OYSTER-BEDS OF LOUISIANA. 



89 



under the influence of tbe spring freshets, and that it ceases with the 

 influx of Salter water in the fall. A change in the salinity of the water 

 may perhaps stimulate reproduction, but it happens that the water is 

 more and not less dense during the summer, when the oyster is spawn- 

 ing copiously, than it is in winter when only sporadic cases of sexual 

 activity x)revail. 



The following table shows in condensed form the conditions prevail- 

 ing at several places during the latter part of August, 1897 : 



Density. 



Grand Pass, St. Bernard Parish 



Tliree-mile Bayou, St. Bernard Parish. 



Salt Works, Plaquemines Parish 



Bay Adam, Plaquemines Parish 



Bayou Cook, Plaquemines Parish 



Aug. 31 

 ...do 



Aug. 25 

 Aug. 24 

 ...do ... 



1. 0176 

 1. 0128 

 1.0151 

 1. 0076 

 1.0106 



Spawning freely. 



Uo. 

 Not spawning. 



Do. 

 Spawning. 



It will be seen that there is uo relation shown between the density 

 of the water and the cessation of spawning, and that the relative as 

 well as the absolute densities at the different seasons are not deter- 

 mining factors is seen when we consider the geographical relations of 

 Bayou Cook and Bay Adam. No increase in salinity could take place 

 in the latter, where spawning had ceased, without having a prior effect 

 upon the former, where spawning still continued. At the same time it 

 is apparently a well-established fact that in certain places, e. g., Salt 

 Works, Wilson Bay, Bayou Provengal, and others, the oysters cease 

 spawning and become fat very early in the season. Closer investiga- 

 tion would doubtless show that this was not due to one, but to a variety 

 of causes, embracing density, temperature, and amount of food matter 

 available. 



The young fry of the oyster, which freely swims in the water, is often 

 wafted long distances and widely distributed by the currents, a fact 

 which accounts for the establishment of new beds and the frequent 

 rejuvenation of old ones which have been destroyed. An instance of 

 the latter, in Quarantine Bay, is noted in another connection in this 

 report. In order that these minute fry may succeed in establishing 

 themselves, it is necessary that they should find some clean, solid body 

 to which to fasten, a fact that must be borne in mind when considering 

 the question of oyster-culture and the use to be made of exhausted 

 beds, such as are found in Barataria Bay. 



RATE OF GROWTH OF LOUISIANA OYSTERS. 



In the waters of Louisiana the oyster reaches a good marketable size 

 within three years of the time of its fixation, this fact being estab- 

 lished not as the result of more or less loose estimates, but from 

 authentic data established by experience. It is rarely possible to 

 determine with accuracy the age of oysters upon the natural beds, 

 but occasionally circumstances arise which make such determinations 



