Single Turnover Active Fluorometry of Enclosed Samples for Autonomous Phytoplankton Productivity (STAFES-APP)

单细胞光合生物（统称为浮游植物）的初级生产是海洋生态系统和海洋碳生物地球化学循环的重要组成部分。此外，浮游植物负责地球上大约一半的光合作用，因此它们的活动也是全球碳循环的主要组成部分。目前用于测量浮游植物初级生产的技术和技术不足以解决这一关键生态系统和生物地球化学过程变化的许多时空尺度，限制了我们现在和未来对该过程动态的理解和建模能力。此外，目前用于初级生产的所有可用测量技术都容易出现相当大的方法学错误，包括协议相关的变异性（精度）以及技术之间关于测量精确度和测量效果（准确性）的差异。使用机器人观测平台（即所谓的海洋自主系统（MAS））原位测量海洋中浮游植物生产力的能力，将代表我们监测和了解浮游植物生产力的能力发生了重大变化，从一些最小的变异尺度到代表地球上一些最大的生态系统和最大生态梯度的大洋盆地尺度。因此，当前的提案旨在开发一个可部署的 MAS 系统来测量浮游植物的初级生产。浮游植物初级生产的自主测量是一个相当大的挑战，因为目前可用的大多数技术无法轻易适应 MAS 观测平台。在本提案中，我们建议利用浮游植物的有用特征来提供测量初级生产力的手段。具体来说，照射到绿色色素叶绿素（光合作用装置的基本组成部分）上的任何光的一部分将作为不同波长的荧光重新发射。这种发射的荧光的强度和动态可以与发生的光合作用的量定量相关。因此，通过仔细设计测量系统、协议和数据分析技术，可以利用作为该过程的副产品发射的荧光来推算光合作用的速率。对此类技术的使用已经进行了数十年的研究。然而，直到最近，技术能力的增强（包括降低的功率要求和高质量的多光谱光学）与理论理解的提高（包括新的测量和数据分析协议）相结合，使我们能够真正利用这种“活性叶绿素荧光”作为浮游植物初级生产的强大自主测量手段。因此，我们的目标是设计、构建、测试、部署和验证一种新颖的测量系统，该系统利用这些进步来促进跨多个平台对浮游植物生产力的新测量，并解决广泛的科学挑战。

Primary production by unicellular photosynthetic organisms, collectively called phytoplankton, is a crucial component of oceanic ecosystems and the biogeochemical cycling of carbon in the oceans. Moreover phytoplankton are responsible for around half the photosynthesis on Earth and hence their activity is also a major component of the global carbon cycle. Current techniques and technologies for the measurement of phytoplankton primary production inadequately resolve many of the spatio-temporal scales over which this crucial ecosystem and biogeochemical process varies, limiting our understanding and ability to model the dynamics of this process now and in the future. Moreover all currently available measurement techniques for primary production are prone to considerable methodological errors, including protocol dependent variability (precision) and differences between techniques concerning what precisely they measure and how well the measure it (accuracy). The ability to measure phytoplankton productivity in situ in the ocean using robotic observation platforms, so-called marine autonomous systems (MAS), would represent a step change in our ability to monitor and understand phytoplankton productivity from some of the smallest scales of variability up to the oceanic basin scales which represent some of the largest ecosystems and greatest ecological gradients on the planet. The current proposal thus aims to develop a MAS deployable system for the measurement of phytoplankton primary production. Autonomous measurements of phytoplankton primary production represent a considerable challenge, as the majority of techniques currently available cannot readily be adapted to MAS observational platforms. In this proposal we propose to take advantage of a useful characteristic of phytoplankton to provide the means to measure primary production. Specifically, a proportion of any light shone onto the green pigment chlorophyll, which is a fundamental component of the photosynthetic apparatus, will be re-emitted as fluorescence at a distinct wavelength. The intensity and dynamics of this emitted fluorescence can be quantitatively related to the amount of photosynthesis taking place. Consequently, through the careful design of measurement systems, protocols and data analysis techniques it is possible to derive the rate of photosynthesis using the fluorescence which is emitted as a by-product of the process. Use of such techniques has been investigated for a number of decades. However it is only recently that both enhanced technological capabilities, including reduced power requirements and high quality multi-spectral optics, combined with improved theoretical understanding, including new measurement and data analysis protocols, have combined to put us in a position where we can realistically employ such 'active chlorophyll fluorescence' as a robust autonomous measure of phytoplankton primary production. We thus aim to design, build, test, deploy and verify a novel measurement system which takes advantage of these advances to facilitate new measurements of phytoplankton productivity across multiple platforms and in the address of wide-ranging scientific challenges.