Dissolved organic phosphorus (DOP) has a dual role in the surface ocean as both a product of primary production and as an organic nutrient that fuels primary production and nitrogen fixation, especially in oligotrophic gyres. Although poorly constrained, the geographic distribution and environmental controls of surface ocean DOP concentrations influence the distributions and rates of primary production and nitrogen fixation in the global ocean. Here we pair DOP concentration measurements with a metric of phosphate stress, satellite-based chlorophyll a concentrations and a satellite-based iron stress proxy to explore their relationship with upper 50 m DOP stocks. Our results suggest that phosphate and iron stress work together to control surface ocean DOP concentrations at basin scales. Specifically, upper 50 m DOP stocks decrease with increasing phosphate stress, while alleviated iron stress leads to either surface DOP accumulation or loss depending on phosphate availability. Our work extends the relationship between DOP concentrations and phosphate availability to the global ocean, suggests a linkage between marine phosphorus cycling and iron availability and establishes a predictive framework for DOP distributions and their use as an organic nutrient source that supports global ocean fertility.

溶解有机磷 (DOP) 在表层海洋中具有双重作用，既是初级生产的产物，又是促进初级生产和固氮的有机营养物，特别是在贫营养环流中。尽管限制很少，但表层海洋 DOP 浓度的地理分布和环境控制会影响全球海洋中初级生产和固氮的分布和速率。在这里，我们将 DOP 浓度测量与磷酸盐胁迫指标、基于卫星的叶绿素 a浓度和基于卫星的铁应力代理来探索它们与上层 50 m DOP 库存的关系。我们的研究结果表明，磷酸盐和铁应力共同作用以控制盆地尺度的表面海洋 DOP 浓度。具体而言，上部 50 m DOP 库存随着磷酸盐胁迫的增加而减少，而减轻的铁胁迫会导致表面 DOP 积累或损失，具体取决于磷酸盐的可用性。我们的工作将 DOP 浓度和磷酸盐可用性之间的关系扩展到全球海洋，提出了海洋磷循环和铁可用性之间的联系，并为 DOP 分布及其用作支持全球海洋肥力的有机营养源建立了一个预测框架。