This article was downloaded by:[CSIR Order]On: 31 December 2007Access Details: [subscription number 772699002]Publisher: Taylor & FrancisInforma Ltd Registered in England and Wales Registered Number: 1072954Registered office: Mortimer House, 37-41 Mortimer Street, London W1T 3JH, UK

Toxicological & EnvironmentalChemistryPublication details, including instructions for authors and subscription information:http://www.informaworld.com/smpp/title~content=t713653210

Environmental contamination using accumulation ofmetals in marine sponge, Sigmadocia fibulatainhabiting the coastal waters of Gulf of Mannar, IndiaJ. Venkateswara Rao a; P. Kavitha a; K. Srikanth a; P. K. Usman a; T. GnaneshwarRao ba Toxicology Unit, Biology Division, Indian Institute of Chemical Technology,Hyderabad, Indiab Geophysical Chemistry Lab, National Geographical Research Institute, Hyderabad,India

Online Publication Date: 01 July 2007To cite this Article: Rao, J. Venkateswara, Kavitha, P., Srikanth, K., Usman, P. K. and Rao, T. Gnaneshwar (2007)'Environmental contamination using accumulation of metals in marine sponge, Sigmadocia fibulata inhabiting the coastalwaters of Gulf of Mannar, India', Toxicological & Environmental Chemistry, 89:3, 487 - 498To link to this article: DOI: 10.1080/02772240601150588URL: http://dx.doi.org/10.1080/02772240601150588

PLEASE SCROLL DOWN FOR ARTICLE

Full terms and conditions of use: http://www.informaworld.com/terms-and-conditions-of-access.pdf

This article maybe used for research, teaching and private study purposes. Any substantial or systematic reproduction,re-distribution, re-selling, loan or sub-licensing, systematic supply or distribution in any form to anyone is expresslyforbidden.

The publisher does not give any warranty express or implied or make any representation that the contents will becomplete or accurate or up to date. The accuracy of any instructions, formulae and drug doses should beindependently verified with primary sources. The publisher shall not be liable for any loss, actions, claims, proceedings,demand or costs or damages whatsoever or howsoever caused arising directly or indirectly in connection with orarising out of the use of this material.

Dow

nloa

ded

By:

[CS

IR O

rder

] At:

07:0

2 31

Dec

embe

r 200

7

Toxicological & Environmental Chemistry, July–Sep. 2007; 89(3): 487–498

Environmental contamination using accumulation

of metals in marine sponge, Sigmadocia fibulata

inhabiting the coastal waters of Gulf of Mannar, India

J. VENKATESWARA RAO1, P. KAVITHA1, K. SRIKANTH1,P. K. USMAN1, & T. GNANESHWAR RAO2

1Toxicology Unit, Biology Division, Indian Institute of Chemical Technology, Hyderabad

500 007, India and 2Geophysical Chemistry Lab, National Geographical Research Institute,

Hyderabad 500 007, India

(Received 7 December 2005; in final form 30 November 2006)

AbstractCoastal marine ecosystems in many parts of the world are under unrelenting stress caused by urbandevelopment, pollutants and other ecological impacts such as building of infrastructure, landreclamation for port and industrial development, habitat modification, tourism and recreationalactivities. The present work is a first extensive field study using the marine sponge, Sigmadocia fibulataas a bioindicator to detect metal pollution between inshore and offshore environment of the ‘Gulf ofMannar’, India. Samples of S. fibulata were collected from different places of inshore (0.1–0.5 km)and offshore (3–5 kms) locations. Metal concentrations in water and bioaccumulation in sponges weredetermined by ICP-MS (Inductively coupled plasma-mass spectrometry). Enrichment of metalcontamination was more in the inshore, when compared to offshore environment. Higherconcentrations of metals Fe, Al, Ni, Mn, Cu, Cr, Co, Ba, Zn, V, Pb and Cd in inshore waters(3–6.4 times than offshore) may be due to the discharge of monsoonal rains, carrying a discharge ofindustrial and agricultural wastes and sewage directly into the coast. This is substantiated by a highlysignificant positive correlation between concentrations of metals in the water and accumulation insponges. The bioaccumulation of metals in sponge tissue were in order of Fe>Al >Ni>Mn>Cu>Cr>Co>Ba>Zn>V>Cd>Pb in both the inshore and offshore regions. Apparently, themacromolecule composition (sugars, proteins and lipids) was significantly reduced by theaccumulation of metals in inshore sponges. The current findings indicated that the frequentmonitoring is necessary to assess the eco-health of the marine environment by choosing bio-indicatorspecies like S. fibulata, which provide accurate, reliable measurements of environmental quality.

Keywords: Sponge, metals, bioindicator, bioaccumulation, Sigmadocia fibulata

Correspondence: J. Venkateswara Rao, Scientist, Toxicology Unit, Biology Division, Indian Institute of Chemical Technology,Hyderabad 500 007, India. Tel.: þ91-40-27193191. Fax: þ91-40-27173227. E-mail: jv@iict.res.in; jv@india.com

ISSN 0277-2248 print/ISSN 1029-0486 online � 2007 Taylor & FrancisDOI: 10.1080/02772240601150588

Dow

nloa

ded

By:

[CS

IR O

rder

] At:

07:0

2 31

Dec

embe

r 200

7

Introduction

The marine environment is continuously subjected to chemical pollution, which can have adetrimental effect on aquatic organisms living in that environment. The Gulf of Mannar(GOM), located on the southeast coast of India, is the first Marine Biosphere Reserve,which is endowed with rich marine flora and fauna. The GOM possesses a coastline of315 km starting from the pilgrim town of Rameshwaram and ending at the industrial townof Tuticorin. During the past three decades there has been a dramatic surge in industrialdevelopment on the coast with the establishment of a number of large scale industriesincluding a thermal power plant, fertilizer, chemical and mineral processing plants, textilemills and nearly 500 small-scale industries. Each year several new synthetic chemicals enterthe market, many of which are likely to pose impacts on the marine environment [1].

The major pollution problems met with the GOM include discharge and disposal ofuntreated and partially treated domestic and industrial waste, discharge of industrial coolantwaters, spilling of cargo such as chemicals and metal ores, fishing activities such asmechanized fishing vessels, draining of waste engine oils, painting of fishing vessels, shapingof metal lining of fishing boats, dumping of waste and trash fish, etc. [2]. The inshore areasusually get disturbed with more critical water pollution problems than offshore. The heavymetal burden in seawater may vary from time to time depending on the entry of effluentsinto the waters. In the previous studies sea urchins, mollusks, lobster and rock crabs havebeen used to study metal contamination in relevance to the environmental monitoringprogram [3–7]. In the current scenario, for assessing environmental health, the accumu-lation of toxic metals in tissues of sedentary animals would be more appropriate whilecomparing with periodically estimated concentrations in water and sediment. A suitablebioindicator possessing benthic and sedentary nature would be helpful for estimatedbioaccumulation of pollutants, in turn, which reveals the exact status of the environment.

Sponges have some of the characteristics as good bioindicators and are convenient toolsfor characterizing the state of a marine ecosystem [8,9]. Because of their feeding habits,sponges can accumulate a wide range of pollutants from both the suspensions and dissolvedphases. Since sponge communities have long life spans and are benthic organisms, they arecontinuously exposed to metals and get accumulated over a prolonged period. Hence, theyhave been frequently used to reveal the environmental crises by the accumulation ofpollutants of a selected area. High concentrations of pollutants have been reported inseveral sponge species like hydrocarbons [10], organochlorinated compounds [11]and metals [12–14].

Selection of a proper bioindicator species is instrumental in assessing the environmentaldamage from the impacts of anthropogenic activities and industrialization, which is essentialin monitoring the Gulf of Mannar Biosphere Reserve (GoMBR) areas. Previous reports alsoindicated that the sponge communities can remain stable for long periods and can be usedas suitable biomonitors of metal contamination in coastal areas [15,16]. Hence, in thepresent study, a representative sponge Sigmadocia fibulata (benthic and sedentary) waschosen as bioindicator and were collected from different areas of inshore and offshorelocations of the GOM. Metal concentrations in sea water and accumulation in S. fibulata

were analyzed by Inductively Coupled Plasma-Mass Spectrometer (ICP-MS).

Methods

Two different zones were chosen to analyze themetal contamination based on the presence ofmetals in water and their accumulation in S. fibulata, depending on the distance from the

488 J. V. Rao et al.

Dow

nloa

ded

By:

[CS

IR O

rder

] At:

07:0

2 31

Dec

embe

r 200

7

shore. Samples were collected from the shallow sub-tidal region between 15 and 25 feetby snorkeling and skin-diving during collection trips in 2004 at Mandapam coast, GOM(Lat. 9�50, Long. 79�50 E), India, at both inshore (0.1–0.5 km away from the shore, namelyPeriapatnam, Sunnimuntal, Pakeerpalli, Sethukarai and Pamban) and offshore (3–5 kmaway from the shore, namely closer to the islands of Muyali, Manali, Pulli Reef and Shingle)locations (Figure 1). Three samples from each locality of five different places of inshoreand offshore locations were collected. Immediately after being collected the samples werefrozen and kept at �20�C until the analytical work was started. The voucher specimenswere submitted to the National Institute of Oceanography (NIO), Goa, India for depositorypurposes and were identified at the Vizhinjam Research Centre of Central Marine FisheriesResearch Institute (ICAR), Vizhinjam, Thiruvananthapuram, India.

Among the collected sponges S. fibulata, which belongs to the class of Demospongia;order: Haplosclerida and family: Adociidea were chosen based on the availability in bothareas and were analyzed individually to study the bioaccumulation of metals.

Treatment of the samples for metal analysis

Each frozen sample of S. fibulata from both the areas was tested for heavy metal analysisusing the method of McCarthy and Ellis [17]. Briefly, 1 g of wet sample was digested with10mL of nitric acid 70% (Analytical grade) of SD (Shanthabhai Dharamjee) FineChemicals, in a microwave vessel in an IFB (Indian Fine Blanks Ltd) Microwave Oven,India. The program was repeated once again to ensure the total digestion of all samples.After completing the heating program the vessels were cooled at room temperature and

Figure 1. Map showing the collection sites of the study area GOM in Tamil Nadu (TN), India.

Environmental contamination using accumulation of metals 489

Dow

nloa

ded

By:

[CS

IR O

rder

] At:

07:0

2 31

Dec

embe

r 200

7

carefully vented in a fume hood. The contents of each vessel were quantitatively transferredto a Teflon� beaker and evaporated to incipient wetness. The residues were re-dissolved in20mL of 1 : 1 HNO3 and brought to a final volume of 250mL (14% HNO3). Clearsolutions were obtained in all cases. A procedural blank solution was also prepared. Thenthe digested samples were analyzed for heavy metals using ICP-MS (Model: Perkin-ElmerSCIEX, Model ELAN� DRC II ICP-MS (Toronto, Ontario, Canada). The inter-elementaleffects during analysis were taken care of by using built in Elan 2.1 version software.

Seawater analysis

A simple and rapid method of determining trace metals in seawater is used based uponmetal complexation with ammonium pyrrolidine dithio-carbamate (APDC) and extractioninto methyl iso-butyl ketone (MIBK), following the method of Brooks et al. [18]. In thisstudy, after the APDC/MIBK extraction of trace metals from seawater samples, ICP-MSwas used for element determination.

The collected seawater samples were passed through ‘0.4 mm’, filter paper prior toanalysis to eliminate the suspended particles in order to eliminate the additionalcontribution of metal concentrations in seawater. The pH of filtered seawater (20mL)was adjusted to 2 with dil. HNO3 followed by 1mL of 1% APDC and 5mL of MIBK wereadded. The samples were shaken for 2min and allowed to stand for 10min for phaseseparation. The aqueous phase was drained and the MIBK phase was transferred in aseparating funnel. Five millilitre of 25% HNO3 was added and shaken for back extraction.After phase separation, the aqueous phase was transferred in a test tube for further analysisby ICP-MS.

Biochemical estimations

In a separate set of experiments the total tissue content in each sample was analyzed bydigesting 1 g of individual sample (three dry tissue samples from each location) in 30% ofKOH and boiling at 100�C for 10min. The undigested calcareous spicules were carefullycollected and washed twice and quantified. The values were subtracted from the initial tissueweights, to obtain the total tissue content of the sponge. Additionally, the sponge sampleswere separately processed for estimating macromolecules like carbohydrates, proteins andlipid contents in individual samples. The total carbohydrate content was assayed bythe phenol–sulphuric acid method [19] and the total protein content was estimated usingFolin–phenol reagent according to the procedure of Lowry et al. [20]. The total lipid contentwas measured by using a 1 : 2mixture of chloroform : methanol according to the procedure ofthe Bligh and Dyer method [21]. The quantification of the macromolecules was calculatedper gram dry tissue of the sample (excluding calcareous spicules).

Statistical analysis

Metal concentrations in seawater and sponges were individually compared among the fiveregions using one-way analysis of variance (ANOVA) in both inshore and offshore zones.P<0.001, P<0.01 and P<0.05 were accepted as levels of statistical significance. Thevalues of metal accumulation in sponges (mg g�1 of wet weight, ppm) and metalconcentrations in water (mgL�1, ppb) were calculated using Origin-6 statistical softwareand presented as mean�SE of 15 samples (three samples from each location of fivedifferent places) of inshore and offshore locations. The bio-concentration factor (BCF¼

concentration in sponge/concentration in water) of metals in S. fibulata was calculated

490 J. V. Rao et al.

Dow

nloa

ded

By:

[CS

IR O

rder

] At:

07:0

2 31

Dec

embe

r 200

7

based on the ratio of mean accumulation of individual metal in sponge and availableconcentration in water.

Results

About 20–25 varieties of sponges belonging to class Demospongiae are available in theexperimental zone of the GOM (Mandapam coast). Among them only S. fibulata waschosen in the present article based on its cosmopolitan distribution in both inshore andoffshore locations. The available mean metal concentrations in surrounding waters of bothinshore and offshore are summarized in Table I. Enrichment of heavy metal concentrationswas more (3–6.4) in inshore waters than offshore.

The mean values of individual metal concentrations obtained in sponge samples ofinshore and offshore collected from five different locations are presented in Figure 2.

The total amount of accumulated metals in inshore samples is 494mg g�1 (wet tissue),which is 2.92 times more than offshore samples (169 mg g�1). Among these metals Fe and Alare accumulated in major quantities in both inshore and offshore (240 and 218 mg g�1 ininshore and 26 and 122 mg g�1 in offshore) samples. Mn and Ni accumulation occupied thenext position in both the shores i.e. inshore 7 and 15 mg g�1 and offshore 3 and 10mg g�1.The mean values of copper concentrations are 5.58 and 3.2 mg g�1, respectively. However,the mean values of other metals, namely Ba, Cd, Co, Cr, Pb, V and Zn are comparativelyless, ranging from 0.45 to 1.83 mg g�1. The one-way-ANOVA tests turned out to besignificant on a level of 5% for each metal estimated between the locations of inshore andoffshore. According to the ‘F’-test, Al, Fe, Cd, Zn, Co and Mn possessed significantvariations in both inshore and offshore samples. Similarly, the results of water analysis inboth shores also show significant differences in Fe, Mn, Cd and Co (Tables II and III).

Based on the data, it appears that there is a positive correlation between concentrations ofheavy metals present in water and corresponding accumulation in sponge tissues. The orderof metal concentrations [Fe>Al>Ni >Mn>Cu>Cr>Co>Ba>Zn>V>Cd>Pb] in

Table I. Metal concentrations in bottom water samples from inshoreand offshore locations.

Metal concentration in mgL�1* (ppb)

Metals Inshore Offshore

Al 33.19� 3.15 6.37� 0.56Ba 0.24� 0.01 0.18� 0.030Cd 0.07� 0.008 0.04� 0.006Co 0.33� 0.049 0.10� 0.014Cr 0.62� 0.031 0.19� 0.009Cu 0.82� 0.06 0.22� 0.05Fe 53.23� 5.93 8.26� 0.53Mn 2.26� 0.318 0.83� 0.05Ni 2.49� 0.23 0.81� 0.07Pb 0.13� 0.006 0.09� 0.004V 0.18� 0.009 0.07� 0.003Zn 0.24� 0.012 0.13� 0.006

*Each value is the mean�SE of 15 samples (three samples from eachlocation of five different places) of inshore and offshore locations.

Environmental contamination using accumulation of metals 491

Dow

nloa

ded

By:

[CS

IR O

rder

] At:

07:0

2 31

Dec

embe

r 200

7

*

S. fibulata (A1=Inshore, A2=Offshore)

0.3

0.2

0.1

0.0

0.2

0.1

0.0A1 A2

***

Met

al c

onte

nt (

µgg−1

wet

wei

ght)

AluminiumIron

Met

al c

onte

nt (

µgg−1

wet

wei

ght) Copper

CobaltM

etal

con

tent

(µg

g−1 w

et w

eigh

t) ChromiumVanadium

Met

al c

onte

nt (

µgg−1

wet

wei

ght) Zinc

Lead

Met

al c

onte

nt (

µgg−1

wet

wei

ght)

NickelManganese

**

**

*

***

*

*

*

*

*

*

*

**

**

*

**

***

*

**

***

Met

al c

onte

nt (

µgg−1

wet

wei

ght) Cadmium

Barium

250

200

150

100

50

0

15

12

9

6

3

0

6

5

4

3

2

1

0

1.8

1.5

1.2

0.9

0.6

0.3

0.0

0.5

0.4

0.5

0.4

0.3

A1 A2

A1 A2 A1 A2

A1 A2

A1 A2

*

**

Figure 2. Bioaccumulation of metals in the tissues of S. fibulata (mg g�1 wet weight), analyzed byICP-MS in both inshore and offshore localities (The collection sites are described in the Methodssection and marked in Figure 1). A1¼ Inshore samples (0.1–0.5 km, away from the shore) andA2¼Offshore samples (3–5 km, away from the main land, undisturbed area). Values are mean�SEof three individual observations of five different locations. Values are statistically significant at***P<0.001, **P<0.01 and *P<0.05.

492 J. V. Rao et al.

Dow

nloa

ded

By:

[CS

IR O

rder

] At:

07:0

2 31

Dec

embe

r 200

7

water and accumulation in sponges in both inshore and offshore locations appeared to besimilar, but the degree of concentration was high in inshore in comparison with offshorelocations.

The relative BCF values of each metal in inshore and offshore locations are presented inFigure 3. BCF values are of the same order of magnitude between inshore and offshoresponges, although metal concentrations are much higher in inshore waters than in offshoreones. It is evident from Figure 3 (inset A) that the metal concentrations in inshore watersare 1.4–6.5 times more than offshore estimated metals.

The mean amounts of tissue and the content of macromolecules (carbohydrate, proteinand lipid contents) of inshore and offshore sponges were presented in Figure 4. The spongespecies collected at offshore area have higher quantities of macromolecules per gram tissueweight. The percentage increase of tissue content, hexoses, pentoses (carbohydrates),proteins and lipids were higher in offshore species than inshore with 32, 31, 32, 55 and27%, respectively. It is evident from the results that the accumulated metals have significanteffects on the formation of tissue and the quantities of macromolecules.

Table II. ANOVA for metals in seawater and sponges between locations inshore.

Water Sponges

SS df F P SS df F P

Al 595 4 5.661 0.012 Al 4763 4 11.69 0.001Ba 0.027 4 9.857 0.001 As 0.207 4 5.954 0.010Cd 0.004 4 5.5 0.013 Cd 0.145 4 6.759 0.006Co 0.142 4 5.666 0.012 Co 0.581 4 5.405 0.013Cr 2.489 4 3.851 0.038 Cr 0.055 4 3.657 0.043Cu 1.851 4 5.457 0.013 Cu 7.074 4 196.5 0.001Fe 2113 4 6.583 0.007 Fe 2048 4 23.25 0.001Mn 129.1 4 9.074 0.002 Mn 0.363 4 6.176 0.009Ni 3.225 4 3.781 0.040 Ni 0.211 4 4.308 0.027Pb 0.145 4 7.723 0.004 Pb 0.011 4 5.6 0.012V 0.162 4 4.376 0.026 V 0.022 4 5.6 0.012Zn 0.658 4 8.849 0.002 Zn 0.071 4 9.421 0.002

Table III. ANOVA for metals in seawater and sponges between locations offshore.

Water Sponges

SS df F P SS df F P

Al 21.81 4 5.95 0.010 Al 1413 4 7.65 0.004Ba 0.024 4 4.13 0.031 As 0.024 4 3.87 0.037Cd 0.001 4 4 0.034 Cd 0.018 4 3.75 0.040Co 0.025 4 7 0.005 Co 0.052 4 3.61 0.045Cr 0.046 4 4.14 0.031 Cr 1.462 4 3.60 0.045Cu 0.196 4 7.67 0.004 Cu 3.626 4 4.14 0.031Fe 17.10 4 5.08 0.016 Fe 4.083 4 4.08 0.032Mn 0.213 4 3.55 0.047 Mn 0.154 4 3.86 0.037Ni 0.323 4 5.14 0.016 Ni 0.365 4 3.89 0.036Pb 0.022 4 4.75 0.020 Pb 0.027 4 4 0.034V 0.010 4 5.4 0.014 V 0.029 4 4.62 0.022Zn 0.082 4 9.36 0.002 Zn 0.030 4 3.5 0.049

Environmental contamination using accumulation of metals 493

Dow

nloa

ded

By:

[CS

IR O

rder

] At:

07:0

2 31

Dec

embe

r 200

7

Discussion

The concept to develop and use bioindicators [22,23] to monitor marine environments isat the base of our studies. For a couple of years now, ICP-MS, due to the high accuracy ofits analytical data and excellent detection limits, has proved to be the best analyticaltechnique for the determination of metals in seawater, sediments and in tissues [24,25].ICP-MS has the distinct advantage of being able to measure several metals present withinthe sample, which significantly shortens the evaluation time with more accuracy.

Previous workers used concentration of metals in water and sediments at inshore as anindication of anthropogenic activities at the GoMBR [26]. Values for metals dissolved inseawater (mgL�1) have been reported as 0.64 for Cd, 13.15 for Pb [26], 14.8 for Fe and6.42 for Mn at the GOM [27]. The concentration of metals in water may vary depending onseason, load of effluent released from sources, diffusion capacity of metals andphysicochemical properties of seawater. The concentrations of Fe and Mn in seawaterswere altered seasonally and were ranging from 4.5 to 130 mgL�1 and 0.5 to 25mgL�1,respectively [27]. In the present study Fe and Al concentrations are very high, which couldbe attributed to industrial wastes from various chemical industries located around thesampling vicinity and also due to untreated domestic sewage, which is being dumped intothe harbor. Metal concentrations may be more in sediment in comparison to seawater,which may be varied from time to time due to the entry of effluents. However, due to water

Figure 3. Bio-concentration factor (BCF) of metals in S. fibulata. BCF¼ accumulated concentrationin tissue (mg g�1)/concentration of metals in water. Inset [A]: Concentration-ratio among the metalsbetween in and offshore waters.

494 J. V. Rao et al.

Dow

nloa

ded

By:

[CS

IR O

rder

] At:

07:0

2 31

Dec

embe

r 200

7

currents the dispersion of sediments may also be possible. Hence, previous workers usedsome benthic free living invertebrates as bioindicators that are capable of accumulatingmetals due to prolonged exposure, to study the status of contamination in a particularlocation. The blue crab, Portunus pelagicus indicated the contamination of metals in themarine environment of the Kuwait region by accumulating high concentrations of metalsafter a decade, in the 1991 Gulf War [28]. The migrating organisms may be suitableindicators for a larger zone instead of confined areas. The selection of benthic and sedentaryorganisms could be ideal to select as bioindicators for notified regions. Among them the firstmulticellular organisms like sponges would be ideal. Sponges filter large amounts of waterand accumulate heavy metals from the surrounding medium. They are attached to thesubstratum, have a relatively long life span and are much less influenced by transientchanges in the environment [9]. In the previous studies high concentrations of Cd were

A1 A20

10

20

30

40

50

60

Pro

tein

con

tent

(m

gg−1

)

A1 A20

100

200

300

400

500

600

***

*

*

**

A1 A2

A1 A20

5

10

15

20

25

30

Tot

al li

pids

(m

gg−1

)

*

0

2

4

6

8

10

12PentosesHexoses

Tot

al c

arbo

hydr

ate

cont

ent (

mg

g−1)

*

**

*

*

*

Tis

sue

cont

ent (

mg

g−1)

Figure 4. Effect of metals on tissue, proteins, carbohydrates and lipid contents in S. fibulata (mg g�1

dry weight). Each value is the mean�SE of 15 samples (three samples from each location of fivedifferent places) of inshore and offshore locations. The collection sites are described in the Methodssection and marked in Figure 1. A1¼ Inshore samples (0.1–0.5 km, away from the shore) andA2¼Offshore samples (3–5 km, away from the main land, undisturbed area). Values are statisticallysignificant at ***P<0.001, **P<0.01 and *P<0.05.

Environmental contamination using accumulation of metals 495

Dow

nloa

ded

By:

[CS

IR O

rder

] At:

07:0

2 31

Dec

embe

r 200

7

reported in the Antarctic sponges – Rosella sp., Tedania sp. and Axociella sp. [29],and the average values ranged from 12–40 mg g�1 for Cd and 28–70 mg g�1 for Zn insponge tissue [30], which were comparatively higher than the values presented in thepresent study.

The trace metal accumulation varies between individual sponges, among species andbetween metals [31]. The bioaccumulation of metals in sponge tissues could be theprolonged effect of exposure to the contaminated waters as filter feeders; they are exposedto pollutants present in waters and accumulate impurities present in phytoplankton or othersuspended matter. Hence, a single marine sponge species must be selected as a bioindicatorfor comparing the environmental status of any two selected regions based on metalaccumulation within the sponges. Bioaccumulation of Cu, Pb and V in tissues ofMediterranean sponge, Crambe crambe altered the behavior and physiological responses,such as changes in shape, growth rates and reproduction [32]. Similarly, Ravera [33]observed that the influence of accumulated metals altered the reproduction and embryonicdevelopment of marine Crustaceans and Molluscans.

In the present experiment, we have chosen a sponge S. fibulata as a bioindicator based onthe availability in both inshore and offshore locations to reveal the environmental crises bythe accumulation of metals in their tissues of a selected area. In general the accumulatedmetals produce their toxicity by forming complexes or ‘ligands’ with organic compounds.These modified biological molecules lose their ability to function properly, and result inmalfunction or death of the affected cells. The most common groups involved in ligandformation are oxygen, sulfur and nitrogen. When metals bind to these groups they mayinactivate important enzyme systems, or affect protein structure. Therefore, the spongespecies existing at offshore areas have maximum quantities of macromolecules present pergram tissue weight.

The present findings indicated the accurate assessment of inshore and offshoreenvironment pollution status at the GOM, India using a same sponge species S. fibulata.Our results demonstrate that the heavy metal concentrations were significantly higher at theinshore region, which may be due to enhanced anthropogenic activities or industrialization.The concentrations of metals in seawater and marine sponges at the GoM provide abaseline for future research into environmental contamination of the GOM. The presentfindings may also be considered as an important warning signal for the health of existing fishin such locations. The marine coastal environment of the GOM at Mandapam coastrevealed significant levels of all metals measured in the present study. The study also showsthat the benthic and sedentary sponges in the coastal environment are capable ofconcentrating metals even when the environmental levels are fairly low. At this point of timewe have collected sponges of similar size (three replicates from each locality) assuming thatthey have similar age groups. Further experiments are warranted to evaluate theaccumulation of metals versus age groups of the sponges.

Acknowledgements

The authors are thankful to the Task Force Network Programme of the Council ofScientific and Industrial Research (CSIR) and the Department of Ocean Development,Govt. of India for financial assistance and are also thankful to the Director, IICT forconstant encouragement. IICT communication no: 041230.

496 J. V. Rao et al.

Dow

nloa

ded

By:

[CS

IR O

rder

] At:

07:0

2 31

Dec

embe

r 200

7

References

1. Alink GM. Genotoxins in waters. Prog. Clin. Biol. Res. 1982;109:261–276.2. Ramachandran S, Sundaramoorthy S, Natarajan R. Status of coastal marine pollution in Tamil Nadu.

In: Natarajan R, editor. Coastal zone of Tamil Nadu. Status reports – Vol. III. Institute of OceanManagement – Center for Water Resources. Madras: Anna University; 1989.

3. Fallis BW. Trace metals in sediments and biota from Strathcona Sound, N.W.T., Nanisivik., MarineMonitoring Programme, 1974–1979. Canadian Technical Report of Fisheries and Aquatic Sciences1982;1082:34.

4. Peerzada N, Eastbrook C, Guinea M. Heavy metal concentration in Telescopium from Darwin Harbour,N.T., Australia. Mar. Pollut. Bull. 1990;21:307–308.

5. Warnau M, Ledent G, Temara A, Bouquegneau JM, Jangoux M, Dubois PH. Heavy metals in Posidonia

oceanica and Paracentroutus lividus from seagrass beds of north-western Mediterranean. Sci. Tot. Environ.1985;171:95–99.

6. Chou CL, Haya K, Paon LA, Burridge L, Moffatt JD. Aquaculture-related trace metals in sediments andlobsters relevance to environmental monitoring program ratings for near-field effects. Mar. Pollut. Bull.2002;44:1259–1268.

7. Chou CL, Paon LA, Moffatt JD. Cadmium, copper, manganese, silver and zinc in rock crab (Cancer irroratus)from highly copper contaminated sites in the Inner Bay of Fundy, Atlantic Canada. Bull. Environ. Contam.Tox. 2002;68:885–892.

8. Bettershill CN, Abraham R. Sponges, indicators of marine environmental health. In: Hooper, JNA, editor.Proceedings of the 5th International Sponge Symposium, ‘Origin and Outlook’. Vol. 44. Memoirs of theQueensland Museum; 1999. p 50.

9. Perez T. Evaluation de la qualite des milieux cotiers par les spongiaires: etat de l’art. Bull. de la Soc. Zoolog.de France 2000;125:17–25.

10. Zahn RK, Zahn G, Muller WEG, Kurelec B, Rijavec M, Batel R, Given R. Assessing consequences of marinepollution by hydrocarbons using sponges as model organisms. Sci. Tot. Environ. 1981;20:147–169.

11. Perez T, Wafo E, Fourt M, Vacelet J. Marine sponges as biomonitor of polychlorobiphenyls contamination:Concentration and fate of 24 congeners. Environ. Sci. Technol. 2003;37:2152–2158.

12. Carballo JL, Naranjo SA, Garcia-Gomez JC. Use of marine sponges as stress indicators in marine ecosystemsat Algeciras bay (Southern Iberian Peninsula). Mar. Ecol. Prog. Ser. 1996;135:109–122.

13. Webster NS, Negri AP, Wolff CW, Maclean WJ, Munro MHG, Battershill CN. Human impacts andmicrobial ecology of Antarctic sponges. Bolletino dei Musei e degli Instituti Biologici dell’Universita diGenova 2002;209:66–67.

14. Perez T, Vacelet J, Rebouillon P. In situ comparative study of several Mediterranean sponges as potentialbiomonitors of heavy metals. In: Pansini M, Pronzato R, Bavestrello G, Manconi R, editors. Spongescience in the new millenium. Vol. 68. Bolletino dei Musei e degli Instituti Biologici dell’Universita diGenova; 2004. pp 517–525.

15. Dayton PK, Robilliard GA, Paine RT. Benthic faunal zonation as a result of anchor ice at McMurdo Sound,Antarctica. In: Holdgate MW, editor. Antarctic ecology. Vol. 1. London: Academic Press; 1970. pp 244–258.

16. Hansen IV, Weeks JM, Depledge MH. Accumulation of copper, zinc, cadmium and chromium by the Marinesponge Halichondria panicea Pallas and the implications for biomonitoring. Mar. Pollut. Bull.1995;31:133–138.

17. McCarthy HT, Ellis PC. Comparison of microwave digestion with conventional wet ashing and dry ashingdigestion for analysis of lead, cadmium, chromium, copper and zinc in shellfish by flame atomic absorptionspectroscopy. J. Assoc. Off. Anal. Chem. 1991;74:566–569.

18. Brooks RR, Presley BJ, Kaplan IR. APDC-MIBK extraction system for the determination of trace elements insaline waters by atomic-absorption spectrophotometry. Talanta 1967;14:809–816.

19. Dubois M, Gilles KA, Hamiltion JK, Rebers PA, Smith F. Calorimetric method for determination of sugarsand related substances. Anal. Chem. 1956;28:350–358.

20. Lowry OH, Rosebrough NJ, Farr AL, Randall RJ. Protein measurement with Folin–phenol reagent. J. Biol.Chem. 1951;193:265–275.

21. Bligh EG, Dyer WJ. A rapid method of total lipid extraction and purification. Can. J. Biochem. Phys.1959;37:911–917.

22. Armitage PD, Pardo I, Furse MT, Wright JF. Assessment and prediction of biological quality.A demonstration of a British macro invertebrate–based method in two Spanish rivers. Limnetica1990;6:147–156.

Environmental contamination using accumulation of metals 497

Dow

nloa

ded

By:

[CS

IR O

rder

] At:

07:0

2 31

Dec

embe

r 200

7

23. Roberts RD, Gregory MR, Foster BA. Developing an efficient macrofauna monitoring index of an impactstudy. A dredge spoil example. Mar. Pollut. Bull. 1998;36:231–235.

24. Philip RB, Leung FY, Bradley C. A comparison of the metal content of some benthic species fromcoastal waters of the Florida Panhandle using high-resolution inductively coupled plasma mass spectrometry(ICP-MS) analysis. Arch. Environ. Contam. Tox. 2003;44:218–223.

25. Kajiya T, Aihara M, Hirata S. Determination of rare earth elements in seawater by inductively coupled plasmamass spectrometry with on-line column pre-concentration using 8-quinolinole-immobilized fluorinated metalalkoxide glass. Spectrochim. Acta Part B 2004;59:543–550.

26. Palanichamy S, Rajendran A. Heavy metal concentration in seawater and sediments of Gulf of Mannar andPalk Bay, Southeast coast of India. Indian J. Mar. Sci. 2000;29:116–119.

27. Ganesan M, Kannan L. Iron and Manganese concentrations in seawater, sediment and marine algae ofTuticorin coast, southeast coast of India. Indian J. Mar. Sci. 1995;24:236–237.

28. Al-Mohanna SY, Subrahmanyam MNV. Flux of heavy metal accumulation in various organs of the intertidalmarine blue crab, Portunus pelagicus (L.) from the Kuwait coast after the Gulf War. Environ. Inter.2001;27:321–326.

29. Bargagli R, Nelli L, Ancora S, Focardi S. Elevated cadmium accumulation in marine organisms from TerraNova Bay (Antarctica). Polar Biol. 1996;16:513–520.

30. Negri A, Burns K, Boyle S, Brinkman D, Webster N. Contamination in sediments, bivalves and sponges ofMcMurdo Sound, Antarctica. Environ. Pollut. 2006;143:456–467.

31. Patel B, Balani MC, Patel S. Sponge ‘sentinel’ of heavy metals. Sci. Tot. Environ. 1985;41:143–152.32. Cebrian E, Marti R, Uriz JM, Turon X. Sublethal effects of contamination on the Mediterranean sponge

Crambe crambe: metal accumulation and biological responses. Mar. Pollut. Bull. 2003;46:1273–1284.33. Ravera O. Influence of heavy metals on the reproduction and embryonic development of fresh water

Pulmonates (Gastropoda, Mollusca) and Cladocerans (Crustacea, Athropoda). Comp. Biochem. Physiol.1991;100C:215–219.

498 J. V. Rao et al.