Report on participation in "Kuroshima Research Institute Training Activities" in June 2024
Our company is conducting training activities to help our group employees experience the activities of Kuroshima Research Institute and the environment of Kuroshima. This year, it was held in June 2024 for 3 nights and 4 days. This report will include participants' reports. ====
I participated in the training activities listed above from June 24th to June 27th, 2024.
<Characteristics of Kuroshima>
This is a flat island with a circumference of 13km, made up of raised coral reefs, and the neighboring islands such as Shinjojima, Kohamajima, and Taketomijima have similar terrain. Meanwhile, Ishigaki Island and Iriomote Island have mountains.
Because there is no river, water is supplied from Iriomote Island through a pipeline on the seabed. Because there are no rivers, malaria is less common than Iriomote Island, so Kuroshima has a long history of settling.
<<Egg-laying confirmation the day before>>
At Nishinohama, we actually dug and Kameda, a trainee at Kuroshima Research Institute, to check the egg-laying location of the green sea turtle, which Maeda, a trainee from Kuroshima Research Institute, confirmed the night before. We know the approximate location, and even after Kameda stings into the sand with a thin metal rod and searching for the area where the sea turtle had hardened with its legs, it took less than an hour to find the eggs after they began digging.
Eggs immediately after laying are soft and dented to withstand the impact of laying, but gradually become hard. Also, the embryo's position is determined if it is more than one day after spawning, so if the egg is turned over, the embryo will die and it cannot be hatched.
<<Coast Cleaning>>
Cleaning was carried out at Nishinohama. Styrofoam, plastic bottles with Chinese and Korean labels, and fishing gear of all sizes were scattered around.
Since the garbage cannot be disposed of on Kuroshima, the bags are packed together in flexicon bags, then transported to the port and then to Ishigaki Island. Although the total number of flexicon bags was 5-6, we were able to clean only about 1/3 of the Nishinohama area.
Even plastic bottles do not produce waste that has drifting into recyclable waste, making it non-combustible waste. It is not clear what kind of ingredients used in overseas plastic bottles, and since they are made with sand and salt, it is likely to be difficult to burn them and turn them into energy.
Furthermore, although styrofoam and fishing equipment were noticeably deteriorated due to UV rays, it appears that it would be difficult to completely remove the finer styrofoam from the sandy beach
, so I felt the need to regularly clean the coast.
<Fooding experience for farms>
Kuroshima raises 2,800 beef cattle for a population of 221, and calves are sold to fattening companies on Ishigaki Island and outside the prefecture for around 500,000 yen per cow.
There is also a magnificent auction on the island, and auctions are held once every two months. At the ranch where I was able to experience feeding this time, they will be auctioned about 10 to 15 of them each time.
Ranches on the island mainly raise cows and calves, and cows give birth to calves through artificial insemination, so bulls are sold when they are calves. In addition, cows suffer from heat stroke just like humans, so measures such as mist spraying were taken inside the farm.
<Egg-laying confirmation>
After dinner at the inn, under the leadership of Nakanishi of the Kuroshima Institute, we walked along the western beach and explored the landing and spawning of sea turtles.
About five minutes after I started walking, I discovered traces of them growing out of the sea. It is said that the species of sea turtles can be seen through evidence of landing, and the things we found this time were alternating hand marks, indicating that they were hawksbills, smaller than green sea turtles. It is also said that the location of eggs spawning is distinctive depending on the species of sea turtle, with hawksbills often located in the bushes deep in the sand, while green sea turtles often located just before the bushes deep in the sand. It took about an hour for the eggs to fill the hole, so it would likely take about two hours from landing to return to the sea again.
The next day, Nakanishi told me that he had discovered that it was a hawksbill that had been released on the tag on the legs 20 years ago.
<<Releasing the sign>>
The weight, length of the instep and width of the green sea turtle from the Kuroshima Research Institute were measured, and two sign tags were attached to its feet and released from the beach near the port. This survey shows how many years and how many distances are they travelling, and how many years they are, as well as how they live in the ocean, where they grew up when they were young, like the hawksbill the night before.
<<A tour of the Tsushima Maru Memorial Museum>>
On the last day, we moved to Naha and visited the Tsushima Maru Memorial Museum.
The Tsushima Maru was one of the Nippon Yusen cargo ships, and was conscripted by the Japanese Army during the Pacific War. On the way to Nagasaki from Naha, carrying a total of about 1,700 civilians and children as an evacuation ship, the ship was sank after a torpedo attack from the US Navy submarine "Bofin," which resulted in a large number of deaths, including the captain. The exact number of passengers, deaths and survivors is unknown. One of the reasons why it is unknown is that after the Tsushima Maru incident, Okinawa became a battlefield and its homes and belongings were burned down, and that the remaining families were also sacrificed. The memorial hall displayed the history of the sinking, records of the US military, and photographs of the victims.
[Impressions]
The range of sea turtles inhabited by species, but the number of loggerheads seen has changed due to recent rise in seawater temperatures. Previously, hawksbills were at the northern limit of the Yaeyama Islands and loggerheads were at the southern limit of the Yaeyama Islands, but gradually hawksbills can also be seen north of the Yaeyama Islands, and the number of loggerheads seen in the Yaeyama Islands is decreasing. Global warming has an impact not only on abnormal weather but also on ecosystem distribution, but it has been discovered that it is not enough to maintain sandy beaches where sea turtles can lay eggs. Kuroshima also has almost no lights and is recognized as Japan's first starry sky reserve. Not only did the stars that were actually hard to understand the constellations, but I was able to see shooting stars and StarLinkTrain with the naked eye.
You can experience things you probably wouldn't have experienced with your own choice, such as laying sea turtles, clear sea waters on Kuroshima, coral reefs seen while snorkeling on AKARI, and starry sky like planetariums. Participating in this training is a great opportunity to expand your own knowledge, and I would also like to express my gratitude to Kuroshima Research Institute for their full support of this valuable experience. I think it would be great if KYK will continue to repay the favor to the ocean through coastal cleaning and regular support for the Kuroshima Research Institute, and that each employee will be aware of global warming and reducing GHG, and will consider the direction KYK will move towards.
- Kuroshima Research Institute Report
- Report on participation in "Kuroshima Research Institute Training Activities" in June 2024