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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 various estimates to the contrary, arising out of the increased price of oysters, and the lack of care and protection to the oyster-beds. Admitting that the Northern beds are practically exhausted, and have become mere fatteningplaces 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, opposite 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 currents, 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, oysters 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. Pocomoke 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 subjected.

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 interposed between the soft bottoms (which are destructive to young broods) and the drifting "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 diminution of the number of oysters might have been effected by deposits of earthy or vegetable 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 bottom 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 escaped. Inasmuch, however, as no such impairment 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, being dismissed as inadequate, the real cause is to be sought in the agency of man.

The oyster-fishery in these localities is carried on chiefly by 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 meshwork, large enough to hold two or three bushels. 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 sail, 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 defined, the vessels frequently drag quantities of shells and oysters beyond the boundary of the beds. After "culling" the oysters, or separating 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. Will 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

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fluid in order to be fertilized. Hence, the more compact the bed, the greater the chance of the ova and spermatozoa coming in contact. If the mature, spawn-bearing oysters are very much diminished in number, or widely separated from each other, the chances of contact are slight, and there is a failure of reproduction. But the removal of brood-oysters is not the sum total, by any means, of the effects of the dredging. Millions of young oysters, unfit for market, are carried off sticking to the shells of the mature oysters, and nearly as many young are destroyed by being thrown from the dredging-vessels upon soft or unfavorable bottoms. As, then, theoretically, dredging would extend the beds and destroy their fecundity, it may be asked whether this has been, practically, the case.

The testimony of the fishermen is unanimous as to the extension of area, some of the beds having doubled in size during the last thirty years. They also testify that the beds have materially deteriorated during this period.

Stronger evidence, however, is afforded by investigation, made in 1879, in regard to areas in Chesapeake Bay where oysters existed in a locality known to very few fishermen. Here the oysters were found in clusters of from three or four to twelve or fifteen, with clean, white shells, and the spaces between the larger ones filled with the young growth and barnacles. The mature oysters were long and narrow; whereas, in beds worked for some time, oysters are usually single, or in clusters of two or three, the animals are fatter and thicker, and the shells are dirty, with much mud or sand clinging to them. These new beds were found to be hard, and the clusters more firmly attached to the bottom, while the beds in the sound were soft, and the oysters easily obtained by means of the dredge. All the oysters examined during the season of 1879 were measured and distributed into four classes, the first two the mature, the last two the young growth. Over twenty thousand were measured and classified, and the ratio of the young growth to

the mature was found to be 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 three to six. Thus on the new beds the young outnumbered the mature, while 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 opening the valves without letting in mud or sand. Thus the dredge causes the destruction indirectly 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 débris. On the unworked beds, this latter amounted to 30 per cent of the whole quantity of matter brought up; while in the sounds the débris 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 approxiinately; and in accordance with this the number to the square yard should be 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 concluded 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 less than on the newly discovered beds in the bay, and in no case was the number much greater. In Pocomoke Sound, on every bed the number of oysters to the square yard was considerably less than in 1878, and also much below 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 outnumber 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-oysters, 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 production, and at the end of three years, again, the ratio would change, while the number of oysters 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 remain in the minority; so that, if the fishing continue, the 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 be about 120 days, and in that time there would be removed, by the estimate of 1878, over 184,000,000 oysters, and, by the 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; and 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 attained the age of one year. If none of the oysters 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 the young growth would be in a more hopeless minority than before.

There are, then, three indications of the deterioration 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 débris 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

OYSTER-BEDS, DETERIORATION OF.

productive power is entirely destroyed. This deterioration and impaired fecundity can only be accounted for by the excessive and exhaustive fishery in the sounds, from which heretofore the beds in the bay have been free. Quite probably, were the remaining beds in Chesapeake Bay examined carefully, they would show indications of deterioration similar to those discovered in the Tangier and Pocomoke beds.

It can hardly be doubted that this deterioration is due to the severe fishing, and that in time, unless this is stopped, it will produce utter 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 seventy years (1800 to 1868), 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 quantities till 1843. From 1823 to 1848 it is supposed 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 thenceforward there was a constant decrease. 1850 to 1856 the decrease was from 50,000,000 to 18,000,000. From 1859 to 1868 the decrease 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 hindered from fishing. In 1870 there was a complete wreck of the bottom, which could only be remedied by a total prohibition of the fishSimilar results oceries for several years.

From

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-
But the failure of beds
poned for some time.
in different localities may occur at any time,
and probably those of Chesapeake Bay will not
last many years. The deterioration and exhaus-
tion of our beds would cause great distress and
inconvenience in the United States, where the
oyster is no luxury simply, but a means of sup-
port to large numbers. Not only are oysters
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 process of reproduction, and the conditions influencing the rate of increase. For material employed here we are indebted to articles contributed 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 mixture 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 sandsloughs, 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 varieties 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 matter. 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 lightcolored reproductive organs and the darkcolored digestive ones, packed together in one The mouth of the oyster is continuous mass. is known as the "gills." that part nearest the hinge, and what is usually called its "beard 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 the mouth, by the action of myriads of small vibrating hairs, called cilia. These cover the surface of the gills, and cause a strong current to set into the lips of the valves, thus bringing in not only what is suitable for food, but other minute particles of matter.

The European oyster (Ostrea edulis) and the American oyster (Ostrea Virginiana) are varieties of the same family, and, though differing in several particulars, are not so dissimilar but that the conditions favorable to the growth and life of one may be considered as equally so for the other. With each variety the formation of the generative matter is gradual, and the spawning-season of both is during the early summer months, its advent depending probably

upon the temperature, the higher temperature hastening and the lower retarding that event. Generally, both in Europe and America, the spawning-season may be said to be from June 1st until August 15th, though variations of the temperature and density of the surrounding waters may expand or contract that period considerably.

All authorities upon the early stages of the European variety concur in the statement that the young oyster, or "spat," is formed by the fertilization of the eggs of the female while within the shell of that animal, and that the "spat" is held between the gills and thus protected by the parent until the shell is formed. Many authorities are also of the opinion that the parents are hermaphrodites; but the accuracy of this view is open to much doubt. The most material difference between the European and American varieties is in the manner of impregnating the eggs of the female. According to the best authorities, the eggs of the European variety are fertilized by the passage of the male fluid into the water, and thence between the valves and gills of the female. The young resulting from the union of the ova and spermatozoa are held and protected within the gills of the female until the shells are formed, and until they are quite well advanced in development, having at the time of their expulsion locomotive powers of their own, which enable them to swim about and seek a fit place for attachment.

The American variety differs in this, that the young oyster is not found within the gills of either parent, nor does the fertilization take place within the shell, but the contents of the generative organs of both sexes are expelled into the water, there to stand the chance of coming into contact. It is evident that a large measure of protection is afforded the young of the European variety by the inclosing shells of the parent, and that this protection is given during the most precarious stages of their existence, while the ova and spermatozoa of the American oyster are not only left to a happy chance for their successful union, but the resulting young are exposed, unprotected, to all the vicissitudes of climate, and to the ravages of all enemies.

After the formation of the shell and the development of the locomotive powers, the young of both varieties begin their search for a permanent resting-place or point of attachment. Such points of attachment must soon be obtained, or the young oyster perishes. Any moderately rough, hard substance, provided the surface is clean, is suitable for the purpose, and such objects, placed so as to attract the young brood, are called "cultch." Pieces of wood, planks, stones, old shells, tiles, etc., have been successfully used. Upon finding the "cultch," the "spat" attaches itself firmly, and thenceforward, so far as its own power is concerned, is located for ever.

The development is now one of ordinary

growth, the animal having passed through its embryonic life; its organs are formed and in active operation; it is but immature. The American variety increases more rapidly than the European. Observations during the summer of 1879 in Chesapeake Bay show that, in the first three months of existence, the oyster increases in size from a hardly visible speck to an average length of one and a quarter inch, and a few were over two inches long. After the first year the increase is not so rapid, and oysters of two or three years of age are about two inches broad and three inches long. In three years, at the most, the American oyster is considered mature. With the European variety the growth is much slower, and at maturity they are very much smaller than the American oyster.

With all animals Nature strives to provide against the destruction of the young after birth by insuring a sufficient number to allow for all ravages; and the greater the danger to the immature the larger will be the number provided to meet those dangers. Hence, as the embryo European oyster receives some protection and the American none, it is inferred that the number of American embryos in any community will be subjected to greater danger, and consequently it is probable that a larger number of eggs and spermatozoa are provided, that the production may not be less. Investigations seem to support this conclusion. Professor Möbius, in his work on the oyster and oysterculture, estimates the number of eggs spawned by the European variety as nearly 2,000,000, and his estimate is supported by Eyton, in his "History of the Oyster and Oyster Fisheries." Professor Brooks estimates the possible number of eggs spawned by the American variety to be as large as 60,000,000, and the average number to be over 9,000,000, or about nine times as many as the European variety spawns. The number of embryos surviving and matur ing can not be accurately stated for either variety, as we have not data sufficient to determine the question. The results, however, of Professor Möbius's examinations of the Schleswig-Holstein beds are valuable and suggestive. These were made by government officials from 1730 to 1852, in the following manner: Each bed was dredged over in three or six places, according to its size, and the oysters taken were divided into three classes, and carefully counted. The classes were styled marketable, medium, and young growth. The first were the full growth and mature, from two and three quarters to three and a half inches in length and breadth, and about seven tenths of an inch thick. The medium oysters were those half grown, from six to seven tenths of an inch thick, and about three inches in breadth. The young growth were those of one or two years old.

From these observations, made annually, Professor Möbius discovered that there were on an average 421 medium oysters to every

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