Effect of terrestrial and marine humics on copper speciation in an estuary in the Great Barrier Reef Lagoon

Studies carried out over several years on a tropical estuary, the Ross River Estuary, have shown that copper speciation is influenced by both terrestrial and marine humic substances. While terrestrial humic substances are mobilized by high freshwater runoff in the monsoonal season, Trichodesmium blooms mobilize high concentrations of marine humics to the inshore zone and increase labile forms of copper. The marine humics are more soluble than the terrestrial humics and persist in coastal waters of the Great Barrier Reef lagoon for many months prior to the wet season.