ちょっと長浜まで（２）姉川　　Let’s go to Nagahama! #2: Ane River

　姉川は琵琶湖にそそぐ河川の一つですが、長浜を含んだ湖北地方において広大な流域を誇ります。伊吹山から流れ下る本流、支流の高時川の上流に位置して菅並の集落など山間部をめぐる丹生川、岐阜県の揖斐川水系と分水嶺をなす支流である杉野川、それらの上流部ではそれぞれの豊かな渓相、中流・下流では広々とした景観を誇り、飲料・農業用水の提供・憩いの場の提供などを通して人々の暮らしに根付いてきました。「姉川の戦い」で知られる古戦場跡がある、というとピンとくる方も多いでしょう。

Ane River flows into Lake Biwa, and the region of its total system is very large in Kohoku area, which includes Nagahama. The mainstream comes from Mount Ibuki, and Nyu River, which is a branch of Ane River and the upper part of Takatoki River, runs through mountain areas like Suganami, while Sugino River, another branch, streams on one side of the divide whose other side is the Ibi River system in Gifu prefecture. These rivers show various beautiful views of relatively small flows with trees and rocks in mountains, and they grow up to wide streams with open and relaxation spaces, playing the roles of drinking and agriculture water supplies. A part of Ane river is also well acknowledged as a memorial park of an old battle field more than 400 years ago, known as Battle of Ane River.

姉川の下流部（難波橋付近）。広々とした穏やかな流れ。奥に、伊吹山が望める。Ane River, in the downstream region, near the Namba bridge, which is close to Lake Biwa. The stream spreads widely and slowly. Mt. Ibuki is in the background.

　自然の豊かさを満喫できる川です。上流部にはイワナ・アマゴといった渓流魚が生息し、また初夏には琵琶湖から遡上する小鮎が中流・下流域で群れをなして泳ぐ光景が見られます。先日、下流部で釣り竿にルアー（疑似餌の一種）をつけて投げてみると、琵琶湖水系の固有種であるハスがかかりました。小鮎を追ってきた30 cm弱の力強い魚体は、銀色に輝き美しい。リリースしながら周りを見渡しても誰もいらっしゃらず、さらさらと流れる川の岸辺、少し吹く風の中で、この豊かな自然を独り占めというぜいたくな時間でした。

This river is very active with its nature, which is typical in Japanese rivers whose total gradient in drop is steep. Iwana and Amago, which are Japanese trouts, live in the mountain regions because they prefer low-temperature water less than 20 degrees of Celsius. In the downstream region in the early season of summer, a huge number of small fish, Ko-Ayu, which tastes so delicious, go up from Lake Biwa and forms groups. When I visited Ane river near Lake Biwa and casted a lure, which is an artificial bait imitating Ko-Ayu, a nearly 30-cm long fish, Hasu, followed and bit it, then we encountered each other. Very beautiful, with its glittering silver body. Releasing it to the water, I found nobody around me in my view; I enjoyed all this rich time of nature in the background sounds of murmuring water and whispering winds.

ルアー（フローティングミノー）で釣り上げたハス。初夏から夏にかけて、20 cmから30 cmのものがよく釣れる。同時期に、釣り人に人気のある小鮎が多くみられ、上流部にはアマゴも生息する。Hasu, which was almost 30-cm long, had bitten my lure (floating minnow), an artificial bait for fishing. We find their swimming figures from beginning to middle summer. Ko-Ayu is very popular, favorites of many amateur fishers, and Amago, which is one of the Japanese trouts, lives in the mountain region.