Work

Heavy metal concentrations suggest pollution risk varies between sea turtle species in the northwest Atlantic Ocean

Year: 2025

Type: article

Abstract: Heavy metal pollution poses an increasing threat to marine life globally. Due to bioaccumulation, the risks of heavy metal pollution are particularly acute for large species at high trophic levels although this will vary based on a species' diet and foraging location. Here, we assessed exposure risk to heavy metal pollution in three sea turtle species: the green ( Chelonia mydas ), Kemp's ridley (Lepidochelys kempii), and loggerhead ( Caretta caretta ) turtles. Specifically, we collected skin and scute samples from deceased turtles found after cold-stunning in Cape Cod Bay, Massachusetts, USA (green: n = 8, Kemp's ridley: n = 30, loggerhead: n = 17). Using ICP-MS, we analyzed samples for aluminum, arsenic, cadmium, cobalt, chromium, iron, manganese, nickel, lead, selenium, silver, and zinc concentrations. Across all species, heavy metal concentrations were predominantly higher and more variable in scute than skin. When comparing species, PCA analysis revealed loggerhead turtles had the least variability in metal heavy concentrations, potentially driven by a generalist foraging strategy, relative to green and Kemp's ridley turtles. Nevertheless, all three species had concentrations of As and Cd near values considered toxic in vertebrates with loggerhead turtles having the highest concentrations. These findings underscore the importance of considering inter-specific differences when assessing the risks of heavy metal exposure in sea turtles and highlight As and Cd as key pollutants of concern in the northwest Atlantic. • First study of heavy metal concentrations in green and loggerhead turtles in northwest Atlantic. • Metal concentrations in scute are more variable than in skin. • Loggerheads had less variability in metal concentrations relative to green and Kemp's ridleys. • As and Cd pose potential health risk to sea turtles in the northwest Atlantic.

Source: Chemosphere

DOI: 10.1016/j.chemosphere.2025.144190