Observations of red drum mortality in the Gulf of Mexico
Approximately 3,704 large red drum (Sciaenops ocellatus) were found dead from 30 June 1981 to 9 July 1981 on the Gulf of Mexico beach from Cedar Bayou to Port Isabel, Texas. No other fish species were found. Autopsied fish did not show any signs of external injury. Plankton collected in nearshore Gulf waters were representative of those usually present and were not known to be toxic to fish. None were sufficiently abundant to produce anoxic conditions. Bacteria (Vibrio sp.) were found in the liver and brain tissue, but these are normally present in the environment and may have invaded the tissues after death. Causative factors of this mortality remain unknown.