资源环境科技发展态势分析平台

The stoichiometry of physical nutrient supply may provide a constraint on the spatial distribution and rate of marine nitrogen (N₂) fixation. Yet agreement between the N₂ fixation rates inferred from nutrient supply and those directly measured has been lacking. The relative transport of phosphate and nitrate across the Gulf Stream suggests that 3‐6 Tg N year^‐1 must be fixed to maintain steady nutrient stoichiometry in the North Atlantic subtropical gyre. Here, we show direct measurements of N₂ fixation consistent with these estimates, suggesting elevated N₂ fixation in and near the Gulf Stream. At some locations across the Gulf Stream, we measured diazotroph abundances and N₂ fixation rates that are 1‐3 orders of magnitude greater than previously measured in the central North Atlantic subtropical gyre. In combination, rate measurements and gene abundances suggest that biogeochemical budgets can be a robust predictive tool for N₂ fixation hot spots in the global ocean.