DECLINE OF THE OYSTER FISHERY 103 



in sustaining the race from generation to generation is the mean temper- 

 ature of the breeding season, which is more likely to be adversely affected. 



Man the Oyster's Greatest Foe. — All these causes of destruction have 

 been in operation for century upon century and have been offset by the 

 enormous powers of reproduction of the oyster, of repair to injuries, and 

 of accommodation to changing conditions. Before the advent of man, 

 and at the present time where man does not interfere, the oyster was and 

 is capable of holding its own in the struggle for existence. But where 

 man interferes, with his reasoned methods of fishing and his selfish dis- 

 regard for the future of the fishery, he disturbs the balance which has 

 obtained between the natural and opposed powers of production and 

 destruction, and in a comparatively few years reduces the productivity 

 of the natural beds to the verge of depletion. The oyster, in its simple, 

 undesigned, mechanical mode of life, hampered by all its specializations 

 and loss of sensory and locomotory organs, cannot evade or defend itself 

 against the persistence and contrivances of man. If the oyster could 

 reason it would regard man as its greatest enemy, for he not only calculat- 

 ingly takes every specimen that he finds but in various ways destroys 

 others that he cannot see and almost maliciously interferes with the 

 habitats of all stages of the developing young. 



In the first place man strikes at the very existence of the oyster in 

 fishing for and removing from the beds the full-grown, mature, breeding 

 individuals and those next in size that should take their places. In 

 doing this he removes spat on the adults, that are too small for use and 

 should be left in the water where they can grow up. At the same time 

 the removal of all these takes away their shells and reduces the amount 

 of natural cultch in the water. The process of fishing cannot help but 

 break down the natural surfaces of the beds, burying living oysters under 

 dead shells or tumbling them into mud. Oyster fishing on the Canadian 

 coast is accomplished with oyster-tongs which somewhat resemble a pair 

 of rakes fastened together like scissors and operated from boats above 

 the beds — two men in a boat taking from 3 to 6 barrels per day. 



In a similar manner the fishing for quahaugs interferes with oysters 

 and spat and stirs up mud in the water to settle on to the surfaces of shells, 

 rendering them unsuitable for the attachment of larvae. 



The digging of "mussel-mud" by farmers is in several ways injurious 

 to oysters. A "mud-digger" consists of a framework suspending a huge 

 dipper-like scoop with a bale and a long beam for a handle. The scoop 

 is lowered through a hole cut in the ice and controlled by men at the end 

 of the beam. The power is applied through a chain that passes from the 

 bale over a pulley and is wound around a vertical windlass turned by a 

 horse. The framework may be slid along to fresh places as the old ones 

 become exhausted. The so-called "mussel mud" is composed largely 

 of decaying oyster shells with some mussel, clam, quahaug or other shells 



