Bio:
Hidekatsu Yamazaki (HY) is an Emeritus Professor at Tokyo University of Marine Science and Technology and currently serves as Visiting Professor at Sun Yat-sen University and Visiting Researcher at the Okinawa Institute of Science and Technology. Trained in ocean engineering at Tokai University and Texas A&M University, where he earned his Ph.D., HY has devoted more than four decades to advancing our understanding of turbulence and biological–physical interactions in aquatic systems. His international career has included appointments at Johns Hopkins University, the University of Victoria, the University of Wisconsin, Woods Hole Oceanographic Institution, and Shanghai Ocean University, reflecting the global scope of his collaborations and influence.
His research integrates field observations, theoretical analysis, and instrument development to address some of the most fundamental questions in oceanography: How does turbulence shape the distribution, behavior, and survival of plankton? How do fine-scale physical processes cascade upward to influence marine ecosystem structure and biogeochemical cycles? By tackling these questions, he has made pioneering contributions to topics such as stratified turbulence, plankton thin layers, harmful algal blooms, and the coupling of physical and biological models.
HY has authored over 200 peer-reviewed articles in leading journals, served as editor or associate editor for Limnology and Oceanography, Journal of Marine Systems, Aquatic Biology, and Frontiers in Marine Science, and contributed as section editor to the Encyclopedia of Ocean Sciences. His expertise has been sought on numerous international panels, including GLOBEC and GEOHAB, where he helped shape global strategies for understanding marine ecosystem dynamics under climate change. In addition to academic research, he holds patents on fisheries forecasting methods and fluorescence sensors for phytoplankton, bridging science and applied technology.
Abstract:
Life of the earth appeared roughly 3.8 billion years ago and spent nearly 3 billion years as single-cell organisms. Due to the limitation of molecular diffusion, a single cell can be no more than 1 mm scale, in which the viscosity dominates (the Kolmogorov scale). Under this condition, life stayed another half billion years before multicell organisms emerged. At the present date, most phytoplankton cells are below the Kolmogorov scale. Even a large faction of zooplankton is also not free from the viscosity of water. It would be unwise to assume that all microscale organisms do not pay attention to the immediate surrounding fluid motions. In fact, many microscale organisms swim more than 10 body-lengths per second, whereas most large-scale organisms swim an order of one body-length per second. Clearly, microorganisms have the ability to manipulate the properties of water. In order to maintain the population, phytoplankton require sunlight and nutrients; zooplankton pay attention to feeding, mating and escaping from predators. In this presentation, I will show how I studied the interaction between turbulence (physics) and planktonic organisms. In order to study these scientific questions, I developed a series of observational equipment, as well as numerical models. I will briefly show the history of these developments.
