24 



The salinity and food conditions in these places were practic- 

 ally the same as in the larger bodies of water near by. 



South of Grand Pass Des Isles the first inlet of any size is 

 a pass which connects Bay Wilson with the Gulf. This pass 

 is about one mile long and two hundred yards wide. The water 

 is from twelve to twenty feet deep in the channel, which is very 

 narrow, the greater part of the width of the bayou being occu- 

 pied by the mud flats. The bottom is composed of firm mud in 

 the channel, while the flats are extremely soft, except on the 

 areas occupied by reefs of small coon oysters. 



Bay Wilson, at the head of the pass just mentioned, is about 

 two miles long and one and one-half miles wide. Along the 

 southern part of the bay there is a channel where the depth of 

 water varies from twelve to twenty feet. Over the whole of the 

 northern part of the bay the depth is from two to four feet. 

 Along both sides of the channel across the southern side of the 

 bay, and for some distance up into the shallow portion, there 

 are many old reefs ; but so far as could be determined, no living 

 oysters beside those that had been bedded. In the northern 

 part of the bay the bottom is made up of soft mud and there 

 are no old reefs of any size. 



The salinity of the water was 1.0158, and the supply of food 

 organisms abundant. 



For some years past the hard areas on the old reefs along 

 the -channel through Bay Wilson have been used for bedding 

 grounds for planting seed oysters brought from some of the 

 bays to the westward. Of late there has been a general complaint 

 from the lessees of these bottoms that the oysters have not done 

 so well as in past years, and some of the men have gone so far 

 as to give up their leases. 



While several conflicting opinions have been brought for- 

 ward as to the cause of the failure of these plants, an examina- 

 tion of the conditions seems to point to the ravages of the boring 

 sponge {Cliona sulphurea) as the chief cause of the trouble. All 

 of the staked-off areas as well as the old reefs were examined 

 and every shell brought up, whether those of living oysters, or 

 those that had long been on the reef as dead shells, were com- 

 pletely honeycombed by the burrows of this sponge. At one of 



