The History and Current Status of Nomura’s Jellyfish Utilization and Challenges (2007–2024)

The History and Current Status of Nomura's Jellyfish Utilization and Challenges (2007–2024)

**Situation in 2007**
Nomura's Jellyfish (Nemopilema nomurai) proliferated in the Sea of Japan, causing significant damage to fisheries, especially off the coasts of Yamaguchi and Shimane prefectures. These jellyfish, weighing over 200 kg each, broke fishing nets and reduced fish catches, leading to substantial economic losses. Meanwhile, demand for dried jellyfish products grew in the Chinese market, with some processed in Ehime prefecture for health-related food products.
In the pharmaceutical field, collagen derived from jellyfish attracted attention for use in cosmetics and regenerative medicine. Research institutions like Yamaguchi University and Tottori University conducted resource surveys and developed efficient harvesting methods. The Japanese government invested over 300 million yen in 2006 to mitigate damage and promote utilization. However, sustainable management was needed to prevent overharvesting and protect the ecosystem.

**Situation in the 2010s**
The frequency of Nomura's Jellyfish outbreaks decreased significantly after 2014, with fewer reports of fishing damage. This was attributed to climate change and alterations in the marine environment. However, the decline in jellyfish outbreaks caused a shortage of dried jellyfish products for the Chinese market. During this time, Japanese companies focused on research and development, advancing medical applications of jellyfish.
Notably, the University of Tokyo and Kyoto University collaborated to develop a new mucosal treatment drug using jellyfish-derived mucin. Chiba University also pioneered bio-plastics using jellyfish polymers as a solution to marine waste problems. However, 2017 saw another large-scale jellyfish outbreak, with renewed fishing damage reported in Fukui and Ishikawa prefectures.

**Current Situation in the 2020s**
In the 2020s, massive Nomura's Jellyfish outbreaks re-emerged as a severe issue. In 2021, over 1,000 jellyfish were caught in a single fixed net off the Oki Islands in Shimane prefecture, intensifying fishing damage. Bottom trawl fisheries also suffered from broken nets and decreased fish quality, highlighting the need for comprehensive measures. Meanwhile, the utilization of jellyfish continued to advance.
Marine Bio Co., Ltd. developed products such as "JelliCollagen®" and "JelliMucin®" extracted from jellyfish for use in medical and beauty fields. Mucin is particularly promising for osteoarthritis treatment, with applications expanding in the pharmaceutical industry. Additionally, research into greening materials using jellyfish progressed, focusing on highly water-retentive "jellyfish chips" for slope greening technologies. These materials are gaining attention as environmentally friendly organic resources.

**Summary**
From 2007 to the 2020s, Nomura's Jellyfish presented challenges such as fisheries damage, alongside opportunities in food, medical, greening materials, and bio-plastics. To balance utilization and environmental conservation, scientifically based management and policy support are crucial. Efforts to align utilization with ecosystem protection remain a key focus for the future.