Page 8 - TraceMetals_seagrass_algae

124 L. Campanella et al. / Environmental Pollution 111 (2001) 117±126

Table 9
Means and ranges of metal concentrations in leaves of Posidonia oceanica reported by various studiesa

Cd Cr Cu Pb Zn Notes

(mg gÀ1 dry wt.)

3.94 ± ± 4.14 ± 31 stations along the Italian coast. Orignal data
(1.95±8.57) (1.85±9.54) were recalculated on a dry wt. basis using the mean
± ± ± fresh/dry wt. ratio reported from the authorsb
2.81 ±
(2.02±3.87) 3.65 8.81 ± Six stations along the Tyrrhenian coast (Civitavecchia,
± (1.75±.73) (7.67±10.20) ± Rome)c
2.94 ±
± (2.24±3.88) ± ± Three sampling areas (18 sites) in the Aegean Sea
43.4 (Greece)d
20.8 ± 18.0 39.5 (27.1±97.7)
(2.7±44.0) (2.8±148) (10.5±123) 159 Seven stations in the Lesbos Island (Greece), a
2.26 1.39 12.8 7.35 (144±179) contaminated areae
(2.1±2.4) (0.96±1.67) (10.2±16.2) (5.96±8.35) 168
1.0 14.1 3.4 112 Nine stations in the Antikyra Gulf (Greece), a
2.22 ± 11.6 0.91 (105±118) contaminated areaf
(1.13±2.78) 0.50 (5.7±20.2) (0.70±1.18)
(0.31±0.74) Three sampling areas in the NW Mediterranean (France,
Italy). Leaves+epiphytesg

Island of Ischia (Italy)h

Four `clean' stations in Favignana Island (Italy)i

a Means of overall data reported in each study, ranges of mean values recorded in di€erent sites or areas.
b Constantini et al. (1990).
c Taramelli et al. (1991).
d Catsiki and Panayotidis (1993).
e Catsiki et al. (1994).
f Malea et al. (1994).
g Warnau et al. (1995).
h Schlacher-Hoenlinger and Schlacher (1998a).
i This work.

contents of one or more metals even in an unpolluted Catsiki and Panayotidis, 1993; Warnau et al., 1995;
area. However, when metal concentrations in the Schlacher-Hoenlinger and Schlacher, 1998a). Di€er-
biomonitored habitat are rather low, little or no inter- ently, the sequence observed by Malea et al. (1994) is:
action between metals occurs and it is possible to speak Zn>Pb>Cd>Cu.
of background levels.
The possible existence of any regulatory mechanism
On the contrary, if we consider a heavily polluted within tissues, as well as of metal interactions as a
area, competition between di€erent metals becomes consequence of exposure to known environmental con-
fairly probable. This may be the case of metal con- centrations, must be carefully evaluated in order to
centrations observed by Malea et al. (1994) in samples assess the usefulness of biological species as trace metal
of P. oceanica collected in an area contaminated from monitors. Moreover, an understanding of the kinetics of
natural and anthropogenic emissions. In fact, beside accumulation is needed if information on the time per-
huge Cd and Pb contents these authors have found low iod of integration for a given metal is required. There-
concentrations of Zn in the seagrass leaves (Table 9). fore, further studies are needed in order to evaluate the
Since the inhibiting in¯uence of Cd on Zn uptake is a robustness of the organisms selected in this study for
well-known process (e.g. Phillips, 1977; Luoma, 1983), routine use in marine biomonitoring.
these results might be not unexpected.
5. Conclusions
In such a case, of course, many inversions in the usual
sequence of metal contents in biomonitor tissues may The seagrass Posidonia oceanica (L.) Delile, the brown
be observed. In fact, we have found that in the leaves algae Padina pavonica (L.) Thivy, and the two gastro-
of P. oceanica from Favignana Island metal concentra- pod molluscs Monodonta turbinata Born and Patella
tions decrease according to the order: Zn caerulea L., have considerable potential as cosmopolitan
>Cu>Cd>Pb>Cr. This is the sequence commonly biomonitors of trace metals in the Mediterranean. These
observed, sometimes with the occasional inversion of
Cd and Pb (Sanchiz et al., 1990; Costantini et al., 1991;