Ayu (Plecoglossus altivelis) — the sweetfish — is Japan’s most culturally significant freshwater fish and the centrepiece of a river fishing tradition of considerable depth. The fish runs Japan’s clean mountain rivers from late May through September, ascending from coastal estuaries to upstream feeding grounds; this seasonal migration makes it simultaneously a sporting target and a culinary prize. Ayu fishing brings together artisanal tackle-making traditions, strict fishing protocols, spectacular river landscapes, and some of Japan’s finest seasonal cooking.
What Makes Ayu Special
Fresh-caught ayu have a distinctive watermelon-like fragrance (their Japanese name connects to sweetness and their flesh has a clean, mild flavour with none of the muddy earthiness of pond fish). The fish is eaten whole — gutted but otherwise intact, seasoned with salt and grilled on skewers (shioyaki) over charcoal. The presentation of a salt-grilled ayu on a curved skewer that mimics the fish swimming upstream is one of Japanese cuisine’s most aesthetically composed presentations. Ayu are also prepared as tsubo-yaki (simmered in soy and mirin) and as confiture for rice dishes, but shioyaki is the definitive preparation.
Traditional Fishing Methods
The primary traditional technique for ayu fishing is tomozuri (friend fishing) — using a living decoy ayu tethered to a line to lure territorial wild fish into striking the decoy and becoming hooked on attached treble hooks. Ayu are aggressively territorial during summer feeding; the decoy provokes attack. Tomozuri requires specialised long rods (6-9 metres), custom terminal tackle, and considerable reading of river flow to present the decoy in productive water. The technique produces a visual and physical experience unlike any other form of fishing: the long rod bending against the mountain river current, the flash of silver as a wild fish strikes, the combination of precision and strength required to land the fish without breaking the delicate line.
Key Ayu Rivers
Japan’s finest ayu rivers are concentrated in areas of high rainfall and clean mountain geology. The most celebrated include: the Nagara River in Gifu Prefecture (home of the famous ukai cormorant fishing tradition using trained cormorants to catch ayu); the Kiso River in Nagano/Gifu; the Toyoko River in Toyama; the Shimanto River in Kochi, claimed to be Japan’s last truly clear river; and the Yoshino River in Nara and the Ota River system in Hiroshima Prefecture.
Ukai: Cormorant Fishing
Ukai (cormorant fishing) — in which trained cormorants wear neck rings preventing them from swallowing large fish, allowing fishermen on wooden boats to retrieve catch from the birds — is practiced on the Nagara River at Gifu City and Seki City, on the Uji River at Uji (Kyoto Prefecture), and at several other locations. Evening ukai on the Nagara River, with the fishing boats lit by flaming baskets (kagaribi) mounted at the prow, is one of Japan’s most visually dramatic traditional practices and has been performed for the Imperial Family annually for over 1,300 years. Tourist viewing boats accompany the fishing fleet from May through October. For broader outdoor activity context, see the guide to Japan river activities.