That statement is true
If fishing related activities are left unregulated by the government, fishers could utilize dangerous method such as using bombs that might destroy the ecosystem in the fresh water. This could make the fish population in a certain area become extinct.
Regulating fishing in freshwater would prevent such things from happening. This create positive economic impact by ensuring that the source of income would not be eliminated from the destruction of environment.
if it wasn't regulated then fishers could over-fish a species, have it go extinct, then the price of fish would dramatically increase and many fishermen would lose their jobs since all the fish are dead.
b brown mice / white sand dunes