In the aquaculture sector, red tide presents a significant challenge, causing annual damages ranging from hundreds of millions to tens of billions of yen in ports near Fukuoka alone. Red tide stems mainly from sea eutrophication, fostering abnormal phytoplankton growth. These events can lead to fish suffocation or mass mortality due to phytoplankton clogging gills or producing toxins. Hence, there's a pressing need for red tide prediction and mitigation measures. Our research lab monitors phytoplankton in marine areas and studies red tide-causing algae like Raphidophyte Chattonella, Diatom Thalassiosira, and Dinoflagellate Karenia. We investigate their toxicity to fish using omics and behavioral analyses.

Various chemical substances, like pesticides and pharmaceuticals, are found in aquatic environments due to human activity, posing risks to aquatic organisms. Traditionally, toxicity assessments relied on mortality, but attention has shifted to 'ecological death' where behavioral changes indirectly lead to mortality. Our lab pioneers this concept, aiming to apply 'ecological death' as a toxicity indicator. We focus on medaka fish, developing methods to quantify responses to predators, shoaling, and aggression. These behavioral assessments offer a more holistic approach to evaluating chemical toxicity, beyond mortality alone.

In aquatic environments, microplastic pollution, particles smaller than 5 mm, poses a significant concern. Microplastics are divided into primary (manufactured) and secondary (degraded) categories, both capable of adsorbing chemicals. Despite this, much remains unclear about their toxicity and impact on organisms. Hence, our lab investigates the combined toxicity of chemicals and microplastics through exposure experiments, behavioral and omics analyses, alongside analytical chemistry and mathematical modeling. By comprehensively assessing their effects, we aim to better understand and address the environmental implications of microplastic pollution.

In addressing environmental challenges, the environmental monitoring is essential, especially in coastal areas where river inflows and ocean drift contribute to pollution. Our lab focuses on using wharf roaches as pollution indicators: widely distributed globally, their scavenging behavior earns them the title 'cleaner of the sea'. By monitoring them, we can assess pollution across wide coastal areas. We conduct ongoing research to refine this monitoring method, advancing our understanding and management of coastal pollution.