Part 9

I think it quite possible that an arrangement might be devised whereby the greater part of the labor might be saved. Perhaps a series of breeding tanks arranged in proximity to the fish troughs, into which the water containing the larvae might be drawn when desirable by the simple opening of faucet, would solve the problem.

Various methods of serving the food have been tried, but at present everything is given with a spoon. The attendant carries the food with the left hand--in a 2-quart dipper if chopped meat, in a larger vessel if maggots--and, dipping it out with a large spoon, strews it the whole length of the trough, being careful to put the greater portion at the head, where the fish nearly always congregate. Finely chopped food, for very young fish, is slightly thinned with water before feeding. At one time the finest food was fed through perforations in the bottom of a tin dish; the food was placed in the dish, which was dipped into the water a little and shaken till enough of the food had dropped out of the perforations; this practice was laid aside because it was thought that the food was too much diluted.

In feeding maggots it was, at first, the practice to place them on small "feeding boards" of special construction suspended over the water in the troughs and let them crawl off into the water; but whatever advantage this method may have had in furnishing the meal to the fish slowly was more than counterbalanced by the extra labor of caring for the boards and by the offensive odor, and it was abandoned. For use in feeding fish in a pond a box containing a series of shelves, down which the maggots slowly crawl, was found sufficiently useful to be retained.

It is the common practice to feed all meat raw except the lights, which chop better if boiled first, except also occasional lots of meat that are on the point of becoming tainted and are boiled to save them. All meats fed direct to the fish are first passed through a chopping machine. The machine known as the "Enterprise" is the one now in use. It forces the meat through perforated steel plates. The plate used for the smaller fish has perforations 2 inch in diameter, and for coarser work there are two plates 3/16th inch and 3/8th inch, respectively. It is operated by a crank turned by hand.

Food is given to those fish just beginning to eat four times a day (in some cases even six times). As the season progresses the number of rations is gradually reduced to two daily. In winter such fish as are carried through are fed but once a day. The cleaning of the troughs has been a troublesome matter, and the subject of much study and experiment, but nothing more satisfactory has been found than the following practice: The troughs are all to be cleaned daily--not all at one time, but as time is found for it in the intervals of other work. To facilitate cleaning, the troughs are inclined about 2 inches. The outlet is commanded, as already explained, by a hollow plug.

When this is drawn the water rushes out rapidly and carries most of the debris against the screen. The fishes are excited, and, scurrying about, they loosen nearly all dirt from the bottom; what will not otherwise yield must be started with a brush, but after the first few weeks the brush has rarely to be used except to rub the debris through the outlet screen. Owing to the inclination of the trough the water recedes from the upper end until the fishes lying there are almost wholly out of water, but, although they are left in that position sometimes for 10 or 15 minutes, no harm has ever been known to result.

It has been the common rule at the station to count all the embryos devoted to the process of rearing, either before or after hatching; to keep an accurate record of losses during the season, and to check the record by a recount in the fall. When eggs are counted they are lifted in a teaspoon.

The counting of small fish is effected in this way: The fish are first gathered in a fine, soft bag-net, commonly one made of cheese-cloth, and from this, hanging meanwhile in the water, yet so that the fish cannot escape, they are dipped out a few at a time, in a small dipper or cup, counted, and placed in a pail of water or some other receptacle.

This counting is generally preliminary to weighing, and in this case the fish, after counting, are placed in another bag-net, in which they are lowered, several hundred at a time, into a pail of water which has been previously weighed, and the increase noted. With care to avoid transferring to the weighing pail any surplus water, this is a correct method and very easy and safe for the fish.

In conclusion, I submit some estimates of cost. In September, 1893, we fed fry that were estimated at the close of the month to number 238,300. There were also a few hundred larger fish.

From the known total outlay for food, attendance, and superintendence a suitable allowance is made for the maintenance of the older fish, and the balance is charged to the fry. By this method we arrive at the following results:

Cost...................Total........Per fish. Food $155.00 $0.00065 Attendance 99.79 .00042 Superintendence 205.96 .00086 Total 460.75 0.00193

Applied to the rearing operations of 1891, a similar calculation gives us this result: The fry that were carried through the season from June to October, inclusive, cost, for food, attendance, and superintendence, $0.0081 each; that is, about four-fifths of a cent each for the term of five months.

ARTICLE VII

NOTES ON THE CAPTURE OF ATLANTIC SALMON AT SEA AND IN THE COAST WATERS OF THE EASTERN STATES

By Hugh M. Smith, M. D., Assistant in charge of Division of Statistics and Methods of the Fisheries.

Bulletin of the United States Fish Commission, Vol. 14, Page 95, 1894.

In carrying out its most important function--the maintenance and increase of the supply of food fishes--the U.S. Commission of Fish and Fisheries, in addition to direct efforts to increase the abundance of fishes naturally inhabiting our various rivers, lakes, and coast waters, has given considerable attention to the experimental introduction of fishes into regions or streams to which they were not native.

The wonderful success which has followed the planting of shad and striped bass fry in the waters of the Pacific coast is well known. The results attending the recent attempts of the Commission to establish a run of salmon (Salmo salar) in some of the large rivers of the Atlantic coast have been so noteworthy in the case of the Hudson as to afford reasonable ground for expecting the early inauguration of a regular fishery, should the present rate of increase in the abundance of the fish be maintained. Similar striking results may also be anticipated in all the more northern streams of the east coast, including the Housatonic, Connecticut, and Merrimac, in which salmon were at one time found in abundance and are now taken in small numbers, if the ascent of the adult fish to the headwaters for the purpose of spawning is permitted and if sufficiently extensive fish-cultural operations are continued.

The primary purpose of this paper is to record some of the apparent results of salmon propagation in our rivers as shown by the occurrence of the fish at points on the coast or at sea more or less remote from the places where fry have been deposited.

While an interesting and instructive compilation might be made of the instances of the capture of salmon in the Hudson, Delaware, Susquehanna, Potomac, and other rivers in which the fish has been acclimated, such a work is not necessary in view of the notice which has already been accorded the matter in the public press and in the reports of several of the State fish commissions, notably the New York commission.

So much yet remains to be learned regarding the lines of migration of the salmon to and from the rivers, its winter habitat, the existence of an "instinct of nativity" which is supposed to impel the return of the fish to the place where hatched, the extent of the coastwise distribution of salmon originally belonging in a given river, and numerous other practical and scientific questions, that the presentation of any data bearing on the occurrence of the fish outside of the rivers may be regarded as acceptable and timely.

In an interesting article on "Salmon at Sea," communicated to the issue of Forest and Stream for February 18, 1892, Mr. A. N. Cheney, the well-known angling expert and writer on fish-cultural matters, discusses the question of the whereabouts of salmon after they leave the rivers, and quotes the following from a previous contribution by himself on the subject:

"There is a certain mystery about the habits and movements of the sea salmon, after it has left the fresh-water rivers in which it spawns and gone down to the sea, that never has been satisfactorily explained. One theory is that all the salmon of the rivers along a coast may journey down to the sea, and then move ultimately in one great body southward along the coast until they find water of suitable temperature, with an abundance of food, in which to spend their time in growing fat until the spawning instinct warns them to return, when they proceed northward, each river school entering its own particular river as the main school arrives opposite the river month.

"Another theory is that the salmon of each river, as they arrive at its mouth after descending from its headwaters, go out to sea sufficiently far to find the conditions of temperature and food which suit them, and there they remain, separate from the salmon of other rivers, until it is time for them to return to fresh water. Considering the certainty with which the salmon of any particular river return again to the stream of their birth, the latter theory seems the more tenable of the two."

Another object of this paper is to solicit correspondence from fishermen, especially those engaged in the coast and offshore fisheries, concerning the circumstances of the capture of salmon in their nets, and to bring to their attention the opportunity they will thus have of increasing the knowledge of the movements of the salmon, of aiding in the determination of the results of fishcultural operations, and of ultimately if not immediately benefiting themselves by supplying information that will conduce to the most effective application of artificial methods.

To this end it is the intention to send the paper to fishermen engaged in the mackerel, menhaden, and other sea fisheries, and to operators of pound nets, traps, and other shore appliances, with the hope that instances of the capture of salmon may be communicated to this Commission and notes on the size, condition, movements, etc., of the fish be furnished.

To aid in the identification of the salmon when caught by fishermen who have not previously met with the fish, a figure is presented.