2026.07.15
What the Decline of Wild Eels Teaches Us: The Natural Ecosystem
Hello everyone. As we pass mid-July, the intense summer heat has truly arrived. In Japan, we have a cultural tradition of eating eel (Unagi) around this time of year, leading up to Doyo no Ushi no Hi (The Day of the Ox), to recover from summer fatigue.
To our foreign residents and visitors: do you like eel? I know many friends from abroad who previously disliked eel but instantly fell in love with it after trying Japanese Unagi.
It has become global news that wild Japanese eels are rapidly declining, and today, over 99% of the Unagi consumed in Japan is farmed. It is a bit of a serious topic today, but I would like to introduce you to the current situation of Unagi in Japan.
The Decline of Eels: A Breakdown of Environmental Balance First of all, why have wild eels decreased so drastically? The fact that over 99% of the eels eaten in Japan are farmed is a staggering number. There are three main reasons for this:
Overfishing of Fry: Massive amounts of young eels (glass eels) migrating from the ocean are caught to be used for aquaculture.
Habitat Deterioration: The concreting of riverbanks and the construction of dams have destroyed the natural mud and reed beds where eels grow.
Climate Change: Rising sea temperatures and changing ocean currents have made it difficult for young eels to successfully reach Japan.
The decline of eels is not simply due to overfishing; the fundamental cause is the collapse of the natural cycle (ecosystem).
The Evolution of Japan's Innovative Aquaculture Technology However, as mentioned earlier, the market is now sustained by over 99% farmed eels. I eat eel myself, and I can confidently say that farmed eels are incredibly delicious, easily rivaling wild ones.
This is thanks to the evolution of Japan's innovative aquaculture technology. At eel farms, the water quality, temperature, and nutritional balance of the feed are thoroughly managed 24 hours a day to ensure the most comfortable environment for the eels. Farmed eels raised in these perfect conditions are plump, tender, fatty, and of exceptionally high quality.
Being able to enjoy such high-quality Unagi at a reasonable price is a privilege of living in Japan. If you have been hesitant about trying eel before, I highly encourage you to give Japanese Unagi a try!