Phytoplankton community diversity and Ecosystem function from Sentinels (Phytodiverse)

Phytoplankton play a central role in the Earth System. Through photosynthesis, they are responsible for the uptake of 50 Gt C per year, equivalent to that of terrestrial plants, driving major processes in the ocean carbon cycle. Through this production of organic carbon, phytoplankton form the basis of almost all life in the ocean. The biological diversity of phytoplankton has a strong influence on the structure of the trophic webs in the ocean and hence on the biological diversity distribution of marine life. In addition, some aspects of phytoplankton diversity are readily available to ocean color radiometry, and potentially even more so with the advent of hyperspectral satellites. Because of the central role of phytoplankton in structuring global marine biodiversity and the advent of hyperspectral sensors to characterise that biodiversity, the time is ripe to focus the effort on developing algorithms that takes most advantage of the combination of current space assets and climate quality datasets. However, this effort cannot be carried out in isolation by the Space Agencies. Development of new algorithms require new and abundant in-situ datasets, or model data in the absence of in situ, which have been collected and advanced in Europe through EC funded projects.

The Phytodiverse project intends to respond to the urgency in defining and producing indicators of ocean health, by  exploiting novel datasets. These include satellite hyperspectral ocean colour data (from PACE). It will advance the development of algorithms adapted to the new datasets to quantify change in phytoplankton communities and  investigate its connection to climate driven processes (slow and extreme), combining all these processes to produce a workflow to inform policy. Phytodiverse will build on connections with ongoing EC projects to guide the next steps to monitor, understand and prepare for plankton changes at the global scale.

In particular, Phytodiverse will advance the following elements:

1. Primary observations: it will combine data from ESA satellites in orbit (Sentinel-2 and Sentinel 3) with  hyperspectral data from other satellites in orbit (PACE) to produce a new Remote sensing reflectance spatially sharpened product. Existing ESA datasets (OC-CCI) will also be used in the analysis as a baseline.
2. Biodiversity Models: it will advance phytoplankton diversity (an EOV) through an investigation on  community composition algorithms which exploit hyperspectral capabilities, in combination with a bespoke  niche-based Species Distribution Model for phytoplankton.
3. Essential Biodiversity Variables: it will deliver a dataset of community composition and ecosystem function (EBV) based on the algorithms’ advances
4. Biodiversity change indicators: it will compute temporal and spatial change indicators from our products providing information on the science cases and towards integration with the global monitoring for biodiversity