Oil spills cause long-lasting mangrove loss, threatening their conservation and ecosystem services worldwide. Oil spills impact mangrove forests at various spatial and temporal scales. Yet, their long-term sublethal effects on trees remain poorly documented. Here, we explore these effects based on one of the largest oil spills ever recorded, the Baixada Santista pipeline leak, which hit the mangroves of the Brazilian southeastern coast in 1983. Historical, Landsat-derived normalized difference vegetation index (NDVI) maps over the spilled mangrove reveal a large dieback of trees within a year following the oil spill, followed by a heigh-year recolonization period and a stabilization of the canopy cover, however 20–30% lower than initially observed. We explain this permanent loss by an unexpected persistence of oil pollution in the sediments based on visual and geochemical evidence. Using field spectroscopy and cutting-edge drone hyperspectral imaging, we demonstrate how the continuous exposure of mangrove trees to high levels of pollution affects their health and productivity in the long term, by imposing permanent stressful conditions. Our study also reveals that tree species differ in their sensitivity to oil, giving the most tolerant ones a competitive advantage to recolonize spilled mangroves. By leveraging drone laser scanning, we estimate the loss of forest biomass caused by the oil spill to 9.8–91.2 t ha⁻¹, corresponding to 4.3–40.1 t C ha⁻¹. Based on our findings, we encourage environmental agencies and lawmakers to consider the sublethal effects of oil spills on mangroves in the environmental cost of these accidents. We also encourage petroleum companies to use drone remote sensing in monitoring routines and oil spill response planning to improve mangrove preservation and impact assessment.

石油泄漏导致红树林长期流失，威胁着全球范围内的红树林保护和生态系统服务。石油泄漏在不同的空间和时间尺度上影响红树林。然而，它们对树木的长期亚致死影响仍然缺乏记录。在这里，我们根据有史以来最大的漏油事件之一，Baixada Santista 管道泄漏，于 1983 年袭击了巴西东南沿海的红树林，探讨了这些影响。历史上，Landsat 派生的归一化差异植被指数 (NDVI) 地图溢出的红树林表明，在石油泄漏后的一年内，树木大量枯死，随后是一年的重新定殖期和树冠覆盖率的稳定，但比最初观察到的低 20-30%。我们根据视觉和地球化学证据，通过沉积物中意外持续存在的石油污染来解释这种永久性损失。使用野外光谱和尖端无人机高光谱成像，我们展示了红树林持续暴露于高污染环境如何通过施加永久性压力条件来长期影响它们的健康和生产力。我们的研究还表明，树种对石油的敏感性各不相同，这使耐受性最强的树种具有竞争优势，可以重新定居溢出的红树林。通过利用无人机激光扫描，我们估计石油泄漏造成的森林生物量损失为 9.8–91.2 吨公顷 我们通过施加永久性压力条件，展示了红树林持续暴露于高污染环境如何影响它们的长期健康和生产力。我们的研究还表明，树种对石油的敏感性各不相同，这使耐受性最强的树种具有竞争优势，可以重新定居溢出的红树林。通过利用无人机激光扫描，我们估计石油泄漏造成的森林生物量损失为 9.8–91.2 吨公顷 我们通过强加永久性压力条件，展示了红树林持续暴露于高污染环境如何长期影响它们的健康和生产力。我们的研究还表明，树种对石油的敏感性各不相同，这使得耐受性最强的树种具有竞争优势，可以重新定居溢出的红树林。通过利用无人机激光扫描，我们估计石油泄漏造成的森林生物量损失为 9.8–91.2 吨公顷⁻¹，对应于 4.3–40.1 t C ha ⁻¹。根据我们的发现，我们鼓励环境机构和立法者在这些事故的环境成本中考虑石油泄漏对红树林的亚致死影响。我们还鼓励石油公司在日常监测和溢油应急计划中使用无人机遥感技术，以改善红树林保护和影响评估。