From Iki to the World: Regenerating Seaweed with Artificial Reefs "Reef Balls" to Revive Abundant Fishing Grounds (Part 2)

The artificial reef "Reef Ball" is gaining attention as one blue carbon initiative to combat global warming. Working alongside Mr. Osamu Ikeda, President of Asahi Tech Co., Ltd., in Nagasaki Prefecture to promote its adoption is Mr. Hisanori Tayama, Representative Director of the General Incorporated Association Marine Habitat Iki.

Reef Balls are not only for climate change mitigation; by regenerating seaweed, they are expected to enrich marine resources and revitalize fisheries and various industries. In Part 2, we hear from Mr. Tayama about his vision for revitalizing Iki City. Additionally, Mr. Takashi Fujii of Dentsu Inc. spoke with people in Iki engaged in seaweed bed restoration through Reef Ball demonstration experiments.

The Impact of Blue Carbon Initiatives on Iki's Industries

Fuji: Mr. Tayama, you are truly passionate about the Blue Carbon theme. What drives your commitment to promoting it?

Tayama: Fishing is a vital industry for Iki, but catches have declined by over 70% in the last 30 years. When fish disappear, income vanishes, livelihoods collapse, and there are no successors. I feel the entire industry is in a critical state. If fishing, our core industry, fails, it will also impact tourism, restaurants, and other sectors. That's why restoring seaweed beds is an urgent priority.

Of course, we also recognize that Reef Balls contribute to climate change mitigation, and we want to support that effort. We aim to share successful examples from Iki with the rest of Japan and the world.

Fuji: Looking ahead to the next few years, say 2030, do you have specific goals you aim to achieve?

Tayama: People might think marine issues only concern fishing cooperatives, fishermen, or those living locally. But I want everyone to realize this is a personal and vital problem that affects us all.

Tayama: One specific goal is creating marine ranches. With fewer fishermen, we'll transform unused ports into marine ranches by enclosing them with nets. We'll restore seagrass beds using reef balls to reclaim a rich marine environment. We envision creating a marine theme park-like facility where visitors can catch and enjoy seafood right there, making the ocean feel accessible to many people.

Globally, food security is recognized as an inevitable major challenge. Beyond climate change mitigation, the ocean's importance as a food source will only grow. In preparing for this, marine ranches could be one solution.

Fuji: What strikes me most about Iki is how truly abundant this island is. The sea is beautiful, the climate is pleasant, and the food is incredibly delicious. Yet, locals are genuinely struggling with issues like coastal erosion and drastically reduced catches. Against this backdrop, Mr. Tayama's efforts are truly remarkable.

Tayama: To be honest, when I first encountered the Reef Ball, I thought it was amazing. I went around explaining it to various people in Iki, looking for someone to experiment with it, but I never imagined I'd be involved in it as a business myself. Even when I quit my job and returned to my hometown of Iki, I hadn't decided on anything specific. I was thinking about contributing to the local community through some kind of business. But as I continued promoting Leaf Ball, I felt I had to take charge myself. That's when I decided to incorporate and start it as a full-fledged business.

Currently, I'm advancing the business of spreading LeafBalls in areas like Iki and Tsushima, but it's still largely in the experimental phase and hasn't fully matured into a commercial venture yet. Therefore, I obtained a drone license and simultaneously started a drone license school business. Within that, I began handling underwater drones, enabling easy checks on LeafBall conditions.

After starting the drone business, I also began receiving inquiries about whether drones could support agriculture. Alongside fishing, agriculture is a vital industry for Iki. Initially, I was enthusiastic about making Iki's agriculture pesticide-free! However, after talking with farmers and seeing the field conditions, I realized the reality wasn't that simple. However, guided by the principle that "thinking about the sea changes agriculture," we've also started initiatives supporting smart agriculture using materials with lower environmental impact. This is how we aim to positively transform primary industries like fishing and agriculture, preserving Iki's prosperity.

Additionally, we provide marine education to students both on and off the island. We want children to truly understand these issues, develop an interest, and take on challenges to solve them. We've come this far driven purely by our passion, so we'd be thrilled if even one more person could share our vision.

Field Tests of Reef Balls and Seaweed Bed Restoration Activities Across Iki

After this interview, we were shown two locations where Leaf Ball demonstration experiments are underway. The first is the former Shinozaki Fishing Port, once used as a fishing harbor. The fishing cooperative has now fenced off this unused area with nets to keep algae-eating fish out, installing Leaf Balls to conduct seagrass bed restoration experiments. We also spoke with Mr. Akira Yamakawa, Section Chief of the General Affairs Department at the Hakozaki Fisheries Cooperative, who is collaborating with Mr. Tayama.

Yamakawa: The low-pressure system in 2014 triggered a significant decline in the seagrass beds around here, and since then, we've seen no signs of recovery. Expert surveys indicate rising sea temperatures due to global warming are the cause. However, seagrass beds have regenerated in some areas, so the exact cause remains unclear. Despite this uncertainty, we've pursued various initiatives related to seagrass bed restoration. We decided to try the leaf balls, largely driven by Mr. Tayama's enthusiasm, and I believe this is the most successful approach we've tried so far. Mr. Tayama has come back multiple times after installation to check on the condition, so we can proceed with the experiment together with peace of mind. The loss of the seaweed beds happened in the blink of an eye, but their regeneration takes an incredibly long time. We intend to continue our efforts steadily.

The other location is Iki Dolphin Park & Resort. We were shown the Leaf Ball experiment being conducted in the pool of this leisure facility, where visitors can interact with dolphins, by Mr. Yoshitake Takada, President of IKI PARK MANAGEMENT Co., Ltd., the facility's operator.

Takada: We've placed several Reef Balls here, and we've confirmed that spores from seaweed originally native to this bay have attached and are growing. We initially thought better sunlight might promote growth, so we considered placement locations. However, it seems that too much direct sunlight can actually hinder growth. Also, since this pool connects to the sea, tidal currents also seem to affect growth. At our facility, seaweed also grows well on nets, so we are exploring various methods and conducting our own experiments.

It's not just Mr. Tayama; many people on Iki are working on restoring seaweed beds. We can only hope these efforts bear fruit and that the rich seas return to Iki as soon as possible. And perhaps the initiatives on Iki will spread nationwide as a model case, contributing to the revival of marine resources throughout Japan.

Mr. Tayama's passion, which extends beyond just fisheries to revitalizing Iki's entire industry, is spreading. More people are supporting the reef ball initiative. If more demonstration experiments succeed, bringing back rich fishing grounds to Iki and reviving its fisheries, it could lead to the revival of marine resources throughout Japan and the world.