Heavy metals (Cd, Cu, Pb and Zn) in two species of limpets (Patella rustica and Patella candei crenata) in the Canary Islands, Spain

Abstract

Nowadays, indigenous molluscs are being utilized more and more as biomonitors. Thus, in order to assess the concentrations of Cd, Cu, Pb and Zn in the Canarian Archipelago (Spain), we have utilized two species of limpets (Patella rustica and Patella candei crenata). We also tested the relationship between the metal levels and biometric parameters such as size and weight. The mean total concentrations of Cd, Cu, Pb, and Zn in P. rustica were 0.37 ± 0.05, 1.77 ± 0.09, 1.27 ± 0.07 and 8.84 ± 0.71 μg g-1 dry wt. (mean ± S.E.) respectively; whereas P. candei crenata as follows; 0.71 ± 0.10, 2.94 ± 0.11, 0.09 ± 0.01 and 33.74 ± 1.15 μg g-1 dry wt. (mean ± S.E.). We found significant differences for metal concentrations between the eastern islands and the western islands for both species. We did not observed evidences that more inhabited islands (Tenerife and Gran Canaria), had the highest metal concentration levels. Natural inputs from the upwelling region and other factors like size, food availability and/or excretion could have contributed to the variability. P. rustica presented negative correlations between metal concentrations and body weight and size, whereas, P. candei crenata showed negative correlations with Pb and with the biometric parameters. P. candei crenata revealed also positive correlation between Cd concentration and size.