710 



OYSTER-BEDS, DETERIORATION OF. 



the mature was found to he as three to two. 

 Over 100,000 oysters were taken from the beds 

 in the sounds, and measured and classified in 

 like manner, and the ratio of young to mature 

 was found to be as throe to six. Thus on the 

 new beds the young outnumbered the mature, 

 wliile on the worked beds in the sounds the 

 mature outnumbered the young growth. 



The action of the dredge is very destructive 

 to the oysters remaining on the bed, by not 

 only roughly detaching them from different 

 objects to which they cling, but also leaving 

 them in such positions as to prevent their open- 

 ing the valves without letting in mud or sand. 

 Thus the dredge causes the destruction indi- 

 rectly of a large number of oysters that remain 

 after its passage, and hence the number of old, 

 empty shells should be greater upon a bed that 

 has been dredged than upon one that has not; 

 and if that number is very large, it shows that 

 the population of the bed has been destroyed. 

 The quantity of matter brought up by the 

 dredge was measured during the season of 

 1879, and also the quantity of oysters and of 

 debris. On the unworked beds, this latter 

 amounted to 30 per cent of the whole quantity 

 of matter brought up ; while in the sounds the 

 debris was much greater, and in Pocomoke 

 Sound it amounted to 97 per cent. 



During the season of 1878 a method was 

 devised by which the number of oysters to the 

 square yard could be determined approxi-. 

 mately ; and in accordance with this the num- 

 ber to the square yard should bo greater upon 

 the old beds than the new. If, on comparing 

 the results of successive seasons on the same 

 bed, it is found that the number of oysters to 

 the square yard is decreasing, it may be con- 

 cluded that too large a number is annually 

 removed. Investigation showed that, on 60 

 per cent of the beds in Tangier Sound, there 

 was a decrease in the number of oysters in 

 1878-'79, and that on 60 per cent of the beds 

 the number of oysters to the square yard 

 was lens than on the newly discovered beds in 

 the bay, and in no case was the number much 

 greater. In Pocomoke Sound, on every led the 

 number of oysters to the square yard was con- 

 siderably less than in 1878, and also much be- 

 low the number on the new beds in the bay. 



It is evident that, if the number of the young 

 growth falls below the number of the mature 

 oysters, the fecundity of the bed is impaired ; 

 yet it does not follow that, if the young out- 

 number the mature, it is a sign of increased 

 production. From the beds in question many 

 millions of oysters are annually removed, of 

 which a large percentage is mature, and, if 

 this removal of one class is excessive, it might 

 show itself in the increased ratio of young to 

 mature. Supposing this to be the case, the 

 young would greatly outnumber the mature 

 for about three years, or the period to pass 

 from youth to maturity. During this period 

 there is a constant removal of the brood-oys- 

 ters, so that, at the end of three years, the ma- 



ture would probably outnumber the young, 

 and the ratio be abnormally small, as it was 

 abnormally large. With this large number of 

 mature oysters there would be increased pro- 

 duction, and at the end of three years, again, tho 

 ratio would change, while the number of oys- 

 ters will constantly be diminishing. In time, 

 however, the brood - oysters will become so 

 scarce that the fertilization of the eggs will be 

 more and more improbable, and the young re- 

 main in the minority ; so that, if tho fishing 

 continue, tho entire destruction of the breeding 

 power will be but a matter of time. 



It was estimated, from careful investigation, 

 that the number of oysters removed, in 1878, 

 was over 1,500,000 per day, and in 1879, over 

 700,000 per day. In the sounds the dredging 

 continues throughout the year, though little is 

 done in the summer months. The law sanctions 

 the working of the beds from October 1st to 

 May 1st. If confined to this period, with only 

 three full working days each week, the dredging 

 season would bo about 120 days, and in that 

 time there would be removed, by the estimate 

 of 1878, over 184,000,000 oysters, and, by tho 

 estimate of 1879, over 89,000,000 oysters. The 

 number of young growth would be, by the first 

 estimate, 148,000,000 ; by the second, 36,000,- 

 000. The statistics of 1879, compared with 

 those of 1878, show that there were twice as 

 many vessels at work in 1878 as in 1879 ; ar.d 

 the difference of young growth is due to the 

 fact that the summer of 1879 was a bad one 

 for the " spat," and consequently there was a 

 failure of "young." The mortality among the 

 young after attachment is about 50 per cent, 

 and consequently only about 74,400,000 of the 

 young removed in 1878-'79 would have at- 

 tained the age of one year. If none of the oys- 

 ters had been removed from the beds, there 

 would have been about 259,000,000 more on 

 the beds than was actually the case, and of 

 that number 71 per cent were mature and 

 spawn-bearing. Now, as 65 per cent of those 

 in the beds are mature, the adding of 250,000,- 

 000 would increase the percentage to 68, or tho 

 young growth would be in a more hopeless mi- 

 nority than before. 



There are, then, three indications of the de- 

 terioration of the beds: The number of the 

 young is either much smaller or much larger 

 than the number of mature oysters, and in the 

 latter case is so large as to be abnormal; the 

 amount of debris found on the beds is much 

 greater than in the newly discovered areas; 

 and the number of oysters to the square yard 

 not only falls below what it should be, but has 

 decreased since the first examination in 1878. 

 Considering the testimony of persons living in 

 the vicinity of Tangier and Pocomoke Sounds, 

 and the results of the comparison of the worked 

 beds in the sound with the unworked ones in 

 the bay, it may be concluded that the former 

 areas are much impaired in productive power, 

 and, the same reasons continuing to operate, 

 there will be a constant deterioration until that 



