Heavy metals in organisms from the Northern Tyrrhenian sea

The Science o f the Total Environment, 20 (1981)131--146

131

Elsevier Scientific Publishing Company, Amsterdam -- Printed in The Netherlands

HEAVY METALS IN ORGANISMS FROM THE NORTHERN TYRRHENIAN SEA

C. LEONZIO, E. BACCI, S. FOCARDI and A. RENZONI

Istituto di Anatomia comparata, Universit~ di Siena, via delle Cerchia 3, 53100 Siena (Italy) (Received March 6th, 1981;accepted in final form April 23rd, 1981)

ABSTRACT

The concentrations of zinc, manganese, copper, cadmium, lead and mercury have been determined in soft tissues of four marine organisms (Mytilus gaUoprovincialis Lmk., Nephrops norvegicus L., Mullus barbatus L., Engraulis encrasicolus L.) collected seasonally from the winter of 1976 to the spring of 1980 in various areas of the Tyrrhenian Sea (western Mediterranean). In all four species levels of all metals, except mercury in all areas are alike while mercury levels vary and, furthermore, are higher than in specimens from other areas of the Mediterranean and also from other seas. The possible natural origin of the mercury from cinnabar (HgS) ore as well as the suitability of the four species as bioindicators is discussed.

INTRODUCTION

During the past decade a large amount of information concerning the distribution of trace metals in the Mediterranean sea has been made available (Cumont et al., 1972; Majori and Petronio, 1973; Thibaud, 1973; Viviani et al., 1973; Fowler and Oregioni, 1976; Roth and Hornung, 1977; and many others). For the last five years we have been determining zinc, manganese, copper, cadmium, lead and mercury* levels in the tissues of four marine organisms belonging to three animal phyla, collected in various areas of the Tyrrhenian Sea. This region, besides receiving many anthropogenic pollutants, is associated with a large area of cinnabar-rich ores where for many years mining was intense, and the weathering of mineralized sediments has evidently increased the concentration of mercury in the terrestrial and marine environment. * Mercury and cadmium were suggested by the FAO/UNEP as a part of "Baseline Studies and Monitoring of Metals in Marine Organisms" (Med II). These two agencies together with the Consiglio Nazionale delle Ricerche (Conts. 79]01439; 8 0 / 0 0 7 7 1 ) a n d the European Economic Community (ENV/390/I) supported the programme financially. 0048-9697/81/0000--0000/$02.50 ©1981 Elsevier Scientific Publishing Company

132 SAMPLING AND ANALYTICAL METHODS

The specimens used in this survey (Fig. 1) were: the mussel (Mytilus galloprovincialis Lmk.) from four sampling stations (M1, M2, M 3 and M4); the Norwegian lobster (Nephrops norvegicus L.) from three stations ($1, $2 and $3); the striped mullet (Mullus barbatus L.) from three stations (T 1, T2 and T3) and the anchovy (Engraulis encrasicolus L.) collected at points scattered over the whole area. Samples were collected every season from winter 1976 to spring 1980.

TUSCANY

, 'tO0

\~r

A

:,

I ,/ r,I)" TV 0

Fig. 1. Sampling area.

10 20

30 Km

~,

133

Fish and crustaceans were caught with trawls; mussels by hand. All samples, with the exception of the mussels, were transported to the laboratory at about 4°C and then frozen (--20°C); the mussels were maintained in clean sea water for 36 hours before freezing. Weight and length were measured according to F.A.O. Fisheries Technical Paper, n. 158. Prior to analysis sub-samples were dried at 105--110°C to determine the water content. Typical values of the ratio fresh/dry weight in the analyzed materials were: M. galloprovincialis 5.0 whole soft parts* N. norvegicus 4.4 muscle M. barbatus 4.2 muscle E. encrasicolus 4.1 muscle Pretreatment of the samples for the analysis of the trace metals was by a wet pressure decomposition system proposed by Stoeppler and Backaus (1978). Mussels were analyzed in pools of 30--40 individuals; single specimens were analyzed for the other three species. Measurements were made using a Perkin-Elmer A.A.S. (300 S), with a deuterium automatic background compensator (and recorder). Mercury was atomized by the cold vapour technique according to the official Italian method (G.U. Rep. It. no. 328, 28-12-1971, pp. 8263--8365); zinc (and sometimes copper and manganese) by the air--acetylene flame, without extraction and concentration procedures; cadmium and lead (and sometimes copper and manganese) by an electrothermal system (Varian CRA 90). Because of the long time required for the electrothermal determinations, in 1978 this system was replaced by the NaDDC--MIBK extraction and concentration procedure described by Julshamn and Braekkan (1975), followed by flame determinations. Interferences were eliminated by the background compensator; interferences due to sensitivity were eliminated by the method of addition, before pretreatment. The precision of the method was satisfactory: the coefficient of variation (C.V.), calculated on 10 replicates of the same sample ranged from 3% for Zn to 20% for Pb. Accuracy of methodology was evaluated by the 1976, 1977 and 1978 intercalibration exercises conducted by the International Laboratory of Marine Radioactivity of the I.A.E.A. (Monaco, Principality of Monaco). Our laboratory code numbers were 68 (1976), 55 (1977) and 18 (1978); results are in the I.L.M.R. Progress Reports Nos. 13 and 16, 15 and 19, 18. RESULTS

AND DISCUSSION

Zinc (Table 1) * I t is recognised that differences in the water content of soft tissues occur and a r e rel a t e d to metabolic condition and/or reproductive stages; different amounts of mantle fluid m a y b e lost during sample preparation.

'78

'7 9

'7 9

'80

Winter

Spring

25300

40000

(3)

(5)

30400±6820

(2)

25240

18600 (3)

(2)

29650 (3)

35800 (3)

37970 (3)

(np)

SD

(5)

34400 ± 7280

28330 {3)

48950 (3)

(3)

47370

(3)

34200

31300 (3)

(5)

37890 ± 8140

(3)

35030

37030 ± 6580 (4)

(3)

29170

27150 ± 7540 (5)

19150 (2)

..~

M3

(np)

SD

(3)

29700

33720 (2)

28270 (3)

(4)

30660±10790

(3)

41570

28330 (3)

(1)

32700

(4)

22380 ± 3270

31100 (3)

37050 + 9280 (4)

(2)

18000

.~

M4 SD

(16)

16640 ± 1950

15790 ± 2870 (6)

15170 ± 1690 (6)

15830±1820 (16)

(16)

16600 ± 2190

16300 ± 2570 (16)

(16)

15360 ± 2270

14570 ± 2800 (51)

(I0)

23710 ± 4410

16170 ± 2250 (16)

15460 ± 2190 (16)

(14)

11950 ± 1 2 1 0

(ni)

St

N. norvegicus a

a Data from S 2 : winter '7 6 ~ = 1 2 6 2 0 , SD = 19 6 1, n i -- 2 4 ; fall ' 7 7 ~ = 2 6 1 5 0 , SD = 3 1 2 0 , n i = 14.

'79

Fall

Summer'79

Spring

Winter '78

FMI

(3)

51670

(4)

(4)

'78

Spring

SD

31150 ± 7950

29630 ( 3)

(np)

(4)

'7 7

Winter

(3)

(3)

(2)

~

M2

37400 ± 2550

30530

'7 7

Fall

SD

.

30200 ± 4420

24300

Summer '7 7

Summer'78

36400

'77

Spring

(np)

24770 + 16500 (7)

'76

.~

Ml

M. galloprovincialis

Winter

Season

(nl)

SD

(16)

15880 ± 2020

14430'± 1400 (7)

15810 ± 1600 (10)

(16)

15760 ± 2220

15660 ± 1120 (16)

(16)

16530 ± 1750

13740 ± 1200 (16)

(10)

16720 1 2310

14350 ± 1630 (15)

(20)

12690± 1080

£

83 (hi)

SD

(8)

2920 ± 910

3130 ± 460 (6)

3 3 7 0 ± 521 (5)

(14)

3590 ± 410

4300 ± 650 (10)

(14)

4700 ± 430

3360 ± 900 (16)

(16)

3830 ± 530

3510 ± 440 (16)

(16)

4760 ± 870

4890 ± 990 (15)

3780 ± 490 (10)

(13)

5190 ± 920

~

TI

M. b a r b a t u s

TABLE 1 T O T A L ZINC C O N C E N T R A T I O N IN B I O L O G I C A L SA M PL E S F R O M T H E N O R T H E R N T Y R R H E N I A N SEA (pg/kg w.w.) (n i = number of individuals; np = n u m b e r of pools).

(hi)

SD

(16)

3530 ± 650

3140 + 200 (6)

(10)

4090 ± 610

(18)

3770 ± 650

3990 ± 900 (16)

3560 ± 530 (16)

(16)

4820 ± 890

3570 ± 470 (10)

4460 + 910 (23)

x

T2 (ni)

SD

(6)

3800 ± 540

3630 + 380 (7)

3390 ± 370 (6)

(5)

4280 ± 470

4040 ± 560 (16)

(5)

3850 ± 430

5340 ± 830 (10)

(10)

3740 ± 960

3190 ± 570 (15)

4730 + 960 (16)

(18)

3110 ± 580

~

T3 (hi)

SD

(16)

15000 ± 5090

16180 + 6110 (8)

14270 ± 4350 (7)

16400 ± 5800 (6)

(16)

17060 ± 4210

12220 ± 5400 (42)

12800 ± 4460 (16)

16450 ± 5880 (13)

20900 + 6670 (13)

(13)

10890 ± 3830

x

E. e n c r a s i c o l u s

CO

135 Concentrations of zinc are homogeneous for each species. Our results agree with those obtained by Ciusa et al. (1974) and Fowler and Oregioni (1976) for similar species from the Mediterranean Sea and by Topping (1973) and Harms (1975) from other marine areas.

Manganese (Table 2) Data are in substantial agreement with those of other authors (Harms, 1975; Fowler and Oregioni, 1976) with concentrations of a b o u t 1.4 ppm in crustaceans, 0.3 ppm in mullets, 0.6 ppm in anchovies and between 2.7 and 2 0 p p m in mussels; no correlation between variability and area, sex (by determination of mantle colour) or size has been observed. The large range of values observed in mussels (M 1 and M 3 were especially high) could be due to the fact that they were collected near the coast, and therefore under the influence of the Mn-rich waters -- flowing from riverine sources (see Brewer, 1975; Graham et al., 1975; Gibbs, 1977).

Copper (Table 3) The situation is analogous to that of zinc.

Cadmium (Table 4) The t w o species of fish and the lobster yield values below 0.02 ppm, while values for mussel were between 0.1 and 0 . 4 p p m . No differences between stations or seasons or from year to year have been observed. Taking into consideration the high concentration factor in the mussel (Jackim et al., 1977), and comparing our values with those reported in the literature (Topping, 1973; Fowler and Oregioni, 1976; Phillips, 1977) cadmium pollution in our area can be excluded.

Lead (Table 5) In fish, lobsters and mussels of M 1 and M4 values are near and sometimes below our detection limits (0.2 ppm) which is in accordance with similar findings obtained in other areas b y Topping (1973) and Harms (1975). At stations M2 and M 3 mussels yield higher values (from 1 to 1.7 ppm at M2, with an exceptional value of 12.7, and from 1.9 to 5.3 ppm at M3). A strong hinterland industrialization (steel factories, etc.) as well as galena (PbS) deposits, m a y be responsible for this local anomaly. Considering the high concentration factor for Pb in the mussel (SchulzBaldes and Lewin, 1974) and the values reported elsewhere in the Mediterranean (Majori and Petronio, 1973; Favretto and Tunis, 1974; Fowler and Oregioni, 1976; Castagna and Sarro, 1977) lead contamination would seem to be relatively low in the western Mediterranean. Often the lead content of marine organisms has been overestimated (Patterson and Settle, 1976).

Mercury (Table 6) Mussel. At stations M1, M2 and M 3 results were similar, at M4 there

MI

'7 9

Spring

'79

'80

Winter

Spring

8440 (2)

10830 (3)

1 2 1 0 0 -+ 4 5 5 0 (5)

M2

SD

M3 SD

(rip)

6460 (3)

1730 (3)

S1 SD

11300 (3)

12230 (3)

7070 (2)

7200 (1)

1420 ± 420 (16)

1 6 7 0 ± 210 (6)

1510 ± 230 (6)

6500 (3)

10400 (2)

1640 ± 420 (16)

8470 ± 2730 (4)

1230± 540 (16)

1540 + 240 (7)

1 4 4 0± 190 (10)

1380 ± 630 (15)

1030 ± 480 (16)

1280 ± 360 (16)

960 ± 370 (16)

2520 ± 1480 (10)

1520 ± 400 (15)

SD

330 ± 110 (13)

290 + 90 (10)

3 4 0 + 140 (11)

2 1 0 ± 70 (16)

2 7 0 ± 60 (16)

(15)

2 4 0 ± 80

2 0 0 ± 50 (i0)

(ni)

240 + 70 (8)

3 1 0 ± 70 (6)

300 ± 50 (5)

2 7 0 ± 50 (14)

1600 ± 930 (16)

1320 ± 780 (16)

1 5 8 0 ± 620 (16)

1210 ± 530 (49)

1610 ± 710 (13)

S3

(ni) 1760 ± 950 (20)

~

19080 (3)

1830 (3)

1900 (3)

1200 (1)

4400 ± 1090 (4)

(16)

1190 ± 350

1570 ± 560 (16)

SD

15300 ± 3600 (4)

(ni) 1360 ± 490 (14)

E

12600 (3)

SD

T1

M. barbatus

28O ± 90 (10)

2700 (3)

1670 (3)

M4 (rip)

N. norvegicus a

645O (2)

6980 ± 3620 (5)

6020 (3)

9980 ± 2450 (5)

15830 (3)

(5)

3860 ± 880

E

3306 ± 1456 (4)

20300 (3)

3666 ± 610 (4 )

(3)

(np)

177o

E

(pg/kg w.w.)

a Data f r o m $2 : winter ' 7 6 E = 1 9 3 0 , SD = 8 7 8 , ni = 24; fall ' 7 7 £ = 1 3 6 0 , SD = 4 6 0 , n i ~ 14.

'79

Fall

Summer ' 7 9

'7 8

Winter

7500 (2)

3330 (3)

'7 8

Fall

'7 8

Spring

3570 (3)

'77

Winter

7900 (3)

Summer '7 8

'7 7

20100 (3)

Summer ' 7 7

Fall

16900 (2)

'77

Spring

SD

8200 ± 4150 (5)

(np)

'76

E

M. galloprovincialis

CONCENTRATION

Winter

Season

TABLE 2 TOTAL MANGANESE

SD

260 + 80 (16)

3 2 0 ± 40 (8)

2 8 0 ± 50 (6)

2 4 0 ± 40 (10)

300 ± 130 (18)

270 ± 70 (16)

3 1 0 ± 70 (16)

3 7 0 ± 140 (8)

(10)

300 ± 7 0

2 7 0 ± 110 (13)

(hi)

T2

1120 + 290 (13) 780 ± 240 (13)

320 ± 60 (11) 7 7 0 +- 2 8 0 (16)

3 0 0 + 50 (6)

2 8 0 + 70 (7 )

48O + 160 (16)

3 7 0 ± 80 (8)

390 ± 90 (7)

380 ± 60 (16) 2 8 0 +- 30 (5)

2 5 0 ± 40 (6)

660 + 240 (31) 220 + 60 (16)

16o ± i i o (5)

360 ± 13o (9)

330 ± 19o (5)

430 ± 17o (15)

SD (ni)

E. encrasicolus

.~ SD (hi)

T3

¢.~ O'~

TABLE 3

Ml

SD

'79

Spnng

'79

Winter

1200 (2)

1340 (3)

1520+440 (5)

M2 SD

(np)

1100 (3)

1620 (3)

1680 (3)

1130 ( 3)

1 4 6 0 ± 11 0 (4)

3850 (3)

1130 ± 160 (4)

980 (3)

.~

M3 SD

(np)

1100 (3)

2500 (3)

2100 (3)

3020 (3)

2600 (3)

1700 (3)

1100 ± 260 (5)

2030 (3)

(4)

2790 ± 590

3130 (3)

1390 ± 350 (5)

1700 (2)

~

2020 (3)

1820 (2)

1540 (3)

1680+490 (4)

1450 (3)

1980 (I)

2850 (1)

890 ± 300 (4)

1800 ± 370 (4)

1630 (3)

SD (rip)

M4 SD

(ni)

83 SD

5830 ± 1020 (16)

6 0 8 0 ± 1180 (6)

5590 + 720 (6)

6300 ± 1400 (16)

6200 ± 1080 (16)

5460 ± 870 (7)

6030 ± 1200 (10)

7400 ± 2560 (14)

(16)

SD

SD

SD

(8)

3 0 0 ± 70

(6)

(16)

4 4 0 + 130

(6)

(7)

4OO -+ 7O

7 3 0 -+ 2OO (16)

1730 + 4 4 0 (42)

65O ± 120 (13)

5 2 0 -+ 70 (13)

3 9 0 + 150 (13)

(n~)

3 8 0 + 80 390 ± 110

(7)

3 3 0 + 100

(6)

3 6 0 ± 70

(5)

3 8 0 -+ 70

(16)

360 + 120

(5)

3 9 0 ± 150

(9)

4 1 0 -+ 9 0

(5)

3 4 0 ± 80

4 7 0 +- 1 4 0 (15)

3 3 0 -+ 1 0 0 (16)

4 1 0 ± 90 (18)

(ni)

T3

(6) 360 + 30 (16)

3 3 0 + 70 (6)

340 ± 70 (10)

380 ± 110 (18)

(16)

390 + 120

320 ± 110 (16)

360 ± 2 0 0 (16)

440 ± 180 (10)

440 ± 140 (14)

(n9

T2

E, encrasicolus

3 3 0 + 50

340 ± 40 (5)

3 7 0 ± 80 (14)

360 ± 100 (10)

340 ± 210 (14)

4 9 0 ± 70 (10)

(16)

(16)

350 ± 110 (16)

4 1 0 ± 90 (16)

400 ± 110 (15)

310 ± 80 (10)

240 ± 90

7710 ± 2040

6860 + 2170 (16)

SD

390 ± 60 (13)

(hi)

Tl

M. barbatus

5830 + 1970

5640 ± 1040 (16)

5640 ± 1380 (10)

7150 ± 2220 (15)

4490 ± 1610 (20)

~

(16)

a

9770 ± 3250

6360 ± 1800 (16)

6100 ± 2120 (44)

5410 ± 1880 (13)

3960 ± 1220 (16)

5490 + 1480 (16)

4940 ± 1840 (14)

(ni)

S1

•

N. norveglcus

a Data from $2 : w i n t e r ' 7 6 2 = 4 7 1 0 , SD = 1 2 7 4 , n i ~ 2 4 ; fall ' 7 7 £ = 1 0 7 5 0 , SD = 4 8 7 0 , n i = 14.

Spring '80

'7 9

Fall

Summer'79

'78

Winter

2400 (2)

1330 (3)

'78

'78

Spring

Fail

'7 7

Winter

2650 ± 1100 (4)

2420 (3)

'77

Fall

Summer'78

3000 (3)

Summer'77

1200 + 460 (7)

(np.)

3850 (2)

'7 6

.~

M. galloprovincialis

Spring '77

Winter

Season

T O T A L COPPER C O N C E N T R A T I O N (pg/kg w.w.)

100

'77

'77

'78

Fall

Winter

Spring

(3)

(3)

'79

',80

Winter

Spring

170

(I)

(3)

170

140

80

(3)

(3)

160

(3)

(2)

140

(2)

(3)

(3)

(3)

(5)

M4 SD (rip)

(3)

(3)

(1)

100

130

100

(3)

(2)

(3)

(4)

170-+ 20

220

100

100

150 + 40 (4)

90 -+ 15 (4)

(4)

100 -+ 20

70

~

a Data from $2 : winter '76 ~ < 2 0 , n i = 24; fall '77 ~ <20, n i = 14.

'79

Fall

(3)

200

140

S u m m e r '79

120

220

(2)

'79

150

Spring

300

'78

(3)

(3)

150 -+ 40

130

Winter

100

(3)

150 + 40 (4)

110

(5)

80 -+20

'78

(3)

(4)

130

150 + 60

(4)

(3)

180 -+ 60

180

170 + 70 (5)

130 + 50 (4)

(4)

90 + 10

(2)

(3)

SD (rip)

M3

90

£

Fall

Summer '78

i00

Summer'77

(2)

160 -+ 50 (4)

200

'77

Spring

SD (rip)

60 + 20 (7)

'76

M2

SD (np)

~

M1

M. galloprovincialis

Winter

Season

TABLE4 T O T A L CADMIUM C O N C E N T R A T I O N ( p g / k g w . w . )

S3 (ni)

<20 (16)

<20(6)

<20(6)

<20 (16)

<20 (16)

<20 (16)

<20 (16)

< 2 0 (7)

<20(10)

<20 (16)

<20 (16)

<20 (16)

(1{S)

<20

<20 (32)

<20 (10)

<20 (20)

<20 (15)

x

<20 (51)

<20 (30)

<20(16)

<20 (24)

<20 (14)

S~ (n i)

N. norvegicus a

Tl (n i)

<20 (8)

<20 (6)

<20 (5)

<20 (14)

<20 (14)

< 2 0 (10)

<20 (16)

<20 (16)

<20 (16)

<20 (15)

<20 (10)

<20(13)

x

M. barbatus

T: (hi)

<20 (16)

<20 (6)

<20(10)

<20 (18)

<20 (16)

<20 (16)

<20 (16)

<20 (I0)

<20 (23)

<20 (18)

x

<20 (6)

<20 (7)

<20 (6)

<20 (5)

<20 (16)

<20 (5)

<20 (9)

<20 (I0)

<20 (15)

< 2 0 (16)

< 2 0 (8)

<20 (6)

<20 (16)

< 2 0 (16)

<20 (420

<20 (16)

<20 (13)

<20 (13)

<20 (13)

<20 (18) <20 (16)

x (n i)

T3 x (n i)

E. encrasicolus

'78

Spring

'78

'79

'80

Winter

Spring

(3)

440

(2)

(3)

(2) 340±280 (5) 680 (2) 350

<200

200

(4)

SD

(np)

M2

(3)

500 (3)

900 (3) 1130 (3)

(3)

1700

(4)

1700

12700

1020±220 (5)

1130 ± 290 (4)

980 (3)

~ SD

(3)

(3)

2340 ± 1080 (5)

(3)

(3) 2430 (3) 3600 (3) 2370 (3) 1900

1900

(5)

3210 ± 680

2230

5240± 1400 (4)

3270

(2) 2420 ± 80 (5)

2630

(rip)

M3

M4 SD

(4)

(3)

(3)

(3)

(I)

<200

330

(3)

(3)

(4) 540 (3)

<200

430

250

850

330 ± 160 (4)

<200

<200

(3)

(np) <200

~

a Data from $2 : winter '76 £ < 200, n i = 24; fall '77 i < 200, n i = 14.

'79

FMI

Summer'79

Spring '79

Winter '78

Fall

Summer'78

'77

Winter

(3)

(3)

(2)

(7)

480±250

<200

'77

Fall

<200

<200

'77

Spring

<200

Summer'77

'76

Winter

(np)

SD

M. galloprovincialis

Season

Mt

CONCENTRATION(pg/kgw.w.)

TABLE5 T O T A L LEAD

(ni)

(ni)

$3

<200(16)

<200(6)

<200(6)

<200 (16)

<200(16)

<200(16)

<200(7)

<200(10)

<200(16)

<200(16)

<200(16)

<200 (16) <200(16)

< 2 0 0 (32)

< 2 0 0 (10)

<200(15)

<200 (20)

x

< 2 0 0 (51)

< 2 0 0 (30)

<200(16)

<200(25)

<200 (14)

SI

N. noruegicus a

T1 (hi)

<200(8)

<200(6)

<200 (5)

<200(14)

<200(16)

<200(14)

<200(10)

<200 (16)

<200(16)

<200(16)

<200(15)

<200(10)

<20 (13)

2

M. barbatus

<200 (16)

<200 (8)

<200 (6)

<200(10)

< 2 0 0 (18)

<200 (16)

<200(16)

<200(16)

<200(10)

<200(23)

<200(18)

(ni)

T2

T3 (hi)

<200 (6)

<200(7)

<200(6)

<200 (5)

<200 (16)

<200 (5)

<200 (9)

<200 (10)

<200 (15)

<200 (16)

<200(18)

)~

< 2 0 0 (16)

< 2 0 0 (8)

< 2 0 0 (7)

< 2 0 0 (16)

<200(16)

<200(42)

<200(16)

<200(13)

<200(13)

<200(13)

(hi)

E. encrasicolus

03 ¢,0

400

250

Summer'77

'77

'77

Fall

Winter

(5)

120 ± 60

(2) 750 (3)

590

(4)

580 ± 120

(4)

1100 ± 200

(3)

(hi)

Sl SD

1140 ± 440 (16)

(6)

120 ± 220

(6)

940 ± 510

(22)

1280 + 390

(16)

1470 ± 530

(42)

1110 ± 380

1310 ± 730 (31)

(51)

1160 ± 580

480 ± 180 (30)

670 ± 250 (30)

(24)

820 ± 310

830 ± 450 (19)

.~

N. norvegicus a

SD (ni)

83

(16)

1070 ± 630

(7)

1230 ± 220

(16)

840 ± 490

1070 ± 290 (25)

(33)

710 ± 350

(16)

1920 ÷ 700

1090 ± 420 (22)

(32)

970 ± 260

430 ± 140 (10)

(27)

930 + 330

680 ± 390 (20)

~

* Data f r o m S 2 : winter '76.~ = 920, SD = 294, n i = 24; fall '77 ~ = 770, SD = 196, n i = 20.

(2)

(3)

(3)

290

60

(3)

Spring '80

(1)

(2)

80

300

280

(2)

(3)

'79

150

(3)

Winter

(3)

140

(3)

110

140

(4)

(5) 180

540 ± 30

140 ± 40

100

(1)

300

(3)

170

(4)

460 ± 130

(4)

(3)

550 (3)

(5)

1830 ± 370

190 ± 60

'79

290 ± 80 (5)

(2)

SD (np)

M4

970 ± 400 (7)

~

590 ± 110 (5)

70

(2)

Fall

'79

Spring

260

(3)

100

(4)

150 ± 40

(3)

180

(5)

160 ± 70

130 ± 50 (4)

(4)

90 ± 10

290

130

'78

Winter

(3)

280

(4)

100 ± 20

(4)

370 ± 50

(3)

(3)

(2)

205 ± 50 (5)

M3 ~ SD (np)

Summer'79

'78

Fall

S u m m e r '78

Spring '78

190

'77

Spring

(7)

160 ± 50

SD (np)

'76

M2

SD (np)

~

MI

M. galloprovincialis

Winter

Season

TABLE 6 T O T A L M E R C U R Y C O N C E N T R A T I O N (pg/kg w.w.)

(5)

(16)

(16)

(8) 1080 ± 320 (16)

160 -+ 60

1650 ± 880 (18)

1220 ± 930

190 + 60

(8)

(6)

(9) 2120 ± 490

(6)

(7)

(6) 1190 ± 950

(12) 1980 ± 860

150 + 50

1180 ± 730

(16)

190 -+ 90

200 ± 60 (16)

150 + 40 (42)

110 ± 20 (18)

1370 ± 780

970 ± 890 (49)

2810 ± 2600 (5)

750 ± 190

2020 ± 1060 (41)

(7)

540 ± 320 (18)

1270 ± 1030 (16)

1560 ± 1010 (16)

160 ± 50

610 ± 1130 (21)

1220 ± 620 (24)

1800 ± 910 (25)

160 ± 40 (7)

(15)

(I0)

2500 ± 1680

(21)

120 ± 30

170 ± 70 (30)

1350 ± 760

460 ± 190 (19)

1590 ± 900 (23)

SD (ni)

200 + 80 (13)

~

E. encrasicolus

910 ± 970

(32)

1240 ± 680

(14)

480 ± 290

1210 ± 840 (16)

(14)

1820 ± 1010

(15)

1010 ± 650

790 ± 580 (34)

(39)

920 ± 970

520 ± 450 (16)

270 ± 340 (25)

(10)

420 ± 140

1240 ± 830 (24)

SD

1220 ± 750 (18)

(hi)

SD (hi)

SD (hi) 110 ± 60 (17)

T3

T2

Wl

M. barbatus

~.a d~ c~

141 Hg pg.g-I

size classes

v,w'

16-25mm ["] 2 6 - 3 5 m m ~] 3 6 - 4 5 m m

2-

0 l

Ioo m

Fig. 2. Mercury concentration in mussels from M4 (nine substations). were substantial differences within the station. Therefore after the first analyses, we decided to subdivide the station into several substations and specimens were collected from rocks only 20--30 meters apart. The results obtained show an extreme range of variability (from 0.1 to 1.8 ppm) within a population gathered from a strip of shore no longer than 100 meters (Fig. 2). A plausible explanation of this irregularity has n o t been identified. Norwegian lobster. Specimens of the same sex and of the same b o d y weight, even when caught in different seasons and at different sampling stations, show very similar concentrations, ranging from 0.4 to 1.5 ppm. Plot of average Hg concentrations in males and females shows that in the same body-weight class, values are higher in females than in males (Fig. 3). This difference probably depends on the different growth rate in the t w o sexes (Vives and Sau, 1963; Farmer, 1973); in the same body-weight class a male is younger than a female and therefore has had a shorter period of exposure. Striped mullet. Striped mullet values were from 0.11 t o 2.81 ppm. No correlation between mercury content and season, year or geographic location (i.e. near cinnabar ore or anthropogenic inputs) of the stations has been found; rather in the fishing ground (Fig. 4) we observe a tendency towards an increase of Hg content with the depth of water and with b o d y weight (Fig. 5). Regarding the former correlation, high mercury concentrations in animals living at greater depths have been observed in various species fished in the Tyrrhenian basin (Renzoni and Baldi, 1975). In this same species (striped mullet) additional corroborating results have recently been obtained (Bacci et al., 1979) with values as high as 8 p p m in occasional specimens fished from between 350 and 400 meters of depth.

142 Hg J /.jgg-i ww 3.

0

2

I 0

• •

•

.i', l

body weight (g)

Fig. 3. Correlation between total Hg and body-weight in Nephrops norvegicus. (95% C.L.). o, females; e, males. • = single value.

Hg /jg g-I w ~

2-

t O.

60

80

I00

120

140 "~13"00

320

340

depth (m)

Fig. 4. Mullus barbatus. Total Hg against depth of the fishing ground (95% C.L.). Concerning the correlation with specimen size, mercury increases along with b o d y weight in all the stations, in spite of a high degree of variability within the same size class. In T2 there is less variability than in TI and in T3, perhaps as a consequence of a greater regularity of the depth of the fishing ground in T2, almost always around 110 meters deep.

143

Hg pg~-i wv 4-

T

D T1 r-] T2

~] Tz

16"25

26"35

36-45

46-55

I

56-65

66-75

76-85

86-95

96-105

body weight (g)

Fig. 5. Correlation between total Hg and body-weight in striped mullet. (95% C.L.).

Anchovy. In the anchovy the overall average is around 0.16 ppm, a value quite similar to those reported for other areas of the western mediterranean (Baldi et al., 1978), but higher than those for the North Sea and for the Atlantic. A slight increase of Hg levels with body size has been observed, confirming the preliminary observations reported elsewhere (Bacci et al., 1979). COMMENTS

The research performed for this project is part of our c o m m i t m e n t to the FAO/UNEP Pollution Monitoring Program for the Mediterranean Sea. Among other objectives the programme intends to evaluate the suitability of various marine organisms as "bioindicators" for one or more pollutants. After five years of analyses some comments can be made upon this subject. The concentrations of zinc, manganese, copper, cadmium and lead in the muscle o f the Norwegian lobster, striped mullet and anchovy do not vary with size, sex, season or station. Instead there is a typical value for each species indicating that t h e y appear to be able to regulate body levels of these elements, at least in the muscle (Phillips, 1977). For zinc, manganese, copper and cadmium, but n o t for lead, the same situation seems to hold for the mussel. Lead levels f o u n d in the samples collected at stations M 2 and M3 are considerably greater than in those from the other two stations, indicating contamination but only for a limited section of the basin adjacent to a highly industrialized area. Consumption of marine organisms with lead levels as low as those f o u n d in this study pose no risk to h u m a n health. For mercury our observations would seem to demonstrate that:

144

(a) for coastal waters the mussel is a good bioindicator as levels of mercury in water are clearly reflected by levels f o u n d in its soft tissues (see the difference between our stations M 1 and M 2 ). However, the fact that at M4 the differences between samples separated by only a few tens of meters are greater than one order of magnitude indicates that the mussel can only be used to evaluate conditions prevailing over very small areas. (b) the Norwegian lobster, inasmuch as it is both a stationary species and an accumulator of mercury, is particularly suitable for monitoring deep areas; (c) the striped mullet is not a very suitable organism because of cyclic changes in mercury levels from shallow to deep waters which precludes it from reflecting the state of contamination of a given area; (d) the anchovy, which is pelagic, can only provide a rough idea of the general conditions of a basin, such as the western or the central or the eastern section of the Mediterranean Sea, because it often covers large distances in its movements from one area to another. In conclusion the observations of the last five years, together with former results regarding marine organisms of the Tyrrhenian Sea, show that except for a few high values o f lead in mussels for a restricted area, the only anomalous concentrations found are for mercury. For the Tyrrhenian Sea several reports (Renzoni and Baldi, 1975; Bernhard and Renzoni, 1977; Bacci et al., 1979) have already indicated t h a t the anthropogenic input of mercury cannot be responsible for the high levels in organisms, at least not those caught at considerable distances from the coast and in water as deep as 700 meters. The abundant cinnabar deposits in Tuscany are probably the main sources for high mercury levels in the organisms reported here. Similar mercury-bearing deposits are scattered throughout the Mediterranean basin and can account for high mercury levels in both pelagic and benthic organisms (Stoeppler et al., 1977; Renzoni et al., 1978; Stoeppler et al., 1979; Stoeppler and Ni~rnberg, 1979).

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145 piombo di alcune specie ittiche del Mar Ligure. Quad. Merceol. Bologna, 13 (1974) 114--124. Cumont, G., G. Viallex, H. Leliewe and P. Robenrieth, Contamination des poissons de met par le mercure. Rev. Int. Oc~anogr. M~d., 28 (1972) 95--127. Farmer, A. S., Age and growth in Nephrops norvegicus (Decapoda: Nephropidae). Mar. Biol., 23 (1973) 315--325. Favretto, L. and F. Tunis, Typical level of lead in Mytilus galloprovincialis LInK from the Gulf of Trieste. Rev. Int. Oc~anogr. M~d., 33 (1974) 67--73. Fowler, S. W. and B. Oregioni, Trace metals in mussels from the N. W. Mediterranean. Mar. Pollut. Bull., 7 (1976) 26--29. Gibbs, R. J. Transport phases of transition metals in the Amazon and Yukon Rivers. Geol. Soc. Am. Bull., 88 (1977) 829--943. Graham, W. F., M. L. Bender and G. P. Klinkhammer, Manganese in Narragansett Bay. Limnol. Oceanogr., 21 (5) (1976) 665--673. Harms, U., The levels of heavy metals (Mn, Fe, Co, Ni, Cu, Zn, Cd, Pb, Hg) in fish from onshore and offshore waters of the German Bight. Z. Lebensm. Unters.-Forsch., 157 (1975) 125--132. Jackim, E., G. Morrison and R. Steele, Effect of environmental factors on radiocadmium uptake by four species of marine bivalve. Mar. Biol, 40 (1977) 303--308. Julshamn, K. and O. R. Braekkan, Determination of trace elements in fish tissues by the standard addition method. At. Absorpt. Newsl., 14 (1975) 49--52. Knauer, G. A., The determination of magnesium, manganese, iron, copper and zinc in marine shrimp. Analyst, 93 (1970) 476--480. Majori, L. and F. Petronio, Marine pollution by metals and their accumulation by biological indicators (accumulation factor). Rev. Int. Oc~anogr. M~d., 31/32 (1973) 55--90. Patterson, C. C. and D. M. Settle, The reduction of orders of magnitude errors in lead analysis of biological materials and natural waters by evaluating and controlling the extent and sources of industrial lead contamination introduced during sample collecting and analysis. In: P. La Fleur (Editor), Accuracy in Trace Analysis, National Bureau of Standards, 1976. Phillips, D. J. H., The use of biological indicator organisms to monitor trace metal pollution in marine and estuarine environments -- A Review. Environ. Pollut., 13 (1977) 281--317. Regier, L. W., P. M. Jangaard, H. E. Power, B. E. March and J. Bierly, Composition and Nutritive Characteristics of Atlantic Canadian White Fish Meals. J. Fish. Res. Board Can., 31 (1974) 201--204. Renzoni, A. and F. Baldi, Osservazioni sulla distribuzione di Hg nella fauna del Mar Ligure e del Mar Tirreno. Acqua Aria, 8 (1975) 597--602. Renzoni, A., M. Bernhard, R. Sara and M. Stoeppler, Comparison between the Hg body burden of Thunnus thynnus from the Mediterranean and the Atlantic. IVes Journ~es ]~tud. Pollutions, Antalya C.I.E.S.M., (1978) 255--260. Roth, I. and H. Hornung, Heavy metal concentrations in water, sediments and fish from Mediterranean coastal area, Israel. Environ. Sci. Technol., 11 (1977) 265--269. Schulz-Baldes, M. and R. A. Lewin, Lead uptake from sea water and food, and lead loss in the common mussel, Mytilus edulis. Mar. Biol., 25 (1974) 177--193. Stoeppler, M., F. Backhaus, W. Matthes, M. Bernhard and E. Schulte, Mercury in Marine Organisms of the Mediterranean and other European Seas. Rapports et Proc~s Verbaux XXVth Congress and Plenary Assembly of ICSEM, Split, 20--30 October 1976, Rapp. Comm. Int. Met M~dit., 24 (1977) 39--42. Stoeppler, M. and F. Backhaus, Pretreatment studies with biological and environmental materials. I. Systems for pressurized multisample decomposition. Fresenins Z. Anal. Chem., 291 (1978) 116--120. Stoeppler M., M. Bernhard, F. Backhaus and E. Schulte, Comparative studies on trace metal levels in marine biota. I. Mercury in marine organisms from western Italian coast, the Strait of Gibraltar and the North Sea. Sci. Total Environ., 13 (1979) 209-223.

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