Demand has long since risen above natural supplies, and in fact the Japanese have been breeding eels artificially for more than 100 years. Even so, supplies have always been too low, and as a result, the need for imports was soon felt.
為了增加鰻魚供應，早在一百年前，日本人就開始研究鰻魚的人工養殖，但由於日本國內消費量不斷增加，再加上鰻苗來源有限，及天然養殖環境的限制，至今鰻魚產量還是供不應求。