Let's clean up the paradise for seabirds and sea turtles! Beach cleanup activity on Mukojima Island in the Ogasawara Islands.

Sumida Aquarium has been conducting beach cleanup activities in the Ogasawara Islands since 2023.

I have been working on Chichijima Island three times so far, and through talking to the local people, I have learned that there is a lot of washed-up debris on the uninhabited island, making its collection difficult.

This time, we'd like to introduce a beach cleanup activity we conducted on Mukojima, an uninhabited island located at the northernmost tip of the Ogasawara.

 What kind of island is Mukojima?

Mukojima is an uninhabited island belonging to Ogasawara Village, with an area of ​​approximately 2.57 square kilometers. People lived there until around 1944, but there are no permanent residents now. The island retains a rich natural environment, serving as a nesting ground for sea turtles and a breeding ground for seabirds, and is home to many wild animals. Because a valuable ecosystem remains, it is not a place where just anyone can freely enter except for the beach.

On the other hand, this island is also a place where a large amount of marine debris washes ashore. Debris floating in the sea is carried by ocean currents and wind, and one after another washes ashore on this uninhabited island. This information has been gathered from surveys conducted by the Tokyo Metropolitan Government, as well as from local fishermen and rangers.

 Cleaning up an uninhabited island is not easy.

You might think, "If there's trash, just pick it up." However, cleaning up on Mukojima Island is not that simple.

Mukojima is located about 70 kilometers north of Chichijima, and the boat trip takes about four hours one way. There are no regular ferry routes or ports, so large ships cannot dock directly. Furthermore, there are no accommodations, so we have to obtain permission to stay overnight when we are conducting our activities. In addition, transportation, equipment, and the transport and disposal of waste require a lot of expense and effort. Only after such thorough preparation can we finally carry out the beach cleanup.

In addition, to prevent any impact on the ecosystem, strict measures are taken to prevent the spread of invasive species before arriving on the island. Plant seeds and other organisms attached to luggage and clothing are removed one by one, and items brought in are frozen to prevent contamination by organisms. Mud is also removed from footwear and disinfected before heading to the island.

Finally, off to Mukojima Island!

After all these preparations, the day of the event finally arrived.

On that day, the wind and waves were calm, and a beautiful "Bonin Blue" sea stretched out before us. Having often seen rough seas in the Ogasawara during the winter, I was relieved.

In reality, whether or not we can go to Mukojima Island largely depends on the weather. If the sea conditions are bad, we cannot take the boat out. For this reason, beach cleanup at Mukojima Island is an extremely difficult activity to carry out.

After sailing for about three and a half hours from Chichijima, we finally arrived at Mukojima, enjoying the view of the Ogasawara Islands and the blue sea.

However, landing on the island is not easy. Since there is no port on the island, people and goods have to be transported back and forth multiple times by rubber boats from large ships. Just getting ashore was quite an ordeal.

A massive amount of washed-up debris spread out before my eyes.

Upon finally arriving at the beach, what greeted my eyes was a massive amount of washed-up trash, a stark contrast to the beautiful scenery.

The amount of trash scattered around was so great that it was hard to believe it was an uninhabited island, and it really brought home to me the seriousness of the marine debris problem. I changed my mindset and immediately started cleaning up.

It was scorching hot that day. There was absolutely no shade, so we had to be careful not to get heatstroke while working. Since it wasn't easy to leave the island, we collected the trash while taking frequent breaks and staying hydrated.

As evening approached, our work for the day came to an end. Since our activities would continue the next day, we pitched our tents on the beach and spent the night there.

At night, there were no artificial lights whatsoever, and the only sounds were the waves and the cries of seabirds. I woke up several times in the unfamiliar environment, but the starry sky was so beautiful that it made me forget the fatigue of the day.

The collected trash and the results of the cleanup

The next morning, a cool breeze blew, making for a pleasant awakening, a stark contrast to the heat of the previous day. After breakfast, we continued cleaning the beach and loaded the trash we had collected the day before onto the boat.

The most common type of trash collected was plastic bottles. Many pieces of footwear, such as sandals and shoe soles, were also found. Cans, dishes, and pens were present, but not in large quantities. Among the unusual items found was a motorcycle seat.

Removing the collected garbage is also a very difficult task. Because large ships cannot dock at the beach, the garbage is transported by making multiple trips back and forth in rubber boats. Of course, it's all done by hand.

Through these efforts, we were able to collect a total of 13 cubic meters of washed-up debris.

Seeing the beach, which had been covered in trash, gradually return to its original state gave me a great sense of accomplishment.

The animals I encountered on Mukojima Island

During this trip, we encountered many animals and their traces. The photos, from top left, show traces of a green sea turtle's movement, a hermit crab, a giant rock crab, a skinny blenny, a green sea turtle swimming in the ocean, and a pair of boobies.

There were signs of sea turtles having come ashore on the sandy beach, and green sea turtles were swimming leisurely in the sea. Giant rock crabs and slender frogfish were spotted near the shoreline of the rocky area, and a pair of boobies were seen on the cliffs. Hermit crabs were also active on the beach at night, making me realize that Mukojima is an island supported by abundant nature.

Through this activity

What I realized again through this activity is how difficult it is to conduct a cleanup on an uninhabited island. Preparation and travel require a lot of time and effort, and the activity itself is heavily dependent on the weather. And on the day of the activity, it was a test of physical endurance under the scorching sun.

On the other hand, most of the collected waste does not originate from the island. Garbage that drifts in the ocean and washes ashore from far away is affecting the lives of animals such as seabirds and sea turtles.

The problem of marine debris is not something that happens in a distant ocean; it is connected to our daily lives. While collection and transportation require a lot of time and effort, by working together, people from all walks of life can move forward step by step.

Sumida Aquarium will continue to work in cooperation with Ogasawara Village and other related organizations to engage in conservation activities and public awareness campaigns in order to pass on the rich nature and animals of the Ogasawara to future generations.

Thank you to everyone who helped with this beach cleanup activity.

• To Mr. Masayoshi Onodera, Assistant Section Chief, Industrial Tourism Division, Ogasawara Village
• To: Ms. Naomi Inoue, Head of Natural Environment Section, Environmental Division, Ogasawara Village
• To Mr. Riki Kawai, Roads and Rivers Section, Civil Engineering Division, Ogasawara Branch Office, Tokyo Metropolitan Government
• To Mr. Kosuke Honda, World Natural Heritage Coordination Specialist, Ogasawara Nature Conservation Office, Kanto Environment Bureau, Ministry of the Environment
• To: Mr. Yosuke Saito, Section Chief, National Forest Division, Ogasawara General Office, Ministry of Land, Infrastructure, Transport and Tourism
• To Mr. Jun Minamide, Environmental Conservation Department, Ogasawara Ocean Island Research Association (NPO)

Comments from everyone　

Through this marine debris cleanup activity on Mukojima Island, I was reminded once again of the reality that even uninhabited islands, which are usually out of sight, are accumulating a large amount of washed-up debris, impacting their precious ecosystems.

On the other hand, we also reaffirmed that there are various challenges in collection activities, such as the difficulty of accessing the collection sites and the significant burden involved in transporting and processing the waste.

While solving these challenges is not easy, there is great significance in diverse stakeholders such as government, local communities, businesses, and NPOs working together and building upon their activities.

Unfortunately, even on clean beaches, new trash inevitably washes ashore. Nevertheless, we aim for a marine life free of marine debris, and by expanding the circle of individual action and cooperation, we hope to pass on the rich nature and wildlife of the Ogasawara to future generations.