Methanol Concentrations and Biological Methanol Consumption in the Northwest Pacific Ocean

Methanol metabolism can play an important role in marine carbon cycling. We made contemporaneous measurements of methanol concentration and consumption rates in the northwest Pacific Ocean to constrain the pathways and dynamics of methanol cycling. Methanol was detected in relatively low concentrations (<12-391 nM), likely due to rapid biological turnover. Rates of methanol oxidation to CO2 (0.9-130.5 nmol L-1 day(-1)) were much higher than those of assimilation into biomass (0.09-6.8 nmol L-1 day(-1)), suggesting that >89.7% of methanol was utilized as an energy source. Surface water acted as a net methanol sink at most sites, with an average flux of 9 mu mol L-1 day(-1). Atmospheric deposition accounted for 22.7% of microbial methanol consumption in the mixed layer, illustrating that the atmosphere is less important than internal processes for driving methanol cycling in these pelagic waters.

Automated summary

Methanol metabolism plays a crucial role in marine carbon cycling. Through simultaneous measurements of methanol concentration and consumption rates in the northwest Pacific Ocean, we have gained insights into the pathways and dynamics of methanol cycling. Methanol was found in relatively low concentrations, indicating rapid biological turnover. The rates of methanol oxidation to CO2 were significantly higher than the rates of assimilation into biomass, suggesting that methanol is primarily used as an energy source. Surface water served as a sink for methanol, with atmospheric deposition accounting for a small fraction of microbial methanol consumption.