The Barre daily times. (Barre, Vt.) 1897-1959, 1906-06-18
RECON- ENDATIONS FOR
ROXBURY HATCHERY
Prof. M c. Marsh Reports on the Con,
dition of Fish Culture and Ad-
yises Pan System.


! his report to State Fish and Game Com
missioner II. G. Thomas ON the condi-
lions at the hatchery at Roxhny, which
resulted in the loss Of great numbers of
Try. The report in substance says:
By order OF the United States COM
missioner 81 fisheries, Il visit was made
to the state hatchery at Roxbury, vt,
on April 9.l4, 1906, for the purpose.
of determining ii possible BY brief ex
animation the cause OF mortality then
IN progress among the brook fry in the
hatchery tronghs.
The conditions are learned from the
superintendent OF the hatchery, as fol
lows: About 100000 brook trout fry
were Matched the present season. OF
these 100000 were from Carolina, Il.
Ii; 100000 from the Roxbuly hatchery
/ stock fish, and 10000 from the United
States station IN Colorado. Up to April
1 2 about 100000 Of these We're esti-
mated 10 have died and the loss was
upon the Carolina and Roxbury fry,
chiefly upon the former, and began about
| March J, when the sac was about two
thirds absorbed There had been no loss
upon the Colorado fry, but the sac had
not yet reached the same stage ID alb
| sorption as in the other lots. In ad
dition TO the brook-tront fry there were
in tToughs $4,000 brown trout with the
sac absorbed and feeding, about 100000
| lake trout fry in sac and 5000 yearing
lake front, and no unusual loss had oc-
| CURED or was occurring upon any Of
| these.
| Losses have occurred at this hatch
cry during the previous years. III the
spring of 1895 the brook trout fry sui
fered heavy los in one Cor in few
| trnughs. On one morning onc-haIf the
number III single trough was dead and
most Of the dead were lying on bot
| tom without having turned over, and
/ did not show that the were dead until
| stirred up. In 1897 the fry in two
tronghs, about 10000, Matched from
| the last eggs laid down, were lost with
/ the sac two.thirds absorbed. while other
/ troughs containing more than million
/ fry, were not affected. In 1904 b loss
\ began i'll February when the eae was
two-tllirds absorbed while other trouahs
containing more than a million fry were
/ not affected. In 1904 loss began IN
February when the sac vas two thirds
absorbed and all the brook trout fry,
| some 100000, were lost. These fry
were from eggs taken at the Roxbury
station. The superintendent il Of the
| opinion that All these losses ~ differ
ent years, including the presnt, were
| of the same nature,
"Thc dying and dead brook trout fry
during the week beginning April 8 had
/ i rather characteristic appearance. Many
| bad no sign Of the sac remaining, while
with many there was still considerable
remnant. Perhaps the most prominent
/ general symptom was the lack Of deyel
opment of the body. The trunk was
largely wasted away, or more accurately
| had never grown 60 its proper fullness,
and on this account the head seemed
larger than normal size. The gills were
not Of the normal red color but were
/ paler and sometimes nearly white, In
lIife. and the fry were therefore anaemic.
/ When the sac had been entirely or very
nearly absorbed, ~ large bubble Of gas
could be seen through the skin in the
abdominal cavity, which il nearly filed.
The abdominal organs occupied relative
| " small space, in comparison with this
| quantity of gas. The fry did not feed
well and the little food taken WAS as
/ simulated They were, in brief, suffer
ing from anaemia,s accompanied by
general condition allied to that express.
ed BY the term marasmus, on each
eNia.
by actual determination the water
certainly had no excess nor marked de-
| fcieney Of oxygen. Unfortunately this
does not speak for the condition Of the
water at all times II may have varied
since the eggs Of the past fall and win.
ter were laid down to degree seriously
aHcctiug them dtirng Incubation, aud
il Is not possible 60 find out now wlcth-
e. or TO what extent this variation has
occurred Anacmia without apparent
immediate cause has been heretofore OBJ
served ia older trout fry where infec.
ton by bacteria Or animal parasites has
been excluded by cultures aud inoe,ia,
ton experiments. In the present case
There was(pa tine for ipoenlsiions, but
Textures Tor bacteria, as Car as they 20,
are negative. With fry IL the sac
stage. or just beyond, the difficulties in
the way Of getting unconiaminatcd sam.
pies of blood are great, and ordinary re.
suits ON culture media are not thorough
~ conclusive.
"rhe relation OF anaemia and low
oxygenation Is so we'll recognized that
/ IL Is impossible 10 avoid considering
| II as involved IN the present ease es-
pecialIv in view Of the rather limited
volume OF water used. The flow per
trough OF about three gallons per min.
ute on G0,00D 60 10000 eggs. and on
about 10000 fry. has obtained in pre-.
yious seasons when 10 unusual mortal.
1 ity occurred, and cannot therefore be
regarded as necessarily inadequate, Fish
cutursts IN general would no doubt
consider il rather close e. the limit
Of safety and ut the Roxbury hatchery
| IL was the maximum flow per trough
delivered TO the hatchery and would
have been Increased had the water been
available.
Recommendations
Experience Of recent years has led
to The belief expressed by the writer
that hatcheries using spring water should
never be without an installment for
infinitely dividing the water. allowing
great area of exposure To the atmos-
phere for aeration and deaeration. Ex
pcricnec with such devices has not yet
been prolonged and they are not IN gen
crHl use II Is perhaps wise &C present
TO advise their use only on a few or
half of the troughs Of hatchery, lcav-
ing some troughs with the usual method
u water delivery for purposes OF com
parson (controD. In this way will
any virtue they possess best be brought
TO view. II Is recommended that in
future seasons the Roxbury hatchery
set up on at least two or three trouglIs
! with q pan system substantially like