Yakushima Sea Turtle Conservation Activities

Sea turtles from Yakushima

The main setting for sea turtle spawning on Yakushima is Nagatahama (general name for Inakahama, Maehama, and Yotsusehama), which is Yakushima's largest sandy beach. The beach is known as the largest loggerhead turtle spawning site in the North Pacific Ocean and is also registered as the Ramsar Treaty Wetlands. In addition, egg laying has been confirmed at Kuriohama and Nakahama.  

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The loggerhead turtle that spawns eggs on Yakushima is the loggerhead turtle, but a small number of green sea turtles have also been identified.
According to sources from the Ministry of the Environment, these sea turtles spend most of their lives in the sea, with only females landing on the sandy beaches to spawn. It is said to take about 30 years to mature.

Both loggerhead and green sea turtles have been designated as endangered species by the Ministry of the Environment's Red List and the International Union for Conservation of Nature (IUCN).

The fact that sea turtles take as long as 30 years to mature means that today's lower egg-laying success rates and worsening survival rates of baby turtles will have a direct impact on populations decades later. If a herd of turtles in a year fails to survive due to degradation of the sand or the effects of climate change, the absence of a breedable adult of that generation will manifest 30 years later. Such time lags make it difficult to see the true scale of population decline and the effectiveness of conservation measures, so continuous long-term monitoring is essential. This shows that sea turtle protection is not a short-term solution, but a multi-generational effort.

Egg-laying season

Female sea turtles emerge from the sea with full strength and choose safe locations higher than the high tide line. Then, skillfully use the hind legs to dig into a body pit for the entire body over time and a deep egg chamber for laying eggs. Loggerhead turtles lay an average of 90 to 130 eggs at a time. After laying eggs, they carefully pour sand on their hind legs, camouflage the nest, and return to the sea.  

The spawning period on Yakushima is mainly from late April to early August, with the peak activity being from 21:00 PM to 3:00 AM.

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Given the enormous energy sea turtles spend on spawning and the vulnerability in the interjection, we can see how important a quiet, unobstructed sandy beach is. Even a slight interference with light or human presence, sea turtles can cause "fake landings" in which they give up spawning and turn back into the sea. 

Therefore, Nagatahama will refrain from entering the sandy beaches due to local rules from 20:00 to 5:00 from May 1st to September 30th.

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The child turtle's journey

The eggs left by sea turtles are warmed by geothermal heat in the sand and hatched in about 45 to 75 days. The hatching season on Yakushima is from early July to late September. The hatched turtles cooperate to dig into layers of sand for three to seven days, waiting for the darkness of the night, crawling out of their burrows all at once, heading for the sea.  

The main clue for the baby turtles heading towards the sea is that the ocean air appears brighter than the land side. However, this instinctive behavior can backfire in modern times. The lights of streetlights, private homes, and flashlights lure the baby turtles in the opposite direction to the sea, causing them to be fatal.

Additionally, sandy beaches trampled by human walking make it difficult or impossible for turtles to enter the ground on their own. In recent years, the rate of catching turtles that hatch at Nagatahama reach the sea (return rate) has only been around 35-50%, and it has been pointed out that this is due to the solidification of sand. Garbage on the sand also serves as a major obstacle for small turtles.

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To protect sea turtles: Conservation activities on Yakushima

A variety of organizations and people work together to protect the sea turtles and their spawning grounds in Yakushima.

Sea turtle conservation in Yakushima can be said to be a multifaceted model in which the national government, local governments, specialized NPOs, and local communities cooperate. Each entity brings its own strengths (legal authority, scientific expertise, field management capabilities, local knowledge, etc.) to enable a more comprehensive approach.

For example, the Nagatahama Sea Turtle Observation Rule was born from a joint organization of the Yakushima Town Ecotourism Promotion Council.

The transition of once relatively free access to beaches to managed observation tours is an example of an adaptive management strategy that seeks to balance a growing tourist interest and the need for sea turtle conservation. Rules such as light-free use and guided guidance aim to provide an inspiring experience for people, while minimizing disturbances.

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Introducing the Sea Turtle Observation Group

The hotel introduces this sea turtle spawning tour.
If you would like to promote understanding of sea turtles, please apply by clicking the link below.

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[Night Sea Turtle Tour]
On the beach in silence, you may be able to witness the moment when the mother turtle is laying her life, with guidance from a specialized guide. This special space is reverberating only by the sound of the waves, and it will be an unforgettable experience that will bring you close to the mystery and strength of life. Why not watch over the ancient activities while learning the rules for protecting sea turtles?

‍→ Click here for details on the evening tour

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In conclusion: Yakushima Sea Turtle and Our Responsibility

THE HOTEL YAKUSHIMA Representative / Chairman of Yakushima Tourism Association Goto Shin

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Yakushima's sea turtles are extremely important even in the entire North Pacific Ocean. However, the future of sea turtles is under numerous threats, including local human disturbances, light pollution, and global climate change and marine plastic pollution.

Egg-laying numbers data vary from year to year, increasing in one year and may decrease in another year. This variability is important for a broad view based on short-term trends alone, with long-term monitoring and flexible management that is appropriate for the situation.
The challenge of balancing economic activity, such as tourism, with sea turtle protection, will continue in the future. Finding sustainable solutions that benefit both the local economy and the wildlife is key to long-term success. This requires ongoing dialogue and cooperation between all stakeholders.

We hope that more people, including those who visit Yakushima, will learn more about these efforts to protect sea turtles and the environmental issues they face . We believe that this is an essential and important step in creating a sustainable community that connects rich bounty to the future, and in continuing to protect the irreplaceable existence of sea turtles.

We must engrave each and every one of us with a common responsibility to protect this precious natural heritage so that the sea turtles of Yakushima can continue to come to the sandy beaches of this beautiful island.

It will be a gift for future generations.

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P.S.:

The reason why sea turtles on Yakushima can return to the island's sandy beaches for generations can only be achieved through the years of deep understanding and cooperation from local villages who have watched the beach every day and have cherished coexistence with sea turtles. The story of the lives of sea turtles is not only connected to the beautiful sea and sandy beaches, but also to the warm feelings of the people living there.

We also offer a tour called "Sato Tour" that is run right next to the beach where sea turtles nurture their lives, and that lets you get to know the lives and culture of the people of Yakushima. You may encounter old stone walls that tell the history of the island, a path filled with wisdom from life, and above all, the smiles of the people who live there.

We hope you will visit the mysterious nature and the brilliance of life that sea turtles teach you, as well as the deep charm of the village, another treasure on the island. We hope that by learning about both the beaches and villages of Yakushima, your trip will become even more enriched.