<論説>近世における「水田漁猟」の展開と河川流域の環境変化

Abstract

本稿では環境史の視点から、近世畿内の水田で行われた魚漁と水鳥猟、すなわち「水田漁猟」の実態を解明することを試みた。丘陵上の溜池での魚漁は、天保期には入札制と養魚が行われる段階にあったが、これは淀川・大和川上流の山地荒廃に伴い、丘陵谷口に位置する溜池で土砂流入が問題となり、その修築費用をまかなうために取られた方策であった。一方、淀川沿岸の低湿田での「魚鳥漁猟」については、堀上田との関わりが重視された。淀川の築堤と上流山地からの土砂流出は、淀川自体の河床上昇をもたらし、付近の水田に悪水滞留・湛水田化を引き起こした。その対応として、既存田の堀上田への転換が十九世紀前半の摂津・山城でみられたが、これは米の収穫率の向上以外に、堀潰れでの魚鳥漁猟を目的としていた可能性が高い。その背景には、京・大坂での「生洲」を中心とする魚鳥の商品需要があり、近世後期の「水田漁猟」が都市消費と直結していたことは重視される。

This study addresses the satoyama, a managed rural environment including human settlements, and paddy fields that constitute Japan's "secondary natural environment" and attempts to elucidate the actual state of fishing and hunting of waterfowl conducted in paddy fields in early modern times from the standpoint of environmental history. Based on a reexamination of documents from villages in the provinces of Settsu, Kawachi, and Yamashiro, it became clear that fishing in the highland reservoir ponds occurred contemporaneously with the stage of the bidding system and pisciculture during the Tenpō era (1830-1844). In the upland areas of the Yodogawa river basin, even in the reservoir ponds situated in the highland valleys discharges of sediment became a problem in the latter part of the early modern period because the runoff had not been stopped by the start of the construction projects to dam the silt begun in the 17th century. I indicate the possibly that this policy was adopted in order to cover the cost of high-level construction needed for reservoir ponds. On the one hand, I propose that in regard to paddy fishing and hunting in the paddy fields along the banks of the Yodogawa, the relationship to the paddies built in wetlands (horiageta in Japanese) was particularly important. The embankments of the Yodogawa and the runoff of sediment from highlands upriver raised the river bottom throughout the early modern period, and caused the drainage problem there due to the inflow from various rivers. As a response to stagnant polluted water and flooding of the paddies on the riverbanks that accompanied this situation, there was a visible switch to the pre-existing horiageta in the first half of the nineteenth century in Settsu and Yamashiro, but it highly probable that in addition to improving the rice harvest, this was intended for fishing and hunting in the trenches (horitsubure) of the wetland paddies. In other words, the construction of the horiageta, in the extreme wetlands where a second harvest was difficult, it can be characterized as a policy of quasi-double cropping, combining cultivation of rice with hunting and fishing. An important factor behind the increasing activity of fishing and hunting in the paddy fields in the latter stage of the early modern period was the demand for the products such as freshwater fish and waterfowl by the restaurants, called ikesu, of Kyōto and Ōsaka. Through the historical analysis found in this study, I have been able to illuminate the relationship of environmental change in early-modern rivers to hunting and fishing in paddy fields as well as the new development of fishing and hunting in paddy fields as a response to stagnant polluted water of riverside paddy fields and the deterioration of the highland headwaters of the Yodogawa, which could not be detected in studies of Meiji and later times. Moreover, I have also drawn attention to the fact that fishing in paddy fields had the effect of enticing additional waterfowl to feed on the fish and fallen ears of rice. In this sense, an ecosystem that included human activities was created by these paddy fields. However, it is also important to emphasize that that the ecosystem was created on the basis of links to the consumption patterns in urban areas.