Rhodolith Physiology Across the Atlantic: Towards a Better Mechanistic Understanding of Intra- and Interspecific Differences

Coralline algae are important components in a large variety of ecosystems. Among them, rhodoliths group free-living coralline red that cover extensive coastal areas, from tropical to polar regions. In contrast other ecosystem engineers, limited research efforts preclude our understanding their physiology, underlying mechanisms, drivers and potential differences related species under varying environments. this study, we investigated the photosynthetic calcification mechanisms six Atlantic rhodolith different latitudes, as well intra-specific one four locations. Laboratory incubations light levels provided simultaneous photosynthesis- calcification-irradiance curves, allowing assessment inter- on coupling between these two processes. Stable isotope analysis specific inhibitor experiments were performed characterize compare carbon-concentrating (CCMs), involvement ion-transporters for calcification. Our findings showed significant physiological partially driven by local environmental conditions (light, temperature). High variability was found photosynthesis calcification, CCM-strategies, importance ion transporters enzymes involved While strongly correlated with all species, strength link species-specific. Calcification also be reliant light-independent The latter high plasticity expression among influenced environment. Overall, demonstrate (1) is biologically-controlled process (2) associated display suggesting not only individual, but community responses changes, such climate change.