After spending about 2 weeks visiting major cities in Japan, I left the main island of Honshu for Hokkaido. Destination? Onuma Quasi-National Park (大沼国定公園Onuma  Kokutei Kouen), at the southernmost tip of the island, near Hakodate city (函館). The aim of the workcamp? 1 ½ weeks of mostly environmental work. Along with six other volunteers (two of them Japanese and the rest international), we built rafts to depollute water and cut some plants for forestry work. I did not know much about environmental work before this workcamp. Eighteen rafts and some tree-cutting later, here is what I learned:

  1. Building rafts: It may seem strange just hearing about it, but our main work was to build rafts to depollute lake water. Explanation: Onuma Park has three lakes. Two of them, Lake Onuma and Lake Konuma (大沼 and 小沼) are quite polluted. Visibility of the water is low, some species have become extinct; there is little underwater life in general. At first, people thought this was due to man-made pollution. However, they soon realized that it was caused by intensive agriculture and animal grazing instead. Worrying about the long-term consequences of this process, a university professor decided to design a project to protect the lakes.
  • Why are the lakes important locally? They are vital to agriculture, as they provide water for irrigation. They mean a lot to the people because the national park is quite a beautiful area and home to many species of plants and animals. Tourism is also one of the main activities that people live off of.
  • Why was it important to set up this project? Other than the local degradation aspect, this pollution problem has a wider impact. The lake water goes into the sea. Not interfering at the root of the problem would mean spreading the pollution to other places. On the other hand, solving the pollution problem early causes less trouble to other people. The rafts thus represent a sustainable means to prevent further pollution.
  • How do the rafts help to depollute?  The rafts improve the visibility of the water so that underwater life can redevelop. Their main function is to trap algae floating on the surface of the water into a net. By bringing in more light, there is more underwater oxygen production, and the water becomes a more habitable space. Roots and dirt are also placed on top of the rafts, so that new plants can grow and wildlife is once again attracted to the lake.  (Esthetically, I thought it had a third advantage of making the rafts become virtually invisible. Ducks seemed to like them as well, as they made their nests on the rafts.)
  •  Do they work?  From what is known, they do seem to have a positive impact on the lakes. According to a series of recent surveys, Onuma Lake has been gaining on average 20 cm per year in visibility (80 cm visibility in 2007, 120 cm in 2009.


  1. Cutting plants: For two days, we participated in another activity, aimed at protecting the forest (rather than the lakes) of the park. We worked with the forest rangers of Onuma to clear paths in one area of the park. Like 40 other percent of forests in Japan, the forest in Onuma Park is man-made, rather than natural. The forest rangers are responsible for its conservation, and aim to restore it to a natural forest state over a period of about 100 years. Clearing the paths helps them patrol the forest. Our work meant simply cutting unwanted plants, but it also had the effect of protecting special species from parasite plants. (Potential damage can come from animals or other plants, if those use all the nutrients in the soil or monopolize all of the available sunlight).  This work was therefore more straightforward than the raft-making, but it was also more physically demanding: we worked our way by going slowly uphill and the forest was very humid.

Other activities: Towards the end of the workcamp, we took part in a third activity, with a cultural focus. We had the chance of helping at an o-matsuri (お祭り), a Japanese festival.  It was a sort of o-Bon (お盆) matsuri, a festival held to remember and celebrate the dead. Families write the names of their dead on lanterns and put them on the lake to float. The spirits of the dead are supposed to be attracted to these lights and follow them. In Japan, this festival is generally held in early July or early August; however, because of tourism issues in Onuma, the local government decided to have it at a different time.  It was touching to see it take place, especially because of the earthquake and tsunami which happened in March.

As a group, we wanted to make the most of the festival, therefore we unanimously decided to attend it while wearing yukata (浴衣). Yukatas are a sort of summer kimono that people (both men and women) wear for the festivals. (They can also be worn on a daily basis, generally by the elderly, and the less fancy ones can be used to sleep in). We wore them for the lantern ceremony, to enjoy the o-matsuri and to watch hanabi (花火, literally ‘flowery fire’), the fireworks. 



The o-matsuri and wearing the yukata were the cultural highlight to this workcamp. However, they were not the only cultural experience we had; we were able to experience a lot more. We slept on futons (布団), in the traditional style, ate on a traditional low table (without chairs), and tried some local specialties. While touring the village upon our arrival, we had free o-dango (お団子), a typical Japanese sweet. We also tried local ice cream and cheese, as milk is also renowned in the area. 抹茶ソフトクレムはおいしいです ! (Matcha sofuto kuremu  wa oishi desu!,  Matcha –Japanese traditional green tea- ice cream is delicious!) Last but not least, we tastedジンギスカン (Jingisu Kan), a kind of dish with a special meat named after… the warrior! (I think it was named as such in an attempt to mock him.)

Conclusion: This workcamp was a very intense 10 days where we were able to experience many things. The aim of the workcamp was well-explained to us. We could understand the type of work we were doing and why we were doing it. We were also treated very kindly by the people we worked with and there was an excellent atmosphere within our group. This made the activities interesting and enjoyable. I did have some doubts about the effectiveness of our work at some point, but I do feel like it was important in the end, and that I have gained a lot from this workcamp. It will remain an amazing memory. 皆、ありがとうございました ! (Minna, arigatou gozaimashita; thank you so much everyone!)