Temperature, salinity and body-size influences depuration of heavy metals in commercially important edible bivalve molluscs of India
Temperature, salinity and body-size influences depuration of heavy metals in commercially important edible bivalve molluscs of India
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Date
2022-08-01
Authors
S. Chinnadurai
K. Elavarasan
V. Geethalakshmi
V. Kripa
K.S. Mohamed
Journal Title
Journal ISSN
Volume Title
Publisher
Elsevier
Abstract
The effect of temperature, salinity and body-size on depuration of naturally accumulated heavy metals in clams,
mussels and oysters harvested from Ashtamudi and Vembanad estuaries of Kerala, India were investigated using a
static depuration system. Before depuration, the concentrations of heavy metals such as Ni, Co, Fe, Mn, Cu, Pb and
Zn were analysed and it was found that the Fe, Zn, Cu and Pb contents in all the three bivalve molluscs were above
the prescribed limit which poses a significant health risk to bivalve consumers. To protect consumer food safety,
depuration experiments were conducted at varying temperatures, salinities and body-sizes. The clams, mussels and
oysters depurated under the room temperature depuration system (RTDS) showed a better reduction of heavy metals
compared with low-temperature depuration system (LTDS). ANOVA showed clams and mussels depurated at RTDS
significantly (p < 0.05) reduced the heavy metals than LTDS. However, there was no significant (p > 0.05) difference
in oysters between RTDS and LTDS. Further, clams and mussels depurated at low salinity (15-psμ) showed high
resistance against Pb reduction. But, all the heavy metals, particularly, Pb, Fe, Zn and Cu were effectively removed at
higher salinity depuration (25-psμ and 35-psμ). Moreover, irrespective of the body-size of clams, mussels and oysters
used for depuration, a significant (p < 0.05) reduction in all metals (Ni, Co, Fe, Mn, Zn, Pb and Cu) was observed.
Relatively, the medium-size bivalves showed higher reductions compared to small-size bivalves. Based on the experiments conducted, we recommend 48 h depuration using the static system under room temperature (30 ± 1 ◦C)
with a salinity range of (25–35 psμ) using medium-size bivalves (clam>30 mm; mussel >45 mm, and oyster >65 mm
length) as optimum conditions for producing safe bivalves for consumption in the tropics.
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Keywords
Research Subject Categories::FORESTRY, AGRICULTURAL SCIENCES and LANDSCAPE PLANNING::Animal production::Fishery
Citation
https://doi.org/10.1016/j.chemosphere.2022.135879