Similarities and differences of metal distributions in the tissues of molluscs by using multivariate analyses

Abstract

Multivariate analysis including correlation, multiple stepwise linear regression, and cluster analyses were applied to investigate the heavy metal concentrations (Cd, Cu, Fe, Ni, Pb, and Zn) in the different parts of bivalves and gastropods. It was also aimed to distinguish statistically the differences between the marine bivalves and the gastropods with regards to the accumulation of heavy metals in the different tissues. The different parts of four species of bivalves and four species of gastropods were obtained and analyzed for heavy metals. The multivariate analyses were then applied on the data. From the multivariate analyses conducted, there were correlations found between the soft tissues of bivalves and gastropods, but none was found between the shells and the soft tissues of most of the molluscs (except for Cerithidea obtusa and Puglina cochlidium). The significant correlations (P < 0.05) found between the soft tissues were further complemented by the multiple stepwise linear regressions where heavy metals in the total soft tissues were influenced by the accumulation in the different types of soft tissues. The present study found that the distributions of heavy metals in the different parts of molluscs were related to their feeding habits and living habitats. The statistical approaches proposed in this study are recommended for use in biomonitoring studies, since multivariate analyses can reduce the cost and time involved in identifying an effective tissue to monitor the heavy metal(s) bioavailability and contamination in tropical coastal waters.

Relationship between element concentrations and body size in the Lake Maggiore population of Unio pictorum mancus (Mollusca, Bivalvia)

“…Moreover, the shells of long-living, slowgrowing mussel species could serve as records of longterm variation (e.g., on an interannual scale) (Gillikin 2005;Vander Putten 2000;Lazareth 2003). In fact, we found that heavy metal accumulation in shells was not correlated with that in soft tissues (Yap et al 2010).…”

Assessment of essential elements and chemical contaminants in thirteen fish species from the Bay Aratu, Bahia, Brasil

“…PCA has been applied in this way for the evaluation and classification of analytical results (Chaves et al, 2010;Nascimento et al, 2010;Bentlin et al, 2011;Yap et al, 2010;Santos et al, 2010). The applied PCA resulted in two significant PCs (PC1 and PC2), accounting for 84% of the total variance of the presented data.…”

“…Thus, CA was applied, in the present case, to the autoscaled data to achieve this objective. The similarities between samples were calculated on the basis of the squared Euclidean distance, whereas the Ward method (a hierarchical agglomerative system) was used to establish the clusters (Yap et al, 2010). The dendrogram of cluster analysis to the scores of the first two principal components are presented in Figure 4.…”

Byssus of Green-Lipped Mussel Perna viridis as a Biomonitoring Biopolymer for Zinc Pollution in Coastal Waters

“…Inc., Tulsa, OK, USA, 1984–2011). Studies on the links between a dependent variable and independent factors have demonstrated this in several instances [ 70 , 71 , 72 , 73 , 74 , 75 ].…”