Manganese is an essential micronutrient for marine phytoplankton growth and suggested to be apotentially (co-) limiting factor regulating primary production in high nutrient low chlorophyllregions.Dissolved manganese serves as a useful chemical tracer of many marine biogeochemicalprocesses,such as coastal inputs,hydrothermal activity,benthic fluxes from sediments andanoxic/suboxic conditions.As a result of its biogeochemistry,the distribution of dissolved manganesein open ocean typically spans from less than 100 picomolar in the deep ocean to several nanomolar inthe surface waters.