CalcUlating the strength of the Plastic pump In counteracting the Deep export of Oceanic carbon (CUPIDO)

进入我们海洋的塑料数量正在增加(每年800万吨)对我们星球的健康具有全球影响。随着这种塑料碎片在海洋中降解，即使在没有任何新投入的情况下，碎裂也会将颗粒大小从大塑料转移到较小的微塑料。因此，微塑料污染的问题在未来几年只会增加。然而，微塑料被运送到深海的方式在很大程度上仍然是未知的。这限制了我们确定塑料碎片对海洋生态系统的影响以及如何缓解这些影响的能力。微塑料碎片与浮游动物的动态群落相互作用。这些处于海洋食物链底部的小型生物摄取微塑料，并将其重新包装成粪便颗粒，在海底垂直迁移的循环中，粪便颗粒可能会沉积在海洋深处。微塑料也可能被结合到浮游动物的身体组织中，在生命结束时，这些组织将作为身体的一部分下沉。我要介绍一个新的概念“塑料泵”，用来描述塑料融入生物过程的过程，以及随后向深处移动的过程。塑料泵可能与海洋的生物能力相互作用，将碳从表面输送到深处(这一过程被称为生物碳泵，BCP)。进一步阐明塑料泵和BCP之间的相互作用很重要，因为BCP通过吸收和储存人类活动产生的大气二氧化碳到深海，在减缓气候变化方面提供了关键的生态系统服务。塑料泵的干扰可能会降低BCP的效果。这一点尚未确定。CUPIDO将进行两次邮轮探险，其中将使用生物地球化学、材料科学和生物学的一套尖端方法。这些方法包括浮动和系泊平台，这些平台不仅将确定塑料浓度随季节的深度分布，还将确定塑料如何在这些深度与自然生态系统相互作用。它还将部署一种独特的设备，根据我自己的设计和规格自行制造，通过在现场条件下孵化预先选择的中微塑料来评估海洋塑料如何在长时间内发生变化。丘比多将专注于南大洋(SO)和地中海(MS)的两个地区。两个选定区域(相对原始和污染严重)的对比条件使得可以比较分析塑料泵对海洋在低(SO)和高(MS)塑料输入区域内输出和固定碳的能力的影响。我的Cupido团队将测量塑料的特性作为暴露在海洋环境中的函数的变化；塑料在日常和季节性时间尺度上的垂直分布和出口，以及浮游动物作为塑料通过水柱的媒介所起的作用。将对这些丰富的新数据进行分析和建模，以预测：(I)塑料通过水柱在特定水层中的积累，以及(Ii)塑料和碳的通量在塑料碎片投入量高和低的地区在年度循环中如何变化。总体而言，Cupido将解决浮游动物和食物网相关过程在促进塑料通过水柱下沉方面发挥主要作用的假设。这些机制将降低海洋生态系统将碳从表面转移到深海的能力(导致生物量控制计划减慢)。BCP在降低大气二氧化碳水平方面提供的服务对缓解气候变化具有经济意义。通过塑料泵各部件的参数设计，Cupido将评估微塑料垃圾对BCP的经济影响，以及抗击海洋塑料污染的价值，以恢复缓解气候变化的水平。

The amount of plastic entering our oceans is increasing (8 million tonnes p.a.) with global implications for the health of our planet. As this plastic debris degrades in the ocean, fragmentation will shift particle size from large plastics to smaller microplastics, even in the absence of any new inputs. Thus, the problem of microplastic pollution will only increase in future years. However, the ways in which microplastics are transported to the deep ocean are still largely unknown. This limits our ability to determine the impacts of plastic debris on the ocean ecosystem and how these can be alleviated. Microplastic debris interact with dynamic communities of zooplankton. These small organisms, which are at the base of marine food chains, ingest microplastics and repackage them into faecal pellets which may become deposited deep in the ocean over the cycle of diel vertical migration. Microplastics may also become incorporated into zooplankton body tissue which, at the end of life, will sink as part of the carcass. I am introducing a new concept of the "Plastic Pump", to collectively describe the process of incorporation of plastics into biological processes and their subsequent movement to depth. The Plastic Pump may interacts with the biological capability of the ocean to export carbon from the surface to depth (a process known as Biological Carbon Pump, BCP). Further elucidation of the interaction between the Plastic Pump and the BCP is important since the BCP provides a critical ecosystem service in mitigating climate change through uptaking and storing anthropogenically-derived atmospheric CO2 in the deep ocean. Interference by the Plastic Pump may reduce the effectiveness of the BCP. This has yet to be determined.CUPIDO will undertake two cruise expeditions where a suite of cutting edge approaches, at the intersection of biogeochemistry, material science, and biology, will be used. These approaches include floating and moored platforms that will not only determine depth profiles of plastic concentrations over seasons, but also how plastics interact with the natural ecosystem over these depths. It will also deploy a unique device, built in-house to my own design and specifications, to evaluate how oceanic plastics alter over long time scales through incubating pre-selected meso- and microplastics in in situ conditions. CUPIDO will focus on two regions located in the Southern Ocean (SO) and the Mediterranean Sea (MS). The contrasting conditions of the two selected regions (relatively pristine vs. highly polluted) allow for a comparative analysis of the impact of the Plastic Pump on the ocean's ability to export and sequester C within a low (SO) and high (MS) plastic input regime. My CUPIDO team will measure how the characteristics of plastics alter as a function of exposure to the marine environment; the vertical distribution and export of plastic over daily and seasonal timescales, and the role of zooplankton as vectors of plastics through the water column. This wealth of novel data will be analysed and modelled to predict: (i) the accumulation of plastics in specific water layers through the water column and (ii) how the flux of plastics and C alters over an annual cycle in regions of high and low plastic debris input. Overall, CUPIDO will address the hypothesis that zooplankton and food web associated processes play a major role in promoting the sinking of plastic through the water column. These mechanisms will decrease the ability of the marine ecosystem to transfer C from the surface to the deep ocean (resulting in a slowing of the BCP). The service provided by the BCP in lowering atmospheric CO2 levels has an economic significance to the mitigation of climate change. Through parameterising the various components of the Plastic Pump, CUPIDO will assess the economic impact of microplastic debris on the BCP and the value of combatting marine plastic pollution to restore levels of climate change mitigation.