48 OYSTER CULTURE EXPERIMENTS IN LOUISIANA. 



discharge of fresh water from the land. A low specific gravity, such 

 as obtains in Three-mile Bay and vicinity, indicates a close relation 

 to land drainage, as compared with another locality, such as Caligo 

 Bay, in which the specific gravity is high. If land drainage and its 

 contained fertilizing salts are highly important, as we generally sup- 

 pose, in stimulating the growth of oyster food, it would be expected, 

 other things being equal, that a low specific gravity would be cor- 

 related with a high food content as compared with a high specific 

 gravity in the same system of waters. An examination of the fore- 

 going table exhibits no such relation between the salinities and the 

 food contents of the waters, when the various connected waters are 

 compared with others in the same system or chain. The authors 

 have prepared tables showing the specific gravity and food content 

 of the waters at various times in each of the localities enumerated in 

 the foregoing table of averages, and these show the same apparent 

 lack of correlation, a high food content occurring sometimes with a 

 low and at other times with a high specific gravity in the same 

 locality. 



It is probable that these results are to be regarded as nonconclusive 

 rather than as showing that a relationship does not exist. The un- 

 controlled factors, particularly the stirring up of the bottom by 

 wave action, are too important to be disregarded and their influence 

 can be overcome only, apparently, by making many more observations 

 than were possible under the conditions of the present investigation. 

 Deductions from work of this character, unless the observations can 

 be carried on systematically almost daily throughout the year, are 

 likely to be misleading, and the investigations of the oyster food of 

 Louisiana waters can be regarded as shedding no light on the effects 

 of introducing river water in such localities as Bay Adam with the 

 purpose of improving the conditions for fattening oysters. 



SUMMARY AND CONCLUSION. 



The following epitomizes the results of the experiments and in- 

 vestigations of the oyster regions of Louisiana, east of the Atchafa- 

 laya River, between April, 1906, and January, 1909, and the deduc- 

 tions which the authors draw from their observations : 



1. It is believed that the future of both the natural beds and 

 oyster culture in Louisiana will be benefited by greater restrictions 

 on the issuance of permits to take unculled oysters from the natural 

 beds. A too general practice in this respect tends to the depletion 

 of the natural beds of not only oysters, but the shells that are essen- 

 tial for their future prosperity, and at the same time has the effect of 

 discouraging the planting of shells on leased bottoms. 



2. A limited issuance of such permits to take unculled stock from 

 designated beds which are known to be overcrowded or which are 



