27 



no matter how long it may be left undisturbed. The reason for 

 this is obvious; the dead shells that are in the reef, and there 

 may be quantities of them, are worm eaten, and covered with 

 all kinds of foreign growth. This, as stated in the first part of 

 the bulletin, absolutely prevents the attachment of any spat. 

 Such animals as the hydroids, sea anemones, tunicates and others 

 that constitutes this growth, will devour every oyster larva that 

 settles within their reach. Other forms will smother the young 

 immediately or shortly after its attachment. Thus on these old 

 "moss-covered" shells there is no chance for the young oyster 

 to live, much less grow, and build up the reef. In this case 

 then, a reef, no matter how prolific it may have been formerly, 

 is a depleted reef, and will remain absolutely barren, until arti- 

 ficial conditions produce a suitable bottom. 



A so-called depleted reef, may, if left untouched, recover in 

 the course of time. In the case mentioned above, the supposition 

 was made that all living oysters had been taken off the reef, pre- 

 venting possible hope of recovery. Here, we take the supposition 

 that there are still a few live oysters left on the reef. If left un- 

 disturbed, these will either be killed or will die, and the two 

 valves of the shells separate. No matter how foul the outsido 

 of the shell may be, the inside is always clean so long as the 

 oyster lives. Upon the death of the old oyster, then, there are 

 left exposed the two clean surfaces of the inside of the valves. 

 These form suitable places for the attachment of spat, and they 

 are soon utilized by oyster spawn in the water. Out of the num- 

 bers that become attached, several may survive. These in turn 

 may be broken off and separated, and then killed or die, exposing 

 their surfaces for attachment. Thus in the course of years, the 

 reef may again build up and become profitable, the time de- 

 pending on the number of oysters left on the reef. Usually, 

 however, the time taken for such a reef to recover will be six 

 or eight years. The nucleus of recovery being the inner shell of 

 oysters as they die. The idea being, that a reef will recover, 

 not due to the actual presence of the adult oyster, but to the 

 fact that it leaves behind it when it dies a center for young 

 oysters to grow. 



Louisiana has at present but few natural reefs which can be 

 considered as such. In many places there are reefs, so-called 



