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

Simple Summary The current study aimed to confirm the use of marine mussels' byssus (BYS) as a biomonitoring biopolymer for zinc (Zn) by comparing it to copper (Cu) and cadmium (Cd) pollution in coastal waters. The current analysis discovered four significant evidence-based points. First, the field-collected populations showed that the BYS was a more sensitive, concentrative, and accumulative biopolymer for the three metals than for total soft tissues (TST). Second, the results of the interspecific comparison showed that the mussels' BYS was a significantly better biomonitoring biopolymer for identifying coastal areas exposed to Zn, Cd, and Cu pollution and demonstrated the role of the BYS as a route for the excretion of metal wastes. Third, the BYS was more reflective of metal bioavailability and pollution in coastal waters. Fourth, and most crucially, the field-based cage transplantation investigation amply demonstrated the accumulation and removal of the three metals by the BYS in the Straits of Johore in both contaminated and unpolluted areas. In conclusion, the mussel BYS was verified to be a superior biopolymer to TST for determining Zn (as well as Cd and Cu) bioavailability and contamination in tropical coastal waters. The present study aimed to confirm the use of the byssus (BYS) of the green-lipped mussel Perna viridis as a biomonitoring biopolymer for zinc (Zn) by comparing it to copper (Cu) and cadmium (Cd) pollution in coastal waters under experimental field conditions, based on the transplantation of caged mussels between polluted and unpolluted sites in the Straits of Johore (SOJ). Four important evidential points were found in the present study. First, the 34 field-collected populations with BYS/total soft tissue (TST) ratios > 1 indicated that the BYS was a more sensitive, concentrative, and accumulative biopolymer for the three metals than TST. Significant (p < 0.05) and positive correlations between BYS and TST in terms of the levels of the three metals were observed. Second, the data obtained in the present study were well-supported by the interspecific comparison, which indicated that the BYS of P. viridis was a significantly better biomonitoring biopolymer for the identification of coastal areas exposed to Zn, Cd, and Cu pollution and played the role of an excretion route of metal wastes. Third, the higher positive correlation coefficients for the metals between the BYS sedimentary geochemical fractions than the TST sedimentary geochemical fractions indicated that the BYS was more reflective of metal bioavailability and contamination in coastal waters. Fourth, and most importantly, the field-based cage transplantation study clearly indicated the accumulation and elimination of the three metals by the BYS in both polluted and unpolluted sites in the Straits of Johore. In sum, the BYS of P. viridis was confirmed as a better biopolymer than TST for Zn, as well as Cd and Cu, bioavailability and contamination in tropical coastal waters.