Interview with Shogo Arai: Pioneer in Seaweed Research and Key Figure in Sea Vegetable Industry

ー When did you first become involved with Sea Vegetable as a partner?

It all started in May 2018. I was invited as a lecturer on "Prospects for the New Seaweed Industry" by Professor Masao Ono of Kochi University, who heads the Ocean Forest Creation Promotion Council. Jun Hachiya, who co-founded Sea Vegetable in 2016, was also there. I mentioned my expertise in marine fieldwork, and Mr.Hachiya remembered that conversation. He reached out to see if we could collaborate on something. From November 2019, I gradually got involved, and by the summer of 2020, amidst the full swing of COVID-19, I joined forces more actively. Alongside co-founders Jun Hachiya and Tomohiro Tomohiro, we visited researchers and fishermen from Hokkaido to Okinawa, diving into the seas around those areas.

 ーHow many different places did you dive into?

During COVID times, I was traveling 2-3 times a month, so I must have visited over 10 places in a year. About 20 years ago, when I visited some places known for their diverse seaweed, I was shocked to find not a single large seaweed growing there. Even my favorite spots like Kushimoto Town in Wakayama and Amami Oshima had no large seaweeds left. It was like a desert—clean water but strange without the vibrant marine life I remembered. The marine environment has dramatically changed, especially over the past few years.

ー I heard you introduced Shui Ishizaka, who leads Sea Vegetable's test kitchen, to the co-founders of Sea Vegetable?

Yes, I received a message from a Japanese staff member at noma saying, "We're opening INUA in a year, and we'd like your help with sourcing seaweed." From there, I began to interact with chefs from noma and later INUA, teaching them about seaweed and coordinating with fishermen to harvest and supply it. At the same time, I was approached about finding chefs who would use Sea Vegetable's seaweed, so I introduced Chef Ishizaka from INUA. He's incredibly sincere and approaches cooking like a monk in training. I believed he could master seaweed cuisine.

Afterward, when INUA closed during the pandemic, he expressed a strong desire to work more with seaweed, which led to his involvement with Sea Vegetable.

Training Natural Observational Skills through Hands-On Fieldwork

ー What drives your passion for marine fieldwork?

Since kindergarten, I've always loved being out in the field. I was born in Ashikaga, Tochigi, a landlocked prefecture without a coast. During my childhood, I went on bus trips organized by the local community to the Pacific side—probably around Oarai in Ibaraki. We enjoyed swimming in the sea and stayed overnight in beach houses, all of us sleeping together. I vividly remember those times when the beach was littered with a vast array of colorful seaweed washed ashore. Seaweed that had been beached closer to the pine forest had bleached white over time, while those a bit closer to the sea were pink, and those nearest to the shore were red. In the 1950s, colors weren't as prevalent in daily life, so the natural gradient of colors fascinated me deeply, and that memory remains vivid in my mind. That initial experience sparked my interest in seaweed.

ー So you developed an interest in the sea from that time? 

Yes, exactly. In my daily life, I would fish using various methods in rivers and play around. Since I was young, I wondered why certain fish were only found in specific places or why they hid where they did. Through observation and understanding the reasons behind them, my resolution to see details on the ground grew stronger.

This carried over into university and beyond; even when I put on a diving tank and dove into the sea, I'd speculate that rare species weren't near those distant rocks but rather on the rocky spots slightly lower down the sandy ground. Solving such puzzles became a joy for me. This approach has been applied to seaweed research, where I integrate quantitative and qualitative perspectives, collecting scientific data and writing papers, which in turn reveal areas where I need improvement. I've continued this cycle for a long time in my life.

Creating 'Marine Forests' Together

ー Can you tell us about your current projects with Sea Vegetables?

We’re focusing on three main areas. First, I send rare seaweeds harvested from the sea to our test kitchen team to help develop new seaweed-based dishes. Second, I provide the necessary knowledge for seaweed research. At Sea Vegetables, we practice ocean surface cultivation, but the suitable growing areas for seaweeds differ by species due to seasonal and temperature changes. I specialize in observing unique environments, identifying places where seaweeds thrive unexpectedly, and analyzing these correlations. I share these observations with the Sea Vegetables team to aid in their seaweed ecology research.

The third focus is promoting seaweed cultivation in depopulated areas, peninsulas, and remote islands. Due to the aging population of fishermen, many fishing villages might disappear within five to ten years. Currently, there are about 300,000 fishermen, with an average age likely over 60. The captains I work with are in their 70s, and even the younger ones are in their mid-50s. In ten years, we might have no one left to operate the boats. To encourage young people to return, we need to diversify, combining stable fishery practices with agriculture and seaweed cultivation. Since fish stocks are declining, we aim to increase seaweed, which serves as fish feed, and sell it domestically. This might eventually lead to exports to Europe and America.

アカクラゲとヒトエグサ。山口県宇和島。（2013年：新井さん撮影）

ー Seaweed cultivation relies heavily on collaboration with fishermen. What kind of fishermen do you work with?

The common trait among fishermen collaborating with Sea Vegetables is their broad perspective. They often sell their catches themselves or have returned to fishing after working as company employees. Traditional fishermen tend to keep their methods and fishing spots secretive, but those with urban experience are more open to sharing information and forming regional connections. As I travel across Japan, I seek out cooperative fishermen and fisheries cooperatives, introducing them to the Sea Vegetables team. Success stories often encourage other local cooperatives to approach us, creating a positive cycle.

ー Is there a fishing town that stands out as a role model?

I’ve spent a lot of time in Matsushima, Karatsu City, Saga Prefecture. When I first started visiting, there were 60 to 70 people; now there are around 40, but with over 10 young people aged 25 to 35, making it the highest youth ratio in Japan. In this fishing community, when young people express a desire to become fishermen, their parents always insist they work outside the island for three years first. If they still want to return to fishing afterward, the community supports them wholeheartedly. What’s remarkable about Matsushima is how everyone cooperates. If young people want to create a glamping site, the whole community helps, from laying turf to supporting their growth.

ーWhy isn't the island community more conservative?

Cultivating Seaweed Within Nature’s Cycles

ー What are your hopes for Sea Vegetables in the future?

There are two main areas. First, I want to create an environment where young researchers can make a living while studying seaweed, similar to the Seaweed Camp. Currently, there are very few researchers in Japan who actually dive into the sea. I aim to train researchers who can dive, deploy them across various prefectures, and conduct fieldwork together while they also work as research staff.

Second, I believe it’s essential to work beyond interdisciplinary boundaries and vertical divisions, aiming for an overall optimization of nature. I hope that in the future, Sea Vegetables will take on projects that consider the entire natural cycle, including mountains and forests, not just the sea. It’s important to maintain the sense that seaweed cultivation is part of a larger natural flow, where wild seaweed, fish, and shellfish coexist, and humans live harmoniously within this system. Seaweed grows solely with sunlight and nutrients from the sea, but those nutrients originate from the humus of mountain forests.