The hypoxic zone in the northern Gulf of Mexico is among the most dramatic examples of impairments to aquatic ecosystems. Despite having attracted substantial attention, management of this environmental crisis remains challenging, partially due to limited monitoring to support model development and long-term assessments. Here, we leverage new geostatistical estimates of hypoxia derived from nearly 150 monitoring cruises and a process-based model to improve characterization of controlling mechanisms, historic trends, and future responses of hypoxia while rigorously quantifying uncertainty in a Bayesian framework. We find that November-March nitrogen loads are important controls of sediment oxygen demand, which appears to be the major oxygen sink. In comparison, only ~23% of oxygen in the near-bottom region appears to be consumed by net water column respiration, which is driven by spring and summer loads. Hypoxia typically exceeds 15,600 km2 in June, peaks in July, and declines below 10,000 km2 in September. In contrast to some previous Gulf hindcasting studies, our simulations demonstrate that hypoxia was both severe and worsening prior to 1985, and has remained relatively stable since that time. Scenario analysis shows that halving nutrient loadings will reduce hypoxia by 37% with respect to 13,900 km2 (1985-2016 median), while a +2°C change in water temperature will cause a 26% hypoxic area increase due to enhanced sediment respiration and reduced oxygen solubility. These new results highlight the challenges of achieving hypoxia reduction targets, particularly under warming conditions, and should be considered in ecosystem management.

中文翻译：

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贝叶斯机制建模是墨西哥湾缺氧的特征：1968-2016年和未来情景。

墨西哥湾北部的低氧区是对水生生态系统损害最明显的例子之一。尽管引起了广泛的关注，但是由于有限的监控以支持模型开发和长期评估，对这一环境危机的管理仍然面临挑战。在这里，我们利用从近150个监测巡回航行和基于过程的模型得出的缺氧的新地统计估计值，在严格量化贝叶斯框架中的不确定性的同时，改善了对缺氧的控制机制，历史趋势和未来响应的表征。我们发现11月至3月的氮负荷是沉积物需氧量的重要控制因素，这似乎是主要的氧气汇。相比下，在春季和夏季的负荷驱动下，净水柱呼吸消耗了近底部区域约23％的氧气。低氧通常在6月超过15600平方公里，在7月达到顶峰，在9月下降到10000平方公里以下。与以前的一些海湾后播研究相反，我们的模拟表明，缺氧在1985年之前既严重又在恶化，并且自那时以来一直保持相对稳定。方案分析表明，相对于13,900 km2（1985-2016年中值），减少一半的养分负荷将使缺氧量减少37％，而水温+ 2°C的变化将导致缺氧面积增加26％，这是由于泥沙呼吸增加和减少氧溶解度。这些新结果突显了实现减少缺氧指标的挑战，尤其是在变暖条件下，