There are also migratory fish in fresh water, like the white fish, the salmon, trout, and the siscowet, which live in the abyssal depths of the great lakes and swim up into the shallows and creeks in winter to spawn their eggs, and the brook trout and dace, which for a similar purpose ascend from the pools and quiet meadow stretches to the pebble-paved ripplets near the spring sources of the brooks in which they live.
Having, in a general way, classified fish according to their habits, we are in a position to consider the manner in which man has succeeded in exterminating them. As a general rule, fish deposit their eggs in shallow water, and the time of egg-laying is very closely dependent upon the temperature of the water. The eggs of a fish are, as every one knows, enclosed in two sacs, or ovaries, which are situated close to the walls of the abdominal cavity, and separated from the water by thin walls of skin and flesh, rarely, even in the largest fish, more than a sixteenth of an inch in thickness. Experiment has shown that the temperature of the blood in the abdomen of a fish deviates very little from that of the water in which it is floating. Experiment has also shown that as soon as the water has reached a certain degree of warmth, variable with each kind of fish, the eggs are sure to be laid within a very few hours. This being the case, it usually happens that great schools of fish always congregate together at one time upon the spawning grounds. Since the spawning grounds of many kinds of fish are in shallow water, and the fish are at that time most easily caught, it happens that many of the most extensive fisheries are carried on in the spawning season. The delicious little smelts which our neighbors in Maine and New Brunswick send us by the hundred car-loads each winter, packed in little boxes of snow, are always full of eggs—so are the lake white fish, when they are caught, and the shad, and the Potomac herrings, and the cod, and the mullet, and the herring, and in early spring the mackerel.
Now consider how easy it is, taking these fish so much at a disadvantage, to diminish their numbers, simply by catching them. The man who catches a spawning cod destroys anywhere from 5,000,000 to 7,000,000 of eggs, a spawning halibut at least 2,000,000, a shad from 50,000 to 2,000,000. Is not the American breakfasting on broiled shad roe a modern representative of him who killed the goose which laid the golden egg? When we consider that the yearly catch of mother-fish along the New England coast does not fall short of ten to fifteen millions of individuals, we may gain an adequate idea of the destruction of fish life by the fisheries.
Still it is not necessary to be alarmed at these figures. They are presented simply in illustration of the immense possibilities of destruction when the fisheries are carried on at the spawning season. As a matter of fact, cod are just as abundant along our coasts as they ever were, and it has not yet been demonstrated that any kind of sea fish has ever been diminished in numbers by hook and line fishing or by netting them at a distance from the shore.
Some kinds of fishes, however, enter narrow bays and estuaries to spawn, and if they are there recklessly destroyed, the local supply at least may be permanently interfered with. This has apparently been the case with certain species in Narragansett Bay, Rhode Island. For instance, the scuppaug or porgy has been seriously diminished in numbers in certain seasons, years ago; the supply will probably be replenished from adjoining waters by the reparative tendencies of nature, if this indeed has not already been done. So, too, the halibut has been exterminated in Massachusetts, where it was once so abundant as to be regarded as a nuisance by the fishermen. It is in the inland or freshwater fisheries, however, that the work of extermination has been thorough, and here, from the nature of the case, the work once accomplished, it is beyond the power of nature to remedy the damage. If I could take the reader with me next May to one of the many little streamlets of Cape Cod, flowing southward into Nantucket Sound, I could show him a scene which he would never forget. The little rill has been encased at bottom and sides with planks, so that it flows for a mile or two, down to its junction with the sea, in a straight trough not over fifteen inches wide, and a foot in depth. At a convenient level place a shed has been built over the trough, and in the floor is a kind of cistern, through which the waters of the brook flow as it goes on its course. In the shed stand two men, each with a great scoop of netting, with which they labor, dipping the fish out of the cistern as they fill it, swimming up the trough from the sea. Several barrels are taken out every day, and in some of these streams one or two thousand barrels always reward a season’s work, the brook being the property of the township, and the privilege of fishing being sold at auction for the benefit of the public. Dip! dip! dip it is all day long, and as the little alewives are tumbled into barrels and carts, the eye of the practiced observer notes the plump sides and the brilliant iridescent coloring of the silvery scales, which indicate that the fish are loaded with a precious burden of eggs, to deposit which in the pond at the head of the stream is the motive which leads them to press forward so blindly into the trap men have set for them.
In these enlightened days the town laws generally require that the brooks shall be unobstructed for one or two days each week, and so a few fish get by the barriers and are allowed to perpetuate their kind. In the past, however, many excellent “herring brooks” have been completely deprived of their fish.
This illustrates how completely man has the destinies of river fish under his control. Suppose that instead of a fish house with movable barriers, an impassable dam had been built. Of course the fish would have been locked out, and their kind exterminated in that immediate region. This is precisely what has happened in almost every river and stream on the Atlantic coast of the United States. Shad and salmon were formerly abundant in every river of New England—and shad and alewives in every considerable stream south to Florida. Now, they are excluded, either entirely or in great part from the waters in which they once swarmed in great schools. Take, for instance, the Connecticut River. In colonial days, salmon were there in immense numbers. All summer long they were swimming up from the sea to the headwaters of the river, to Massachusetts, New Hampshire, and Vermont, where they deposited their eggs in the cool, clear rapids of the main river and its tributaries. They were so abundant that the shad fishermen used to require their customers to take one salmon with every shad, and, as the hackneyed old story goes, the apprentices were accustomed to stipulate in their papers that they should not be required to eat salmon above three times a week. In 1798 a dam was built across the river at Miller’s Falls. Next year many salmon were seen at the base of the dam, the following year a smaller number, and in less than ten years salmon had entirely disappeared from the Connecticut. Not a salmon was seen in those waters until seventy years later, when, in 1871, a single artificially bred fish was caught at Saybrook. I could show you a map prepared by an associate of mine, in which the present and former limits of the shad are shown, and you would see how they once ranged clear up into the mountains, far up the Susquehanna into New York State, up the Connecticut into New Hampshire and Vermont, and how now, in many rivers, they are confined to very restrictive stretches at the river mouths.
The dams operate in still another way. We have considered hitherto only their influence upon the sea fish which ascend the rivers to spawn. Their effect upon the resident fish is quite as baneful. As the suckers, and the bass, and the cat fish, and dace, and trout, grow large, they naturally go down stream in search of deeper water and wider pools, where they get more room and better food. If they luckily escape the baskets and traps set for them in every dam, they never can get back. The streams are gradually sifted out and left tenantless.
Little need be said of the manner in which ponds are drained dry in order to get all the fish in them, in which immense seines are hauled in little lakes, clearing out everything, great and small, of the use of explosives, lime, or cocculus indicus, in the work of wholesale destruction. The fact stands undisputed and undisputable, that in many parts of the United States the native fish are actually exterminated, and the mud turtles, muskrats and fresh water clams left as sole occupants. Even the harmonious bull-frog has been devoured by man, and only his diminutive cousins, the cricket frogs and hylas left—the aquatic choir can henceforth perform only soprano and contralto songs, unless the fish culturist finds some way of bringing back the basso whose obligatos we once admired.
Oysters, scallops, and lobsters are going the same way. Although they live in free waters, they are stationary in their habits, and wholesale gathering will soon complete the work of extermination so recklessly begun. The forthcoming census reports on the fisheries will show conclusively the need of immediate protection.