descriptions of the mortality In 1945 to the burying and consequent 

 suffocation of the oysters by the enormous load of silt and sand 

 brought onto the reefs by the flood waters. There is little doubt 

 that many acres of natural oyster reefs and planted beds were harmed 

 in this way, althoiigh three months after the flood competent investi- 

 gators found serious mortality without evidence of slltation on some 

 of the reefs. At the present time, four years later, areas such as 

 Point Clear, Waveland, and beds near Petit Pass which supported ex- 

 tensive oyster reefs in the pa.st, are now composed mainly of a 

 «ticlgr-to-soft mud. Soundings made through this mud showed the 

 presence of buried oyster shells. It is difficult to tell how 

 muoh of this condition is a hold-over frcm 1945 , and how much is 

 a result of the hurricane of 1947, This condition Is confined, 

 however, to the western-most part of Mississippi Sound at the 

 present time, affecting perhaps less than 10 per cent of the 

 oyster producing area in the Sound. 



Initial investigation of the area in the summer of 1948 

 suggested that movement of this layer of silt by stozm action 

 sight aoeotmt for the reported annual losses of spat since 1945, 

 For this reason, turbidity indices were recorded on all water 

 samples eolleoted in Mississippi Sound and Lelce Meohant, 



During one particular survey trip in April, 1949 in Mississippi 

 Sound a strong east wind approaching storm proportions made the water 

 very rough and presumably put into suspension a large emount of loose 

 silt. The greatest turbidity recorded at this time differed little 

 from Station 20 in Lake Mechant where oysters flourished under a con- 

 tinuously high turbidity. In my opinion the high turbidity present 

 cannot be a significent factor in itself in the observed oyster 

 mortalities. The surveys Indicate also that at the present time, 

 the soft mud on the bottom is sufficiently consolidated so that the 

 averege rough water condition will not increase the turbidity enough 

 to be harmful to oysters, 15ie shallowness of the water throughout 

 the Sound insures a thorough mixing of the water with the result 

 that surface and bottom turbidities did not usually vary significantly 

 from each other. 



In Area I, turbidities were not apparent to the naked eye and by 

 testing ranged from 10 to less than 1 per cent of light interference. 



In Area II, the range and degree of turbidity was far greater 

 but was not enough in itself to prevent the feeding activity of 

 oysters. The range in turbidity during the period February to June 

 was 76.7 to 21,1 being greatest during time of storm and showing no 

 clear cut relationship to the direction of flow of fresh water 

 across the sound from the Pearl River, 



16 



