Abstract Black drum (Pogonias cromis) movement in Texas bays is reported for fish tagged and released with internal abdominal anchor tags between November 1975 and August 1980. Intrabay movement was substantial with almost one-half (44%) of the recaptured tagged fish moving more than 10 km. Few fish were returned from the Gulf or from outside of the bay in which they were tagged. Of the fish which left the bay where tagged, 75% were recaptured in adjacent bays. There were no significant differences in movement patterns among bay systems nor was there a detectable relationship between minimum distance moved by black drum and either time free until recapture, seasons, or size of fish. No mass migration of fish in the winter or during the spring spawning period was noted. Texas bay systems can be considered closed systems for fish of about 210-510 mm long (total length) when managing black drum stocks. Due to their substantial intrabay movement but restricted interbay movement, local populations of black dru...