Research on the morphology, taxonomy, and distribution of microalgae for mitigation of fisheries damage caused by harmful algal blooms.
Microalgae (such as phytoplankton) are an important group that supports marine bioproductivity as primary producers. However, some species produce toxic substances that are harmful to marine life and humans. Proliferation of harmful microalgae causes fish mass mortality (harmful red tides), and accumulation of algal toxins in bivalves and other shellfish (shellfish poisoning) causes health hazards. Red tides and shellfish poisoning caused by such harmful algae occur every year along the coast of Japan. Research is being conducted to mitigate red tide damage and prevent shellfish poisoning, but we do not fully understand the microalgae that can only be observed under a microscope, and unreported harmful algal species are often found. In our laboratory, research on the phylogeny, taxonomy, and distribution of harmful microalgae are conducted, focusing mainly on coastal areas in Japan and Southeast Asia. We have identified undescribed species based on morphological and molecular characteristics, and have described seven new genera and 28 new species, including dinoflagellates and raphidophytes. We have differentiated intraspecific groups of harmful microalgae to clarify the global distribution and ecological characteristics. These research results have been disseminated not only through scientific papers but also through workshops and training courses held in Southeast Asian countries, to share the information directly with local researchers responsible for harmful algal bloom monitoring.
Educational content
Understanding the structure and phylogeny of unicellular microalgae
For undergraduate students, I teach courses covering topics such as the evolution of unicellular microalgae, characteristics of algal groups, types of harmful algae, and countermeasures against harmful algal blooms. In practical classes, I am in charge of microscope observation and identification of phytoplankton. We strive to convey information in easy-to-understand language, incorporating not only existing knowledge and research findings on microalgae, but also information obtained directly from local researchers through field surveys, training courses, workshops, and other activities conducted in coastal areas of Japan and Southeast Asia. In the laboratory, undergraduate and graduate students belong to the department of Aquatic Bioscience. The laboratory and seminar are shared with the Aquatic Bioscience and Environmental Science Laboratory, and students are able to study not only phytoplankton but also zooplankton, oceanography, and other related fields. The laboratory members are mainly studying on taxonomy and phylogeny research on harmful microalgae in marine environments. We collect seawater samples from Japan and Southeast Asia, isolate cells under a microscope, and establish culture strains. Culture strains are examined by electron microscopy, molecular phylogeny, pigment analysis, and others to investigate the evolution, phylogeny, taxonomy, distribution, and ecology of unicellular microalgae.
Prospects for joint research and industry-academia collaboration
Joint research and training courses on microalgae
We conduct research on the phylogeny, taxonomy, distribution, ecology, and other aspects of microalgae. We conduct joint research with universities, research institutions, and companies in Japan and overseas, utilizing our knowledge of the taxonomy and identification of microalgae, as well as techniques such as culture strain, ultrastructural observation, molecular phylogeny, and pigment analysis. Previous studies have included research on the taxonomy and phylogeny of dinoflagellates; the endosymbiotic chloroplasts in dinoflagellates (University of Tsukuba); toxic dinoflagellates producing azaspiracid (Fisheries Technology Institute); identification of dominant and co-occurred dinoflagellates in a harmful bloom in eastern Hokkaido (Fisheries Technology Institute, Hokkaido Research Organization, Hokkaido University, etc.); phylogeography of the raphidophyte Chattonella in Southeast Asia (University of Malaya, University of Malaysia Sarawak, etc.); harmful dinoflagellates of the genus Karenia along the Philippine coast (Central Luzon State University, University of the Philippines Diliman); microalgae in Vietnamese aquaculture ponds (Nagasaki University, Can Tho University); and microalgal communities and pigment composition in Asian aquaculture ponds (joint research with companies), among others. In addition, we support training workshops on the identification of harmful algae both in Japan and overseas. We have held training courses in Southeast Asian countries for local researchers in charge of harmful algal bloom monitoring and young researchers, providing them with knowledge and skills related to the classification and identification of harmful algae.
