Sulfur, e-waste contaminants and sharks

Area of Science:

• Marine Biology
• Ecotoxicology
• Environmental Chemistry

Background:

• Marine apex predators are increasingly exposed to environmental contaminants.
• Non-lethal methods for assessing contaminant exposure in sharks are limited.
• Understanding elemental profiles in marine predators is crucial for conservation.

Purpose of the Study:

• To quantify essential, toxic, and technology-critical elements, including rare earth elements (REEs), in the whole blood of two shark species.
• To establish baseline elemental concentration profiles and assess inter-individual variability.
• To evaluate whole-blood elemental profiling as a non-lethal ecotoxicological tool.

Main Methods:

• Blood samples were collected from two shark species (Carcharhinus obscurus and Carcharhinus plumbeus) in the Eastern Mediterranean Sea.
• Freeze-dried whole blood was analyzed using inductively coupled plasma mass spectrometry (ICP-MS).
• Multi-element concentration profiles and rare earth element patterns were determined.

Main Results:

• Elemental profiles in shark whole blood differed between the two species.
• Sulfur and lithium were found at relatively high concentrations.
• Rare earth element patterns were similar between species, with lower values for light/middle REEs and higher values for heavy REEs.

Conclusions:

• Whole-blood elemental profiling is a viable, minimally invasive method for contaminant surveillance in sharks.
• This study provides essential baseline data for monitoring threatened marine predators.
• The findings support future non-lethal ecotoxicological studies in vulnerable coastal ecosystems.