BEGIN:VCALENDAR VERSION:2.0 PRODID:-//Memento EPFL// BEGIN:VEVENT SUMMARY:EESS talk on "Coral Biophotonics and Microscale Canopy Effects" DTSTART:20190319T121500 DTEND:20190319T130000 DTSTAMP:20260930T211144Z UID:1b90353a70f49002b2f0b0f1557b0260145c12c8fe6f2df72b5b2677 CATEGORIES:Conferences - Seminars DESCRIPTION:Dr Michael Kühl\, Professor\, Microenvironmental Ecology\, De pt. of Biology\, University of Copenhagen (DK) and Climate Change Cluster\ , University of Technology Sydney (AU) is trained in marine biology and mi crobial ecology but have broad interdisciplinary interests ranging from te chnicalities of sensor development\, over a fascination of single cell mic robiology and behaviour\, to studies of microenvironmental controls and mi crobial interactions in aquatic communities and ecosystems\, but also in m edical biofilms and chronic infections. Michael Kühl enjoyd working at th e boundaries and interfaces of different scientific disciplines and implem ent sensor chemistry\, photonics\, 3D bioprinting and advanced imaging app roaches in his research. His research interests include: Microenvironmenta l ecology of surface-associated microbial communities\, aquatic plants and marine symbioses\; Microsensor and imaging techniques for biogeochemical analysis of microenvironments\, mass transfer and metabolic rates\; Optica l properties and photobiology of sediments\, photosynthetic tissues and bi ofilms\; Microbial behaviour and activity in gradient systems. Graduated f rom University of Aarhus (1992)\, M. Kühl founded and headed the Microsen sor Research Group at the Max-Planck-Institute for Marine Microbiology (19 92-1998)\, and is leading the Microenvironmental Ecology Group at Universi ty of Copenhagen (1998-present)\, where he holds a professorship  in aqua tic microbial ecology. He is also an adjunct professor at University of Te chnology Sydney (since 2010) and has been a vising professor at the Singap ore Centre for Environmental Life Sciences Engineering at the Nanyang Tech nological University (2011-2015).\nAbstract:\nSurface-associated assemblag es of oxygenic microbial phototrophs (microalgae and cyanobacteria) in bio films and photosymbioses are characterized by a high optical density and ( sub-)mm-thick  photic zones\, wherein steep and dynamic gradients of ligh t\, temperature\, pH\, O2 and other chemical species modulate photosynthet ic performance. While application of various microscale methods has given detailed insight to photosynthesis in such gradient environments\, links b etween the optical properties and structural complexity of such assemblage s remain largely unstudied. My group has employed microsensors and novel i maging techniques to explore structure-function relationships and photosyn thetic quantum efficiency in biofilms\, sediments and corals. In this semi nar\, I present a new conceptual view of how light harvesting is balanced against light protection in corals\, enabling optimization of the photosyn thetic performance of their microalgal symbionts under a wide range of opt ical niches. Based on recent studies of the coral microenvironment\, I arg ue that high photosynthetic efficiency in corals is largely modulated by t he microscale optical properties and three-dimensional structure of coral tissue distribution over the underlying skeleton. Such links between coral function and morphology can be understood in the framework of canopy effe cts\, in analogy to the function of plant canopies (albeit at much larger scales)\, enabling efficient and flexible light harvesting. I review the c urrent evidence for how corals modulate their light microenvironment. This includes recent findings about scattering and light propagation in coral tissue and skeleton that together with tissue plasticity (expansion/contra ction) can explain the high efficiency of coral photosynthesis. I also bri efly discuss the relevance of these findings for our understanding of othe r compact photosynthetic structures like biofilms and microbial mats. LOCATION:GR C0 01 https://plan.epfl.ch/?room=GRC001 STATUS:CONFIRMED END:VEVENT END:VCALENDAR