Making Tokyo Bay More Habitable for Marine Life

Preventing Seafloor Sludge from Being Stirred Up

"To improve the water quality of Tokyo Bay, we focused on the sludge accumulating on the seafloor. Sludge is mainly caused by household and industrial wastewater. It sometimes emits a foul odor and causes so-called 'blue tides'. Blue tides occur when a strong wind stirs up the sludge, releasing a large amount of toxic hydrogen sulfide. The hydrogen sulfide kills marine life," says Takakura. When this happens, the sea surface turns light blue, hence the name.

"We hypothesized that steel slag would be effective in preventing the sludge from being stirred up." Steel slag is a byproduct of making iron from steel. For the past five years, Innoqua has been researching ways to use steel slag to improve the marine environment in collaboration with JFE Steel Corporation.

"Treatment until now has been to scatter sand to prevent sludge from being stirred up, but this method is not very effective because when wastewater flows into the sea, even more sludge accumulates on top of the sand. We conducted proof-of-concept testing for laying steel slag on the seafloor over three months in Tokyo Bay's Central Breakwater area."

Proprietary "Biosphere Transfer Technology"

Innoqua's trademarked Biosphere Transfer Technology proved useful in this test. It is a unique technology that reproduces the marine environment in an aquarium, using an AI and Internet of Things (IoT) device which the company developed to control parameters such as water quality, temperature, and light. To conduct the test, they first reproduced the seafloor environment of Tokyo Bay in an aquarium at Innoqua's laboratory and collected base data.

"We could not constantly monitor Tokyo Bay like an aquarium, leaving us unable to track progress. This presented some difficulties for us, but we recovered the steel slag from the seafloor, analyzed the matter stuck to its surface, found that it was hydrogen sulfide, and thereby confirmed that the slag was helping to prevent the release of hydrogen sulfide into the sea."

The next step is to bring life back to Tokyo Bay. "First, we aim to increase the growth of seaweed, which in turn should attract many organisms. Then, those organisms' self-cleansing effect will enable sustainable improvement of the marine environment." This will in turn improve the water quality of Tokyo Bay. The project is ongoing.

Takakura had this to say about the Tokyo Bay eSG Project: "By participating in the project, we were able to conduct testing in Tokyo Bay smoothly. I also feel that the TMG's announcement that such a project is underway has increased attention to the environmental business."

New Business Opportunities Emerge from the Ocean

Improving the marine environment has the potential to lead to sustainable urban development. "For example, we expect to see more research that will lead to solutions to social issues, such as the creation of low environmental impact energy sources like tidal power generation and algae biomass fuel, as well as new drugs for cancer and other diseases developed from marine organisms. As the term 'blue economy' suggests, marine resources have tremendous potential for business."

Innoqua is planning to build a next-generation research facility called bioArk in Tokyo where they recreate the marine environment using the Biosphere Transfer Technology.

"We want to make this facility a showcase for how marine life can be used in architecture, design, robot development, and other social applications. We hope that it will be a place where interest in marine life creates new innovations that will change the world."

New innovations born from the ocean might lead to urban development for the next 50 to 100 years.

Takakura Yota

CEO of Innoqua Inc. Born in Hyogo Prefecture, Japan in 1994. After graduating from the Faculty of Engineering, Tokyo University, he established Innoqua Inc. in April 2019, and both conceived and developed Biosphere Transfer Technology to reproduce coral reefs and other marine ecosystems in indoor spaces. In 2021, he became a director of the ROHTO Foundation for Children's Future and was selected for Forbes JAPAN's "30 Under 30" list.

SusHi Tech Tokyo, short for Sustainable High City Tech Tokyo, is a Tokyo-based concept that aims to create sustainable new value by overcoming global urban challenges through cutting-edge technology, diverse ideas, and digital expertise.
https://www.sushi-tech-tokyo2024.metro.tokyo.lg.jp/