Francis Winslow

“ 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 with those shells find a final resting-place on the shell-heaps of the packing-houses. Nearly as many young are destroyed by being thrown from the dredging-vessels upon soft or unfavorable bottoms, no care being exercised, in the hurry and press of work, to see that the young are returned to the beds or other suitable ground. ”

“ The probability of all our beds arriving in time at the forlorn condition of the European oyster-banks has been foreseen, and Professor Möbius warns us of the consequence of our exhaustive fishery in the following words: "In North America the oysters are so fine and so cheap that they are eaten daily by all classes; hence they are now, and have been for a long time, a real means of subsistence for the people. This enviable fact is no argument against the injuriousness of a continuous and severe fishing of the beds. ”

“ Though we have no record extending over any length of time, and none of different localities, yet the observations during the summer of 1879 in Chesapeake Bay show that in the first three months of existence the oyster in that locality 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. The lower and attached side grows the most rapidly, and during this first period the growth is mainly in length; there is, of course, a development in all directions, but the greatest is toward the lips of the shell. ”

“ As the number of dredging-vessels employed directly in the fishery is, for a time at least, constant, it follows that, the larger the area open to these workers, the less exhaustive will be the fishery of any particular locality, for the fishermen will naturally seek the most productive fields for labor, and leave old and worn-out beds for those newly discovered and well stocked. Therefore, one of the best means of affording protection to the overworked beds is the discovery of new ones, as thus without prohibitory laws the fishery will be transferred from the former to the latter. ”

“ Upon finding the "cultch," the "spat" attaches itself firmly, and is thenceforward, so far as its own power is concerned, located for ever; all future movement and change of position are due to causes, natural or otherwise, over which it has no control.
The development now is one of ordinary growth, the animal having passed through its embryonic life; its organs are formed and are in active operation; it is but immature. The increase in size and the development of the different parts, or, in other words, the growth, are much more rapid with the American variety than with the European. ”

“ The "medium" oysters are considered by Professor Möbius to be those descendants of the "marketable" ones that have survived their most precarious years of existence and escaped their principal enemies, and are consequently likely to reach their full growth. They thus represent the total number of oysters spawned which have survived in the struggle for existence. From his experiments Möbius decides that about one million eggs are spawned by each oyster, and that about forty-four per cent, of the oysters on a bed spawn each season. ”

“ With the European variety the growth is much slower, and at maturity they are very much smaller than the American oyster: but this difference is immaterial to the question under consideration, and all that is necessary to notice is the consequence of the different methods of propagation.
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 dangers to which the immature of any species is exposed, the larger will be the number provided to meet those dangers. ”

“ The thousand mature oysters in the community would, then, spawn ten billion eggs, and, as the young European oyster has been found to spawn about one third as many eggs as the mature animal, we will consider the same to be true for the American variety. The five hundred young would, then, spawn 1,600,000,000 eggs, or the total number in the community would spawn 11,600,000,000 eggs, from which would result five hundred oysters, or about twenty million eggs or oysters would perish where one was preserved! ”

“ The beds should not be opened for fishing until the "spat" has acquired strength to resist the action of the dredge—until the end of January, for example. When a bed has well-established breeding qualities, a fourth or fifth part of its entire area should be set apart as a reserve, and dredging over such part entirely prohibited. A fishery guard-boat should, whenever practicable, take part in the working of each bed. When a bed is foul, or encumbered with weeds or other matter noxious to the development or adherence of the "spat," it should be opened for dredging until cleaned. ”

“ 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. The swimming period is of short duration, and the powers of locomotion are not very great; consequently, such points of attachment must soon be obtained, or the young oyster perishes. Any moderately rough, hard substance, provided that the surface is clean, is suitable for attachment, and such objects, when exposed for the purpose of attracting the young brood, are called "cultch." ”

“ The evil of excessive fishery then exists, and, continuing, can have but one effect, and we have seen how disastrous is that result. Our oyster-beds are, however, so extensive, the animals are so widely distributed, and are so easily transported and transplanted, that the total failure of the American oyster-beds must be postponed for some time. But the failure of the beds of different localities may occur at any time, and it is more than probable that those of Chesapeake Bay will be practically exhausted before many years. ”

“ Numbers send forth the products of generation at unfavorable times and in either an unripe or overripe condition, and some fail to void the fluids at all, but only unfortunate combinations of natural causes have those effects; and it is probable, if not absolutely certain, that in most spawning-seasons all the animals spawn. Dr. Brooks estimates the number of eggs voided by the American oyster at from nine to sixty millions; for convenience, we may take ten millions as the average number, which is probably less than what is actually the case. ”

“ 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. This separation and detachment of the groups of animals are much more noticeable upon a bed which has been much worked. Upon an unworked bed, or one in its natural state, the oysters grow in clusters, and are firmly cemented to the bottom. Upon a bed which has been frequently dredged, the animals are single, and have no hold upon the bottom. ”

“ In the locality which has been investigated an inefficient law is entirely disregarded. An oyster-guard exists, but pays no attention to the duties assigned it, and the fishery is governed solely by the demands of the market and the necessities of the oystermen. What should be done in this locality, now that the condition of the beds is known, will be apparent to any one ”

“ It is evident, then, that the vast number of eggs spawned by the oyster is no assurance that even a small proportion of them will reach maturity, or that any external or abnormal agency, natural or unnatural, may not be sufficient to destroy the beds by removing either young or old oysters, or in other ways preventing them from reproducing their kind. ”

“ If none of the oysters had been removed from the beds during the dredging-season of 1878-'79, we would have had, when the last season's investigation was in progress, about 259,000,000 more oysters on the beds than was actually the case, and of that number seventy-one per cent, were mature and spawn-bearing. Now, as sixty-five per cent, of those in the beds are mature, the addition of the 250,000,000 would increase the percentage to sixty-eight, or the young growth would be in a more hopeless minority than before. ”

“ If, however, the destruction of the mature oysters or the non-production of the young is accomplished by means that are harmful only to those individuals directly affected, a cause for the diminution is discovered in harmony with the existing facts. ”

“ As already pointed out, the mortality among the American embryo oysters must be much greater than among the European, and, in order that there might be some idea of the decrease in number and increase in size of our own variety when in the natural beds, there were deposited at various points in Tangier and Pocomoke Sounds, Maryland and Virginia, during the summer of 1879, a number of earthenware tiles as "spat"-collectors. ”

“ Without, for the present, going into the question of propagation, which will be subsequently discussed, it may be stated here that both male and female of the American variety of oyster expel the generative matter into the water, where the eggs must meet the male fluid in order to be fertilized. ”

“ 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, but the density is not important, except within wide limits, though the specific gravity should not fall below 1·01 at 60° Fahr., distilled water being represented by 1·00. 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. ”

“ But as the number of consumers increases in America the price will also surely advance, and then there will arise the desire to fish the beds more severely than hitherto; and, if they do not accept in time the unfortunate experience of the oyster-culturists of Europe, they will surely find their oyster-beds impoverished for having defied the bioconotic [2] laws. ”

“ The action of the dredge is very destructive to the oysters remaining on the bed. They are not only roughly detached from each other and from the different objects to which they cling, but are, no doubt, frequently left in such positions as will prevent the opening of the valves without allowing the entrance of mud or sand, and thus insuring destruction. ”

“ It is only possible to speak with entire accuracy of a limited portion of the entire area covered by oysters in these States, but, as the influences affecting the beds are very similar, it may be assumed with safety that the condition of the beds of one district will be, approximately, that of all; at least, it is certain that beds or localities presenting like peculiarities will be in a similar condition as regards reproduction. The only locality in this country which has been thoroughly studied lies on. the eastern shore of Chesapeake Bay, opposite the mouth of the Potomac River. ”

“ Stones, ballast, old pieces of earthenware, water-pipes, and old shells form excellent cultch, and, if any of these are scattered about the beds, a good catch may be confidently expected. Care must be taken to deposit the cultch upon those bottoms sufficiently consistent to support it, and also to make the deposit upon such areas as lie in the direction of the tidal currents, so that the young brood, rising from the natural beds, may be carried over the newly exposed cultch. ”

“ The beds in the sounds were soft and easily penetrated. The dredge took the oysters readily, and without great effort. There was much mud among the oysters, and the amount of old broken shells and other débris was quite large. It is evident that in any community there must be in the life of a given generation a depletion of number in each successive stage of existence, or, in other words, as the age of the generation increases, the number of individuals decreases. ”

“ Since 1866 the beds have become so impoverished, from the excessive and continual fishery, that in 1876 only forty men and less than forty boats could find employment, and, small as that number is, they could not take more than sixty or one hundred oysters a day, while formerly, in the same time, one boat could take from ten to twelve thousand. ”

“ An organized and systematic effort to discover new beds and to extend the old ones. Continued experiments, in order to ascertain the possibility of artificially raising the oysters in sufficient numbers to restock impoverished areas. The maintenance of a commission to have charge of all matters pertaining to the fishery—the commission to be composed of intelligent men, having special knowledge of the subject and allowed considerable power, and to be so appointed and constituted that their acts will be influenced by no considerations other than those for the good of the beds. ”

“ To cause, then, either an increase or diminution of the number of oysters or the size of the bed, a new factor must be brought into operation, when, all conditions being changed, the life of the animals begins anew and progresses differently. ”