The Fisherman and the Forest
May 25, 2010
This past weekend I met a fisherman named Gori-san. When not plying his trade on the Pacific coast Gori-san can be found in the mountains of Iwate prefecture planting trees. Gori-san understands that the health of the ocean, from which he makes his livelihood, is dependant on healthy forests. In Iwate and Miyagi prefectures fishermen have committed themselves to the task of re-establishing healthy forests in the mountain watersheds that feed the ocean. It is a phenomena that was started some twenty years ago when a fisherman named Hatakeyama Shigeatsu made the connection between declining oyster populations, mountain forests and the rivers which feed the ocean.
Hatakeyama-san knew from experience that declining fish stocks were connected to the health of the forest but he struggled to find any scientific research to verify this. Scientific specialists were seemingly not interested in the connection between ocean, forest and river. Eventually Hatakeyama-san did manage to locate research papers by a Professor Katsuhiko Matsunaga of the School of Fisheries Sciences of Hokkaido University that explained, in scientific terms, what he empirically knew.
According to the research conducted by Matsunaga-san a decline in upstream broad-leaf forests had led to a decline in fluvic acid iron that is created when the humus formed by the falling leaves of trees is dissolved in rainwater and carried to the ocean through the river systems. The fluvic acid iron is essential for the growth of phytoplankton, the presence of which is in turn essential for the formation of rich ecosystems in coastal areas.
A decline in Japan’s broad-leaf forests had resulted from the vast plantations of coniferous trees that were established to supply the timber industry. Hatakeyama-san saw that this trend could be reversed especially as Japan’s timber industry was now itself in decline. Armed with the scientific evidence Hatakeyama-san was able to convince other fishermen of the urgent need to re-establish diverse forests of broad-leaf and deciduous trees in the mountain watersheds. When plantation trees are clear cut by forestry workers the fishermen replant appropriate species to restore the health of the ocean on which they are so dependent.