Heavy Metals in Organismsand Sediments from theDischarge Zone of theSubmarine Sewage Outfall ofHavana City, CubaHUMBERTO GONZALEZ * 1,MARIO POMARESà, MARTA RAMIREZ  andIBIS TORRES  Departamento de Contaminaci�on, Centro de Ingenier�õa yManejo Ambiental de Bah�õas y Costas, Apdo 17029, CP11700, La Habana, CubaàDepartamento de An�alisis, Instituto de Materiales yReactivos, Universidad de La Habana, Cuba

A submarine sewage outfall is located o� Chivo Beach,1 km north-east of Havana Bay. This outfall discharges168,000 m3 dayÿ1 of wastewaters from Havana, thecapital city of Cuba. The e�uent constitutes untreatedurban wastewater from approximately 600,000 inhabi-tants from the city, mixed with industrial wastewater.

Studies by Gonz�alez and Brugmann (1991) demon-strated that this outfall represents the main point sourceof heavy metals (mainly Cu, Pb and Zn) in the HavanaCity region. However, the a�ected area does not exceeda radius of 2 km because the conditions of the outfallzone favour the dilution of the pollutants, due to theirrapid exchange with the open sea (Gonz�alez and Torres,1990). Gonad tissues of Echinometra lucunter, a sea ur-chin of wide distribution in the coastal rocky zones ofthe Caribbean, accurately re¯ected Hg and Fe pollutionnear the outfall, although seasonal variations were also

observed (Ablanedo et al., 1990). Ziegler (1996) dem-onstrated the toxicity of the sewage e�uent to twospecies of Caribbean crustaceans, a crab and a shrimp.

The present work constitutes part of multi-disciplin-ary research carried out in Cuba for the GEF-UNDPRegional Project entitled ``Planning and Management ofHeavily Polluted Bays and Coastal Areas in the WiderCaribbean''. The aim of the study was to update theinformation on the environmental quality of the zone, inorder to assess changes in pollution levels and to providebaseline data for the proposed new submarine outfall.This outfall must replace the previous discharge, andwill be longer to guarantee a better dilution of pollu-tants.

Divers collected seven surface sediments in March1997 (Fig. 1). One of these, from 2 km east of the dis-charge point, was chosen as the reference (R) station forthe area. Samples were lyophilized and nylon sieves wereemployed to separate the fractions <63 and 63±150 lm.Both fractions were digested with 0.5N HCl to solubilizethe bioavailable fraction (Chester and Voutsinou-Taliadouri, 1981) and the coarser fraction was digestedwith HNO3/HCl (McKown et al., 1978).

Sea urchin samples were collected in March, May andAugust 1997, at three sites: two on the shore line ap-proximately 400 m to both sides of the outfall, and thethird from 30 km east of the discharge (considered as areference sample because of the absence of pollutantsources in that area). The organisms were classi®ed ac-cording to their size, and composite samples were takenof the gonads. All samples were lyophilized, manuallyhomogenized in an agate mortar and digested withHNO3/HClO4 (Gonz�alez et al., 1991).

Cu, Pb, Zn, Cr, Ni, Al, Fe and Mn were determined inthe sediments and gonads, by means of a Hilger-Ana-lytical Polyvac E-1000 inductively coupled plasmaatomic emission spectrometer. The analytical precision(n� 3) was <10%; the analytical accuracy was veri®edusing dog®sh muscle reference material (Table 1) fromthe National Research Council of Canada.

Figure 2 shows results for the ®ne sand fraction (63±150 lm) after strong digestion. The spatial distributionof the metals was heterogeneous, with the highest levelsat the discharge point and toward the east, especially atstation 6, which exhibited the highest levels of all themetals other than Al. The greatest di�erences were forCu and Fe, with values at station 6 being 78 and 25 timeshigher, respectively, than those of the reference station.The prevalence of higher concentrations in the east ap-pears to be due to the hydrodynamics of the area, wherethe prevailing surface and bottom currents run towardthe east, causing sediment transport in this direction.

Table 2 provides a comparison of the present datawith the results obtained one decade ago in the samearea (Gonz�alez and Torres, 1990). Despite the di�eren-ces in the precise number and location of sampling sites,the data show that the pollution loads in sediments haveremained similar. The pollution is characterized mainly

Edited by D. J. H. Philips

The objective of BASELINE is to publish shortcommunications on di�erent aspects of pollution ofthe marine environment. Only those papers whichclearly identify the quality of the data will be con-sidered for publication. Contributors to Baselineshould refer to `BaselineÐThe New Format andContent' (Mar. Pollut. Bull. 24, 124).

Marine Pollution Bulletin Vol. 38, No. 11, pp. 1048±1051, 1999

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Marine Pollution Bulletin

*Corresponding author1 Present address: Aguas de Cartagena S.A.E.S.P., A.A. 4240, Car-

tagena de Indias, Colombia.

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by Cu, Pb and Zn, which correlates to the compositionof the wastewater discharged through the outfall.

A comparison with data for other Cuban coastal ar-eas (Gonz�alez, 1991, 1996; Gonz�alez et al., 1997a,b), is

valid due to the use of the same sampling and analyticalmethodology. This revealed that Cu, Pb and Zn con-centrations in the Chivo Beach area are up to two ordersof magnitude greater than those in other coastal regionsof Cuba, while Nipe and Levisa Bays sediments exhibitdistinct levels of Fe, Mn and Ni, due to the negativein¯uence of nickel mining and metallurgical activities inthese bays (Gonz�alez et al., 1997a).

Table 3 shows results for Cu, Pb and Zn in the bio-available fraction of the sediments. The distributionpattern is similar to that noted after strong digestion,with the highest concentrations located at the dischargepoint and in the eastern area. These levels are alsogreater than those from other Cuban coastal regions.

It may be concluded that the levels of Cu, Pb, Zn andNi in sediments from some stations in the Chivo Beach

Fig. 1 The location of sampling sites o� Chivo Beach.

Fig. 2 Concentrations of heavy metals (lg gÿ1) in the 63±150 lmfraction of sediments after HNO3/HCl digestion.

TABLE 1

Determination of heavy metals in NRCC dog®sh muscle referencematerial (lg gÿ1 dry weight).

Certi®ed values Our resultsa

Cr 3.60�0.40 4.38 (3.88±4.95)Cu 5.22�0.33 4.89 (4.73±5.21)Fe 63.6�5.3 70.6 (69.4±71.8)Mn 1.32�0.26 1.09 (0.89±1.36)Ni 1.20�0.30 1.34 (0.78±1.62)Zn 21.3�1.0 24.8 (23.8±25.8)

a n� 3; mean (range).

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area pose a threat to marine organisms due to the pos-sibility of adverse biological e�ects, according to thecriteria of Long et al. (1995).

Di�erences in urchin size occurred among stations,but these could not be avoided. Table 4 summarizes theresults for urchins. Most of the elements decreased inconcentration in gonads in May, coinciding with thedevelopment of the gonads prior to the reproductiveperiod (August). By contrast, Ablanedo et al. (1990)found no change in elements levels in E. lucunter sam-pled between March and July at six stations covering theHavana City coastline.

Urchins from the eastern station exhibited the highestlevels of most metals in the ®rst two sampling periods,suggesting a relationship between the metal bioavail-ability in sediments and their bioconcentration by theurchins. A comparison of these data for Cu, Zn, and Fewith those obtained during 1986±1987 at the mouth ofHavana Bay (Ablanedo et al., 1990) reveals similarconcentrations.

Ablanedo, N., Gonz�alez, H., Ram�õrez, M. and Torres, I. (1990)Evaluaci�on del erizo de mar Echinometra lucunter como indicador

de contaminaci�on por metales pesados, Cuba. Aquatic LivingResources 3, 113±120.

Chester, R. and Voutsinou-Taliadouri, F. G. (1981) The initialassessment of trace metal pollution in coastal sediments. MarinePollution Bulletin 12, 84±91.

Gonz�alez, H. (1991) Heavy metal surveys in sediments of ®veimportant Cuban bays. Biogeochemistry 14, 113±128.

Gonz�alez, H. (1996) Heavy metals in sediments and ®shes fromCienfuegos Bay, Cuba. In Proceedings of the InternationalConference on Pollution Processes in Coastal Environments, ed. J.Marcovecchio, pp. 164±169. Mar del Plata.

Gonz�alez, H. and Brugmann, L. (1991) Heavy metals in littoraldeposits o� Havana City, Cuba. Chemistry and Ecology 5, 171±179.

Gonz�alez, H. and Torres, I. (1990) Heavy metals in sediments around asewage outfall at Havana, Cuba. Marine Pollution Bulletin 21,253±255.

Gonz�alez, H., Ram�õrez, M. and Ablanedo, N. (1991) Heavy metals in®sh (Micropogonias furnieri) from Cienfuegos Bay, Cuba. MarinePollution Bulletin 22, 469±471.

Gonz�alez, H., Ram�õrez, M. and Torres, I. (1997a) Impact of nickelmining and metallurgical activities on the distribution of heavymetals in sediments of Levisa, Cabonico and Nipe Bays, Cuba.Environmental Geochemistry and Health 19, 57±62.

Gonz�alez, H., Torres, I. and Ram�õrez, M. (1997b) Evoluci�on de lacontaminaci�on por metales pesados en los sedimentos de la bah�õade La Habana. Res�umenes IV Congreso de Ciencias del Mar, LaHabana.

Long, E. R., MacDonald, D. D., Smith, S. L. and Calder, F. D. (1995)Incidence of adverse biological e�ects within ranges of chemical

TABLE 2

Comparison of heavy metal concentrations (lg gÿ1) in the 63±150 lm fraction of the sediments, 1987 and 1997.a

Year Al Cr Cu Fe Mn Ni Pb Zn

1987 2300±15800 22±225 24±567 5600±47800 95±232 3.5±94 50±967 68±32181997 1889±6947 49±124 14±1075 3039±77782 68±279 99±169 321±768 294±980

aData for 1987 are from Gonz�alez and Torres (1990).

TABLE 4

Heavy metal concentrations (mean�standard deviation; lg gÿ1 dry weight) in gonads of the sea urchin Echinometra lucunter.

Month n Al Cr Cu Fe Mn Ni Zn

March 2 25�2.3 4.7�0.29 1.9�0.42 74�8.3 <0.13 1.5�0.01 248�217Reference May 3 12�0.88 3.8�0.24 1.3�0.27 53�12 <0.13 1.1�0.07 186�111

August 3 8.6�4.9 3.6�0.76 0.58�0.38 76�24 <0.13 <0.50 412�138March 2 12�0.85 4.2�0.01 1.3�0.04 61�2.1 <0.13 1.4�0.11 183�1.4

West May 4 12�2.4 3.7�0.70 1.6�0.11 49�5.0 0.55�0.27 0.90�0.10 163�128August 2 19�0 6.6�1.2 2.9�0.18 60�6.2 0.90�0.28 3.0�0.08 363�25March 4 39�21 8.3�0.81 1.5�0.25 129�17 0.65�0.78 2.8�0.25 284�59

East May 4 12�1.9 4.8�0.81 1.1�0.05 77�12 <0.13 1.3�0.23 235�59August 3 17�1.5 5.2�1.1 2.6�0.38 61�3.5 0.90�0.30 2.0�0.50 254�116

TABLE 3

Bioavailable concentrations of heavy metals (lg gÿ1) in sediments of the discharge zone of the submarine sewage outfall at Chivo Beach.

Cu Pb Zn

<63 lm 63±150 lm <63 lm 63±150 lm <63 lm 63±150 lm

West side (n� 2) 19±77 5.2±7.7 40±66 10±18 133±208 39±55Discharge point 130 9.6 330 56 1688 318East side (n� 3) 44±1277 3.8±1228 82±498 17±463 250±562 61±707Reference 9.2 3.5 14 <10 29 17

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concentrations in marine and estuarine sediments. EnvironmentalManagement 19, 81±97.

McKown, M. M., Tschirn, C. R. and Lee, P. P. F. (1978) Investigationof matrix interferences for AAS trace metal analyses of sediments.Report No. EPA-600/7-78-085, 140 pp., Cincinnati, Ohio.

Ziegler, F. (1996) Ecotoxicological experiments testing: the toxicity ofa sewage e�uent of Havana, Cuba, to two species of Caribbeancrustaceans. SWEDMAR Working Papers 12/96, 31 pp., Gothen-burg.

Heavy Metals in Corals FromHeron Island and DarwinHarbour, AustraliaG. ESSLEMONT 1

Centre for Coastal Management, Southern CrossUniversity, P.O. Box 157, Lismore, NSW 2480, Australia

High, but not necessarily toxic, heavy metal concentra-tions associated with human activities such as harbourdredging or sewage and urban stormwater dischargescan be used as tracers for monitoring purposes (e.g.Reichelt and Jones, 1994). Scleractinian corals are po-tentially useful indicator organisms for environmentalmonitoring, because their skeletons assimilate records ofcertain metals over hundreds of years. For example,nutrient availability over time can be traced in thegrowth-bands of coral skeletons, by measuring concen-trations of metals recycled by the biosphere (Shen andSanford, 1990), and the availabilities of several heavymetals which are toxic to marine organisms have beenmeasured similarly (Linn et al., 1990). Studies have alsobeen reported on the use of soft corals or coral tissuesfor monitoring purposes (Denton and Burdon-Jones,1986; Hanna and Muir, 1990), but relevant work islimited.

This study supplements work on metal accumulationby coral tissues and skeletons completed by McConchieand Harriott (1992), and Esslemont (1997). Here, heavymetal concentrations (cadmium, lead, copper, zinc,nickel, and chromium) are reported in skeletons of Go-niastrea aspera and Acropora nobilis from Heron Island,and in G. aspera and Montastrea annuligera from Dar-win Harbour. The methodology di�ers somewhat fromthe earlier works, because sample pre-treatments wereapplied to isolate metals that substitute for calciumwithin the aragonite lattice. By contrast, the earlierworks represent total metal concentrations in skeletons,or only metals on skeleton surfaces accumulated by

adsorption onto exposed carbonate. This study also re-ports cadmium, lead and copper concentrations in tis-sues of G. aspera and A. nobilis from Heron Island, andthe partitioning of these metals between tissue andskeleton phases.

Corals were sampled from the Darwin Harbour es-tuary as detailed by Esslemont (1997), and from the reef¯at and harbour wall of Heron Island during September1992 (Fig. 1). The procedure of preparing and analysingtissues was that of McConchie and Harriott (1992),except that tissues were oven-dried (40oC for 30±40 h)rather than being digested fresh.

Skeleton portions weighing 4.5�0.2 g were sampledto represent recent growth (1 cm from the outer calicefor G. aspera and M. annuligera, and 7 cm from branchtips for A. nobilis). Organic and non-coralline compo-nents were removed from skeletons as follows: (1) Re-action at room temperature (20°C) for 1 h in 5 ml ofhydrogen peroxide (pH adjusted to 8.2 with sodiumhydroxide), then at 70°C for 3.5 h using a water bath. (2)Rinsing with excess Milli-Q water, accompanied bystanding in an ultrasonic bath (10 min). (3) Reaction atroom temperature in 10 ml of reducing chelate (2% di-ethyldithiocarbamate (w/v), pH 5, 70 g lÿ1 L-ascorbicacid) for 10 min. (4) Repeat of step 2. The sequence wasrepeated two more times. After pre-treatment, sampleswere ashed in covered crucibles (500°C for 15 min), andthen weighed. Samples were then digested in 10 ml of12M hydrochloric acid at room temperature, 5 ml of0.18M lanthanum chloride was added, and samples wereaccurately made to 25 ml with dilute hydrochloric acid.Analyses of cadmium, lead and copper were by anodicstripping voltammetry, and zinc, nickel and chromiumwere analysed by atomic absorption spectrophotometry(AAS).

Skeleton samples were analysed in duplicate, andtissues as single samples. Correction for matrix inter-ferences during analysis was by spike addition withheavy metal standards (BDH), and deuterium lampcorrection was applied during atomic absorption ana-lyses. Detection limits were calculated from blanks,which were inserted at intervals of 10 during the sampleprocessing and analysis sequence. Sample recovery fromtissue digests was calculated using 10 ml aliquots of 10lg gÿ1 mixed-heavy metal standard solutions (BDH):cadmium 76�7%, lead 77�17%, copper 64�14%.Low sample recovery is caused by adsorption of dis-solved heavy metals onto exposed skeleton surfaces,during the sequential extraction of tissues. Comans andMiddelburg (1987) described this adsorption process.

Marine Pollution Bulletin Vol. 38, No. 11, pp. 1051±1054, 1999

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1 Present address: Faculty of Applied Science, University of Canb-erra, ACT 2601, Australia.

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