Phytoplankton and fisheries under regional warming in the global oceans – POSEIDON

POSEIDON aims to understand the response of ocean ecosystems to climate warming and extreme events (e.g., marine heatwaves). Long-term trends (> 23 years) in phytoplankton ecological indicators (biomass, size structure and phenology) will be analysed in different regions, encompassing a range of conditions found in the global oceans. POSEIDON will further investigate the spatiotemporal variability of these indicators under oceanic warming, and examine links between phytoplankton, climate and fisheries. POSEIDON will employ a novel, multidisciplinary approach by integrating contemporary oceanographic datasets, including satellite remote sensing observations, in situ cruise data and Biogeochemical Argo (BGC-Argo) floats. Specific research objectives include:

• Use a combination of remotely-sensed and available in situ datasets to regionally-tune and validate existing algorithms for computing phytoplankton ecological indicators (biomass, phenology and size structure) in several case study regions of the global oceans.
• Apply a marine heatwave detection algorithm on long-term SST data (ESA SST-CCI) and construct an atlas that describes the spatiotemporal distribution of extreme heating events (marine heatwaves [MHWs]) within the regions of interest.
• Utilise remotely-sensed datasets to investigate the response of ecological indicators in identified MHW hotspots.
• Elucidate the impacts of climate change on ecosystem structure through a combination of statistical analysis and metabolic theory (e.g., biomass size spectrum modelling) that describe relationships between phytoplankton indicators and the biomass of pelagic fish species.

Scientific Papers:

• Gittings, J.A., Raitsos, D., Brewin, R.J.W., Hoteit, I. (2021). Links between Phenology of Large Phytoplankton and Fisheries in the Northern and Central Red Sea. Remote Sensing, 13, 231.
• Gittings, J. A., Brewin, R. J. W., Raitsos, D. E., Kheireddine, M., Ouhssain, M., Jones, B. & Hoteit, I. (2019). Remotely sensing phytoplankton size structure in the Red Sea. Remote Sensing of Environment, 234, 111387.
• Gittings, J. A., Raitsos, D. E., Kheireddine, M., Racault, M.-F., Claustre, H., & Hoteit, I. (2019). Evaluating tropical phytoplankton phenology metrics using contemporary tools. Scientific Reports, 9(1), 674.
• Gittings, J. A., Raitsos, D. E., Krokos, G., & Hoteit, I. (2018). Impacts of warming on phytoplankton abundance and phenology in a typical tropical marine ecosystem. Scientific Reports, 8(1), 2240.
• Gittings, J. A., Raitsos, D. E., Racault, M., Brewin, R. J. W., Pradhan, Y., Sathyendranath, S., & Platt, T. (2017). Remote Sensing of Environment Seasonal phytoplankton blooms in the Gulf of Aden revealed by remote sensing. Remote Sensing of Environment, 189, 56–66.
• Papagiannopoulos, N., Raitsos, D. E., Krokos, G., Gittings, J. A., Brewin, R. J. W., Papadopoulos, V. P., Pavlidou, A., Selmes, N., Groom, S., & Hoteit, I. (2021). Phytoplankton Biomass and the Hydrodynamic Regime in NEOM, Red Sea. Remote Sensing, 13, 2082.
• Gokul, E.A., Raitsos, D.E., Gittings, J.A., Hoteit, I. (2020). Developing an atlas of harmful algal blooms in the red sea: Linkages to local aquaculture. Remote Sensing, 12, 1–14.
• Wang, Y., Raitsos, D.E., Krokos, G., Gittings J. A., Zhan, P. & Hoteit, I. (2019). Physical connectivity simulations reveal dynamic linkages between coral reef regions in the southern Red Sea and the Indian Ocean. Scientific Reports, 9, 16598.
• Brewin, B., Morán, X.A.G., Raitsos, D.E., Gittings, J. A., Calleja, M.L., Viegas, M.S., Ansari, M.I., Al-Otaibi, N., Huete-Stauffer, T.M. and Hoteit, I. (2019). Factors regulating the relationship between total and size-fractionated chlorophyll-a in coastal waters of the Red Sea. Frontiers in Microbiology, 10, 1964.
• Gokul, E.A., Raitsos, D.E., Gittings, J. A., Alkawri, A., Hoteit, I. (2019). Remotely sensing harmful algal blooms in the Red Sea. PLoS One, 14.
• Dreano, D., Raitsos, D. E., Gittings, J. A., Krokos, G., & Hoteit, I. (2016). The Gulf of Aden Intermediate Water Intrusion Regulates the Southern Red Sea Summer Phytoplankton Blooms. PLoS ONE, 1–20.

POSEIDON will contribute to advances in Earth system science by addressing some of the major impacts associated with climate change, as outlined by the IPCC and ESA EO Science Strategy. The project will also exploit ESA EO-based missions (CCI, Sentinel-3), as well as deliverables from other ESA-funded projects (BICEP, ESA-S5POC), to deliver a more complete understanding of the impacts of climate change over several areas of the global oceans, providing knowledge for the responsible management of ecosystem services, including phytoplankton production and fisheries.