The requirement for fish stock conservation became law in 1991 at the same time of the declaration of the Danube Delta as a Biosphere Reserve. Conservation of biodiversity is the major objective of the reserve, with sustainable use of fish stocks introduced as the target objective in the fisheries. The present threat is over‐fishing by more fishermen with new fishing gears entering the fishery after abandonment state monopoly economy. The introduction of a Total Allowable Catch was the first strategy adopted for the sustainable use of the fish resources. Poor quality of catch data, lack of fishing effort data, and unfulfilled model assumptions in the estimation of Maximum Sustainable Yield are the principal constraints to achieve this goal. Limiting the fishery to 1000 individual fishing licenses should be one practical regulation for fish stock conservation.