Okinawa's Coral Reefs: Tourism and Conservation in Balance

Why "Tourism" and "Conservation" Tend to Clash

In fiscal 2025 (April 2025 to March 2026), the number of visitors to Okinawa Prefecture reached a preliminary 10,935,800 — up 9.9% year on year and an all-time high. Domestic visitors numbered 7,994,500 and international visitors 2,941,300, both at high levels, making tourism one of the prefecture's largest industries.

The Sea That Supports the Economy Also Absorbs Its Burden

Okinawa is a top destination for diving and snorkeling, with its clear water and coral reef scenery forming the core of tourist spending. But when visitors concentrate on popular spots, damage accumulates in the same places: physical harm from fins and hands making contact, destruction from boat anchors, and the inflow of chemicals from sunscreen and wastewater. Even if only a small fraction of the roughly ten million annual visitors repeatedly visit the same reef, the localized impact can be significant.

When Coral Reefs Are Damaged, Fisheries and Disaster Protection Waver Too

Coral reefs support fisheries as spawning and nursery grounds for fish, and also function as breakwaters that dampen waves and protect the coastline (for more detail, see our article on coral reef restoration technology). In other words, damage to coral reefs shakes the foundations not just of tourism revenue but of fisheries and disaster resilience as well. Because tourism, fisheries, and disaster prevention interests all overlap on the same reef, the problem resists simple solutions.

"Regulation" Alone Doesn't Last

Uniformly restricting use would reduce environmental damage, but it would also deal a heavy blow to a local economy dependent on tourism, making it hard to win residents' consent. So across Okinawa, the approach has shifted toward treating tourists not as "something to exclude" but as "participants in conservation." The monitoring of Sekisei Lagoon, Onna Village's public-private cooperation, funding mechanisms, and operator certification covered in the following chapters are all concrete examples of this approach.

What matters is that none of these efforts work in isolation. Government publishes survey data, local fishery cooperatives handle the farming and planting techniques, operators follow on-site operating rules, and travelers choose which products and operators to support — because actors with different roles are all watching and acting on the same reef, a middle path between blanket regulation and simply leaving things be is maintained.

Sekisei Lagoon Today — A Front Line of Recovery and Setback

Sekisei Lagoon, spreading between Ishigaki and Iriomote islands, is Japan's largest coral reef area and part of Iriomote-Ishigaki National Park. Coral cover had been on a gentle recovery trend since the major bleaching event of 2022, but 2024 marked another turning point.

The Weight of Being Japan's Largest Marine Park Zone

Iriomote-Ishigaki National Park was designated as Iriomote National Park in 1972, coinciding with Okinawa's reversion to Japan, and took its current name in 2007 when part of Ishigaki Island was incorporated. Covering 40,653 hectares of land and 81,497 hectares of sea (as of 2016), Sekisei Lagoon forms the core of this park area and is Japan's largest marine park zone. Because it is not merely a scenic spot but part of a legally protected national park, the national government continues to conduct ongoing monitoring surveys and update its action plan.

From "Bleaching" to "Death": How Coral Dies

Coral hosts algae called zooxanthellae inside its tissue, relying on their photosynthesis for most of its energy. When seawater temperatures stay above normal for an extended period, this symbiotic relationship breaks down, the zooxanthellae are expelled, and the coral's skeleton shows through as white — "bleaching." Bleached coral doesn't die immediately; some colonies recover once temperatures drop and zooxanthellae return. But the longer high temperatures persist, the longer the coral effectively starves, and more colonies end up dying.

In 2024, High Water Temperatures Lasted Until Late September

Summer seawater temperatures above 30°C typically last only until early September, but in 2024 they continued into late September. This prolonged heat is thought to have dealt a further blow to coral that had already begun to recover. As more colonies fail to recover from bleaching and die instead, coral cover — the proportion of the seabed occupied by living coral — falls in ways that show up clearly in the numbers.

What the December 2024 Survey Found

The Ministry of the Environment surveyed 31 sites from December 1 to 6, 2024, classifying coral within 50-meter-square plots into four categories — "healthy," "pale," "bleached," and "dead" — and recording coverage. The results were as follows.

Why the Survey Is Done in December, After Summer

The annual survey is split into September and December rounds because, in September, the effects of high water temperatures are still unfolding and it's hard to tell how severe that year's bleaching will ultimately become. Re-surveying in December, once summer heat has eased, makes it possible to distinguish how many bleached colonies recovered and how many turned to death. Only by comparing the September and December figures does the true "depth of the wound" that year's heat left on the reef become visible.

A major bleaching event also occurred in 2022, when the bleaching rate reached as high as 92.8%; it fell to 50.2% by December, aided by cooler water temperatures following an approaching typhoon, but coral cover still dropped from 21.6% to 17.0%. A gentle recovery followed, but bleaching advanced again in 2024, and by December that year coral cover had fallen to 13.7%. The bleaching rate appeared to improve from 84.0% in September to 65.5%, but this reflects both colonies that regained their color as temperatures fell and a substantial number that progressed from bleaching to death — leading experts to warn the reef may be approaching a state from which recovery is difficult.

A report on Okinawa Prefecture's "Coral Reef Conservation and Restoration Project," carried out from fiscal 2010 to 2016, found that a full 80% of reef areas around the main island of Okinawa had coral cover of 10% or less. The combination of high water temperatures, crown-of-thorns starfish, and runoff of red clay soil is a structural problem shared widely across the prefecture, not just in Sekisei Lagoon.

Coverage figures alone may look like small fluctuations, but coral reefs also function as breakwaters. Their ability to absorb much of a wave's energy and soften the impact of storm surges and tsunamis weakens as coral cover declines (for more on how reefs can cut wave energy by 97%, see our article Coral Reefs as Natural Breakwaters). Tourism value and disaster-mitigation function are two sides of the same coin — the coral cover figure.

The monitoring system that continuously surveys a wide area like Sekisei Lagoon is itself a critical foundation for coral reef conservation in Okinawa. Without data, it would be impossible to judge whether the reef is "recovering" or "worsening," and the case for local activities like Onna Village's, as well as for the funding schemes discussed later, would lose its evidentiary basis.

The Sekisei Lagoon Nature Restoration Council: Environment Ministry and Local Partners Working Together

The Sekisei Lagoon Nature Restoration Council, which includes the Ministry of the Environment, Ishigaki City, Taketomi Town, fishery cooperatives, dive operators, and NPOs, continues its monitoring surveys alongside ongoing removal of crown-of-thorns starfish (see also How Crown-of-Thorns Starfish Outbreaks Happen and the Front Line of Their Removal). Efforts to support recovery from bleaching are proceeding under the council's 2024–2028 action plan.

Onna Village's "Coral Village Declaration" — 20 Years Turning Farming and Planting into a Tourism Asset

Onna Village, in central Okinawa's main island, has worked on coral farming and planting since the late 1990s (around 1998–99), making it a pioneering area nationally. Led by its fishery cooperative, this activity has grown over more than 20 years into a concrete model linking tourism and conservation.

What "Team Churasango" Has Achieved

"Team Churasango," founded in 2004, has held planting events five times a year, and by October 2023 had planted a cumulative total of 18,000 coral fragments. Across the whole Onna Village fishery cooperative, roughly 24,000 coral colonies were being raised as of 2024. Consumer cooperatives such as Pal System have also taken part since 2009, planting 9,300 fragments by 2017.

The "Nursery" Method: Growing Coral from Broken Fragments

Onna Village's farming is built around a steady, unglamorous method: collecting coral branches that have naturally broken off and fallen to the seabed, growing them to a certain size in nurseries on land or in shallow water, and then planting them onto damaged reef. This technique can increase coral numbers without significantly harming parent colonies, and the fact that fishers can manage it between their regular fishing work is one reason the activity has continued for more than 20 years.

Prefectural Support and Accumulated Expertise

Okinawa Prefecture also carried out its own "Coral Reef Conservation and Restoration Project" from fiscal 2010 to 2016, developing techniques for coral seedling production, intermediate rearing, and planting across three sea areas — Onna, Yomitan, and Zamami villages. The project demonstrated both sexual reproduction (seedling production from eggs and sperm) and asexual reproduction (fragmentation) methods, and also included education and outreach to support local activities. Onna Village's more-than-20-year effort has been built up alongside, and overlapping with, this prefectural technical support.

From the "Coral Village Declaration" to an SDGs Future City

Onna Village issued its "Coral Village Declaration" in 2018, setting out a vision of village-building that unites farming, planting, and tourism. The following year, 2019, it was selected by the Cabinet Office as an "SDGs Future City" and for the "Local Government SDGs Model Project," and cooperation has since expanded to include corporate CSR activities (such as SoftBank's "Future and Coral Project"), donations from financial institutions, and partnerships with tourism operators.

Onna Village's population stood at roughly 11,300 as of 2025. The village's own finances and staff alone could not sustain more than 20 years of continuous farming and planting activity at this scale. By adding corporate CSR funding, participation from co-op members, and experience fees paid by tourists, a small organization like the fishery cooperative has been able to become a broad-based conservation actor. This is also the foundation for "a system where tourists themselves get involved in conservation," discussed in the next chapter.

Experience Programs Where Tourists Themselves Become Conservation Participants

In Onna Village and elsewhere across Okinawa, "coral restoration snorkeling experiences" are offered in which tourists and school trip students actually plant coral fragments. What makes them distinctive is that they are designed not as mere tourist attractions but as environmental education programs that teach the mechanics of bleaching and conservation.

What the Experience Involves, and Roughly What It Costs

In one example from an Onna Village operator, participants spend about 1.5 hours learning about coral ecology and the challenges it faces from an instructor at a coral facility at the fishing port, then write a message on a base plate while wiring a coral fragment to it. Fees are roughly 4,000 yen for adults, 3,800 yen for high school students, and 3,600 yen for elementary and junior high school students (admission included), with some operators accepting participants daily between 9 a.m. and 4 p.m.

Making Sure It Doesn't End with "Just Planting"

Survival rates for planted coral vary widely by individual colony and location, so operators continue regular monitoring and replanting. Some organizations let participants check back later on how "their" coral is growing, turning a one-off experience into something that brings people back. At the same time, some operators temporarily suspend new plantings during periods when water temperatures are too high for coral to have a reasonable chance of survival. Rather than "the more you plant, the better," judging the year's ocean conditions before proceeding is itself part of the conservation experience.

This kind of pause may look, at first glance, like disappointing news for tourists. But continuing to plant when growth prospects are poor is simply wasted effort — and whether an operator is willing to make the call to "wait for now" is itself a useful sign of whether it can be trusted over the long term.

Main Ways to Take Part

• Planting events hosted by the Onna Village fishery cooperative and Team Churasango
• Coral restoration snorkeling experiences run by local dive shops
• Participatory tours offered by co-ops and companies to tourists and members

Experiences like these give tourists a chance to become active participants in "a sea that is protected," rather than simply consuming it. Choosing reef-safe sunscreen, discussed in the next chapter, is a small action in the same spirit.

School Trips as an Ongoing Point of Contact

Coral restoration snorkeling experiences are also becoming established as part of school trip itineraries. Because a new generation of students visits every year, this isn't a one-off event but a mechanism through which the region keeps offering educational opportunities over the long term. Because a decision to pause based on ocean conditions directly affects students' learning opportunities, operators build explanations of coral growth status into the experience itself.

Reef-Safe Sunscreen: The Smallest Possible Action

Research has pointed to certain UV filters in sunscreen as potential contributors to coral bleaching and abnormal larval development, and regulation has moved faster overseas than in Japan.

How Oxybenzone Turns Toxic Inside Coral

In 2008, an Italian researcher first reported that oxybenzone and cinnamate derivatives were implicated in coral bleaching, and in 2015 a study published in an environmental toxicology journal found that even low concentrations could affect coral DNA. A Stanford University research group showed that inside coral, oxybenzone is metabolized into a substance called "oxybenzone glucoside," which has strong photo-oxidative properties and damages cells when exposed to UV light. Effects were observed in experiments at concentrations as low as 10 microliters of sunscreen per liter of water (one part in 100,000) — a level that could plausibly occur in pools or enclosed coves.

In the open ocean, with fewer swimmers, concentrations are diluted and drop; but in enclosed coves like the Blue Cave, or in shallow areas dense with snorkelers, chemicals released from people's bodies can linger. Even without any physical contact, the simple fact that large numbers of people swim in the same spot can itself create a chemical burden — worth knowing regardless of whether regulation exists.

Regions That Have Already Banned Sale or Use

Okinawa Has No Ordinance Yet — Which Is Exactly Why Individual Choices Matter

Okinawa Prefecture and Naha City have not, as of this writing, enacted any ordinance regulating sunscreen ingredients themselves; their efforts remain limited to encouraging the use of environmentally friendly products. Under Okinawa Prefecture's fishery adjustment regulations, harvesting reef-building coral is separately prohibited — a different kind of regulation from sunscreen rules. Because there is no ordinance, which product each traveler chooses translates directly into a difference in the burden placed on the reef.

Rash guards and long-sleeved marine wear, which reduce how much sunscreen you need in the first place, are effective both as sun protection and as a way to cut chemical runoff. More and more marine shops in Okinawa now offer such gear for rent.

Building the Funding for Conservation — Environmental Cooperation Taxes and Lodging Taxes

Planting, removal work, and monitoring all require ongoing funding. In Okinawa, outlying islands have led the way in introducing non-statutory taxes that ask tourists themselves to shoulder some of the cost.

From the Outer Islands: Collecting 100 Yen per Visitor Through an "Environmental Cooperation Tax"

Izena Village introduced an "environmental cooperation tax" in March 2005, and Iheya Village followed in March 2008, both with the consent of the Minister for Internal Affairs and Communications. The system collects 100 yen per person upon entry, whether by air or by boat, with high school students and younger, as well as people with disabilities, exempted. Notably, the tax applies equally to residents' own comings and goings, not just to outside visitors.

Ishigaki City's Lodging Tax, Launching in 2027

Ishigaki City passed a lodging tax ordinance at its city assembly in September 2025. It will levy 2% of lodging fees (capped at 2,000 yen), of which the city retains 1.2% (capped at 1,200 yen) and the prefecture receives 0.8% (capped at 800 yen), with collection targeted to begin in January 2027. Based on 2022 lodging figures for the Yaeyama region, annual tax revenue is projected at roughly 520 million yen. The city's tourism advisory council has proposed allocating 80% of the revenue to secondary transportation measures and industry support, and 20% to capacity-building such as workforce development.

Outlying islands have a limited number of local buses and taxis, and a shortage of transportation options tends to become a problem as visitor numbers grow. From the standpoint of reef burden as well, spreading out traffic so that vehicles and tours don't concentrate excessively in specific locations can be seen as an indirect investment in conservation.

What's the Difference Between an Environmental Cooperation Tax and a Lodging Tax?

An environmental cooperation tax is levied on "entry itself," while a lodging tax is levied on the consumer act of "staying overnight." The former tends to apply to everyone entering an island, including day-trippers, while the latter, limited to overnight guests, is easier to build into hotel and inn billing systems. Though their targets and rates differ, both share the same underlying idea: turning tourism demand itself into a funding source and returning it to environmental and infrastructure investment on the receiving end.

At the same time, introducing such taxes is never without debate. Exactly who should be taxed, on what basis, and how much, differs by local circumstances — and even Ishigaki City's lodging tax has built in more than a year between the ordinance's passage and the planned start of collection (January 2027), using that time to debate how the revenue should be used through its tourism advisory council. For conservation funding through taxation, this kind of careful consensus-building matters more for long-term sustainability than speed of introduction.

Given that Okinawa's visitor numbers have swelled to roughly ten million, even a modest tax rate can, cumulatively, become an ongoing source of funding to support planting, monitoring, and crown-of-thorns starfish removal. At the same time, the careful design of who is taxed and how the money is used — and the effort put into building public consensus — determines whether such a system succeeds.

An Overseas Precedent: The Great Barrier Reef's Environmental Management Charge

On Australia's Great Barrier Reef, home to the world's largest coral reef system, the Reef Authority collects an "Environmental Management Charge" (EMC) of AUD 8.50 per visitor aged four and over. The funds raised go toward a broad range of conservation work, including water quality improvement, water temperature monitoring, and coral farming programs — a system with decades of track record turning tourism demand directly into conservation funding. Okinawa's environmental cooperation tax and lodging tax, though different in scale and scope, share the same basic idea.

Choosing an Operator as a Form of Conservation — Green Fins Certification and Dive Shops

Another way travelers can play a part in conservation is through the choice of which operator to use. Whether a business is run with environmental care in mind is hard to see from the outside, which is exactly why certification programs matter so much.

"Green Fins" Certification, Led by the UN Environment Programme

Green Fins is an environmental certification program for dive and snorkel operators led by the United Nations Environment Programme (UNEP), setting concrete operational standards covering anchoring methods, a ban on feeding wildlife, and waste management. In Motobu Town, Okinawa, around ten dive shops have earned this certification and put low-impact operations into practice.

Earning certification requires operators to keep up regular self-assessments and staff training — it's not a one-time achievement but an ongoing cost to maintain. Even so, more operators are choosing certification, partly because environmentally responsible operations are increasingly becoming a way to stand out and attract customers. The more travelers pay attention to which shop they choose, the stronger the incentive for operators to seek certification — a virtuous cycle.

• Thorough use of anchoring methods that don't damage coral, such as mooring buoys
• No feeding of fish or sea turtles
• Reducing single-use plastic and taking trash back out
• Sharing environmentally conscious rules with tour participants during briefings

A Prefecture-Wide Framework for Public-Private Cooperation

In May 2008, Okinawa Prefecture established the "Okinawa Coral Reef Conservation and Promotion Council." Its aim is to connect, across sectors, the many different people who make use of coral reefs — local residents, fishers, tourism operators, farmers, companies from inside and outside the prefecture, educators, researchers, NPOs, and government — and it continues to run programs such as grants for children's conservation activities and awareness events like "Okinawa Coral Reef Week." The prefecture's "Private-Sector Participatory Coral Reef Ecosystem Conservation Promotion Project" also supports private-sector efforts related to crown-of-thorns starfish removal and planting.

Certification and council membership are not, on their own, a magic bullet that eliminates environmental impact. Meeting a standard only means something when it's regularly confirmed by a third party, so it's worth looking not just at whether a certification mark is displayed, but also at what kind of briefing actually happens on a given tour.

Toward "Umigyo" and Sustainable Marine Tourism

In recent years, an idea called "umigyo" (roughly, "sea business") has been spreading — combining fishing and tourism to link the sea's bounty to the local economy. Japan's Fisheries Agency defines it as "business that makes use of the value and appeal of local resources tied to the sea and fishing communities," positioning it within the Basic Plan for Fisheries and the Long-Term Plan for Fishing Port and Fishing Ground Development, and in March 2023 selected 12 model districts nationwide to promote umigyo. Onna Village's integration of farming and planting with tourism experiences, the funding cycle created by environmental cooperation taxes and lodging taxes, and operator certification schemes like Green Fins are all examples that anticipated the umigyo idea of "earning in order to protect."

Another Backdrop: A Shortage of People to Carry On Fishing Communities

Behind the push for umigyo also lies a decline in the vitality of fishing communities due to depopulation and aging. Linking coral farming, planting, and conservation experiences to tourism is simultaneously an act of environmental conservation and a way of creating new income and employment opportunities for fishers. This kind of economic sustainability is also part of why the Onna Village fishery cooperative has been able to keep its activities going for more than 20 years.

A coral cover figure of 13.7% in Sekisei Lagoon; roughly 24,000 colonies in Onna Village; 100 yen for an environmental cooperation tax — every number covered in this article may look small at first glance. But each one is the result of efforts built up over 20 years or more, reaching a scale that no single one-off measure could achieve.

Whether the record 10.93 million annual visitors are absorbed purely as a burden on the reef, or instead put to work as a source of conservation participants and funding, will be decided by the accumulated choices of government, operators, and travelers alike. The next time you visit Okinawa, consider building even just one of the mechanisms introduced in this article into your own choices.

Choices Every Traveler Can Make

• Try a conservation-related tour, such as a coral planting experience
• Choose reef-safe sunscreen, and apply it before entering the water
• Choose operators that hold environmental certifications such as Green Fins
• Take an interest in how environmental cooperation taxes and lodging taxes are used, and learn about local efforts
• Avoid touching the seabed with fins or hands, and follow the swimming guidance given in briefings

Every one of these can be put into practice with just a few minutes of research while planning a trip. None requires special knowledge or equipment — it's simply a matter of adding a bit of judgment to choices you're already making, whether booking a hotel, buying sunscreen, or reserving a tour.

As the Sekisei Lagoon data shows, coral reef recovery doesn't proceed in a straight line and is strongly affected by the natural condition of high water temperatures. Just as coral that had begun to recover from the 2022 bleaching event lost cover again in 2024, natural variability cannot be fully controlled by human effort alone. That's precisely why how carefully we build up the parts of tourism that humans can control — funding design, operator standards, information for travelers — will determine the next ten years.

Rather than choosing between tourism and conservation, the question is how far a design that lets both coexist can be built up. Okinawa's coral reefs are one of the front lines still searching for that answer.