The Eastern Tropical North Pacific (ETNP) contains the largest oxygen deficient zone (ODZ) in the modern ocean. We determined dissolved concentrations of Fe, Fe(II), and Mn from three cruises in the region. Similar to other reported ODZs, Fe(II) was highest in the depth range associated with the secondary nitrite maximum. The main source of this feature is likely lateral advection of water overlying reducing shelf sediments within a narrow density range centered on the potential density anomaly of 26.5 kg/m³. This density horizon is similar to the Eastern Tropical South Pacific (ETSP) and reflects the intersection of the same density range with a large fraction of the continental shelf bottom waters. We also observed subsurface maxima of dissolved Mn in this density range, in contrast to the ETSP. Deep waters were enriched in Fe within the ETNP, analogous to other eastern boundary upwelling systems as well as the Arabian Sea. We argue that in these systems, reducing conditions on the shelf and overlying water column facilitate a robust shelf to basin shuttle of Fe, moving Fe from the coastal margin to deep plumes. Mn is also transported offshore in the core of the ODZ, and the relationship between Fe(II), Mn, and nitrite is remarkably similar between the ETNP, ETSP, and Arabian Sea. The exception is that Mn supply from the Peruvian shelf is less pronounced than in the other two ODZs, potentially reflecting the absence of large rivers in the Peruvian system.

东热带北太平洋 (ETNP) 包含现代海洋中最大的缺氧区 (ODZ)。我们从该地区的三个巡航中确定了 Fe、Fe(II) 和 Mn 的溶解浓度。与其他报道的 ODZ 相似，Fe(II) 在与次生亚硝酸盐最大值相关的深度范围内最高。这一特征的主要来源可能是在以 26.5 kg/m ^{3的潜在密度异常为中心的狭窄密度范围内覆盖还原陆架沉积物的水的横向平流}. 这一密度范围与东热带南太平洋（ETSP）相似，反映了相同密度范围与大部分大陆架底部水的交集。与 ETSP 相比，我们还观察到在该密度范围内溶解的 Mn 的地下最大值。ETNP 内的深水富含铁，类似于其他东部边界上升流系统以及阿拉伯海。我们认为，在这些系统中，减少陆架和上覆水柱的条件有助于形成强大的陆架到盆地的 Fe 穿梭，将 Fe 从沿海边缘移动到深部羽流。Mn 也在 ODZ 的核心向海上输送，而 Fe(II)、Mn 和亚硝酸盐之间的关系在 ETNP、ETSP 和阿拉伯海之间非常相似。