708 



OYSTER-BEDS, DETERIORATION OF. 



of the North are practically exhausted, and 

 that the production of the Southern beds (of 

 Maryland and Virginia) is greatly diminished. 

 It is not probable, however, that the area of 

 the latter has decreased, notwithstanding vari- 

 ous estimates to the contrary, arising out of 

 the increased price of oysters, and the lack of 

 care and protection to the oyster-beds. Ad- 

 mitting that the Northern beds are practically 

 exhausted, and have become mere fattemng- 

 places for the transplanted Southern oyster, 

 it is still open to question whether the beds of 

 Maryland and Virginia are deteriorating. 



It being impossible to speak with perfect 

 accuracy of the entire area covered by oysters 

 in these States, it may safely be assumed that 

 the condition and peculiarities of beds in one 

 district will serve, approximately at least, to 

 express the condition of all the rest. The only 

 locality which has been thoroughly studied lies 

 on the eastern shore of Chesapeake Bay, oppo- 

 site the mouth of the Potomac River. This 

 was done in 1878 -'79, and includes the survey 

 of the beds of Tangier and Pocomoke Sounds, 

 and ascertaining the depth of the water over 

 the beds, the direction and force of the cur- 

 rents, the character of the bottom, the effect 

 of gales, ice, and freshets, and also of fishery 

 with dredges or tongs. 



Tangier and Pocomoke Sounds are arms of 

 Chesapeake Bay, and lie opposite the mouth of 

 the Potomac, on the eastern side of the bay. 

 The former extends about thirty-six miles 

 north, is separated from the bay by a chain of 

 low, marshy islands, and receives the waters 

 of several creeks and rivers. The shoals on 

 either side of the channel are covered with 

 oyster-beds, and, where there are no beds, oys- 

 ters are scattered in groups or singly. They 

 are also found as continuations of the beds, 

 and, generally speaking, oysters may be taken 

 in varying numbers throughout Tangier, in 

 depths of between one and six fathoms. Poco- 

 moke Sound is twelve and a half miles long 

 and about nine broad near the middle. The 

 channel is narrow and tortuous, and the main 

 body of the sound is shoal, and these shoals 

 covered with oysters, singly or in groups, or 

 in large, well-defined beds. Several creeks and 

 the Pocomoke River empty into this sound. 

 The beds were located and marked off, and the 

 area ascertained approximately. The entire 

 area in both sounds upon which oysters were 

 found amounts to fifty-four square miles. The 

 area of the beds proper, where the vessels for 

 dredging mostly work, amounts to six square 

 miles in Tangier and four in Pocomoke Sound. 

 From the examination made in 1878 it appears 

 that the number of oysters on the beds has 

 greatly diminished during the last thirty years, 

 that the area of the beds has greatly increased, 

 and that there has been no change of the usual 

 natural conditions to which oysters are sub- 

 jected. 



The question then arises, "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 

 appropriate " cultch " contiguous to the bed. 

 This extension is greatest in the direction of 

 the currents, and unless some substance is in- 

 terposed between the soft bottoms (which are 

 destructive to young broods) and the drilling 

 " spat," they will sink into it and be destroyed. 

 Nature offers very little help in the way of 

 preventing this destruction, and hence the 

 great expansion of the beds must be assigned 

 to other agents than natural causes. The dim- 

 inution of the number of oysters might have 

 been effected by deposits of earthy or vegeta- 

 ble matter, so as to bury both old and young 

 oysters ; but there is no evidence of any such 

 deposits ever having been made. Again, a 

 change in the character of the water and bot- 

 tom might deprive oysters of their proper food, 

 and cause their deterioration and destruction ; 

 but such a change would act suddenly, and 

 impair the flavor and vitality of those that es- 

 caped. Inasmuch, however, as no such im- 

 pairment has taken place, but on the contrary 

 the oysters are larger and finer than formerly, 

 no force can be attributed to this as a cause of 

 the diminution of the oysters. These, then, be- 

 ing dismissed as inadequate, the real cause is 

 to be sought in the agency of man. 



The oyster- fishery in these localities is car- 

 ried on chiefly I -y the process of "dredging." 

 This is performed as follows: A dredge or 

 scrape resembles a large iron claw, the nails 

 representing the teeth of the dredge. To the 

 back of this is fastened a bag of iron mesh- 

 work, large enough to hold two or three bush- 

 els. Dredges vary in size from two to five 

 feet across the mouth, and of greater or less 

 weight. Dredging-vessels vary in size from 

 five to thirty tons, and all use two dredges. 

 These are dropped one from each side, and the 

 vessel being kept under easy pail, they fill and 

 are hauled in by a small winch. They are 

 then emptied, and the process repeated. The 

 mud, sand, sponge, etc., are separated from the 

 oysters, and, together with the oysters unfit 

 for market, thrown back into the water. As 

 the limits of the dredging-grounds are not de- 

 fined, the vessels frequently drag quantities of 

 shells and oysters beyond the boundary of the 

 beds. After " culling " the oysters, or separat- 

 ing them from the old shells, these shells are 

 thrown back again, and many young oysters 

 with them. If these fall on suitable grounds, 

 sufficient to support them, they form a small 

 colony, which soon after, by the action of the 

 dredges, becomes attached to the main bed, and 

 thus increases the area of the latter. 



A further question presents itself. TTill the 

 dredging also account for the diminution of 

 the oysters? Without discussing here the 

 question of propagation, it may be stated that 

 the male and female of the American variety 

 of oyster expel the generative matter into the 

 water, where the eggs must meet the male 



