Innoqua Inc. (Tokyo, Japan, CEO: Yota Takakura), as an environmental startup working on research, conservation and education relating to coral reefs, has succeeded for the first time in Japan in controlling the timing of brooding of coral (Acropora digitifera) in a closed aquarium system (Toranomon, Tokyo). 

The success of this experiment in a highly reproducible artificial environment makes it possible to artificially guide coral spawning, which is limited to once a year for many coral species in nature, and is expected to dramatically advance research. 

We are continuing to conduct the experiment for the success of coral spawning in a completely artificial environment in 2022, which will be Japan's first successful coral spawning event in a closed and controlled aquarium.

Image taken with the microscope of Takashi Nakamura’s Laboratory,  Tokyo Institute of Technology

Takuma Mezaki, Director of the Kuroshio Institute for Biological Research, which conducts research on the ecosystem of the Kuroshio basin, supported us to confirm the egg holding based on image data.

For this experiment, we used coral that had been raised in our managed aquarium for more than two years and had not been confirmed to be holding eggs as of August 2021.

Innoqua Inc. has succeeded to raise corals in long-term and healthy status in a completely artificial environment using the unique “Environmental Transfer Technology (※).

“Fully artificial environment” refers to an aquarium (i.e., a closed environment) where artificial seawater is used and parameters such as water temperature, light, and nutrients are controlled by our IoT system.

Based on our "Environment Transfer Technology" and utilizing the water temperature data from coral reef waters in Okinawa, we were able to control the timing of coral brooding by synchronizing the water temperature in the aquarium with the natural world at different times of the year. 

If this experiment progresses to the point where coral can be treated as a model organism for research studies over many generations, like Mouse and Drosophila, it will greatly advance basic coral research and contribute to coral conservation.

※Environment Transfer Technology = A technology that controls various parameters, such as  water quality (dissolved concentration of more than 30 trace elements), water temperature, water flow, lighting environment, and the relationship between various organisms including microorganisms, by IoT device to recreate the environment of a specific aquatic ecosystem in an aquarium

The economic value of coral reefs is about $800 billion USD

Coral is an animal that was born about 400 million years ago and lives mainly in the tropics. They also play an important role in biodiversity, with 25% of marine life living in coral reefs, which account for only 0.2% of the ocean's surface area.They also play an important role in providing shore protection effects and fishing grounds necessary to support human  life, discovering medicines, and providing materials for construction and living tools, etc...

The economic value of the world's coral reefs is estimated to be 800 billion USD (about 93 trillion JPY) over a period of 50 years. (*1) However, it is highly likely that 70-90% of coral reefs will disappear in 20 years due to rising sea temperatures caused by climate change (*2).

Comments from researchers

Professor Masato Ueda / The Organization for Research & Development of Innovative Science & Technology (ORDIST), Kansai University 

Today, coral reefs are facing a catastrophic situation, and a wide range of experts are working on their conservation. Although it is now possible to grow corals by transplanting fragments, it is known to be extremely difficult to reproduce the same life history as that of corals in the wild, even in the ocean.

The fact that we have been able to reproduce spawning in a completely closed system is a major breakthrough in the field of coral research.

The ability to obtain precise data on corals in a completely controlled environment is also extremely important from a scientific perspective. Because of the similarities between vertebrate bones and coral skeletons, this breakthrough is expected to make a significant contribution to the field of bone regeneration research as well.

Dr. Tsuyoshi Watanabe / Faculty of Science, Hokkaido University & KIKAI Institute for Coral Reef Sciences

There are concerns about what will happen to coral reef ecosystems, which are the platforms that nurture the diversity of marine life, due to global warming. On the other hand, it has been confirmed that habitat of coral is expanding northward as larvae from coral spawning are transported by ocean currents.

Research on coral spawning has been progressing, but there are still many unanswered questions.

One of the reasons is that there are many conditions that determine the timing of spawning in natural environments and large aquariums.

The development of technology that can artificially control the timing of spawning in a small aquarium like this one is expected to contribute to the future development of coral spawning research and new developments in coral transplantation projects.

References

*1 WWF Report: The Economics of Worldwide Coral Reef Degradation (2003)

https://www.wwf.or.jp/activities/lib/pdf_marine/coral-reef/cesardegradationreport100203.pdf

*2 IPCC Report: Global Warming of 1.5°C (2018),p8. B.4.2

https://www.ipcc.ch/site/assets/uploads/sites/2/2019/06/SR15_Full_Report_High_Res.pdf