12 



most of the bottom. JMost of the hu'ger oysters in these clusters 

 are dead, but most of those less than one and one-half inches in 

 length are alive and growing rapidly. 



Natural Reefs in Southwest Pass. 



Southwest Passywesterl}' connection between Vermilion Bay 

 and gulf, is about four miles in length. On the eastern side 

 there is a deep, narrow channel, while on the west side there are 

 extensive mud flats that are exposed at low tides. A narrow, tor- 

 tuous channel naviga])le for small boats, passes around on the 

 west side of these mud flats. The greater part of these flats are 

 covered with clusters of raccoon oysters. These are arranged 

 in long, narrow reefs that have their ends perpendicular to the 

 small shallow channels, which cut up the flats. 



The oysters that make up these reefs are arranged in clus- 

 ters of ten to twenty. They are all small and misshapen on 

 account of being so densely crowded. A dense growth of a blue 

 green Alga about one-half of an inch long covers the entire 

 exposed sui-face of oysters and dead shells. Mussels occur abun- 

 dantly in the spaces lietween the oysters of each cluster. The 

 condition of the oyster on these reefs is always poor, as the 

 amount of food material available for each individual is small, 

 and the tiine in M'hich the food may be secured is limited to one 

 or two hours before and after high tide. These oysters are, 

 whil':> the reefs are dry, subjected to intense heat in the sum- 

 mer, and sometimes to freezing tem])erature in the winter. 



On the western side of the small channel mentioned above, 

 there are ]nany small exposed reefs of "coony" oysters, and 

 also a few reefs that are covered at all stages of the tide. Oyf^- 

 ters of good quality are found over limited areas on some of 

 these deep reefs, but in small quantity only. 



On the east side of the main channel of the pass there are 

 a number of scattered reefs that cover the greater part of the 

 area between the chnnnel and tlu^ shore. The reefs near the 

 channel ai-e covered by five to fifteen feet of water, while many 

 of those farther in shore are exposed at low tide. These reefs 

 are made up of highly elongated thin shelled oysters arranged 

 in elnst(M's. The clusters spring from an old empty shell buried 

 deep in the soft mud. As many as twenty-five or thirty oysters, 



