Rich ecosystems in coastal zones include tidal flats, seagrass meadows, and coral reefs. Coastal zones are valuable places for the global environment. However, during the era of rapid economic growth, intense socio-economic activities caused the deterioration of water quality especially in coastal inner bays and enclosed waters, resulting in ecosystem damage. Thanks to subsequent countermeasures, water quality has gradually been improving in some coastal zones; however, recovery of the coastal zone environment including ecosystems remains a formidable challenge. Meanwhile, there are new challenges looming, including the need to utilize the coastal zone functions to alleviate climate change and to address the issue of large-scale oil spills from coastal industrial complexes, etc. Therefore, we are focusing on activities to help restore the coastal environment, alleviate climate change, and develop technologies to better deal with large-scale oil spills. We are also working on elucidating the function of coastal ecosystems in absorbing greenhouse gases (blue carbon) and proposing how their function could be utilized. In addition, we are developing a new system that will be able to predict in real time the status of the aquatic environment in Tokyo Bay, Ise Bay, etc. including the occurrences of red tides and blue tides. Furthermore, we will be developing a next-generation oil recovery system for use by the oil recovery fleet owned by the Ministry of Land, Infrastructure, Transport and Tourism, along with a new technology to deal with oil spills from coastal industrial complexes, etc. that are caused by earthquakes and tsunami.

For our research on examining the previously developed global dynamics model for predicting the speed of carbon dioxide absorption and inundation suppression effects in shallow sea areas, we are continuously gathering data and knowledge on various factors and processes pertaining to the ecosystems, while integrating and improving its sub-models (i.e., wave model, topography and sediment model, ecosystem model, etc.).

For our initiative to create coastal topography and geo-designs that would both assist disaster mitigation and ecological environment preservation, we are evaluating and analyzing the characteristics of the types of topographical and soil environment that can maintain resilience during disasters and allow diverse species of organisms to inhabit, while evaluating their disaster mitigating and energy reduction effects against earthquakes, tsunami, and high waves.

For our research on techniques to improve the functions of seagrass meadow ecosystems, we are developing a model to explain the maintenance and restoration mechanism of seagrass meadows, while also examining methods of facilitating seagrass meadow restoration and assessing their value as a food for fauna inhabiting those meadows in order to evaluate their function as feeding grounds.

For our research and development on techniques for mitigating oil pollution, we are improving our real-time oil movement prediction system, and continuously examining techniques for mitigating oil pollution, including self-extracting bubble curtains for controlling floating oil, application of such bubble curtains to environment management vessels, and extraction of oil from sunk vessels, etc.

For the research on examining the global dynamics model for predicting the speed of carbon dioxide absorption and inundation suppression effects in shallow sea areas, we conducted on-site measurements in large seagrass meadows to observe their CO2 absorption through dissolved refractory organic carbon discharge. We also conducted in-situ surveys of subtropical blue-carbon ecosystems and quantified the carbon flows among different complex ecosystems inhabited by mangroves, seagrasses, and corals. The findings from these studies have enabled us to examine CO2 absorption amounts using the aforementioned global model. In addition, we ran simulations to predict future changes in shallow-water ecosystem areas by the RCP scenario and published our findings in a scholarly paper. Furthermore, we conducted in-depth topographical observations of coral reefs to use the data as a basis for our wave-height reduction calculation using a green-laser-equipped drone.

For our project to create coastal topography and geo-designs that would both assist disaster mitigation and ecological environment preservation, we further developed our integrated assessment and prediction method applicable to coastal benthic ecosystems and geoenvironmental dynamics for a broad area of tidal flats and beaches, and used the developed integrated assessment and prediction model to examine how the major changes in coastal topography and geo-environment caused by meteorological disturbances affected the changes to benthic ecosystems and the distributions, and proved the model's efficacy based on the results of in-situ observations performed in Japan and overseas.

For the cross-sectional observation and analysis of atmospheric and oceanographic issues at bay mouths, we developed a method to continuously and steadily conduct atmospheric observations over extended periods including particulate matter, and performed statistical analysis of wind conditions at bay mouths. In addition, we maintained steady oceanographic observation operations including pH and other marine conditions.

For the numerical examination of how aquatic ecosystems are responding to climate change, we applied the numerical simulation model that we had previously developed to evaluate the effect that topographical changes have had on the amounts of seawater exchanged at bay mouths, and found that the degree of impact of topographical changes on seawater exchanges fluctuates depending on the location and the time of year.

For the development of methods to improve the functions of seagrass meadow ecosystems, we evaluated their value as a food for fauna inhabiting those meadows in order to evaluate their function as feeding grounds, and developed a simplified model that can explain the maintenance and restoration mechanism of seagrass meadows.

For data assimilation study to an actual coastal estuary using real one-year observation data, we conducted the first study to apply the ensemble Kalman filter. It was possible to maintain the ensemble spread by perturbing atmospheric forcing, lateral boundary conditions, and river discharge forcing. This method achieves robust annual data assimilation and reflects seasonal fluctuations.

For the research and development on new techniques that can be used to prevent and remove various types of oil spills caused by natural disasters and other events, we performed an experiment in a large model water tank to test the performance of our next-generation oil recovery system that is being developed, and quantitatively showed that its capability is equivalent or superior to that of the current system in terms of oil recovery efficiency. In addition, we filed a patent application related to this new system. As for the development of our web-application-type simulator for predicting the movement of oil spills at sea, we were able to develop a scalable calculation engine for accelerating the simulation, and also improved its front-end function by adding a new function that enables simulation data to be shared among multiple users. As for our research on the technique to improve the fluidity of high-viscosity oils that remain in sunk vessels so that they can be extracted more easily, we examined a model that was designed to explain the result of a previously conducted beaker experiment, and performed tests to verify the efficacy of the model when it is applied to the hydraulic transmission line system of a vessel, etc. Based on these research findings, we filed a patent application on the concept of our heavy oil recovery method and system.