editorial board and editors, and their respective employees, officers and agents accept no responsibility or liability whatsoever for the consequences of any such inaccurate or misleading data, opinions or statements. 569
Edited by D. J. H. Phillips The objective of BASELINE is to publish short communications for the concentration and distribution of elements and compounds in the marine environment. Only those papers which clearly identify the quality of the data will be considered for publication. Contributors to Baseline should refer to 'Baseline--A Record of Contamination Levels' (Mar. Pollut. Bull. 13,217-218). Marine Pollution Bulh'titt, Volume 22, N()I I I, pp. 566 56,9, lgtll. Printed in Greal Britain
0(125-326X/91 $5.l)0+0.1)(I © 1991 Pergamon Press pie
Heavy Metal Levels in Characteristic Benthic Flora and Fauna in the Central Aegean Sea Few areas in Greece are considered to be polluted by heavy metals, and in most of them studies have been made in order to define the level of metal accumulation in the soft tissues of different organisms (VoutsinouTaliadouri 1982; Vasilikiotis et al., 1983; Catsiki et al., 1986; Satsmatzis et al., 1988). Few papers deal with unpolluted areas. The aim of the present work was to provide information about heavy metals content in benthic organisms in an area which is considered to be unpolluted, Milos island in the Central Aegean Sea. Benthic samples were collected in October 1988 from five areas along the coast of Milos island, by SCUBA at a depth of about 12 m (Fig. 1): reference areas (stations 1, 2, 4), the electricity plant area (station 3) and the semi-enclosed gulf including the port of Milos island (station 5). Species examined were the sea urchin Paracentrotus lividus L., the limpet Patella aspera (Lam.) and the two species of algae Cystoseira sp. and Padina pavonica (L.).
tsl.
MILOS
I
5kin
Immediately after collection, individual samples containing the whole body or one tissue--where appropriate-were studied. The gonads of E lividus, the soft tissues of P. aspera and leaves of P. pavonica and Cystoseira were analysed for metals. The epiphyta from the leaves were removed using a small P.V.C. knife. Great care was taken to clean samples of sediments and any other substance (organic material etc.) from every part of the specimen to avoid contamination (Bernhard, 1976). For the animal tissue the gut contents were not depurated or removed. All samples were transported to the laboratory at -10°C, until analysis. The tissue samples were dried by lyophilization and homogenized; approx. 0.5 g of tissue was digested with 5 ml of nitric acid into special Teflon vessels under pressure at 120°C for 12 h (UNEP, 1982). Determination of nickel, copper, cadmium, chromium, manganese and zinc was made using an air-acetylene flame spectrophotometer. A Varian AA 157 atomic absorption spectrophotometer was used for all measurements; the settings of the spectrophotometer are shown in Table l. The accuracy and precision of the methodology were tested during the UNEP Intercalibration Testing Exercise of 1984 and 1989 (Table 2). The detection limits of the spectrophotometric method were about 0.05 ~tg 1-1. Statistical treatment of the results include the Two Way Analysis of Variance (ANOVA) and the Least Significant Range Test (LSR) were used using the software package STATGRAPHICS. The mean concentration values are shown in Table 3. The brown algae Cystoseira sp. had the lower bioaccumulation rates for all metals with the exception of manganese and nickel. This is in agreement with results cited by Bryan (1976). Low values for most of the metals were also observed for P. lividus. The limpet P. aspera, seemed generally to accumulate heavy metals
I
N t
Aegean
Fig. 1 Location of the sampling stations in Milos island.
566
Sea
Volume 22/Number I l/November 1991
more than the other species. This is particularly evident for cadmium; limpets are good indicators of metal contamination--especially for Cd and usually contain high concentrations under normal conditions (Bryan,
1976). P. aspera also shows high manganese concentrations. However, higher values (average manganese levels) are found in the two algae, Cystoseira and P. pavonica and these two species may be considered as biological indicators for manganese (Table 3). Shellfish and algae concentrate manganese many times more than their surrounding seawater (Mero, 1965). For manganese it should be noted that for each one of the selected species four different bioaccumulation levels were determined: sea urchins < limpets < Cystoseira < Padina. The higher concentrations of this metal in algae, when compared with limpets, is in agreement with the findings of Bryan (1976) and F6rstner & Wittmann (1979). For all cases two-way ANOVA revealed statistically significant differences in metal content between the different species tested (Table 4). Levels of heavy metals in marine organisms of Milos island are generally low. In comparison with those of other areas in the Aegean Sea the concentration ranges of all metals are very similar to those found in clean waters (Grimanis et al., 1976; Voutsinou-Taliadouri, 1982; Catsiki et al., 1987).
TABLE l Settings of atomic absorption spectrophotometer. Metal
Wavelength
Slit
Current (mA)
Flame
228.8 357.9 324.8 232.0 279.5 213.9
0.5 0.2 0.5 0.2 0.2 1
4 7 3.5 11.5 12 5
oxidizing reducing oxidizing oxidizing oxidizing oxidizing
Cd Cr Cu Ni Mn Zn
TABLE 2 Analysis of MA-A-2 (fish flesh) standard reference material (llg g-K dry wt). UNEP lntercalibration 1984. Metal Cu Cd Zn
Certified
N
Found
c%
4.5 5:0.3 0.175:0.3 335:1
6 6 6
4.23 5:0.27 0.405:0.27 34.1 5:0.56
6.9 7.4 1.8
TABLE 3 Mean values 5: Standard Deviation values (std) of bioaccumulation of the six metals at the 5 stations in the four species, sp.l: P lividus, sp.2: P. aspem, sp.3: Cystoseira sp., sp.4: P. pavonica. Ni
Cu
Cd
Mn
Cr
Zn
Station 1
sp.l sp.2 sp.3 sp.4
9.30+5.58 28.60+14.69 21.90_+6.33 28.40+8.32
4.00+ 1.40 10.10+2.30 5.20+ 1.70 5.90+2.60
2.40+0.80 8.30+2.30 2.40+0.70 3.20+0.90
2.20+ 1.04 16.30+11.80 27.20_+35.70 46.50+5.20
3.10+ 1.90 6.17+4.60 2.10-1-2.20 4.40+ 1.50
123.60+69.30 56.50+36.90 24.40_+8.10 21.80-1- 12.3(I
Station 2
sp.l sp.2 sp.3
8.74+5.25 26.905:12.66 17.60+4.99
4.29+2.10 7.60-+2.68 4.205:1.04
2.49+0.90 3.70+ 1.50 1.80+ 1.10
10.75+9.70 32.10+44.50 61.705:24.20
2.48+1.20 5.125:2.30 2.50+2.30
120.025:67.80 31.85_+ 18.00 25.905:7.50
Station 3
sp.l sp.2 sp.3 sp.4
14.10_+19.37 25.505:38.54 10.20+7.37 27.305:2.54
6.305:3.30 12.00+4.30 4.605:0.40 6~70 + 0.80
3.00+ 1.70 7.90+2.20 3.505:0.90 3.105:0.40
2.405:0.80 6.30+2.50 18.605:3.00 75.20_+18.90
3.605:2.80 15.305:31.30 1.60+0.80 4.105:1.50
117.605:22.50 42.605:5.40 47.305:10.60 30.105:2.60
Station 4
sp.1 sp.2 sp.3 sp.4
7.105:2.34 19.10_+13.04 8.905:5.91 19.00_+9.19
3.70+_0.70 12.305:3.70 3.605:0.50 6.705:0.40
1.90_+0.20 11.405:3.90 2.205:0.20 3.205:0.30
1.20_+0.30 11.30+3.50 16.705:1.80 74.005:25.80
1.90+ 1.40 5.805:4.20 1.505:1.10 3.505:1.20
75.805:41.10 50.90-+8.70 22.005:3.90 37.30-+4.40
Station 5
sp.l sp.2 sp.3 sp.4
34.90_+ 19.37 16.00_+11.80 17.70+5.30 22.00+6.90
5.50+2.80 7.905:2.80 4.10_+3.30 5.30+ 1.00
3.40_+ 1.20 5.005:1.70 1.60-+0.70 2.705:0.30
6.30-+4.00 23.005:22.80 65.405:68.40 121.305:9.60
18.205:14.70 5.205:4.50 5.30+3.60 4.10+ 1.00
127.30+ 102.70 43.205:11.8(I 59.t0+41.80 32.205:4.80
TABLE 4 Statistical analysis of the metal bioaccumulation data (two-way ANOVA). Metals
Cu
Main effects (a) Station F (b) Species
P F P
Zn
Ni
Cr
Cd
Mn
4.40 0.002* 69.36 < 0.001 *
1.51 0.202 41.55 < 0.001 *
4.24 (I.003" 11.58 < 0.001 *
6.36 < 0.001" 15.42 < 0.001 *
16.55 < 0.001 * 158.22 < 0.001 *
26.11 < 0.001" 251.15 < 0.001"
2.77 0.002*
3.44 < 0.001 *
3.25 < 0.001 *
4.62 < 0.001"
9.80 < 0.001 *
2.47 0.006*
22.579 199
11.419 198
2.001 195
Interactions "station' by ~species" F P
Residual Sum of squares Degrees of freedom
3.121 197
11.753 201
12.004 202
*Statistical significant difference.
567
Marine Pollution Bulletin
In order to establish any differences between stations or an indication of local natural metal contamination, statistical analysis of the data had been applied. A further reason for this inter-station comparison was the fact that a recent installation of an electricity plant discharges its thermal effluents into the area of station 2. For all metals, except zinc, the two-way ANOVA showed significant differences among samples of the same species collected at the five stations (Table 4, Figs 2-4). Generally the results of the statistical analysis demonstrate a trend of higher concentrations from samples collected at station 5. This could be attributed to the fact that this station, located in the internal part of the main gulf of the island, has limited water circulation (Papageorgiou, personal communication). In addition the neighbouring station has domestic areas and two harbour activities (the main port located northeast of the gulf (Fig. 1) and a secondary harbour facility for barite cargoes in the south of the gulf) which
may also contribute to the elevated levels of heavy metal accumulation). Sediment samples from the stations 1, 2, 3 taken during 1988 showed higher concentrations of nickel in station 2 and relatively higher values of copper and chromium (Voutsinou-Taliadouri, 1989). However, this is not reflected in marine organisms, apart from nickel content in P aspera. The effluents of the electricity plant, discharged near station 2, were high in zinc and lead and slightly enriched in copper and arsenic, but did not affect the sediments (Voutsinou-Taliadouri, 1989) or the biota of the area of station 2. The latter presented relatively high values of zinc and copper at this station. Manganese levels in benthic species tested reach their maximum values at this station and are not related to the concentrations of manganese observed in the sediments (Vout sinou-Taliadouri, 1989). In this study the species was the more important
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.
stations by species
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stations by species Fig. 2 Plot of the means and the 95% of the Least Significance Range Intervals for the station by species interactions, showing the differences between species and stations. A: Copper, B: Cadmium. a = Cystoseira s p . , b = P. p a v o n i c a , c = P. lividus, d = P. aspera.
568
St :5
St 4
St 5
s t a t i o n by species
Fig. 3 Plot of the means and the 95% of the Least Significance Range Intervals for the station by species interactions, showing the differences between species and stations. A: Nickel, B: Chromium. a ~ Cystoseira sp., b ~ / ~ p a v o n i c a , c = P. fividus, d = P aspera.
Volume 22/Number I 1/November 1991
factor which influenced metal bioaccumulation by the tested biota. This could explain the high significant level (P=0.0002) observed at the interactions between station and species (Table 4, Figs 2-4).
m
2.4
We would like to thank Mrs. K. Sapsali for the help she gave us during the sampling.
16-
I/. A. CATSIKI E. PAPATHANASSIOU E BEI National Centre for Marine Research, Agios Kosmas, Hellinikon, Athens 16604, Greece
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In conclusion, although a differentiation between samples from the different localities around Milos island were evident, the levels of metals in marine flora and fauna were low and similar to other clean areas. On the other hand P. aspera was found to be good indicator for most metals (copper, cadmium, chromium, zinc, nickel), while the brown algae for manganese. The existing data could act as reference information for unpolluted areas in the East Mediterranean.
/
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o,! ol
/ c
St l
StY2
St 3
St'4
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Fig. 4 Plot of the means and the 95% of the Least Significance Range Intervals for the station by species interactions, showing the differences between species and stations. A: zinc, B: Manganese. a - Cystoseira sp., b - P pavonica, c " P lividus, d - P aspera.
Bernhard, M. (1976). Manual of methods in aquatic environmental research. Per 3. Sampling and analysis of biological material. EA.O. Fish Techn. Rap., No. 158. Bryan, G. W. (1976). Heavy metal contamination in the sea. In Marine Pollution (R. Johnston, ed.), pp. 185-305. Academic Press, New York. Catsiki, A. V., Panayofidis, P. & Papathanassiou, E. (1986). Impact of tannery wastes to the benthic communities in Geras Gulf (Lesvos isi., Greece). In Environmental Quality and Ecosystem Stability, Vol. IIl A/B (Z. Dubinsky & Y. Steinberger, eds), pp. 883-890. Bar-llan University Press, Ramat-Gan, Israel. Catsiki, A. V., Panayotidis, E & Papathanassiou, E. (1987). Bioaccumulation of heavy metal ions by seagrasses in Greek coastal waters. Posid. Newsletter 1(2), 21-30. F6rstner, U. & Wittman, G. T. W. (1979). Metal pollution. In Aquatic Environment. Springer-Verlag, Berlin. Grimanis, A. E, Zafiropoulos, D. & Vassilaki-Grimani, M. (1976). Trace elements in Sargus annularis and Gobius niger from polluted and unpolluted areas of the Aegean sea. Joumees Etud. Pollutions, Cannes, C.I.E.S.M. 6, 319-322. Mero, J. L. (1965). In Mineral Resources of the Sea (J. L. Mero, ed.), p. 312. Elsevier, New York. Satsmatjis, J., Catsiki, V. A. & Georgakopoulos-Gregoriades, E. (1988). Levels of chlorinated hydrocarbons and metals in demersal fishes. Rapp. Comm. Int. Mer. Medit., Athens, C.LE.S.M. 31, 150. UNEP (1982). Determination of total Cd, Zn, Pb and Cu in selected marine organisms by atomic absorption spectrophotometry. Ref. Meth. for Mar. Pollut. Studies. No. 11. Vasilikiotis, G., Fytianos, K. & Zotou, A. (1983). Heavy metals in marine organisms of the North Aegean Sea, Greece. Chemosphere 12, 75-81. Voutsinou-Taliadouri, E (1982). Monitoring of some metals in some marine organisms from Saronikos Gulf. Joumees ,Etud. Pollutions, Cannes, C.LE.S.M. 6, 329-333. Voutsinou-Taliadouri, F. (1989). Geochemical survey of marine sediments in Milos Island in Preliminary Report "Oceanographic survey in Milos Island", National Center of Marine Research (in Greek).
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