OYSTER-BEDS, DETERIORATION OF. 



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productive power is entirely destroyed. This 

 deterioration and impaired fecundity can only 

 be accounted for by the excessive and exhaust- 

 ive fishery in the sounds, from which hereto- 

 fore the beds in the bay have been free. Quite 

 probably, were the remaining beds in Chesa- 

 peake Bay examined carefully, they would 

 show indications of deterioration similar to 

 those discovered in the Tangier and Poco- 

 moke beds. 



It can hardly be doubted that this deteriora- 

 tion is due to the severe fishing, and that in 

 time, unless this is stopped, it will produce ut- 

 ter exhaustion. Foreign experience aptly illus- 

 trates this. The records of production of the 

 beds of Cancale Bay, on the northwest coast 

 of France, extending over a period of about 

 seventyyears(1800 to!8G8),are very instructive. 

 The beds comprise an area of about 150 acres, 

 and, from 1800 to 1816, produced annually 

 from 400,000 to 2,000,000 oysters. During this 

 period the beds became so thickly stocked that 

 the oysters were in some places a yard thick. 

 Subsequently the fishery was much increased, 

 and the oysters were removed in larger quan- 

 tities till 1843. From 1823 to 1848 it is sup- 

 posed that the dredgers were living on the 

 oysters accumulated between 1800 and 1816. 

 In 1817 the number produced was 5,600,000, 

 and until 1843 there was a constant increase, 

 the number taken in that year being 70,000,- 

 000. In 1848 it was 60,000,000, and thence- 

 forward there was a constant decrease. From 

 1850 to 1856* the decrease was from 50,000,000 

 to 18,000,000. From 1859 to 1868 the de- 

 crease was from 16,000,000 to 1,079,000, the 

 oysters having almost entirely disappeared, 

 though the inhabitants, on account of their 

 suffering, dependent condition, were not hin- 

 dered from fishing. In 1870 there was a com- 

 plete wreck of the bottom, which could only 

 be remedied by a total prohibition of the fish- 

 eries for several years. Similar results oc- 

 curred in other places on the west coast of 

 France, where, when in 1854-'55, 15,000,000 

 oysters were taken from the beds, only 400,- 

 000 could be obtained in 1863-'64. The testi- 

 mony of English experience also corresponds 

 with that just given, and is equally valuable 

 with reference to the course which must sooner 

 or later be taken in our country for the pres- 

 ervation of the oyster-beds from complete ruin. 



It is true that our beds are so extensive, and 

 oysters are so widely distributed and so easily 

 transported and transplanted, that the total 

 failure of the American beds must be post- 

 poned for some time. But the failure of beds 

 in different localities may .occur at any time, 

 and probably those of Chesapeake Bay will not 

 last many yours. The deterioration and exhaus- 

 tion of our bods would cause great distress and 

 inconvenience in the United States, whore the 

 oyster is no luxury simply, but a means of sup- 

 port to large numbers. Not only are oy-t.T> 

 consumed with us in every part of the Union, 

 but immense numbers are also annually ex- 



ported. Hence, by the deterioration of the 

 beds, not only would the price be much in- 

 creased for all classes, but the poorer among 

 our citizens would many of them be thrown 

 wholly out of employment. 



To this statistical and historical account we 

 subjoin a description of the natural history of 

 the oyster, with special reference to the proc- 

 ess of reproduction, and the conditions influ- 

 encing the rate of increase. For material em- 

 ployed here we are indebted to articles con- 

 tributed by Lieutenant Francis Winslow. 



An oyster-bed, in its natural and undisturbed 

 state, consists of a long, narrow ridge of shells 

 and oysters, lying generally in brackish water, 

 on and surrounded by sticky bottoms, a mixt- 

 ure similar to clay and mud being the most 

 favorable. The form and area of the bed are 

 variable, but naturally the length is greater 

 than the breadth, and the greatest dimension 

 is usually in the direction of the current. The 

 bed itself is made up of masses of shells and 

 oysters, covering areas of different sizes, and 

 separated from each other by mud or sand- 

 sloughs, though frequently it is unbroken, and 

 the animals spread evenly and continuously 

 over the entire area. The oyster thrives best 

 in slightly brackish water, and the finest va- 

 rieties are usually found in water of a lower 

 specific gravity than that of the sea. The main 

 necessity is that the water should contain a 

 sufficient amount of lime to furnish the animal 

 with the principal constituent of its shell. 

 That part of the oyster usually known as the 

 heart is a muscle, called the adductor muscle; 

 its office is to keep the valves or shell closed, 

 and prevent the ingress of hurtful mutter. 

 The two valves are hinged at the round, blunt 

 end of the shell, and between this hinge and 

 the adductor muscle lies the body of the oyster, 

 or visceral mass, which is made up of the light- 

 colored reproductive organs and the dark- 

 colored digestive ones, packed together in one 

 continuous mass. The mouth of the oyster is 

 that part nearest the hinge, and what is usu- 

 ally called its " beard " is known as the " gills." 

 The oyster lies on its side in the shell, and the 

 minute animal and vegetable matter contained 

 in the water forming the food of the animal 

 is passed between the gills to tlie mouth, by tho 

 action of myriads of small vibrating hair;', 

 called cilia. These cover tho surface of tho 

 gills, and cause a strong current to set into tho 

 lips of tho valves, thus bringing in not only 

 what is suitable for food, but other minute par- 

 ticles of matter. 



The European oyster (Ottren ednlis) and tho 

 American oyster (Ottrea Viryiiiitimi) are vari- 

 eties of the MUM family, Uld, though differing 

 in several particulars, aro not so dissimilar bur 

 that the conditions favorable to tho growth 

 and life of one may be considered as equally 

 so for the other. With each variety the forma- 

 tion of tho generative matter is gradual, and 

 the spawiiii:ir--e:iM>n <>f both is during tho early 

 summer months, its advent depending probably 



