NTT DATAThink Daily

  • Home
  • Earth Report
  • Earth News
  • About "Think Daily"

Earth News



A natural forest with rich biodiversity in Miura open to the public!

2014.07.29 Sasa Tomo

An opening ceremony held in the Forest of Koajiro open to the public

On the edge of Miura Peninsula in Kanagawa Prefecture, Japan, there is a forest overlooking the Bay of Sagami. A national trust has promoted the conservation of this roughly 70 hectares of forest. The project is finally completed and the Forest of Koajiro was opened to the public on July 20. On July 19, a ceremony was held prior to opening and members of the trust and other people enjoyed a concert and the natural walking trails in the forest's abundant nature.

The Forest of Koajiro is called the "forest of miracles", as its nature has been preserved in Kanagawa despite the surrounding continued urbanization. This precious green zone with its aquatic ecosystem catchment basin from the head to the mouth of the tidal flat remains untouched, and is home to over 1800 species of flora and fauna. Especially about 50 species of crab living there have been identified so far, occupying a different habitant for each species all the way from upstream of the Uranogawa River in the middle of the forest, through reed bed, marsh, to river mouth (mud flat, sand beach, rock reef and shallow water.)

The red-clawed crabs (Chiromantes haematocheir: Akategani in Japanese), known as a "crab living in forest", dig holes in the soil as homes and eat nuts and insects, etc. in the forest. At the spring tide in summer night, a swarm of red-clawed crabs heads to the sea to release their larvae, called zoea. The larvae grow in the inlet, and then change into crabs. In the fall, they return to the forest and hibernate there before the winter coming. The next summer, yellow tiny red-clawed crabs appear in the forest.


Abodes of red-clawed crabs in the forest

In the opening ceremony, a local children's chorus in the Koagiro region, and an opera singer from neighboring city Yokosuka, performed after ribbon cutting. Participants then took a walk along the valley or the seaside and tidal flat to observe the nature. On the seaside and tidal flat course, participants walked along a path, listing to the bullfrog's croaking from the pond and observing the fiddler crabs (uca lacteal) and sand bubbler crabs (Scopimera globosa) that were busily waving their claws on the sand beach facing the inlet. All over the mud flat, there were tiny mud balls left after dotillid crabs (Ilyoplax pusilla) ate, and crabs were darting in and out of small holes. The gatherings for observing red-clawed crabs releasing their larvae zoeas on this mud flat are held on the night of the spring tide form July to August.


Observing dotillid crabs on the sand beach

Along the walk, we could hear the chirp of cicadas and the song of the Japanese bush warbler and see black kites hovering overhead the dense green forest and various kinds of dragonflies flying in the valley below. As a rich ecosystem protected despite its location in a metropolitan area, the Forest of Koajiro needs to be passed on to future generations.

Related URL/media

Read by Think theme


The area of this news

Kanagawa, Japan (Japan

Sasa Tomo

Bookmark and Share