Popular Science Monthly/Volume 44/November 1893/The Conservation of our Oyster Supply
|THE CONSERVATION OF OUR OYSTER SUPPLY.|
By ROBERT F. WALSH.
OYSTER culture, properly so called, the production of spat by aid of artificial methods, has never been resorted to in this country," And "as the scarcity of seed is one of the greatest difficulties now encountered by the oyster planter, this subject offers an interesting field for investigation."
These statements occur in the Report of the United States Commissioner of Fish and Fisheries for the year ending June 30, 1889; and as the propagation of spat by artificial means has not been resorted to since that time, it will be interesting to examine the general conditions of our oyster supply, and, from ascertained results in foreign waters, consider whether or not such methods would tend toward restocking our depleted oyster beds, or economically increasing the oyster supply.In the consideration of this subject it will be well, first, to give a brief, general account of the conditions of the existing, working, and outworked oyster beds; and, having ascertained these conditions, as nearly as possible, and made some necessary comparisons, we can more easily consider the advisability of raising spat by artificial methods. The natural oyster of America can not continue to be produced in such abundance as we have been accustomed to find it. The beds of South Carolina have practically given out; the famous oyster beds of Maryland and Virginia—in the Chesapeake Bay region, which Captain Collins calls "the most important oyster region of the world"—are being so depleted of oysters that the "gravest apprehension" is caused as to their future; and only in Connecticut has there been a marked increase, both in the acreage of oyster beds and oyster production,
Fig. 1.—Oyster Flat in South Carolina showing Extent of Raccoon Area
and in the methods, number of persons, and capital employed for the building up of the industry.
In the present conditions an oyster famine is not a far-away nor impossible contingency. We have been large consumers of oysters, and we did not sow where we had reaped. Luckily, this condition of affairs attracted the serious attention of the United States Fish and Fisheries Commission ; exhaustive investigations were made, and finally, in the autumn of 1891, Mr. Bashford Dean proceeded to France, under instructions from the United States Commissioner of Fish and Fisheries, and there, at the great French homes of oyster culture around Arcachon and Auray he examined the French methods of artificial culture, his obser- vations being chiefly made so as to be as pertinent as possible to the conditions of American waters. I can not, however, agree with some of the statements which Mr. Dean makes in the intro- duction to his report. He says that, considering the condition and methods of oyster culture in France, it is apparent that in this country "all costly methods of cultivation could have proved of little practical value." Prof. W. K. Brooks, Mr. E. C. Black- ford, and other authorities are positive in their statements to the contrary. For instance, in his report to the Legislature of New York State, in 1887, Mr. Blackford says : " The rapid deterioration of the natural growth of oyster beds . . . has made it absolutely necessary that the artificial propagation of the oyster should be encouraged to prevent its entire extermination. But, as it will be necessary to enter into this subject more fully later, I shall now briefly examine the general conditions of the industry as it exists to-day, making short historical and comparative allusions as I proceed.
Taking the oyster beds in the order in which I have placed them, we shall first examine those of South Carolina. " The en- tire coast margin " of this State is well provided with natural beds; but, says Mr. Dean, "they are strangely unlike the natural beds occurring further northward." In this region the oyster is found on the margin of the shore in positive reefs, part of which are at low tide exposed so that the oysters live almost "as much in the air as in the water." These ledges are formed of curious clusters those oysters which are on the top being called ""raccoons," because of their peculiar shaj^e. These oysters can barely be said to live, and are in their present condition utterly unfit for the table.
Prof. Ryder says that the cause of this peculiar clustering is that, because of the muddy and unhealthy condition of the bottom in the deeper water, the oysters of South Carolina cling to the shore line and there build upon one another, generation after generation, until sometimes ledges are formed over ten feet in
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height. This crowding together prevents individual develop- ment, and consequently millions upon millions of oysters are lost to the people of this country in this one State alone. That the " planting " of " raccoon " seed in the deeper waters for cultiva- tion would be profitless is shown by the natural growth of the oysters themselves in the marginal waters. They would soon become asphyxiated in the soft, silting mud bottom which occurs along the entire coast line of this State. But it has been demon- strated that, under almost as unfavorable conditions, excellent and healthy grounds could be prepared at comparatively slight cost, as has been so successfully done in Connecticut ; and Mr. Dean shows conclusively that the " raccoons " might be scattered in "marginal waters about a fathom in depth," with an almost certain prospect of successful development. Curiously enough,. in his article on the Biology of the Oyster Grounds of South Carolina, he advocates the artificial collection and rearing of spat.
There are miles upon miles of these "raccoon" ledges, and even islands which have been formed by the " raccoons," upon this part of the coast ; they contain enough seedlings to stock the entire Atlantic coast, and a very little enterprise or judicious State interference would undoubtedly restore to South Carolina and the oyster-consuming population of the United States what must have been in ages past one of the most prolific natural oyster beds of the world.
The conditions in Chesapeake Bay are much more favorable than those which we have just considered. Here Nature has created, as Captain Collins has truly said, the most perfect oyster ground in the universe. But, as is the case with the prosecution of many other fisheries, man either in his greed or ignorance, or both has outraged a bountiful Nature by continuously fishing for the oysters without replanting, and as a consequence this remarkable oyster region is becoming rai)idly less important.
In his report, Captain Collins accounts for the recklessness of the fishermen and oystermen in this way: "The general belief (in the Chesapeake Bay region) has been, that the natural wealtli of the oyster beds is inexhaustible,'" and that, " trained from child- hood to look upon the oyster grounds as their patrimony, ... it is perhaps not remarkable that the fishermen of the Chesapeake have bitterly, and to this time successfully, opposed all attempts at legislation intended to convey proprietary rights in the grounds."
Illustrating their reliance upon Nature, the report just re- ferred to quotes the following paragraph from a local publica- tion : " The value of the oyster business alone to southeast Vir- ginia is nearly $2,500,000 per annum. It is a crop constantly harvested, except in the months of May to August inclusive, and
Fig. 2.—Raccoons Clustered on the Piling of a Wharf at High-Water Mark. Sullivan’s Island, South Carolina.
Fig. 3.-An Oyster Ledge, Showing Living Raccoon Oysters Fringing the Water.
is as constantly replenished by the bountiful hand of Nature." I have already shown how this same greed and ignorance of the Chesapeake oystermen have jeopardized not only their oyster supply but also their means of livelihood.
As a matter of fact it is in this erroneous assumption that lie the truth and reason for the apparent diminution of not only the oyster supply, but also the supplies of other fish food in our waters. Nature distinctly claims her rights when she demands that we must sow where we have reaped ; and in this lies the true axis for the more satisfactory revolution of our fish and other food products.
I shall now pass to the third oyster ground which I have mentioned, and shall more pleasurably outliiie the prosperous conditions existing in Connecticut. Prior to 1784 no restrictions were placed upon the oyster fishery of this State ; it was perfectly free, and as a consequence the beds soon became depleted. In that year the Legislature passed an enactment empowering every, town of the State " to make rules and ordinances for regulating the fisheries of clams and oysters within their respective limits."' This, however, did not materially aid in rehabilitating the beds; but the law continued in operation for seventy-one years 1855 when, the condition of the oyster grounds was so poor, a law was passed enabling private individuals to obtain two acres of ground for the cultivation of oysters. This was the first step in the right direction. The private owners discovered that, instead of plant- ing small oysters, they could collect spat artificially on shells and other objects ; this discovery " led to an extension of deep-water planting," and it was undeniably the source of the present pros- perity of the Connecticut oyster fisheries.
Captain Collins says that at first the planting was confined to shallow waters; but, in 1865, many beds were planted "in as much as twenty feet of water." And so the development in- creased until 1874, when steam was introduced for dredging. In 1881 additional legislation became necessary, in order to enable the owners of private grounds to enlarge their territories, as they complained that the cultivation of oysters in deep waters re- quired much additional and costly apparatus. And since that time the number of acres of oyster grounds owned by individuals according to the Connecticut State Shellfish Commission has increased from 33,987 acres in 1881 to 70,132 in 1889, of which 15,400 were planted. Apart from this calculation there are 19,911 acres of public oyster grounds which, however, can not be dredged by steam.
In 1889 the value of oysters from natural beds amounted to only $31,305, whereas the yield of the cultivated beds was sold for $1,040,372. So that, if Connecticut relied upon her natural beds,
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as do they in Maryland and Virginia, her oyster fisheries would have been a practical failure, as they threaten to be in the Chesa- peake, unless there is si)eedy and judicious State legislation.
As a matter of fact, the present condition of affairs in the Chesapeake points ominously to a not far distant apj^eal from the fishermen of that region to the General Government to assist them in rehabilitating their oyster grounds. Such a contingency is at all times best avoided ; but in this case I have shown, by comparison, that all that is needed in the Chesapeake region, to insure a renewed prosperity of the oyster fishery, is judicious State legislation in the direction of conveying proprietary rights to individuals or companies for the purpose of planting and culti- vating the oyster. This plan has already been attempted in the Chesapeake, but has so far been successfully resisted by the fish- ermen. The prosperity of the Connecticut fisheries is entirely owing to the State enactments conferring proprietary rights ; and there can not be a doubt but that similar legislation in Maryland and Virginia would bring about a return of prosperity to the Chesapeake oyster fisheries.
The usual method employed in Connecticut for the collection of spat is to first clean the ground by dredging and then cover it with shells, to which the spat will adhere, nearly 7,500,000 bushels of shells being used for this purpose during the past five years. " It is estimated that twenty-five or thirty adult oysters produce enough eggs each season to equal the annual product of Connecti- cut waters." So that, were it not for the starfish and other ene- mies which infest this coast, the supplies of food oysters would out- rival in quantity the hundreds of thousands of acres covered by the now useless " raccoons " of South Carolina. No judicious ex- pense is spared to make the oyster beds of Connecticut prolific : if they are too muddy, as are those of South Carolina, they are easily " made," by placing one hundred to two hundred tons of gravel over each acre, and the report of the commissioner states that " this system has produced excellent results."
Of course, there are other oyster grounds on the Atlantic coast besides those which I have mentioned notably the famous Shrewsbury River beds; but they are not so extensive, nor do they so particularly affect the question, by comparison, of the ad- visability of adopting artificial propagation. And now, having briefly explained the conditions of our oyster grounds, we are brought face to face with the statement which prefaces this arti- cle, namely: "As the scarcity of seed is one of the greatest diffi- culties now encountered by the oyster planter," would the propa- gation of spat by artificial means i)rofitably assist in rehabilitat- ing our depleted grounds ?
As I have already mentioned, Mr. Blackford not only thinks
Fig. 4.—Starfishes Destroying an Oyster.
Fig. 5.—Young Oysters (Three to Six Months Old) Set on Shells and an Old Rubber Shoe. From a photograph.
so, but says that the artificial propagation of the oyster " is abso- lutely necessary to prevent its " entire extermination." In a re- port to the General Assembly of Maryland in 18S7, Prof. Brooks also advocates the introduction of artificial propagation in these waters ; Captain Collins suggests that such an experiment would be valuable ; and Mr. Dean says that, although in this countrj^ " all costly methods of cultivation could have proved of little practical value, . . . enough has been said in this connection to show the necessity in practical oyster culture of collecting spat on floating collectors and of allowing it to attain, before planting, a considerable size." And notwithstanding all this testimony, Mr. Richard Rathbun, in the Report of the Commissioner of Fish, and Fisheries for the year ending June 30, 1889, tells us that "the production of spat hj aid of artificial methods has never been re- sorted to in this country, in consequence of the fact that the prac- tical utilit}^ and economy of any proposed system has yet to be established." I should have thought that this matter could have been long since determined at the hatchery at Cold Spring Har- bor, where, I have learned, such experiments have been success- fully made. But, as the artificial propagation is not generally understood, and as it is extremely interesting, I shall briefly ex- plain the most successful and general method employed in France ; and I believe that the most obtuse reader will then see the feasi- bility of carrying on similar operations here.
The collection of the floating spat upon pieces of wood and stone is said to have been discovered by M. de Bon, Commissaire of Marine at St. Servan, France, in 1853 ; and we know that, when he announced his discovery, the matter was " at once taken up most enthusiastically by M. Coste," Professor of Embryology in the College of France. They undoubtedly drew public and scien- tific attention to this all-important branch of oyster culture ; but I find that several years before the discovery of De Bon, the oys- termen of the East River, New York, had not only made a simi- lar discovery, but that they conceived the idea of utilizing it, and used tiles (a recent invention in French oyster culture) for collect- ing the spat, which they planted in the river and sound. Fur- ther, and in circumstantial proof of the statement, it is a fact that in 1855 the year when De Bon made his discovery the Legisla- ture of the State of New York enacted a law " to preserve to the private (oyster) farmers the fruits of their labor."
I am chiefly indebted to Mr. Bash ford Dean's report on the Present Methods of Oyster Culture in France for the following' brief description of the artificial propagation of the oyster in that country : The manner in which the spat or swimming oyster fry is obtained is very simple. Culturists place arched tiles, woodentrays, and other materials in the neighborhood of the natural
Fig. 6.—Oyster Dredging in Long-Island Sound.
Fig. 7.—Tile Collectors.
the tile until October, when they have attained "about the size of a finger nail." The tiles are then carefully placed upon lighters and floated ashore, where the seedling oysters are detached from them "by short pushes of a chisel-like knife." The spat usually
Fig. 8.—Wooden-Tray Collectors.
averages on moderately clean ground about four hundred per tile, but as many as two thousand have been counted on one tile of fourteen inches by six. The seed oysters having been removed from the tile or wood "collectors," they are taken to the low-water line and arranged in flat wire-gauze rearing cases, which "lift from the bottom and prevent the young from being stifled by the shiftings of mud; it also renders the growth regular and rapid, and, above all, it protects the oysters from their enemies," the starfishes, drills, etc. "During the first few months rapid growth renders it necessary to pick out each fortnight and transfer to other cases the largest oysters." This is generally done by women, who at the same time take out the dead shells. And so the process goes on
Fig. 9.—Wooden Trays in Position on Macadamized Bottom.
until the oyster is sufficiently grown for table use, usually two to three years.
Sometimes the river banks or beaches selected for the oyster-developing cages are soft and muddy; and here again the French culturist teaches us a lesson. He is not deterred by the unsuitable bottom; he at once macadamizes it with sand and gravel, giving a crust that is clean and serves admirably for cultural purposes.Another method for collecting spat is in enclosed ponds provided with spawning oysters. Flood gates prevent the escape of the water, which is kept at "an average depth of about four feet." The same style of "collectors" that are used in the open sea "parks" (as each individual's holding is called) are used in these
Fig. 10.—Examining a Tile covered with Oyster Spat.
ponds; but the result in the latter seems to be much more satisfactory. The pond, having been macadamized, is first thoroughly dried "for two months, . . . doing away with all animal and plant
Fig. 11.—Disengaging Seed Oysters from a Tray Collector.
Stringent regulations governing the dredging of the French natural oyster beds have succeeded in rehabilitating the depleted
Fig. 12.—Cases for rearing Seed Oysters at Cancale, France.
Fig. 13.—Sorting the Growing Seed Oysters at Arcachon.
This scene is precisely similar to that which takes place at the opening and closing of the great sturgeon fishing of the Don Cossacks in southern Russia, which I described, in an article on Sturgeon Fishing on the Don, in 1800.
Fig. 14.—The Celebrated French Oyster Park at Breneguy.