approached the maximum. I should have no hesitation in putting 1000
salmon in the inclosure at Dead Brook, which covers an area of less
than 3 acres. Of course the renewal of the water supply, or its
aeration by winds, is of importance here.
The capture and transport of the fish in June involves methods
requiring some explanation. The salmon fisheries about the mouth of the
Penobscot River are pursued by means of a sort of trap termed a "weir."
It is constructed of fine-meshed nets hung upon stakes, arranged so as
to entrap and detain the fish without insnaring them in the meshes.
They swim about in the narrow "pound" of the weir until the retreating
tide leaves them upon a broad floor.
Just before the floor is laid bare, the salmon destined for the
breeding works are dipped out carefully with a cloth bag or a very fine
bag-net and placed in transporting cars or boats, rigged specially for
the purpose, sunk deep in the water, which fills them, passing in at
two grated openings above, and passing out at two others astern, and
covered with a net to prevent escape. In a boat 13 or 14 feet long (on
the bottom) we put 10 or 15 salmon, to be towed a distance of 7 miles.
If the water is cool, twice as many can go safely, but there must be no
delay. It is very important that this car be smooth inside, with no
projections for the salmon to chafe on, and the gratings must be so
close that they cannot get their heads in between the bars.
If conveyance overland is necessary, a wooden tank 3 feet long, 2 feet
wide, and 2 feet deep, with a sliding cover, will take six salmon at a
time for a mile and perhaps farther, and they may be jolted along over
a rough road in comparative safety.
It has been our uniform experience that all the salmon that survive
till autumn were in normal condition as to their reproductive function,
and yielded healthy spawn and milt. On two occasions we suffered
serious losses of eggs. In neither instance could the loss be
attributed to any defect in the inclosure, but on one occasion the
conclusion was reached that the water which was well suited to the
maintenance of the fish was injurious to the eggs, rendering the shell
so soft that they could not be transported safely.
With the exception of the disasters enumerated above, there has been
but one that I can recall, and that was caused by the bursting of our
barriers at Dead Brook under the pressure of a flood.
BUCKSPORT, ME, April 7, 1884.
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 92.5°F. 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 70°F. [21.1°C.]. The lowest monthly mean in
1893 was 35.8° F. [2.1° C.] in February. The highest was 64.6°F.
[18.1°C.] 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.
A very limited trial of fish dried without salt or smoke indicates that
it is, when free from oil, a very superior article; it has, of course,
to be moistened before using. Its preparation presents some
difficulties, but in winter it is easily effected by impaling the whole
fish on sticks and hanging them up, (after the manner of alewives or
herring in a smokehouse) under a roof where they will be protected from
rain without hindering the circulation of air; in this way we have
dried many flounders and other refuse fish from the smelt fisheries,
which are conducted with bag nets in the vicinity of Bucksport.
Doubtless a centrifugal drying machine might be successfully used for
this purpose in summer. Pickled alewives, freshened out in water, have
been found to answer fairly well, when other materials are lacking, at
least to give growth to maggots otherwise started. Fish pomace has not
thus far given satisfaction, but seems worthy of further trial.
It is commonly necessary to expose meat but a single day to obtain
sufficient fly spawn; the larvae are hatched and active the next day,
except in cool weather, and they attain their full growth in two or
three days. To separate them from the remnants of food and other debris
was at first a troublesome task. It is now effected as follows: the
meat bearing the fly spawn is placed on a layer of loose hay or straw
in a box which has a wire-cloth bottom, and which stands inside a
slightly larger box with a tight wooden bottom. When full grown the
maggots work their way down through the hay into the lower box, where
they are found nearly free from dirt.
When young salmon or trout first begin to feed they are quite unable to
swallow full-grown maggots. Small ones are obtained for them by putting
a large quantity of fly spawn with a small quantity of meat, the result
being that the maggots soon begin to crowd each other and the surplus
is worked off into the lower box before attaining great size. No
attempt is, however, made to induce the young fish to swallow even the
smallest maggots until they have been fed a while an chopped liver.
In the above methods maggots are produced and used in considerable
numbers, sometimes as many as a bushel in a day. Through September,
1893, although the weather and some other circumstances were not very
favorable, the average daily production was a little over half a
bushel.
They are eagerly eaten by the fish, which appear to thrive on them
better than on dead meat. Having great tenacity of life, if not snapped
up immediately by the fish they remain alive for a day or two, and, as
they wriggle about on the bottom, are almost certain to be finally
eaten; whereas the particles of dead flesh that fall to the bottom are
largely neglected by the fish and begin to putrefy in a few hours. In
the fish troughs there are, therefore, certain gains in both
cleanliness and economy from the use of maggots which may be set down
as compensating the waste and filthiness of the fly-house.
As the growth of maggots can be controlled by regulation of the
temperature, it is possible to keep them all winter in a pit or cellar,
and advantage is taken of this to use them during winter as food for
fish confined in deep tanks not easily cleaned.
The offensive odors of decaying flesh may be largely overcome by
covering it, on putting it away in the boxes, after the visits of the
flies, with pulverized earth, and it is not improbable that by this or
some other method the business may be made almost wholly inoffensive,
but in its present stage of development it is too malodorous to admit
of practice in any place where there are human habitations or resorts
within half a mile of the spot where the maggots are grown.
As remarked above, only flesh-eating maggots have yet been tried. It
would be well worth while to experiment with the larvae of other
species, such as the house fly, the stable fly, etc. There is also a
white maggot known to grow in heaps of seaweed. Should the rate of
growth of either of these species be found to be satisfactory they
might be substituted for the flesh maggots with advantage.
Occasional use has been made of fresh fish for direct feeding. When
thrown into the water after chopping it breaks up into fibers to such
an extent that it is not very satisfactory, and I do not suppose we
shall use it in the future, unless in a coarsely chopped form for the
food of large fish. A few barrels of salted alewives have been used,
and if well soaked out and chopped they are readily eaten by the larger
fish and can be fed to fry, but are less satisfactory with the latter,
and like fresh fish they break up to such an extent that they are only
to be regarded as one of the last resorts.
Fresh-water mussels have been occasionally gathered in the lake close
to the station when there has been a scarcity of food. Those employed
belong almost wholly to a species of Unio which abounds over a
considerable area of soft bottom, under a depth of 2 to 10 feet of
water. Many were taken with a boat dredge; more were scooped up with
long-handled dip nets of special construction. Finally a wide, flat
dredge was made, to be drawn by a windlass on the shore and manipulated
by means of poles from a large boat.