Tracing anthropogenic and geological sources to the ocean using the osmium isotopic composition of macroalgae

Abstract

Macroalgae is common to the marine environment and is a known metal accumulator, often

possessing an-order-of magnitude greater enrichment in comparison to the host seawater. As such macroalgae could be used as a sensitive monitor of seawater chemical composition, and by inference a tracer of anthropogenic and non-anthropogenic impact to the modern ocean. In this study, we have analyzed the Os isotopic compositions of macroalgae to determine the Os isocopic compositions of surrounded seawater.