In the early morning hush on a mist-draped shoreline, a small group of oyster farmers gather at the water’s edge on Oshima Island, Kesennuma. They pause in respectful silence, gazing up at the dense forest that blankets the steep slopes above—this is not just scenery. It’s guardianship.
For more than three decades, Japanese fisherfolk like these have whispered an ecological truth: the fate of the sea is planted inland. Today, scientific evidence is illuminating their words, yet the heartfelt conviction remains at the heart of a nationwide movement.
Forest Wisdom Rooted in Centuries
Japan’s unique approach stretches back more than a century, yet its foundation lies much deeper. A 1897 law established a system of “protection forests” to cushion the land from erosion, floods, and deforestation. Among 12 million hectares, some are officially “fish forests,” curated woodlands with a singular purpose—to serve the sea.
These forests stabilize slopes, filter sediments, and even provide nutrients, feeding life far below the waves. Indigenous documentation from a millennium ago hints at this awareness: temple records note that shade and wood debris from forests encouraged fish to gather near shore.
In Kanagawa prefecture’s Manazuru Peninsula, the place known to locals as Ohayashi was once grassland. After devastating fires in Edo (now Tokyo) in 1657, the government directed pine plantations—and later camphor trees—introducing what became one of Japan’s first designated fish forests.
Over 160 years later, locals describe it as “the wood where fish gather.” As Masaru Suzuki from the Manazuru Tourism Association reflected, “During [the Edo] period, various domains would plant and maintain trees along the coast.”
This footprint of intergenerational forest management is more than history—it’s living culture. Japan reveres the symbiosis of life-lands and seascapes, guiding a holistic conservation ethic.
Modern Science Confirms Ancient Instincts
Though intuitive, the link between forests and marine diversity went unquantified until recent years. In 2021, researchers at Hokkaido and Kyoto Universities applied environmental DNA (eDNA) metabarcoding to river mouths in coastal watersheds. Their findings were unequivocal: the denser the forest, the richer and more vulnerable the fish communities—supporting long-held fisherfolk claims.
This work brings clarity and weight to forest management policies. It suggests a quiet revolution: preserving forests isn’t just about land—it’s a powerful tool for nurturing coastal ecosystems and sustaining fisheries.
Scaling Stewardship: The “30by30” Promise
Conservation in Japan is advancing beyond localized initiatives. At the 2022 Montreal UN COP15 summit, Japan signed the ambitious “30×30” pledge—to protect 30% of its land and sea by 2030. The government has since allocated over 117 billion yen towards biodiversity efforts through 2025. With 20% of its land and 13% of its national waters under current protection, the move underscores Japan’s commitment to preserving ecological harmony.
This strategy also celebrates OECMs—other effective area-based conservation measures—like satoyama, the countryside mosaics of rice paddies, forests, and streams, essential threads in Japan’s conservation fabric. Local projects such as Yokosuka’s rice-paddy wetlands, protected to nurture fireflies and amphibians, embody this ethos.
Back to the Sea: Seagrass and Blue Carbon
As land stewardship grows, Japan is turning eyes toward the ocean floor. In 2024, in Yokohama, 100 volunteers planted eelgrass (a type of seagrass) to restore coastal meadows while capturing carbon, marking the first time such blue carbon was included in Japan’s greenhouse-gas inventory. This habitat stores roughly 350,000 tons of CO₂ per year—just 0.03% of Japan’s total emissions, and yet the gesture represents new promise.
Seagrass does more than combat climate change—it also stabilizes sediments, softens waves, and sustains fish nurseries, connecting forests to an underwater frontier.
The Fourth Pillar: Underwater Forests and Marine Restoration
Perhaps Japan’s most overlooked but critical frontier is its growing commitment to underwater kelp and algae forests. Organizations like Rakkotai (Mobile Sea Otter) are collaborating with fishermen and scuba divers in coastal regions to remove overgrazing sea urchins, allowing kelp canopies—vital marine forests—to rebound.
These restorations go beyond biodiversity. They help rebuild marine food webs, buffer coastlines, and anchor communities through sustainable fisheries. Thomson Reuters Foundation supported their efforts, supplying legal frameworks—like volunteer agreements and permits—to ensure operations are sustainable and safe.
This fourth pillar weaves submerged forests into Japan’s conservation tapestry—with fish forests on land, satoyama landscapes, seagrass blue carbon beds, and now kelp and algae revivals—all playing in concert.
Balancing Acts: Science, Culture, and Ecosystems
Japan’s forest-ocean stewardship is complex. Success requires nuanced, site-specific approaches. The eDNA studies revealed diversity differences between forests—too much shade can reduce river productivity; too little can weaken banks. That balance must be tailored to each watershed.
Yet this complexity is exactly why Japan offers lessons the world needs.
A layered strategy—combining centuries-old traditions, scientific monitoring, coastal blue carbon, and active restoration—creates resilience against modern threats like deforestation, industrial runoff, and climate storms.
News like the “Revive Our Ocean” initiative, launched in April 2025 across countries like Greece and the Philippines, emphasizes protected coastal zones—an approach Japan has embodied for decades.
Personal Moments and Collective Hope
Back on Oshima Island, a local fisher, Miho Tanaka (a fictional composite), pauses to reflect. “When I was a girl, my grandfather told me: ‘Plant a tree, and the fish will come home.’ I believed it without science until now. Now I’m proud that our work is being studied—and it works.”
At the Yokohama eelgrass planting event, a volunteer biology student—eyes wet with salt and hope—laid hands on dark sands. “I’m in awe,” she said. “To plant something that fights climate change, protects fish, and connects land and sea—it feels like healing.”
These moments speak to the synergy of tradition and innovation, of hope rooted in action.
A Blueprint for a Living Planet
Japan’s four-pillar legacy—protection forests, satoyama, seagrass blue carbon, underwater kelp restoration—is more than a conservation strategy. It’s a story: people and nature, grounded in respect and guided by science, renewing each other.
As other nations strive to meet their “30 × 30” goals, Japan’s tapestry offers a model: link forests to fisheries, waterways to seagrass beds, traditions to trials, and hearts to homes. In that weaving lies hope—and proof that caring for forests really does protect the seas.
