Popular Science Monthly/Volume 87/July 1915/Water Conservation, Fisheries and Food Supply
|WATER CONSERVATION, FISHERIES AND FOOD SUPPLY|
By Dr. ROBERT B. COKER
U. S. FISHERIES BIOLOGICAL STATION, FAIRPORT, IA.
A National Problem
NO subject of national economy has broader significance to-day than that of water conservation. Every one knows that unrestrained floods wreak yearly an enormous destruction of property. Our flood losses have, indeed, been computed at 200 millions of dollars per year. All are aware that the demands of power are contributing to the gradual exhaustion of our coal deposits, while the possibilities of deriving power from the flow of water remain at our grasp. A single water power of recent development has been estimated to effect a yearly saving of 365 thousands of tons of coal even at the very outset of its operations. Every intelligent conservationist, whether farmer, business man or student, observes that over the country-wide the soils are being impoverished by the wash of surface waters, and the fertile lands are being carried away to enrich the sea. If we seek figures again, we are told that one and one-quarter billion tons of silt are deposited annually in the Mississippi River, one half of which serves to impede navigation and the other half to extend the state of Louisiana out into the Gulf of Mexico. One who has observed the soils of the middle west in a state of productivity, and again the same or similar soils in the form of useless and rapidly broadening flats at the tip of the delta of the Mississippi, can not but be deeply impressed with the ultimate wastefulness of permitting the transfer of soils from a place where they are useful to a place where they are injurious.
If we view only the most obvious losses, we begin to realize the significance of water conservation; but still we may be far short of comprehending the magnitude of the forfeit that we regularly pay for an inadequate policy or practise with regard to our supplies of water. While agriculture, and consequently the flood supply of the future, may suffer from the erosion and leaching of soils, economists assure us that there are immense areas of farming lands which are diminished in production, because at the critical season they lack the moisture that might, with different methods of tillage, have been conserved in the soil from the time of water surfeit. Again, while rivers become torrential and destructive, submerging valuable farming lands and taking a toll of property and lives, yet, because the spring waters were allowed to pass quickly away unstored in soils or reservoirs, these same streams at other periods are found to be so restricted in volume and so checkered in course by accumulated drift that the pathways of natural transportation are more or less effectively closed.
It is clearly within reason to say, then, that no other form of material waste can be measured against the stupendous aggregate resulting from the failure to conserve and control and utilize the available supplies of water. It is easy to understate the importance of water conservation, while overstatement would almost seem beyond our powers. Water-power development and the conservation of coal deposits, soil conservation and the reclamation of arid and semi-arid lands by irrigation or by "dry-land" methods, reforestation and flood control, reclamation of overflowed lands and maintenance of inland waterways, stream pollution and fisheries—these several objects, each of great importance by itself, are all, in large measure, aspects of the one comprehensive problem. Each of these admitted obligations has a direct relation to our duty of storing the available water supply in soils or in reservoirs, of regulating its flow from source to sea, and of utilizing it to the maximum at all stages, for power and navigation, for farms and forestry, for sanitation and fisheries. Stated in this way, with all its manifold bearings, the general problem may assume an exaggerated appearance of complexity. Surely water conservation is broad in its relations, and surely its complete realization will not be attained in a day or in a generation, and yet the stages of the solution of the entire problem may be just such matter-of-fact steps as we are repeatedly taking in the ordinary course of practical progress.
Fisheries have been named just above as related to water conservation. The relation might be obvious and yet insignificant: this may be called the prevailing impression. Fresh-water fisheries have been practically entirely disregarded in connection with the conservation of water; nevertheless, it can, I believe, be made apparent, first, that the possibilities of food-supply from fresh-water fisheries in public waters will be realized only as water conservation becomes a reality, and, second, that the proper development of fish-raising as a principal or incidental occupation may, in a very practical and simple way, promote the general object of water conservation.
Fisheries, a Matter of Concern
It is not very difficult to understand why the fisheries so rarely receive mention in discussions of water conservation. In the general mind, fresh-water fisheries do not rank with the bases of industry so much as with the means of recreation. Some industries assert themselves by figures, but, in the way of statistics, the fresh-water fisheries have not the striking appeal of established agricultural industries: statistically speaking, we can not now compare fish with potatoes. Primarily, however, people do not think of fisheries in connection with water conservation, because it is not generally understood that the two have a connection worthy of consideration. It is worth while to inquire if there is a relation of real significance.
The value and the meaning of the fish resources to the people of the United States depends upon the contribution of an important element of food supply and the offering of a peculiar field of recreation. Perhaps, in the mind of the average man of this country, the one benefit would be regarded in equal measure with the other. This is not an inevitable or universal condition; it is an incident of the present state of the fishery. There are countries where the taking of fish for sport is almost unknown, but where the fish resources are regarded as of vital moment to the welfare of the people, and where the capture and the preservation and the distribution of fish are industries that are recognized to be of elemental importance, in similar fashion to agriculture. In many other counties fish forms much more of a staple food than with us, and a far larger proportion of the people find a livelihood in the fishery industries. Our people are not essentially different from others in their appetites and bodily needs.
The basic claim of fisheries to public recognition rests upon the part that fish must play in the future food supply of the country; but how is it to be said what this future part will be? Certainly the future is not to be measured by the present. We know that the fisheries of our principal streams are in a state of depletion except in rare localities, and we know, though we are much less conscious of this fact, that the compensatory development of commercial fishery resources in the rivers, by artificial propagation or by other well-directed means, is relatively slight. Nearly all of our thought, all of our energies, all of our expenditures, have been directed to promote the abundance of game fishes, and perhaps we might have to confess that we were thinking not so much of providing something to eat as of supplying something to catch.
A little reflection, a little common sense, will suggest to us that neither the present nor the past condition of the interior fisheries foreshadows the future. As our country becomes more thickly populated, as the capacities of the lands become more and more severely taxed, as the prices of meats mount higher, it is inevitable that we shall look more to the possibilities of our waters to supply us with food. The true fish conservationist should look forward to something more than the preservation or the protection of existing fisheries: in fact, his ideal may well be a development of fishery resources that is now scarcely conceived in the public mind. We do not want, in fisheries, a restoration of the past, but the inauguration of a future.
Floods and Fishes
On every hand there are explanations of the diminution of the number of food-fish of the rivers; but surely this can be ascribed only in part to the causes of over-fishery or to other direct acts of man. One ultimate explanation, it may be confidently stated, will be found in those very conditions which have indirectly affected the flow of our great streams in so disastrous a way as to create a demand upon the government for the storage of waters and the regulation of the flow of streams. Deforestation, denudation, drainage—to these causes, among others, are ascribed the extreme flood conditions ensuing upon the development of the country, and to these likewise may be attributed a significant change in the condition of our rivers as bearing upon the natural reproduction and sustenance of fish.
The occurrence of spasmodic floods, of comparatively short duration and separated by intervals of extreme low water, have a deleterious effect upon fish life in manifold ways. The first realization of this fact comes with the observation of enormous numbers of young fish left in the overflow ponds isolated by the recession of the flood. The significance of the observation is not in any way grasped if we suppose that these innumerable fish were simply carried out by chance and left by a similar chance. The real phenomenon is this. The flood occurred when the breeding fish were seeking the shallow and warmer waters for the location of their nests and the deposition of the eggs. When the young from these eggs, together with the adults, are left to starve and suffocate and die in the disappearing or diminishing pools, we see, not the loss of a random proportion of the fish life of the stream, but the actual decimation of a generation. Consequently, it should be esteemed of high importance to reclaim and restore to the rivers the fish thus abandoned otherwise to destruction. Such overflow ponds are now, to be sure, a common source of supply for government and state departments seeking fish for general distribution. It is better that the "lost" fish should be used for some good purpose, rather than left to die, but, that our impression may not be confused, it should be remembered that the conservation of fish in the particular stream is regarded and promoted only in so far as the greater part of the fish are returned to the river, and this is done in some cases.
It may not and does not always occur that the flood comes just before the fish have begun to nest. It may occur while the eggs are yet unhatched, and where they have been placed in favored locations along the shores of the streams at low stage. We may then only guess at the destruction which must ensue when the entire condition is suddenly and drastically altered by the untimely arrival of the flood. Clear shallow waters, warmed by the sun, are in a brief space of time replaced by deep and turbid torrents, and the very banks and bottoms are torn away or displaced. To fish life another catastrophe has occurred.
It will not be maintained that any practicable scheme of control, however comprehensive, will prevent altogether the occurrence of high and low stages, but it has been attempted to show that the regulation of the flow of rivers has a very direct relation to the reproduction of fish.
Without successful reproduction we certainly can not have fish; but the abundance of fish, even under natural conditions, does not depend alone upon successful propagation. The young fish must survive and grow, and for these ends their requirements are similar to those of other animals, namely, food and oxygen, principally. Likewise, just as in the case of other animals, the food is derived ultimately from the essential chemical constituents through the intermediation of plants. The rains that wash the soils bring the needed constituents into the streams, but not necessarily in a form available for animal life; for them to become available requires time, sunlight and vegetation.
It is clear that excessive turbidity and extreme conditions of flood have the most direct bearing upon the conditions of food supply for fish. Not only is this the case, but extreme low stages may have a highly deleterious effect. The first result of the decomposition of organic matters brought into the water is the exhaustion of the oxygen supply, and this may proceed to such a point as to make the environment distinctly unfavorable for any form of aquatic animal life. The beginning of mortality among the animals, whether smaller or larger forms, by adding to the amount of decomposing material, only serves to increase the rate of deoxygenation of the water and to accelerate the course of destruction. Such a catastrophe can be checked or restricted as to its duration or territory of action only by the development of sufficient plant-life to effect a restoration of equilibrium, or by the diluting and cleansing effect of an increased flow in the stream. Some of the instances not infrequently reported of enormous mortality of fish in portions of rivers just below cities and in times of low water are most certainly due to this very fact of a disturbance of the established equilibrium between sewage, plants and animals, with a consequent mortality that is self-accelerative to the point of inducing a conspicuous catastrophe.
Conservation of Favorable Environments
There has been developing in recent years almost a new science which deals with the gas-content and the chemical analysis of water, as affecting the value of the water as a habitat for animal life. Surprisingly interesting observations and inferences have been made, but nothing has been learned to gainsay the statement that, to realize anything like the potential abundance of fish-life in our streams, it is necessary to approach more nearly to a condition of stable equilibrium. The primary difference between a natural stream or pond and an artificial fish-cultural pond is that in the latter the conditions are relatively stable and subject to a degree of control.
It is not to be supposed that water-power development has no relation to fisheries except as expressed in the presence or absence of a fishway. It may be inferred from what has previously been said that artificial pools at intervals in the course of a stream, entirely apart from the question of fishways, may bring substantial advantages in providing relatively extensive feeding and breeding grounds for fish, in affording conditions of relative stability, and in tending indirectly to make more uniform the conditions prevailing in the streams below or between the pools.
It becomes increasingly clear that all matters affecting the flow of streams have the most vital bearing upon the promotion of fishery resources, as touching reproduction, nourishment and respiration.
The artificial propagation of fish, even under present conditions, is producing results of significant value; but it is no disparagement of such operations to venture the prediction that the future will show that the effective conservation of fishery resources depends upon the coupling of intelligent fish-culture with comprehensive and well-advised conservation of the environment favorable, both to the natural propagation of fish and to the multiplication of the essential elements of food supply.
The requirements of reasonable brevity prevent our enlarging upon the relation of fisheries to the various other phases of the general scheme of water conservation. Just a few suggestions may be ventured. It has been advocated in at least one state that the reclamation of over-flowed lands should be so administered as not to eliminate entirely the favored breeding grounds of many species of fish. It would seem possible so to coordinate the two objects of retaining "fish-preserves" and providing lateral storage basins for flood waters as to promote simultaneously the conservation of fish and the prevention of floods.
In the irrigation fields of the west, it appears that there is not only a neglect of the possible advantages for fish life, but an unfortunate waste of the existing fish resources, owing to the want of suitable protecting screens in the irrigation laterals. The opportunities and the needs are not, however, unrecognized, and the subject receives serious consideration in some of the states concerned.
Stream pollution by sewage or industrial wastes has the closest relation to fishery problems. Under some conditions a degree of stream pollution may prove distinctly favorable to the abundance of fish: in other cases it is unequivocally injurious. If the matter is one of significance to the fisheries, it is certainly true, on the other hand, that the problem of stream pollution, in its phases of ordinary interest, can not be studied to a definite conclusion except through analyses of the effects of the pollution upon the living aquatic organisms. This is to say, that the study of the sanitation of our streams involves the investigation of the effects upon fish or upon the organisms constituting the food of fish.
The dredging of channels and the construction of wing-dams as aids to navigation exert an unmistakable influence upon the distribution of fish and affect the fortunes of their existence in more or less obvious ways.
The conservation of water upon the farm remains for our consideration; but, if we may be permitted to draw a conclusion at this stage, it is this:—Whether we deal with head-water reservoirs for the regulation of stream flow, with water-power development and the incident pools, with reclamation or irrigation projects, with the dredging and damming for navigation purposes, or with stream pollution by any means, we find a vital relation to fishery problems and to fish-cultural operations. We find also a real necessity for the accumulation of a sufficient store of knowledge regarding the habits of fish, their requirements for feeding and breathing and breeding, and how these requirements are affected by the conditions that may prevail in our streams, lakes and ponds. We need, in short, an effective fishery science.
Water Storage and Fish Culture
We have already expressed the belief that the relation of fishery development to water conservation is not one of dependence only, but one of reciprocal benefits as well. It must be clear that we are speaking of development, not by protection, but by conservation of fish, with all that the term may imply. The word itself is unavoidably repeated frequently in such a discussion, because "conservation" alone seems to embody the whole thought of increase in supply along with development in utilization, as opposed to hoarding or restriction in use.
Could we think of an agriculture based upon protective measures? Could we imagine a modern nation dependent upon corn and cattle and poultry growing wild? Suppose a series of limitations for the perpetuation of crops and stock-yield, similar to the familiar measures for the preservation of fish or game; no scythe to have a blade more than 3 feet long, no individual to take more than 500 ears of corn per day, or to kill more than 10 pigs or 5 sheep or 2 cows per year. The very suggestion has a touch of absurdity: and yet such is the present stage of our civilization or industrial life, as regards the utilization of fish. Not only may we question if this condition is permanent and inevitable, but we may be sure that the time will come when we will want fish to eat much more generally than now, and will get them by raising them in a larger way than is now done. We may have a familiar science of aquiculture just as we now have one of agriculture. It is interesting to note that, at the present time, there are sections of the country and classes of people for which fish forms a really staple food. This demand is so reflected in the commercial fishery that the coarser fishes, which, only a little while ago, were regarded as entirely superfluous or obnoxious, have become the mainstay of the commercial fishermen. It is still more interesting to observe that, among all classes of people, there is a noticeable awakening to the value of fish, and, concomitantly, a tendency to inquire if there is not some way to increase the supply of good table fish.
Let us now imagine that a great impetus could be given to the rearing of fish for table use as an occupation or as an adjunct to ordinary farming operations, until the fish pond were half as familiar as the poultry yard, and then let us inquire if there would be any effect upon the matter of water conservation.
The objects of flood prevention and navigation may be furthered in a temporary way by the construction of levees, by restriction of channels, and by dredging. All of these menus are good; in fact they are essential for immediate relief; but the final accomplishment of the desired ends must be sought in the regulation of the flow of the rivers, and this undoubtedly will come about through the conservation of water at the sources. We sometimes think of this as being possible of attainment only by the construction of large artificial storage reservoirs at enormous expense, and often such a plan is called impracticable. Leaving that question, as we must, to the engineer, we may look to other and smaller measures which are certainly not impracticable. Smaller measure, we say, but we know that the cumulative effect of innumerable small efforts may in the long run be vaster than that of more spectacular and expensive operations.
It is said that much can be accomplished by the proper methods of tilling the soil to prevent run-offs and to compel the filtration of the rainfall into the soil. We are told of large farms that are so worked as to prevent any water at all running off the farm, while at the same time increasing the productivity of the farm with its cultivated fields, grazing lands and forests. The methods are said to be simple and inexpensive, but an inquiry into them is apart from our present purpose.
Besides increasing the absorbent qualities of the soil, there is something which almost every farmer can do, that relatively few now think worth while. He can make one or more ponds in which much of the surface water is caught and stored for the subsequent use of his animals, and he can stock this pond with fish for domestic use, or for the market.
On the one hand, what a considerable addition to the food supply of the country would be found in such productive ponds. We are told of the fabulous wealth represented by the American hen, and so it may yet be with the American catfish, the buffalo-fish, the sunfishes, or the bass. There is much to indicate that one can raise fish with less trouble and with as much profit as one rears poultry.
On the other hand, if one third of the 6,000,000 American farms had one or more fish ponds, what an enormous amount of water might be temporarily stored in these. It would seem that a positive step of some value would have been taken to prevent the destructive floods, to make more uniform the flow of streams, and thus to better navigation and to keep the soil waste upon the farm. "A fish pond for every farm" might yet become the watch-word for every advocate of improved navigation, flood prevention and soil conservation.
Some Practical Steps
It should not be presumed that a fad is proposed or that a simple nostrum is advocated for the immediate accomplishment of nation-wide benefits. Avenues of progress may be opened without calling for a headlong plunge into them. The incline is upward and probably beset with a common number of obstacles and pitfalls. On the one hand, if fish conservation in public waters can be promoted by broader and more positive efforts than are now generally made, it is necessary that thought and investigation should be applied to distinguish with certainty the ways that are right from the ways that are wrong. On the other hand, if increase of fish through private enterprise is practicable and appropriate, the movement will be but faintly advanced by the mere waving of a banner or a summons to the line. The imprudent are easily induced, but in the field of industry, the better recruits are the wise who look for plans and specifications and consider costs and possible returns.
There are many persons now seriously interested in fish rearing and who want to start a fish pond, or, having one, to make it more productive. They ask for information as to the fish and the conditions; but, at the best, the practical data that government or states can give is meager as bearing upon the questions raised. Few efforts for public service would be so apt and so inexpensive in proportion to probable return as the systematic dissemination of information bearing upon fish farming: but the data must be based upon judicious and continued experiment under conditions such as would confront the prospective fish farmers.
Doubtless a great deal of experience has been gained by private persons with interest and initiative, but there has been lacking a clearing house. There are valuable bits of information isolated or scattered and wanting for complete fruitfulness the benefits of interchange of experience, coordination and compilation. It would be practical indeed if the persons interested in effective fishery development would form themselves into associations, limited in territory by the similarity of conditions and problems as well as by the requirements of distance. The advantages to be gained would be palpable; there would be not only a fruitful interchange of ideas and experience, but a more explicit definition of difficulties and problems, so that the public department whose responsibility is to serve would be enlightened as to the form of service required.
The present purpose is fulfilled if the meaning of fish conservation is made clearer, and if the science of fisheries has been related in an unmistakable way to the vital interests of our whole people. The fish conservationist should orient himself with reference to some of the multitudinous phases of human interests and endeavors, and it is equally desirable that his orientation should be understood. One may look far over a landscape with the feet yet firmly upon the ground. A distant goal is not usually to be reached except by a succession of well-ordered steps, but perhaps it is also true that the farther the vision extends, the more readily may the steps be well ordered to the desired end.
- Published by permission of Dr. Hugh. M. Smith, United States Commissioner of Fish and Fisheries; the author alone is responsible for the opinions expressed.
- Wall, Judson G., "Flood Prevention and Its Relation to the Nation's Food Supply," Science, N. S., XL., No. 1019, pp. 44-47, July 10, 1914; signed as chairman of the committee on soil erosion of the Social and Economic Section of the American Association for the Advancement of Science. A strong and suggestive paper, but without mention of fisheries.
- Wall, Judson G., loc. cit.
- American poultry products alone are worth half a billion dollars a year: report of Secretary of Agriculture, D. F. Houston, as quoted in the Review of Reviews, March, 1915, p. 266. This figure is more than double that of the potato crop, and approaches the estimate of value of the wheat crop. With the product of 500 millions from domestic poultry, compare the few millions (about twelve) credited to fresh-water fisheries, and based almost entirely upon wild fish.