ARTICLE V
REPORT ON THE SCHOODIC SALMON WORK OF 1884-85
By Charles G. Atkins.
_Bulletin of the United States Fish Commission_, Vol. 5, Pages 324-325, 1885.
The measurement of the stock of Schoodic salmon eggs at Grand Lake Stream at time of packing and shipment, and the record of previous losses, enable me to complete the statistics, as follows:
Original number taken ...................................1,820,810 The total losses up to that time, including the unfertilized, which were removed before packing............254,410 Net stock of sound eggs..................................1,566,400 Reserved for Grand Lake....................................397,400 Available for shipment to subscribers ...................1,169,000
These were divided among the parties supplying the funds for the work in proportion to their contributions, as follows:
Allotted to the United States Commission...................608,000 Allotted to the Maine Commission...........................234,000 Allotted to the Massachusetts Commission...................187,000 Allotted to the New Hampshire Commission...................140,000
Total....................................................1,169,000
The share of the United States Commission was assigned and shipped, under orders, as follows:
A. W. Aldrich, commissioner, Anamosa, Iowa..................50,000 E. A. Brackett, commissioner, Winchester, Mass..............25,000 H. H. Buck, Orland, Me, to be hatched for Eagle Lake, Mount Desert....................................20,000 Paris, Mich., for Michigan commission.......................50,000 Madison, Wis., for Wisconsin commission.....................50,000 R. O. Sweeny, commissioner, Saint Paul, Minn ...............50,000 South Bend, Nebr., for Nebraska Commission..................20,000 E. B. Hodge, commissioner, Plymouth, N.H....................40,000 Cold Spring Harbor, N. Y., for New York Commission..........60,000 Plymouth, N. H., for Vermont Commission ....................25,000 Plymouth, N. H., for Lake Memphremagog .....................25,000 Central Station, Washington, D.C. ..........................10,000 R. E. Earll, World's Exposition, New Orleans ................5,000 G. W. Delawder, commissioner, Baltimore .....................5,000 Myron Battles, North Creek, N................................5,000 A. R. Fuller, Meacham Lake, N. .............................20,000
F. Mather for transmission to Europe as follows: For Herr von Behr, Germany..................................40,000 For Tay Fishery Board, Scotland.............................20,000 For National Fish Culture Association, England..............30,000
Total to Europe.............................................90,000
Enfield, Maine for Maine Commission.........................58,000
Total......................................................608,000
A few of the shipments have been heard from, and these all reached their destinations safely.
BUCKSPORT, ME. March 31, 1885
ARTICLE VI
METHODS EMPLOYED AT CRAIG BROOK STATION IN REARING YOUNG SALMONID FISHES
By Charles G. Atkins, Superintendent U. S. Fish Commission Station at Craig Brook, Maine.
_Bulletin of the United States Fish Commission_, Vol. 13, Pages 221-228, 1893.
The station of the U. S. Fish Commission at Craig Brook was founded in 1889, on the same site where, in 1871, the first attempt at the artificial spawning of salmon in the United States was made. This site had been selected by the commissioners of fisheries of the States of Maine, Massachusetts, and Connecticut for that experiment because of its proximity to the salmon fisheries of the Penobscot River and the facilities presented for the maturing of the spawn that might be obtained.
The collection of spawn has been carried on in the vicinity annually from 1871 to the present time, with the exception of the three years 1876,1877, and 1878, and since 1879 the development of the spawn has been conducted constantly at Craig Brook. No attempt was, however, made to rear the fry of any species until 1886. Two years later it was definitely determined to found a permanent station at Craig Brook, and in 1889 the purchase of the grounds was effected and permanent improvements begun.
The station is located in the town of Orland, Me., 7 miles east of Bucksport, a seaport on the Penobscot River. Its territory embraces a tract of land extending between Allamoosook Lake and Craig Pond and embracing within its limits the entire length of Craig Brook, which connects those two bodies of water. Its latitude is about 44 degrees 42' N. The mean annual temperature and precipitation are believed to approximate those of Orono, 25 miles distant, namely, 42.48 F. [5.8 C.] and 45.44 inches [116 cm.]. The range of air temperature observed at the station is from 18 F. below zero to 92.5F. above [-27.7 C.
to 33.6 C.]. Frosts not infrequently occur as late as the 1st of June and as early in autumn as the first week in September. The lakes in the vicinity are commonly covered with ice before the end of November, and they are not often released until near the end of April.
The water supply is derived from Craig Brook and from three large and several lesser springs. The source of the brook is Craig Pond, which affords a constant supply of exceedingly transparent water, warm in summer and cold in winter, moderated, however; in both extremes by the water from the springs, which mingles with the brook in its lower course, forming about a third of its volume. It is this mixed water which is mainly used in the rearing of fish. Its temperature ranges from 34 F. [1.1 C.] to 70F. [21.1C.]. The lowest monthly mean in 1893 was 35.8 F. [2.1 C.] in February. The highest was 64.6F.
[18.1C.] in August. The total volume is variable, ranging from 875 to 3,000 gallons and averaging about 1,200 gallons per minute.
The difference of level between the source and mouth of the brook is about 190 feet. The sharpest descent is just above the hatchery and rearing troughs, which therefore receive well-aerated water. The conformation of the ground offers good facilities for the distribution and utilization of the water.
The leading motive in the foundation of this station was the desire to apply to the Atlantic salmon the system of rearing fish to the age of at least several months before liberating them. This motive has determined not only the principal subjects of the work, but also to a considerable extent the fixtures and methods. The scheme of work was determined in outline several years before the acquisition of full title to the premises, and, circumstances rendering it desirable to enter at once on its development, it became necessary to have recourse to movable apparatus, pending authority for permanent improvements.
Hence the erection of a series of small troughs in the open air, which gave such excellent satisfaction that enlargement took the same direction; and it has thus come about that the rearing operations of the station down to the present time have been almost exclusively conducted in open-air troughs. A series of ponds has been constructed, but with the exception of a few small ones none of them have been as yet brought into use.
The troughs are for the most part such as are used in the hatchery for the maturing of spawn, and their form and size have been adapted to the hatching apparatus which has been in use at the Maine station for many years. The eggs are developed on wire-cloth trays measuring 12 and one half inches in width and length, and the troughs are therefore 12 and three quarter inches wide. Their depth is 9 inches and their length is 10 feet 6 inches. Such short troughs were adopted for two reasons:
(1) It was thought that a greater length might involve the exposure of the eggs near the lower end to the danger of a partial exhaustion of the air from the water by the eggs above them;
(2) these short troughs are very convenient to cleanse and to move about for repairs or other purposes. They are made of pine boards seven-eighths inch thick. On the inside they are planed and varnished with asphaltum. When used for rearing fish each trough is fitted with a pair of thin wooden covers reaching its entire length hinged to the sides and meeting each other, when closed, at a right angle, forming; as it were, a roof over the trough. When closed they protect from predatory birds and other vermin; when open they are fixed in an upright position, in effect adding to the height of the sides and preventing the fish jumping out. The time spent in opening and closing the troughs is by this arrangement reduced to a minimum.
Water is fed through wooden tubes, and the volume admitted is regulated by slides The exit of the water is through another tube or hollow plug standing upright near the lower end of the trough, and by its height governing the depth of the water. The outlet tube is movable and is taken out in cleaning. A wire-cloth screen just above the outlet tube prevents the fish escaping.
In a trough of standard size 2,000 fry are generally placed, and to accommodate the large numbers of fish reared we bring into use sometimes nearly 200 troughs which are of necessity placed in the open air. They are arranged in pairs with their heads against the feed troughs, supported by wooden horses at a convenient height from the ground. They are given an inclination of about 2 inches to facilitate cleaning.
The volume of water fed to each trough has varied from time to time, but is ordinarily about 5 gallons per minute, which renews the water every four minutes. The ordinary arrangement is to use the water but once in the troughs, letting it waste into some small ponds in which yearling and older fish are kept; but there is one system of 52 troughs arranged in four series, which use in succession the same water. From these we have learned that young salmon thrive quite as well in the fourth series as in the first. Indeed, by an actual test, with fish of like origin and character in each series, the fish reared in the fourth series were found to grow faster, to an important degree, than those in the first. This phenomenon probably resulted from a somewhat higher temperature which the water acquired in passing through the several series. A like observation has been made on a few salmon maintained for a few weeks, in the warmer water of a neighboring brook.
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.