They said fishing with electrocution and poisons was to blame.
Soe Hlaing Myint, the chief of the Magway fishery department, said eight motorboats and three ordinary fishing boats were seized for using prohibited fishing methods in the past three months.
Fishing during the breeding season worsened the freshwater ecosystem in Magway Region which had already been threatened by a decade of electro-fishing.
Aung Kyaw, a licensed fisherman, said: “The electrocution devices can kill fish heavier than 100kg. Such fishermen usually work at night. They scare us off with weapons when we try to stop them. Their devices can even electrocute humans to death. We can’t find any fish for 10 days in the areas they have electrocuted.”
The devices were imported from China and some people had started using electric-powered nets for a bigger catch.
Soe Hlaing Myint said: “We, together with the police, hunt down the people who use illegal fishing methods in this year’s breeding season. The result is the fish become more abundant and cheaper in the market than the last year. We’d like to urge the fishermen to avoid electro-fishing to preserve the freshwater resources.”
The punishments for practising prohibited fishing methods can be a three-year jail sentence or a maximum fine of 300,000 kyats (US$250) or both.
The licence fee for one fishing net is 2,500 kyats in Magway. The region has nearly 200 fish farms and most of them are put out to tender each year.