14 OYSTER CULTURE EXPERIMENTS IN LOUISIANA. 



they were recognizable only by the presence of old shells more or less 

 buried in the mud. In a few places there were occasional old oysters, 

 but no spat whatever. None of the natural beds appear to have 

 been extensive, and their extermination was readily accomplished by 

 the reckless methods employed in the fishery, particularly under the 

 changes in the salinity conditions which were then in progress. 



A few oysters for local use were annually planted close to Grand 

 Isle and at Grand Bank, and in Bay Coquille some were bedded for 

 market, but in neither place was there any indication of a volunteer 

 growth of young. 



There was no evidence of the existence of beds at any time in the 

 upper part of the bay, and persons familiar with the region stated 

 that none had ever been known north of the Quartelle, a group of 

 four small islands near the center of Grand Lake. About 1903 a 

 small bed was found near Bayou St. Denis, but this was quickly 

 depleted and a careful search in 1905 failed to disclose any oysters 

 whatever on its site. 



In 1898 the whole upper part of the bay was of low salinity, and 

 it was stated that during spring and early summer the water was 

 often nearly or quite fresh for months, and it was manifest that the 

 conditions were not favorable for oyster growth. With the improve- 

 ment of the levee system the volume of , fresh water discharging into 

 the bay has markedly decreased, and the general salinity of the whole 

 region has correspondingly increased. The closure of the head of 

 Bayou Lafourche has had a very marked influence in Bay Coquille 

 and contiguous waters, where the density of 1.0038 observed in 

 March, 1898, has increased to an average of about 1.0186 during the 

 same season of recent years, and at Leeville, immediately on the 

 bayou, where the water was formerly always fresh, a set of oysters 

 has several times occurred. In Bay Tambour the observed density 

 in March, 1898, was 1.0094, while the average for approximately the 

 same season in 1906 to 1908 was 1.0151. In Bay des Islettes there is 

 noticeable a slight rise in salinity, but nearer the sea, as at Grand 

 Isle, there appears to be little or no change. 



Nearer the mouths of Grand Bayou and Bayou St. Denis we have 

 no early data concerning the saltness of the water, though it was 

 stated in 1898 to be almost constantly fresh. During a crevasse in 

 the spring of 1907, when the conditions were such as frequently, if 

 not normally, existed in former times, this water Avas practically 

 fresh for a considerable period, though the average density during 

 other recent years has been about 1.0110. Little Lake, about 10 miles 

 inland from the mouths of the bayous, whore the water was formerly 

 fresh and inhabited by large-mouth black bass, now contains oysters, 

 inidoubtedly derived from fry discharged from the experimental 

 beds at the mouth of Bayou St. Denis. 



