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Coral comeback? JFE and startup use steel slag to restore reefs

  • December 20, 2021
  • , Nikkei Asia , 2:12 a.m.
  • English Press

TAMAKI KYOZUKA, Nikkei staff writer


TOKYO — Japan’s JFE Steel has partnered with Tokyo startup Innoqua to recycle steel slag into artificial beds for coral reefs in a venture highlighting a surge of cross-industry collaboration focused on saving the environment.


JFE recently installed a 1-meter tank in the lobby of its headquarters in Tokyo’s Hibiya business district. Colorful tropical fish meander in the tank, but they are not meant to entertain visitors and employees.


The tank is instead part of a feasibility test for a biodiversity initiative.


Inside the tank, coral grows on 5-cm squares of Marine Block, a product developed by JFE. The group anticipates the material will be the golden egg that leads to new business.


Marine Block is made from slag, a byproduct of steel production. The block is processed using proprietary techniques so that coral can easily attach to it.


Innoqua, which traces its origins to the University of Tokyo, developed the tank itself. The startup possesses technology to digitally analyze conditions inside the tank and to reproduce an optimal environment for growing coral.

The tank uses sensors to constantly gauge eight metrics that affect coral growth, including concentrations of salt, magnesium and nitrate.


Over the next several months, the project will determine the species of corals that are most likely to attach to the Marine Block, as well as their ideal growing conditions. The goal is to transition to large-scale coral breeding.


An experimental coral tank is installed at the lobby of JFE Steel’s headquarters in Tokyo. (Photo by Tamaki Kyozuka)

The Japanese steel industry produces more than 35 million tons of slag a year. Most of it is repurposed as material for infrastructure, such as paving roads.


If slag can be adopted for regenerating coral, it could lead to blue carbon ecosystems in which algae and other marine life are deployed to remove carbon dioxide from the atmosphere.


“Innoqua’s major strength is the ability to perform experiments under conditions where control is possible,” said Yasuhito Miyata, deputy director of JFE’s Slag Business Planning and Control Center.


Not long ago these types of demonstration tests could only be performed in the ocean, where the weather and other factors wildly affect growing conditions. JFE looks to use about 10% of the slag it produces in 2030 for the ports and marine field.


Open innovation, the catchphrase for joint research and development with outside parties, had lost momentum in Japan after initially gaining traction in 2015, as cross-industry tie-ups struggled to deliver results. But interest in the approach is surging again as companies face pressure from their investors and clients to address decarbonization and environmental protection.


The number of corporate partnerships with startups increased 20% on the year in January-June to 1,043, and is on track to beat the full-year record of 1,928 from 2020, according to Initial, a Tokyo-based information services company.


“Inquires related to the environment and sustainability have clearly increased,” said Akihiko Suwa, president of NineSigma Holdings, an open innovation intermediary.


“Companies are having trouble addressing these issues on their own, so they are more seriously considering tapping outside expertise,” he added.


Meanwhile, Japan has witnessed the creation of more environmentally minded startups. Of the 50 companies designated as a promising startup by Japan’s Ministry of Economy, Trade and Industry in October, 24% were in ESG-related fields — a marked increase from 5% previously.

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