Pergamon Wat SCL. Tech. Vol. 39, No. 8, PP. 207-212, 1999 0 I999

Published by Elsevier Science Ltd on behalf ofthe IAWQ Printed in Great Britain. All rights reserved

02734223199 $20.00 + 0.00 PII: SO273-1223(99)00204-8

HEAVY METAL ASSESSMENT IN ALGAE, SEDIMENTS AND WATER FROM THE BULGARIAN BLACK SEA COAST

A. Jordanova, A. Strezov, M. Ayranov, N. Petkov and T. Stoilova

Department of Radiochemishy and Radioecology, Institute for Nuclear Research and Nuclear Energy 72 Tzarigradsko shauvee blvd.. 1784, Sofia, Burgaria

ABSTRACT

The aim of our investigation is a survey of heavy metal pollution in algae, sediments and water from the Bulgarian Black Sea coast and determination of algae species appropriate as bioindicators. The levels of iron, copper, manganese, zinc, lead and cadmium are determined in water, sediments and eight species of macroalgae: (four green: Cladofora fuetevirens, U~Q rigida, Enteromorpha intestinalis and Bryopsis plumosa; hvo brown: Cystoseira crinita and Cystoseira barbala; and two red: Ceramium rubrum and CoraNinu mediferronium), widely distributed in the Bulgarian coastal zone, and dominant in the Black Sea. The studied area is the littoral coastal zone from four locations - Tuzla& Ravda, Ahtopol and Sinemoretz. No significant variations between metal concentrations in algae samples are obtained, while for sediments and water there are significant differences between location and season. The Cladoforra Iaetevirens and Ceromium rubrum species show the highest metal content while Cystoseira crinita and Cystoseira barb&a show the lowest level. The correlation coefficients and concentration factors of the elements are calculated. Q 1999 Published by Elsevier Science Ltd on behalf of the IAWQ. All rights reserved

KEYWORDS

Heavy metals; monitoring; macroalgae; sea water; marine environment; correlation coefficients; concentration factors.

INTRODUCTION

Heavy metal contaminants, arising from industrial and agricultural sources, are often accumulated to relatively high levels in marine organisms. Algae are among the most investigated organisms for detecting metals in the marine environment (Eisler, 1981). Some species of macroalgae have been proposed as bioindicators in coastal zones (Seeliger and Edwards, 1977, Bryan, 1969; Burdin, 1982). The use of biological indicators for marine pollution monitoring gives many advantages over the use of water samples. The concentrations of harmful and toxic compounds are many orders of magnitude higher in biota than in the water column (Cullinane, 1987).

For this purpose large varieties of macroalgae typical and dominant for the Black Sea are chosen. The algae, sediments and water are collected from four locations along the Bulgarian Black Sea coast. The selected locations are remote from industrial sites, so low pollution of the marine environment should be expected and equal conditions for algae vegetation can be assumed.

e Pergamon Waf. Sci. Tech. Vol. 39, No.8, pp. 207-212, 1999©1999

Published by Elsevier Science Ltd on behalf nfthe IAWQPrinted in Great Britain. All rights reserved

0273-1223/99 $20.00 + 0.00

PH: S0273-1223(99)00204-8

HEAVY METAL ASSESSMENT IN ALGAE,SEDIMENTS AND WATER FROM THEBULGARIAN BLACK SEA COAST

A. Jordanova, A. Strezov, M. Ayranov, N. Petkov andT. Stoilova

Department ofRadiochemistry and Radioecology, Institute for Nuclear Research andNuclear Energy, 72 Tzarigradsko shausee blvd., 1784, Sofia, Bulgaria

ABSTRACT

The aim of our investigation is a survey of heavy metal pollution in algae, sediments and water from theBulgarian Black Sea coast and detennination of algae species appropriate as bioindicatoTS. The levels of iron,copper, manganese, zinc, lead and cadmium are detennined in water, sediments and eight species ofmacroalgae: (four green: Cladofora laetevirens, Ulva rigida, Enteromorpha intestinalis and Bryopsisplumosa; two brown: Cystoseira crinita and Cystoseira barbata; and two red: Ceramium rubrum andCorallina mediterranium), widely distributed in the Bulgarian coastal zone, and dominant in the Black Sea.The studied area is the littoral coastal zone from four locations - Tuzlata, Ravda, Ahtopol and Sinemoretz.No significant variations between metal concentrations in algae samples are obtained, while for sedimentsand water there are significant differences between location and season. The Cladofora laetevirens andCeramium rubrum species show the highest metal content while Cystoseira crinita and Cystoseira barbatashow the lowest level. The correlation coefficients and concentration factors of the elements are calculated.© 1999 Published by Elsevier Science Ltd on behalf of the IAWQ. All rights reserved

KEYWORDS

Heavy metals; monitoring; macroalgae; sea water; marine environment; correlation coefficients;concentration factors.

INTRODUCTION

Heavy metal contaminants, arising from industrial and agricultural sources, are often accumulated torelatively high levels in marine organisms. Algae are among the most investigated organisms for detectingmetals in the marine environment (Eisler, 1981). Some species of macroalgae have been proposed asbioindicators in coastal zones (Seeliger and Edwards, 1977, Bryan, 1969; Burdin, 1982). The use ofbiological indicators for marine pollution monitoring gives many advantages over the use of water samples.The concentrations of harmful and toxic compounds are many orders of magnitude higher in biota than inthe water column (Cullinane, 1987).

For this purpose large varieties of macroalgae typical and dominant for the Black Sea are chosen. The algae,sediments and water are collected from four locations along the Bulgarian Black Sea coast. The selectedlocations are remote from industrial sites, so low pollution of the marine environment should be expectedand equal conditions for algae vegetation can be assumed.

207

208 A. JORDANOVA et al.

The purpose of our study is to report the preliminary data for the content of copper, iron, lead, manganese, zinc and cadmium determined in some Black Sea algae, sediments and water collected during Spring 1992-1994 and Spring-Summer 1996 (Forsberg, 1988). The study area is the littoral coastal zone of four sampling locations along the Bulgarian Black Sea coast zone (Tuzlata, Ravda, Ahtopol and Sinemoretz) (Figure 1).

METHODS

The whole plants are collected by hand from the rocky substrate. They are rinsed in clean sea water to remove the attached particulate material. After root separation the remaining materials are dried at 85’C and homogenized in an agate mortar. About 0.5 g of each sample is digested with I-IN03 (Merck).

Sediments are collected by scuba divers from a depth of 1 - 10 m close to the sampling location of algae. The samples are dried and sieved at 0.5 mm fraction. One gram of each sample is digested with I-IN03 and Hz02 (Merck).

BULGARIA

BLACK SEA

Ravda

Figure 1. Sampling location map.

Sea water is collected together with algae at the same location. The water samples are separated by Millipore 0.45 pm filtration into ‘Dissolved’ (D) and ‘Total’ (T) phases and acidified to pH l-2 with HNOs.

Fe, Mn, Zn and Cu in water, sediments and algae material are determined by means of a Pye Unicam 1950 atomic absorption spectrophotometer with air-acetylene flame, while Pb and Cd are determined by a Perkin- Elmer Zeeman 3030 atomic absorption spectrophotometer with HGA 600 graphite furnace.

RESULTS AND DISCUSSION

The heavy metal concentrations for algae and sediments in pg/g dry weight are presented graphically in Figs 2-6, and for the water in &ml are presented in Figs 7- 10.

g 8” vi? b- 8

Spring 92 Spring 93 Spring 96 Summer 96

Figure 2. Element content in algae species Tom Tuzlata.

The results from the sampling show that there is no uniform distribution in the algae species studied. This will limit the comparison of the metal concentrations found for the different sites for some macroalgae. The relative abundance of elements in algae species, sediments and water is Fe>Mn>Zn>Cu>Pb>Cd (Ho, 1987). Fe and Mn could be considered as related to terrestrial inputs, whereas Pb, Cu, Zn and Cd gave

208 A. JORDANOVA et at.

The purpose of our study is to report the preliminary data for thecontent of copper, iron, lead, manganese, zinc and cadmiumdetermined in some Black Sea algae, sediments and watercollected during Spring 1992-1994 and Spring-Summer 1996(Forsberg, 1988). The study area is the littoral coastal zone offour sampling locations along the Bulgarian Black Sea coast zone(Tuzlata, Ravda, Ahtopol and Sinemoretz) (Figure I).

METHODS

The whole plants are collected by hand from the rocky substrate.They are rinsed in clean sea water to remove the attachedparticulate material. After root separation the remaining materialsare dried at 85°C and homogenized in an agate mortar. About 0.5g of each sample is digested with RN03(Merck).

Sediments are collected by scuba divers from a depth of 1 - 10 mclose to the sampling location of algae. The samples are driedand sieved at 0.5 mm fraction. One gram of each sample isdigested with RN03 and H202 (Merck).

,ROMANIA'i

/~----\

Tuzlar ~

BULGARIA 1\ BLACK SEA1

Ravda

AhtopolSinemoretz

TURKEY

Figure 1. Sampling location map.

Sea water is collected together with algae at the same location. The water samples are separated by Millipore0.45 11m filtration into 'Dissolved' (D) and 'Total' (T) phases and acidified to pH 1-2 with RN03.

Fe, Mn, Zn and Cu in water, sediments and algae material are determined by means of a Pye Unicam 1950atomic absorption spectrophotometer with air-acetylene flame, while Pb and Cd are determined by a Perkin­Elmer Zeeman 3030 atomic absorption spectrophotometer with HGA 600 graphite furnace.

RESULTS AND DISCUSSION

The heavy metal concentrations for algae and sediments in Ilg/g dry weight are presented graphically in Figs2-6, and for the water in Ilg/ml are presented in Figs 7-10.

f'glg10000.00

1000.00

100.00

10.00

1.00

0.10

uU

Spring 92

;§ .geU'E ~.e

Spring 93

f!e ~(I)" ;:)

U'E

Spring 96

:'§'" ~SU ~

Summer 96

Figure 2. Element content in algae species from Tuzlata.

The results from the sampling show that there is no uniform distribution in the algae species studied. Thiswill limit the comparison of the metal concentrations found for the different sites for some macroalgae.The relative abundance of elements in algae species, sediments and water is Fe>Mn>Zn>Cu>Pb>Cd (Ho,1987). Fe and Mn could be considered as related to terrestrial inputs, whereas Pb, Cu, Zn and Cd gave

Heavy metal assessment in algae, sediments and water 209

evidence of anthropogenic contamination (Harris, 1998). As a whole there is no remarkable difference between metal concentrations in algae. Iron predominates at all sites in agreement with other published data for algae and macrophytes (Eisler, 1981). The lowest levels we found were for lead and cadmium. Cadmium concentrations are below 1 pg/g at all sites studied during the survey. The algae seem to take up higher concentrations of those metals which take part in physiological processes of plants like Na, Ca, Mg and Fe, and lower concentrations of those which do not participate in these processes, for example Cd and Pb (Malea, 1993). Copper is essential for organisms’ life and its toxicity is connected with the concentrations of other essential elements. Copper content determined in algae during the present investigation is comparable with those reported by Burdin et al. (1982) for algae collected from the Black Sea. The concentration of Mn is in the range lo-100 pg/g in all algae species with the exception of Cerumium rubrum (242 erg/g) and Cladoforu laetevirens (203 &g) from the Spring 1993 season.

The trends of metal accumulation in different species are also analyzed and presented in Table 1. The data indicate that different species demonstrate various degrees of metal accumulation. The highest values are obtained for the species Cladofora laetevirens and Ceramium rubrum, while Cystoseira barbata and Cystoseira crinita show the lowest contents. The species Bryopsis plumosa was taken only once from the Ahtopol site and hence no data from other sites were available for comparison of the determined high contents of Cu, Pb and Cd.

spring 94 spring 96 Summar 96

‘Figure 3. Element content in algae species ffom Ahtopol.

Ctinita Entem- motpha

Ciinita Batbata

Summer 96

Figure 4. Element content in algae species Tom Ravda.

The correlation analysis of all elements in the four species Ceramium rubrum, Cladofora Iaetevirens, Cystoseira barbatu and Cystoseira crinita was performed. Copper and iron correlate with the highest number of elements - 4; Pb, Cd and Zn correlate with 3 elements and Mn with 2. Copper correlates positively with Cd and Pb in Ceramium rubrum and with Zn in Cladofora laetevirens. Iron correlates

Heavy metal assessment in algae, sediments and water 209

evidence of anthropogenic contamination (Harris, 1998). As a whole there is no remarkable differencebetween metal concentrations in algae. Iron predominates at all sites in agreement with other published datafor algae and macrophytes (Eisler, 1981). The lowest levels we found were for lead and cadmium. Cadmiumconcentrations are below 1 J.lg/g at all sites studied during the survey. The algae seem to take up higherconcentrations of those metals which take part in physiological processes of plants like Na, Ca, Mg and Fe,and lower concentrations of those which do not participate in these processes, for example Cd and Pb(Malea, 1993). Copper is essential for organisms' life and its toxicity is connected with the concentrations ofother essential elements. Copper content determined in algae during the present investigation is comparablewith those reported by Burdin et al. (1982) for algae collected from the Black Sea. The concentration ofMnis in the range 10-100 J.lg/g in all algae species with the exception of Ceramium rubrum (242 J.lg/g) andCladofora laetevirens (203 Ilg/g) from the Spring 1993 season.

The trends of metal accumulation in different species are also analyzed and presented in Table 1. The dataindicate that different species demonstrate various degrees of metal accumulation. The highest values areobtained for the species Cladofora laetevirens and Ceramium rubrum, while Cystoseira barbata andCystoseira crinita show the lowest contents. The species Bryopsis plumosa was taken only once from theAhtopol site and hence no data from other sites were available for comparison of the determined highcontents of Cu, Pb and Cd.

Ilglg

1000.00 r

100.00

10.00

1.00

0.10

.. Fe • Cu II Mn • Zn III Pb • Cd

.~ E ...~ A!

" .~ :5"." t'! g. ."0 t'! 8 0

'" mu

Spring 94 Spring 96 Summer 96

'Figure 3. Element content in algae species from Ahtopol.

Ilglg

OO.00סס1 r1000.00

100.00

10.00

1.00

0.10

Crinila Barbata Entero-morpha

Spring 96

Crinita

Summer 96 :!Figure 4. Element content in algae species from Ravda.

The correlation analysis of all elements in the four species Ceramium rubrum, Cladofora laetevirens.Cystoseira barbata and Cystoseira crinita was performed. Copper and iron correlate with the highestnumber of elements - 4; Pb, Cd and Zn correlate with 3 elements and Mn with 2. Copper correlatespositively with Cd and Pb in Ceramium rubrum and with Zn in Cladojora laetevirens. Iron correlates

210 A. JORDANOVA et al.

positively with Cd, Pb and Cu in Ceramium rubrum; with Zn and Pb in Cladofora laetevirens and with Cu in Cystoseiru barbata. Lead correlates positively with Cd in Ceramium rubrum, Cladofora laetevirens and Cystoseira crinita. Negative correlations are obtained between Mn and Zn in Ceramium rubrum, Cladofora laetevirens and Cystoseira crinita, and between h4n and Cu in Ceramium rubrum and Cladofora laetevirens.

r9b . Fe. Cu , 2h

ElllWWllOrpha Crinita

Figure 5. Element content in algae species ffom Sinemoretz.

Table 1. Algae species with minimum and maximum heavy element content

Element

Fe

Mn

Zn

CU

Pb

Cd

Algae species with maximum concentration Cladofora kaetevirens Ceramium rubrum Ciadofora laetevirens Ceramium rubrum Blyopsis plumosa Ceramium rubrum Bryopsis plumosa

Cladofora laetevirens Ceramium rubrum Blyopsis plumosa Ceramium rubrum

Algae species with minimum concentration Cystoseira barbata Cystoseira crinita Cystoseira barbata Cystoseira crinita Ulva rigida

Cystoseira barbata Cystoseira crinita Ulva rigida Cystoseira crinita

Cystoseira barbata Corallina mediteranium

The estimation of the relationships between the elements in algae species from different locations and elements in the ambient marine water shows a close linear correlation (correlation coefficient r = 0.86) between total and dissolved Cu in water and in Ceramium rubrum.

The concentration factors (ratio between the concentration in aquatic species and the concentration in the ambient water) for samples corn the Spring 96 season are in the range of lo2 to 105. The concentration factors found are: lo4 -10’ for Fe; IO3 for Mn and Cu; 1 O2 - lo3 for Zn; lo4 for Pb and Cd. The values are similar for other algae in the Black Sea (Burdin et al., 1982).

210 A. JORDANOVA et a/.

positively with Cd, Pb and Cu in Ceramium rubrum; with Zn and Pb in Cladofora laetevirens and with Cuin Cystoseira barbata. Lead correlates positively with Cd in Ceramium rubrum, Cladofora laetevirens andCystoseira crinita. Negative correlations are obtained between Mn and Zn in Ceramium rubrum, Cladoforalaetevirens and Cystoseira crinita, and between Mn and Cu in Ceramium rubrum and Cladofora laetevirens.

1.00 Ceramium Uhe Enleromorpha Crtnita JI

Summer 96'-------------- -------------------

I "gig10000.00

1000.00

I 100.00

10.00

Figure 5. Element content in algae species from Sinemoretz.

Table I. Algae species with minimum and maximum heavy element content

Element Algae species with maximumconcentration

Algae species with minimumconcentration

Fe

Mn

Zn

Cu

Pb

Cd

Cladofora kaetevirensCeramium rubrumCladofora laetevirensCeramium rubrumBryopsis plumosaCeramium rubrumBryopsis plumosa

Cladofora laetevirensCeramium rubrumBryopsis plumosaCeramium rubrum

Cystoseira barbataCystoseira crinitaCystoseira barbataCystoseira crinitaUlva rigida

Cystoseira barbataCystoseira crinitaUlva rigidaCystoseira crinita

Cystoseira barbataCorollina mediteranium

The estimation of the relationships between the elements in algae species from different locations andelements in the ambient marine water shows a close linear correlation (correlation coefficient r = 0.86)between total and dissolved Cu in water and in Ceramium rubrum.

The concentration factors (ratio between the concentration in aquatic species and the concentration in theambient water) for samples from the Spring 96 season are in the range of 102 to lOS. The concentrationfactors found are: 104 _lOS for Fe; 103 for Mn and Cu; 102

- 103 for Zn; 104 for Pb and Cd. The values aresimilar for other algae in the Black Sea (Burdin et al., 1982).

Heavy metal assessment in algae, sediments and water

TUZla Tuzla Ahtopd TUZk Ahtopol Rada sp92 SP9!J SPN SPW SP@3 SPS

Figure 6. Element cbntent in sediments.

&ml , Fe n Cu . Mn . Zn , Pb . Cd

T D T D T D T D

Spring 96 Summer 96 sprrng 96 Summer 96

Figure 7. Element content in water from Tuzlata. Figure 8. Element content in water Tom Ahtopol.

0.25

0.2

0.15

0.1

0.05

0 u

T D T D

spring 96 Summer 96

Figure 9. Element content in water from Ravda.

pg/mlmFemCumMnmZnmPbmCci

0.2

0.15

0.1

0.05

0 1111 T II

Summer 96

Figure 10. Element content in water Corn Sinemoretz.

Heavy metal assessment in algae, sediments and water 211

Ilg/g

100000

10000

1000

100

10

1

0.1

0.01

TuzlaSp92

TuzlaSp93

AhtopolSp94

TuzlaSp96

AhtopolSp96

RaldaSp96

Figure 6. Element content in sediments.

0.3

0.25

0.2

0.15

0.1

0.05

• Fe .Cu • Mn • zn • Pb • Cd Ilglml • Fe .Cu • Mn • Zn • Pb • Cd

0.35

0.3

0.25

0.2

0.15

0.1

0.05

oT DSpring 96

T DSummer 96

T D

Spring 96

T D

Summer 96

Figure 7. Elern;:nt content in water from Tuzlata. Figure 8. Elem:nt content in water from Ahtopol.

• Fe .Cu lJ Mn. Zn. Pb. Cd

D

Summer 96

T

o

0.15

0.1

0.05

Ilglml. Fe .Cu. Mn. Zn. Pb. Cd

0.2 ,

DT

Summer 96

D

Spring 96

Ilg/ml

0.25

0.2

0.15

0.1

0.05

0T

Figure 9. Element content in water from Ravda. Figure 10. Element content in water from Sinemoretz.

212 A. JORDANOVA et al.

The element content in sediments shows variation between different sampling locations. Fe and Mn predominate at all sampling sites similarly to algae. The measured values for manganese from Tuzlata, Ahtopol and Ravda in Spring 96 and lead from Ahtopol in Spring 96 are at the LLD (Lower Limit of Detection).

Seasonal variation is evident in water samples. The observed increase of metal concentrations during summer may have been influenced by the increase of water temperature. There are no significant differences between ‘Total’ and ‘Dissolved’ heavy metals content, except for Zn from Ravda in Spring 96 and Ahtopol in Summer 96. This fact shows that metals are predominantly in ionic form.

CONCLUSIONS

The heavy metal ranges are determined in marine algae, sediments and ambient sea water and the values are similar to those reported in the Black Sea literature. No additional anthropogenic heavy metal contamination can be assumed in the areas studied.

There are small seasonal variations of heavy metal content in algae species, while an increase of metal concentration is observed in water samples from spring to summer 1996. The metals in water are in bioavailable form.

The algae species Ceramium rubrum, Cladofora laetevirens and Bryopsis plumosa have a higher content of the studied elements in comparison with the other species.

The reported metal concentrations may serve as a base for future investigations of these species and further examination of metal speciation would provide detailed information for heavy metal bio-transformation.

Only three species showed widespread distribution in the study area: Ceramium rubrum, Cystoseira barbata and Cystoseira crinita, however, one of them, Ceramium rubrum, showed the possibility of specific accumulation of the heavy metals studied, thus rendering this algae an appropriate candidate for environmental monitoring.

REFERENCES

Burdin, K., Crupina, M. V. and Saveljev, I. B. (1982). The Black Sea Macroalgae as the object for Biogeochemical Monitoring of Heavy Metals. Chelovek I biosfera, Moskw, 7, 139.

Bryan, G. W. (1969). The Absorption of Zinc and Other Metals by the Brown Seaweed Laminaria Digitata. Journal of Marine Biology 53, 705.

Cullinane, J. P., Doyle, T. M. and Whelan, P. M. (1987). Uses of Seaweeds as Biomonitors of Zinc Levels in Cork Harbour, Ireland. Hydrobiologia, 151/152,285.

Eisler, R. (1981). Trace Metal Concentrations in Marine Organisms. Pergamon Press, New York. For&erg, A., Soderlund, F. A., Pettersson, L. and Pedersen, P. (1988). Studies on Metal Content in the Brown Seaweed Fucus

Vesiculosus, from the Archipelago of Stockholm. Environmental Pollution, 49,245-263. Harris, P.A., Fichez, R., Femandez, J. M. and Badie, C. (1998). Heavy Metals Profdes in Dated Sedimenfs From the Lagoon of

Papeete (Tahiti, French Polynesia): influence of Mixing Phenomena. International Symposium on Marine Pollution, Monaco 5-9 Oct. 1998.

Ho, Y. B. (1987). Metals in 19 Intertidal Macroalgae in Hong Kong Waters. Marine Poflufion Bulletin, 18, 564-566. Malea, P. (1993). Seasonal Variation and Local Distribution Of Metals In Seagrass Halophila Stipulagea in the Antikym Gulf,

Greece. EnvironmentalPollution, 85,77-85. Seeliger, U. and Edwards, P. (1977). Correlation coefficients and concentration factors of copper and lead in sea water and benthic

algae. Marine Pollution Bulletin, 8, 16-19.

212 A. JORDANOVA et al.

The element content in sediments shows variation between different sampling locations. Fe and Mnpredominate at all sampling sites similarly to algae. The measured values for manganese from Tuzlata,Ahtopol and Ravda in Spring 96 and lead from Ahtopol in Spring 96 are at the LLD (Lower Limit ofDetection).

Seasonal variation is evident in water samples. The observed increase of metal concentrations duringsummer may have been influenced by the increase of water temperature. There are no significant differencesbetween 'Total' and 'Dissolved' heavy metals content, except for Zn from Ravda in Spring 96 and Ahtopolin Summer 96. This fact shows that metals are predominantly in ionic form.

CONCLUSIONS

The heavy metal ranges are determined in marine algae, sediments and ambient sea water and the values aresimilar to those reported in the Black Sea literature. No additional anthropogenic heavy metal contaminationcan be assumed in the areas studied.

There are small seasonal variations of heavy metal content in algae species, while an increase of metalconcentration is observed in water samples from spring to summer 1996. The metals in water are inbioavailable form.

The algae species Ceramium rubrum, Cladofora laetevirens and Bryopsis plumosa have a higher content ofthe studied elements in comparison with the other species.

The reported metal concentrations may serve as a base for future investigations of these species and furtherexamination of metal speciation would provide detailed information for heavy metal bio-transformation.

Only three species showed widespread distribution in the study area: Ceramium rubrum, Cystoseira barbataand Cystoseira crinita, however, one of them, Ceramium rubrum, showed the possibility of specificaccumulation of the heavy metals studied, thus rendering this algae an appropriate candidate forenvironmental monitoring.

REFERENCES

Burdin, K., Crupina, M. V. and Saveljev, I. B. (1982). The Black Sea Macroalgae as the object for Biogeochemical Monitoring ofHeavy Metals. Chelovek I biosfera, Moskva, 7, 139.

Bryan, G. W. (1969). The Absorption of Zinc and Other Metals by the Brown Seaweed Laminaria Digitata. Journal of MarineBiology 53,705.

Cullinane, J. P., Doyle, T. M. and Whelen, P. M. (1987). Uses of Seaweeds a~ Biomonitors of Zinc Levels in Cork Harbour,Ireland. Hydrobiologia, 15l1152, 285.

Eisler, R. (1981). Trace Metal Concentrations in Marine Organisms. Pergamon Press, New York.Forsberg, A., Soderlund, F. A., Pettersson, L. and Pedersen, P. (1988). Studies on Metal Content in the Brown Seaweed Fucus

Vesiculosus, from the Archipelago of Stockholm. Environmental Pollution, 49, 245-263.Harris, P.A., Fichez, R., Fernandez, J. M. and Badie, C. (1998). Heavy Metals Profiles in Dated Sediments From the Lagoon of

Papeete (Tahiti, French Polynesia): Influence of Mixing Phenomena. International Symposium on Marine Pollution,Monaco 5-9 Oct. 1998.

Ho, Y. B. (1987). Metals in 19 Intertidal Macroalgae in Hong Kong Waters. Marine Pollution Bulletin, 18, 564-566.Malea, P. (1993). Seasonal Variation and Local Distribution Of Metals In Seagrass Halophila Stipulagea in the Antikyra Gulf,

Greece. Environmental Pollution, 85, 77-85.Seeliger, U. and Edwards, P. (1977). Correlation coefficients and concentration factors of copper and lead in sea water and benthic

algae. Marine Pollution Bulletin, 8,16-19.