Galveston Bay oyster studies: 1972. Project CO-2-3.

Annual death rates among one, five, six and seven year-old oysters (Crassostrea virginica) at the lower East Bay tray station ranged from 70% to over 90%. Labyrinthomyxa marina infection was the principal cause of death although oyster drill (Thais haemastoma) and stone crab (Menippe mercenaria) predation was a contributing factor. Cumulative death rates of 7% to 41% occurred over an eight month period among year- old oysters from middle East Bay which had bee transplanted to stations in Trinity, Galveston, East and West Bays. Labyrinthomyxa marina infection was not a major cause of death and oyster drill predation was important only at one station. Oyster spat setting at 14 public reef stations was poor. The number of spat per bushel sample during peak setting month averaged 35 compared to 500 in 1971. However, market oysters increased in number by the end of the year. Labyrinthomyxa marina became well-established throughout the bay but only at middle Red Fish Bar did infection incidence reach epidemic levels. A heavy oyster fishery was generally concentrated along Red Fish Bay. Over 1390 metric tons meat valued at nearly 2 million dollars were harvested. The State Health Department closed the major harvest center for a 20 day period in March - April due to flood conditions.