Nutrient transition metals in a time series of hydrothermal vent fluids from Main Endeavour Field, Juan de Fuca Ridge, Pacific Ocean

Cabled deep-sea observatories can deliver continuous power and communications linkages to seafloor instruments and sampling devices. Building on this capability, a nine-month time series of hydrothermal vent fluids was recently collected from the well-studied Main Endeavour Field on the Juan de Fuca Ridge (northeast Pacific Ocean) using a novel remotely triggered vent fluid sampling system connected to Ocean Network Canada's NEPTUNE observatory (Seyfried et al., 2022). These samples exhibit very low Mg concentrations (Mg = 0.19–3.07 mmol/kg), indicative of little-to-no contamination by ambient seawater, providing excellent insight into sub-seafloor hydrothermal processes. Here, we present analyses of these samples for transition metals identified as biological nutrients (V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Mo, Cd, and W) and identify possible controlling processes.