JST Vol. 21 (1) Jan. 2013 - Pertanika Journal - Universiti Putra ...

Metal Accumulation in the Mussels
Eugene Ng, Y. J., Yap, C. K., Zakaria, M. P. and Tan, S. G.
During the 10-week duration of transplantation from Sg. Melayu to the sampling site at Kg.
Pasir Puteh, all the metal concentrations were generally found to have increased from 1.49
to 6.93 µg/g for Cd, 7.31 to 25.63 µg/g for Cu, 29.27 to 3150.06 µg/g for Fe, 17.13 to 33.98
µg/g for Ni, 6.13 to 43.59 µg/g for Pb and 8.19 to 184.73 µg/g for Zn (see Fig.2 to Fig.7). In
specific, the heavy metal concentrations for all the metals in Kg. Pasir Puteh were significantly
higher than those in Sg. Melayu (independent t-test, p< 0.05). Meanwhile, Fe accumulated the
highest in the byssus and the total soft tissue while Pb accumulated the highest in the shells
of the mussels transplanted from Sg. Melayu to Kg. Pasir Puteh.
As for Cd, significant differences (one-way ANOVA, SNK, p< 0.05) were registered
between the tissues for the mussels transplanted from Sg. Melayu to Kg. Pasir Puteh for T 0 and
T 2. However, starting from T 6, the total soft tissue and byssus were significantly different from
the shell. For Cu, the shell and byssus were significantly different from the total soft tissues
during the transplant period, i.e. from T 0 to T 10. Meanwhile, significant differences were found
between byssus, shell and total soft tissues for Fe concentrations. The Ni concentrations did
not register any significant difference between TST, byssus and shell. For both sites, significant
differences (one-way ANOVA, SNK, p< 0.05) were registered between the shell and byssus
from the total soft tissues for Pb concentrations from T 0 to T 10. On the other hand, the Zn levels
of byssus and total soft tissue were significantly different (one-way ANOVA, SNK, p< 0.05)
from the shell in both the transplanted mussels.
Table 6 shows the rate of accumulation for all the metals in the different parts of the mussels
transplanted from Sg. Melayu to Kg. Pasir Puteh according to weeks. The rates of the metal
accumulation were fastest in all the mussel parts in week 2 (T=2) but these became slower in
the following weeks and up to week 10 (T=10). During the first 6 weeks of transplantation, the
total soft tissues showed the highest concentration factors (CF) in Cd (2.06), Cu (1.81) and Fe
(2.04) but the lowest CF in Ni (1.11). Meanwhile, byssus showed the highest CF in Pb (2.28)
and Zn (2.28), and the shell showed the highest CF in Ni (1.80). For the period of 10-week
transplantation, the total soft tissues showed the highest concentration factorss (CF) in Cd
(2.06), Cu (1.81) and Fe (2.22). Byssus showed the highest CF in Pb (3.17) and Zn (3.30), while
the shell showed the highest CF in Ni (1.98). These indicated that TST accumulated the highest
Cd and Cu concentrations, while byssus accumulated the highest Pb and Zn concentrations
and the shell accumulated the highest Ni concentration.
The concentrations of Cd in the shell and Ni in TST in the transplanted P. viridis at week
10 reached the values similar to those measured in the initial P. viridis (T 0). Similar findings
had previously been reported for Cu and Zn in the soft tissues of the mussel Mytilus edulis
transplanted to a temperate polluted bay (Roesijadi et al., 1984) and Cr and Cu in Isognomon
isognomon and Co, Ni and Zn in Gafrarium tumidum transplanted from a polluted site to a
clean site in a New Caledonia lagoon (Hedouin et al., 2011). As for Ni in byssus, Fe in TST, Pb
in byssus and shell and Zn in TST from the transplanted mussels (T 10), the levels significantly
increased during the transplantation period but did not reach the values measured in the initial
P. viridis (T 0). This could be due to the transplantation period being not long enough for the
transplanted mussels to accumulate the metals completely. Comparable results had been
84 Pertanika J. Sci. & Technol. 21 (1): 283 - 298 (2013)