OYSTERS AND METHODS OF OYSTER-CULTURE. 295 



DESTRUCTION OF NATURAL BEDS— CAUSES AND REMEDIES. 



llDtil a comparatively recent date our supply of oysters was drawn 

 almost entirely from the natural beds, which were originally so vast that 

 it was a common saying that they were inexhaustible. The fallacy of 

 this view has been abundantly proven, and wherever reliance has been 

 placed upon natural beds solely there has been a decreasing supply to 

 meet an increasing demand. Many causes have been cited to account 

 for the decrease in the productiveness of the oyster-beds, but wherever 

 unprejudiced investigation has been brought to bear upon the subject 

 the verdict has always been that the fishing upon the beds has outgrown 

 their fecundity. 



Vast as is the production of spawn, the chances against its growth 

 to maturity are such as to limit the productiveness of the beds. Much of 

 it fails of fertilization. Most which passes that critical stage becomes 

 a prey to enemies or falls upon unsuitable bottom, where it fails of 

 attachment and sinks in the ooze. Even after the vicissitudes of 

 larval life are passed the infantile spat may be buried in an accumu- 

 lation of organic or inorganic sediment, or it may be devoured by 

 enemies against which it can present no adequate defense. Storms 

 may tear the adult oysters from their attachment and cast them upon 

 the shore, or they may become covered by sand and seaweeds drifted 

 in by the waves; or, again, excessively cold weather may cause their 

 death in exposed places by freezing. 



Numerous as are the perils which beset them under their natural 

 surroundings, they have, upon the whole, found the conditions. favorable 

 for their maintenance and increase until civilized man began his syste- 

 matic attacks. It is true that before the appearance of the white man 

 upon the scene they had disappeared from regions where they were 

 formerly found, but upon our coasts such cases are isolated and rare. 



Without here going into the evidence, it may be asserted as a dem- 

 onstrated fact that overfishing is the cause of the depletion of our 

 oyster-beds, and that it produces its damaging effect in several ways: 



1. It removes the adult oysters, which are either spawning or are 

 capable of spawning, and thereby reduces the reproductive power of 

 the bed as a whole. 



2. It removes the shells, and therefore decreases the available points 

 of attachment of the spawn. When the oysters are not culled on the 

 beds this effect is aggravated by the removal of the dead shells. 



3. Spat and 3'ouug oysters attached to the shells of the adults are 

 removed froni the beds, and as it is impracticable in many cases to 

 detach them they are of necessity destroyed. 



4. The quantity of oysters taken and destroyed from the several 

 causes mentioned is greater than that which is jDcrmitted to annually 

 grow up to take their places. 



Many causes have been assigned as tending to deplete the oyster- 

 beds, and many remedies have been proposed. Various phases of the 



