July 16, 2015 — Today the Japanese consume around 100,000 tons, or 70 – 80 per cent of the worldwide eel catch, but in 2013 the Japanese Ministry of the Environment designated the fish as a species at risk of extinction, and in June 2014 it was placed on the International Union for Conservation of Nature (IUCN)’s Red List of Threatened Species.
In Japan, aquaculture is extremely important to the eel industry’s success, with most eel caught in the wild as juveniles and then raised on fish farms. However, the overfishing of juvenile glass eels has now become a huge problem.
Fed on a diet of fishmeal and kept in fossil-fuel-heated greenhouses, eel are usually collected along the Pacific Coast between December and April and put into tanks where their chances of survival are improved thanks to heating apparatus that helps increase water temperature particularly during the winter, and a circulating filter system in which water is filtered and re-circulated.
Ponds or specialized tanks are then used to grow the eels in temperatures of around 23oC – 28oC, after which regular grading takes place in which the eels are separated according to size and harvested once they are large enough to have reached market value.
Read the full story at The Fish Site