Evidence for the production of copper-complexing ligands by marine phytoplankton in the subarctic northeast Pacific

The availability and toxicity of copper (Cu) to marine phytoplankton involve complexation Cu by dissolved organic ligands uncertain origin structure. As part a GEOTRACES process study we used immobilized copper(II)-ion affinity chromatography (IMAC) isolate obtain information about the distribution potential sources Cu-complexing along Line P in subarctic northeast Pacific. Filtered seawater samples were collected from up five stations during cruises June 2016, 2017, August September 2018. Copper ligand concentrations consistently higher at coastal station P4 than other stations, particularly surface waters. Ligand upper 40 m P26 increased between 2016 2018 following 2014–2016 warming anomaly Pacific, whereas an increase concentration 2017 coincided with seasonal increases carbon (DOC) net community production. At all depth highest maximum chlorophyll coincided. A positive linear correlation suggests that are significant source P. lower expected consistent changes ecology associated anomaly. Comparing results oceanic waters those obtained previously Canadian Arctic terrigenous matter humic substances contribute pool captured IMAC.