New England Salmon Hatcheries and Salmon Fisheries in the Late 19th Century

by Various

As already stated, the activity of the station has been mainly occupied with Atlantic salmon, but there have been reared each year a few landlocked salmon and brook trout, and occasional lots of other salmonoids, such as Loch Leven, Von Behr, Swiss-lake, rainbow, and Scotch sea trout. All these have received the same treatment. With the exception of the rainbow trout, they are all autumn-spawning fishes, and their eggs hatch early in the spring.

The embryos of salmon begin to burst the shell in the month of March, and the 1st of April may be stated as the mean date of hatching. If the open-air troughs are in order--and we aim to have them so--the eggs are counted out into lots of 2,000 or 4,000 each and placed before hatching in their summer quarters. The water is at that time very cold, the development of the alevins is slow, and it is not until the latter part of May that the yolk sack is fully absorbed. June 1 is, therefore, the date when feeding is ordinarily begun. The growth of the fish is at first slow, the water being still cool, but is accelerated as the summer passes away. In October and November, beginning commonly about the middle of October, most of the fish are counted out and liberated, but a small number, rarely more than 15,000, being carried through the winter at the station. The reserved fish are sometimes left until midwinter in their summer quarters, and with a careful covering of the conduits and banking of the troughs themselves each with coarse hay and evergreen boughs it is possible to keep them there the year round; but for ordinary winter storage there is provided a system of sunken tanks covered by a rough shed with a constant water supply. These tanks are molasses hogsheads, securely hooped with iron, sunk nearly their entire depth into the ground, each with an independent water supply and waste, the perforation for the latter being near the surface. They have a capacity of from 100 gallons of water upward, and will carry safely each 500 to 700 fish in their first winter, that is, just approaching the age of one year.

This arrangement has answered its purpose fairly well, and in a very rigorous climate or where the water is very cold it is to be recommended; but since its construction it has been discovered that at Craig Brook it is not at all difficult to protect the ordinary troughs in such a way as to insure their safety from freezing, and their attendance through the winter is less troublesome than that of the sunken tanks.

A list of the articles employed for food at the station since its foundation, if designed to include those used on an experimental as well as a practical scale, would be a long one, and I will content myself with naming the following: On a practical scale we have used butcher's offal, flesh of horses and other domestic animals by the carcass, fresh fish, maggots; and on an experimental scale, pickled fish, fresh-water mussels, mosquito larvae, miscellaneous aquatic animals of minute size.

In the production of maggots we have also made use of large quantities of stale meat from the markets and some barrels of fish pomace, in addition to the articles mentioned above.

The butcher's offal comprises the livers, hearts and lights of such animals as are slaughtered in Orland and Bucksport--mainly lambs and veals. These are collected from the slaughter-houses twice or thrice weekly, and preserved in refrigerators until used. The quantity of such material to be had in the vicinity has been inadequate to our needs and we have been compelled to look in other directions for food.

The flesh of horses has been used only during the season of 1893. Old and worn out horses and those hopelessly crippled or dying suddenly have been bought when offered, and used in the same way as the butcher's offal; the parts that could be chopped readily have been fed direct to the fish so far as needed; and other parts have been used in the rearing of maggots. The season's experience has been so satisfactory that greater use will be made of horse flesh hereafter.

Next to the chopped meat, maggots have constituted the most important article of food, and their systematic production has received much attention. A rough wooden building has been erected for the accommodation of this branch of the work and one man is constantly employed about it during the summer and early autumn months. The maggots thus far employed are exclusively flesh-eaters, mainly those of two undetermined species of flies--the first and most important being a small smooth, shining green or bluish-green fly occurring at the beginning of summer and remaining in somewhat diminished numbers until October, and the other a large rough, steel-blue fly that makes its appearance later and in autumn becomes the predominating species, having such hardiness as to continue the reproduction of its kind long after the occurrence of frosts sufficiently severe to freeze the ground.

In outline the procedure is to expose the flesh of animals in a sheltered location during the day, and when well stocked with the spawn of the flies to place it in boxes which are set away in the "fly house" to develop; when fully grown the maggots are taken out and fed at once to the fish. The materials used for the enticing of the flies and the nourishment of the maggots have been various. Stale meat from the markets has been perhaps the leading article, but we have also used such parts of the butcher's offal and of the horse carcasses as were not well adapted to chopping; fish, fresh dried or pickled; fish pomace from herring-oil works, and any animal refuse that came to hand.

Fresh or slightly tainted meat has been used to greater extent than any other material, and has proved itself equally good with any. Fresh fish is very attractive to the flies, and when in just the proper condition may be equally good with fresh meat, but some kinds of fish are too oily, for instance, alewives and herring, and all sorts thus far tried are apt to be too watery.