45 



as, there being no increase, if they were not in sufficient numbers to prevent the growth of the 

 bed and number of oysters, they would not be sufficient to cause its destruction or deterioration). 



The number of oysters would then, on a limited bed, steadily increase as long as there was 

 sufficient room and food supplied them until they had reached their limit, a rather indefinable 

 one, in that direction, the quality of the oysters not being taken into consideration. Having 

 reached that point, the number of oysters to all intents remain the same as long as the conditions 

 under which they had previously lived were not changed. To cause, then, either an increase or 

 diminution of the number of oysters or size of the bed, a new factor must be brought in, when, 

 all conditions being changed, the life of the animals begins anew and progresses differently. As 

 there can be no doubt that both the beds and oysters of Tangier and Pocomoke Sounds have 

 changed greatly in character since their first discovery, in accounting for that change it is necessary 

 to discover the new factor or factors that have been introduced and that have been instrumental 

 in effecting it. Briefly, the change in the beds has been a material expansion of their limits and 

 a material diminution of the number of oysters upon them, and therefore the causes for such changes 

 must be sought among such as it is known would produce like effects. 



Disregarding for the present the agency of man in the matter, the question is, What natural 

 cause or causes would both expand the beds and diminish the number of oysters? A bed is 

 extended naturally by the drifting spat or "young brood" attaching themselves to any clean, hard, 

 and moderately rough substance contiguous to the bed. The locomotive powers of the "spat" 

 exist for but a short time, and, except when assisted by the current, they can only move a short 

 distance, and unless some suitable object soon presents itself for their attachment they will sink 

 into the soft bottoms and die. 



The principal expansion of the beds so far as could be effected by nature must, however, have 

 been accomplished long ago, the beds being surrounded originally, and indeed at present, by soft 

 bottoms of a character which would be most destructive to the "brood" unless some substance 

 was interposed between it and them for their reception. Natural expansion can only be achieved 

 to any extent in the manner described, and though probably there is and has been a slow extension 

 of the beds due to natural unassisted causes, their great increase in area during the last thirty 

 years must be assigned to other agents. 



The diminution of the number of oysters may be effected by several natural causes. An 

 increased deposit of earthy or vegetable matter upon the beds would, if in sufficient quantities to 

 bury the oyster, effect the destruction of both old and young; but no such deposit has been 

 noticed, nor could it well occur without showing its presence in other ways, principally by changing 

 the channels and causing shoals, and no such changes have occurred, my investigation showing 

 but slight deviations in either channels, shoals, or character of the bottom from that established 

 by the first hydrographic survey of the locality. A change in the character of the water and 

 bottom which would probably follow a change of channel, and might occur without such change, 

 might, by depriving the animals of their proper food, cause their deterioration and destruction; 

 but such a change, though it would certainly diminish the number on the beds, would do so sud- 

 denly and the evil effects would be noticed in the oysters remaining, their quality and flavor, 

 indeed their vitality, being very much impaired. No such impairment has been observed, how- 

 ever, the oysters being larger and finer than when the beds were first discovered. That fact 

 alone will eliminate many quantities from the equation, for any natural cause injurious to all the 

 oysters on the beds would be evident at once by an examination of those found at present. If, 

 however, the destruction or non-production of the necessary number of young is accomplished by 

 means that are not harmful to the mature oyster, a cause is discovered for the diminution of all, in 

 harmony with the existing facts. 



Considering first the destruction of young; large numbers, immense when compared with the . 

 production of other animals, are without doubt naturally destroyed by the falling of the "spat" 

 upon unfavorable grounds, the prevalence of heavy freshets which would drive the "brood" into 

 the bay and probably cause its loss, and the ravages of various enemies. But all these causes 

 have been in operation continually since the first formation of the beds, and the animals have 

 survived and increased while contending with them. Therefore an increase of power for injury 

 must be assigned to one or all of these to account for the diminished number of oysters. Probably 

 the "spat" falls on more favorable ground since the beds were discovered than was formerly the 



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