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

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.

STAFES-APP is an ambitious academic-commercial partnership sensor development project which will generate direct and indirect technological, scientific, economic and societal impact across a wide range of UK marine science end-user and stakeholder communities as well as for the wider public.

Direct short to medium term economic impacts of the project will include the production of a product, "STAFES" which will be commercialised by the UK SME Chelsea Technologies Group. Product launch is expected to occur in 2020-21 with expected sales exceeding £11M in years 1-5. This will deliver jobs and income for the UK. STAFES will be deployable on a wide range of MAS platforms, and will therefore also support the growth of MAS observation systems. This will stimulate economic activity including business for MAS platform, sensors, systems and services companies.

In the medium to longer term, the data returned from widespread STAFES enabled MAS measurements of phytoplankton productivity will subsequently generate impact through directly feeding into process studies and biogeochemical models, as well as providing for high quality and extensive calibration and validation of satellite derived ocean productivity estimates. Such data will enable improved ocean productivity estimation and understanding of ocean processes with widespread economic and societal impacts: in the fisheries / aquaculture sector; understanding of harmful algal blooms; for climate change impact assessment and mitigation / adaptation and; through improved management of exploitation of ocean resources. Depending on the specific outcomes of subsequent MAS deployment of STAFES-APP and the requirements of stakeholders at the time, a non-exhaustive list of potential end users in these areas might include: DEFRA, CEFAS, the UK Marine Science Co-ordination Committee (MSCC), the UK Marine Management Organisation (MMO), the Convention on Biological Diversity (CBD) and the International Maritime Organisation (IMO). The technological and scientific impacts of the project will thus reach beyond the immediate academic beneficiaries to ultimately assist in evidence based decision making in the management of the oceans and climate change.
Members of the general public may also have an interest in both the technological challenges and scientific and socio-economic impacts associated with the project. The general public will benefit over the timescale of the project from interest in research activities and interaction with the researchers involved as generated through use of both mainstream and social media.

Impact will be facilitated through the wide dissemination of information generated from STAFES-APP through multiple routes tailored to target all the sectors highlighted above. In addition to peer reviewed publications and academic conference presentations describing capabilities and providing demonstrations of scientific utility, we will ensure wider dissemination outside of the academic community through online advertising on the CTG website (http://www.chelsea.co.uk/) targeted articles in the trade literature (see examples at http://www.chelsea.co.uk/technical-papers) and attendance at trade-fairs, including Ocean Business (biannual event at NOCS) and Oceanology International (biannual event at London Excel). These events will be attended by (Co-)PIs from UoS and NOC alongside CTG. CTG hold a number of demonstration events at Ocean Business and STAFES will be included from the 2019 event onwards. Finally, the academic (Co-)PIs will incorporate aspects of the project within ongoing teaching, public engagement and outreach activities, including through the highlighting of project specific information within NOC (http://noc.ac.uk/science-technology/research-groups/ote/instruments-sensors) and UoS hosted webpages, including the group websites run by (Co-)PIs (e.g. see http://www.phytoplanktonecophysiology.co.uk/).