Fate of ocean oxygenation in a warming world

氧气对所有高等生命的健康至关重要。自1960年以来，海洋中的溶解氧浓度下降了2%，预计未来还将继续下降，这与人为气候变化有关。未来的除氧与过度捕捞一起威胁着重要的经济渔业和海洋生态系统的可持续性，并将影响全球生物地球化学循环。因此，至关重要的是，我们必须充分了解未来可能会发生什么。目前预测未来的模型模拟带有相当大的不确定性；它们并不都同意，并且严重低估了过去50年的文件减少。这表明，这些模型缺少关键的相互作用，呼吁采取紧急行动，并采取专门和包容的科学方法。Fargo提供了这样一种方法，解决了为什么以及在多大程度上，海水溶解氧浓度可能在变暖的世界中发生变化。Fargo将通过一项创新的专门研究方案研究太平洋的溶解氧浓度，这是目前海洋中最大的低氧水体，它采用了一种新颖的多代理方法，在关键的温暖时间间隔内提供IPCC类型的气候模型模拟：i-美洲航道关闭时的气候变暖(400万年-1500万年)；ii-未来类似的气候变暖(上新世中期暖期，330万至300万年前)；III-更新世的暖期(上一次约80万年的间冰期)。Fargo分为两个阶段：第一阶段(1-4岁)和第二阶段(5-7岁)。头四年的重点是分析，以推进方法开发和重建氧气浓度和相关过程的时间序列，这些过程推动变化(海水变暖、分层、生产力、通风)。Fargo将用来创建这些时间序列的材料涉及被称为有孔虫的微生物的外壳。一些物种漂浮在海洋表面附近，称为浮游有孔虫，可用于评估地下氧气最低限度区域的存在，海水温度等。生活在海底沉积物上或沉积物中的物种称为底栖有孔虫，可用于重建底层水的氧气浓度和通风。Fargo将使用国际海洋发现计划的沉积物来确定在关键的温暖间隔期间，太平洋浅层OMZ氧气最低值区域(例如，氧气水平太低而无法支持有氧生命的区域)的自然范围和强度是否发生了变化。原始的时间序列将为IPCC类型的气候模型模拟提供支持，并提供稳健的测试，以调查模拟在特定时间段是否真实和正确，并确定改进模型模拟的途径。利用这些改进，Fargo将对未来进行模拟，包括1.5度和2度变暖的情景。为了提高人们对海洋除氧的认识，Fargo计划开展几项针对科学同行、政策制定者和普通公众的定制影响和参与活动。为了减缓/减少脱氧和保护我们的海洋环境，Fargo计划与政府(苏格兰和英国)合作制定地区性立法，以管理英国水域水产养殖和农业的营养输入。

Oxygen is critical to the health of all higher life. In the oceans dissolved oxygen concentrations have declined by 2% since 1960, and are expected to continue to decline into the future in relation to man-made climate change. Future deoxygenation, along with overfishing, threatens the sustainability of economically important fisheries and marine ecosystems and will impact global biogeochemical cycles. It is therefore crucial that we obtain a well-informed view about what the future may hold.Current model simulations that predict the future carry considerable uncertainties; they do not all agree and grossly underestimate the document decrease of the last 50 years. This suggests the models are missing key interactions, calling for urgent action and a dedicated and inclusive scientific approach. FARGO provides such an approach by addressing why, and to what extent, seawater dissolved oxygen concentrations may change in a warming world. FARGO will study dissolved oxygen concentrations in the Pacific Ocean, the largest low-oxic water body in the current ocean, through an innovative and dedicated research programme incorporating a novel multi-proxy approach feeding IPCC-type climate model simulations across key warm time intervals:i- warmer climates across the closure of the American sea-way (4-15 million years);ii- warmer climates as future analogue (mid-Pliocene Warm Period, 3.3 to 3 million years ago);iii- Pleistocene warm intervals (interglacials of the last ca. 800,000 years). FARGO is structured into two phases: Phase I (years 1-4), and Phase II (years 5-7). The focus of the first four years is analytical, to advance method development and reconstruct time-series of oxygen concentrations and associated processes that drive changes (seawater warming, stratification, productivity, ventilation). The material FARGO will use to create these time-series involves the shells of microorganisms called foraminifera. Some species float near the ocean surface, called planktonic foraminifera, and can be used to assess the presence of subsurface oxygen minimum zones, seawater temperatures, etc. Species that live on or in sediments at the bottom of the ocean are termed benthic foraminifera and can be used to reconstruct bottom water oxygen concentrations and ventilation. FARGO will use sediments from the International Ocean Discovery Program to determine if there have been changes in the natural extent and intensity of the shallow Pacific Ocean OMZ oxygen minimum, or 'dead', zones (e.g. areas where oxygen levels are too low to support aerobic life), during the key warm intervals. The original time-series will feed the IPCC-type climate model simulations and provide robust tests to investigate if the simulations are realistic and correct for the specific time periods, and identify routes to improve the model simulations. Utilizing these improvements, FARGO will carry out simulations for future, including 1.5 and 2 degree warming scenarios.To raise awareness of ocean deoxygenation FARGO plans several bespoke impact and engagement activities aimed at scientific peers, policy makers, and the general public. To slow/reduce deoxygenation and protect our marine environment FARGO plans to work with government (Scottish and UK) to develop regional legislation to manage nutrient inputs from aquaculture and agriculture of UK waters.