EAGER: Collaborative Research: NSF2026: Is Plastic Degradation Occurring in the Deep Ocean Water Column?

在国家科学基金会综合活动办公室的国家科学基金会2026计划的支持下，来自四个机构的一组研究人员将调查影响塑料碎片的过程及其进入海洋内部后的最终命运。自1950年以来，全球塑料产量呈指数级增长。据估计，每年有500万到1300万吨塑料从陆地流入海洋。然而，模型评估表明，目前进入海洋的塑料中有99%或更多是下落不明的。该项目的目标是了解微生物群落在百慕大附近开阔海域的中深水对塑料碎片的物理改性和生化转化。该项目直接解决了前33名Idea Machine参赛作品中的两个：“想象一个拥有清洁海洋的生活”和“不断变化的星球上的全球微生物群”。研究人员将在美国国家科学基金会资助的海洋通量计划（OFP）系泊地点部署孵化器，以评估600米和3600米水深的塑料降解情况。该项目的结果将进一步了解中深度（600米）和深层（3600米）海洋中塑料颗粒分解的机制过程，以及参与这些深度塑料生物降解的微生物群落。研究结果将对海洋生物地球化学、环境科学和微生物生态学等领域产生广泛的影响。OFP系泊上嵌套的深海培养箱是一种原位研究塑料聚合物降解过程的新方法，对海洋学研究的技术发展具有重要意义。该项目的结果还将提供对全球塑料预算的见解，有可能填补关于塑料命运的知识空白，从而影响塑料管理政策。了解深海微生物群落在合成塑料聚合物降解中的作用对工业界和决策者来说将是非常有价值的信息。为该项目提供聚合物的美国化学理事会的合作将加强学术界和工业界之间的合作。教育是该项目的重要组成部分，该项目包括一名博士后和多名本科生。项目成果将纳入本科课程，并通过外联活动向更广泛的公众传播。研究人员提出验证三组假设：(1)不同的聚合物促进不同微生物组的组装，并且这些微生物组在中远洋和深海环境中存在差异；(2)塑料在海洋内部降解，不同类型的塑料聚合物以不同的速率降解，并且这些速率在中远洋和深海海洋制度之间存在差异；(3)深海微生物群积极降解塑料并利用塑料聚合物作为碳源。这些假设将在位于百慕大东南约75公里的马尾藻海北部的OFP系泊处，在600米和3600米的深度上安装定制的深海孵化器，其中包含定义明确的塑料聚合物薄膜和纤维。所部署的聚合物将代表海洋环境中发现的塑料的多样性，并具有不同的抗微生物降解稳定性（例如，聚乙烯、聚对苯二甲酸乙二醇酯等）。该项目将结合最先进的聚合物化学分析（热分解-GCMS和拉曼，以及微傅里叶红外光谱）和显微镜，脂质分析（GCMS和GCirMS）和核酸测序分析，以确定微生物群落是否可以降解深层中远洋和深海中的聚合物。研究结果将决定生活在无光海洋内部的微生物群落是否积极降解和利用构成塑料的合成碳聚合物，从而在全球塑料的清除中发挥重要作用。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

With support from the NSF 2026 program in the NSF Office of Integrated Activities, a team of researchers from four institutions will investigate the processes that affect plastic debris and its ultimate fate once it enters the ocean interior. Since 1950, global production of plastic has grown exponentially. An estimated 5 to 13 million metric tons of plastic flows from the land and enters the ocean each year. However, model assessment indicates that 99% or more of the plastic entering the ocean is currently unaccounted for. The goal of the project is to understand the physical modification and biochemical transformation of plastic debris by microbial communities in the mid- and deep-waters of the open ocean near Bermuda. The project directly addresses two of the top thirty-three Idea Machine entries: “Imagine a Life With Clean Oceans” and “Global Microbiome in a Changing Planet.” The investigators will deploy incubators to evaluate plastic degradation at 600 meters and 3600 meters water depth at the NSF-funded Oceanic Flux Program (OFP) mooring site. Results from this project will further understanding of the mechanistic processes that govern decomposition of plastic particles in the mid-depth (600 meters) and deeper (3600 meters) ocean, as well as the microbial communities involved with biodegradation of plastics at those depths. The results will have broad implications to the fields of ocean biogeochemistry, environmental sciences, and microbial ecology. With the deep-sea incubator deployed inline on the OFP mooring being a new method to study plastic polymer degradation processes in situ, this research contributes significantly to technology development for oceanographic research. Results from this project will also provide insights into the global budget of plastics, potentially filling the knowledge gap on the fate of plastic and thus affecting plastic management policies. Knowledge of the role of deep ocean microbial communities in the degradation of synthetic plastic polymers will be very valuable information for industry and policymakers. The collaboration of the American Chemistry Council, which is providing polymers for the project, will strengthen the cooperation between academia and industry. Education is an essential part of this project, which includes one postdoctoral researcher and multiple undergraduate students. Project results will be incorporated into undergraduate courses and communicated through outreach activities for the broader public. The investigators propose to test three sets of hypotheses: (1) Different polymers promote the assembly of distinct microbiomes, and these microbiomes differ between the mesopelagic and bathypelagic ocean regimes; (2) Plastics are degraded within the ocean interior, different plastic polymer types are degraded at different rates, and these rates differ between the mesopelagic and bathypelagic ocean regimes; and (3) Deep ocean microbiomes actively degrade plastics and utilize plastic polymers as a carbon source. These hypotheses will be tested deploying custom-built deep-sea incubators at 600 m and 3600 m containing well-defined plastic polymer films and fibers on the OFP mooring, located in the northern Sargasso Sea about 75 km south-east of Bermuda. The polymers deployed will represent the diversity of plastics found in the marine environment and have different stabilities against microbial degradation (e.g., polyethylene, polyethylene terephthalate, and others). This project will combine state-of-the-art polymer chemistry analyses (pyrolysis-GCMS and Raman, and micro-FTIR) with microscopy, and lipid (GCMS and GCirMS) and nucleic acid sequencing analyses, to determine if microbial communities can degrade polymers in the deep mesopelagic and bathypelagic ocean. The results will determine if microbial communities living within the aphotic ocean interior actively degrade and utilize the synthetic carbon polymers that make up plastics, and thus play an important role in the removal of global plastics.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.