Abstract

Microbes in Nature rarely exist in isolation. How stable, functional microbial communities establish, however, is not fully understood. Studies on synthetic communities, ‘constructed’ from few species, have shown metabolic interactions can readily emerge among microbes and can allow for their stable co-existence. The extent and stability of metabolic interactions within natural communities, however, is more difficult to study, especially over time. In this talk, I will explain our attempts to adapt and maintain a natural community in the laboratory for long-term study of species composition, metabolic interactions, and stability. We have ‘adapted’ a freshwater community to the lab under lack of carbon source and application of a 12hr light-dark cycle. This resulted in a microbial community of 17 species, including a filamentous, gliding cyanobacteria. We found that this community maintains species composition stably over a 2-year period of serial passaging. We found evidence for carbon and vitamin sharing among members of this community and genetic capacity of sulfur cycling and anoxygenic photosynthesis functions. We have also found that this system results in reproducible spatial structure formation, including cm-scale granules. We show that these granules harbour anoxic microenvironments, which could sustain some of the genetically encoded anoxic functions. The formation of structural organisation is underpinned by the gliding motility of the filamentous cyanobacteria and we find that the collective motility of many filaments leads to emergent behaviours underpinning iron acquisition. Our findings show that structural organisation driven by one species can significantly shape microenvironments and determine assembly, stability, and function of a larger microbial community. The presented system can act as a model for understanding the formation of cyanobacterial mats and granules found in Nature and how they function to underpin biogeochemical cycling of key compounds. At the same time, the presented (or similar) mid-complexity system can be adapted to biotechnological applications in carbon capture, and sunlight to chemical conversion.

Abstract

Over the past 30 years, satellite-based radar altimetry has revolutionized the measurement of sea level changes on global and regional scales. However, conventional altimeters, designed primarily for open-ocean observations, face significant challenges in coastal zones, particularly within 20 km of the shoreline, where radar signals are contaminated by land reflections. This limitation has impeded precise monitoring of coastal sea level variations, which are crucial for understanding local coastal processes and assessing risks to coastal communities. The Surface Water and Ocean Topography (SWOT) mission, developed by NASA and CNES, represents a breakthrough in coastal sea level observation. Equipped with the innovative Ka-band Radar Interferometer (KaRIn), SWOT offers unprecedented high-resolution (2 km) sea surface height (SSH) measurements across a two-dimensional swath, enabling detailed analysis of coastal sea level dynamics. Furthermore, SWOT's high-resolution SSH mapping enables the detection of extreme coastal sea level events, such as storm surges, providing a novel tool for monitoring and characterizing the processes involved in these phenomena. This project evaluates SWOT's performance in coastal regions by comparing it against tide gauges, ERA5 reanalysis weather model and SCHISM ocean circulation model. This study has the potential to significantly advance our understanding of coastal processes and improve monitoring efforts for extreme events, with a focus on its capacity to detect storm surges, driven by strong winds and low atmospheric pressure during intense weather events like tropical cyclones and extratropical storms which cause abrupt and significant rises in sea level along coastlines.

Visita del DG d’Universitats, Recerca i Ensenyaments Artístics Superiors a l’IMEDEA

Dimarts, 24 de setembre de 2024, a les 09.30 h -  IMEDEA, Esporles

Assistents

Dr. Sebastian Massanet, DG d’Universitats, Recerca i Ensenyaments Artístics Superiors del GOIB

Dra. Salud Deudero, Delegada del CSIC a les Illes Balears

Dr. Jaume Carot, Rector de la UIB

Dr. Gotzon Besterrechea, director de l’IMEDEA

Dra. Marta Marcos, vicedirectora de l’IMEDEA

Dr. Idan Tuval, vicedirector de l’IMEDEA

Abstract

Understanding the 3D dynamics of meso- and submesoscale ocean structures (10–100 km) remains a critical challenge in oceanography. These small-scale eddies, vital to the global climate system, regulate heat balance and transport key elements like salt, carbon, and nutrients. Current methodologies integrate multi-platform in-situ data, remote sensing, and high-resolution model simulations to study these features. However, conventional satellite Sea Surface Height (SSH) measurements struggle to detect smaller currents and eddies. The launch of the SWOT (Surface Water and Ocean Topography) satellite in 2022 represents a breakthrough, offering higher-resolution SSH observations that provide unprecedented insights into ocean dynamics. During SWOT's validation phase in April and May 2023, we conducted two oceanographic campaigns to monitor a small anticyclonic eddy (~12.5 km radius) in the Western Mediterranean Sea. Our study aimed to analyze the eddy's vertical structure using in-situ data and assess SWOT’s capability to detect it. Glider observations revealed the eddy as an intrathermocline feature, and SWOT successfully captured the associated sea level and geostrophic currents, showing significant improvement over conventional altimetry. This study underscores SWOT's ability to resolve both submesoscale and mesoscale structures and highlights the value of integrating satellite and multi-platform data for comprehensive oceanographic insights.