Evening star. [volume] (Washington, D.C.) 1854-1972, 1906-12-31
new. Many Of the species are or can be
come important food fishes.

new. Many Of the species are or can be-
come important food fishes.
Oyster Fattening.
The effort to establish as commercially
feasible the method of fattening oysters
which has been under experiment by the
bureau for several years resulted In an out
put in 1905 of 125 barrels Of oysters OF the
highest grade, the value of which, increased
by the process, was slightly more than
enough to cover the cost Of the work: the
expenses involved are to a considerable ex-
tent fixed, whether the product be great OF
small, and in the case OF the clare az
Lynnhaven a production OF twice OF thrice
the number OF bushels fattened wouiu pu!
slightly increase the cost, leaving out OF
consideration the original value OF tne poor
oysters. If the productiveness OF the Lynn
haven claire can be doubled, as 1t Is hopeo
will be shown during the coming year, the
possible commercial profits should be very
satisfactory, in view of the area involved.
A variety Of unforeseen misfortunes nave
overtaken the experimental sponge 1armS
of the bureau during the past year, ana
the work has been seriusly interfered with.
Enough progress has been maze, however,
to encourage continued effort.
The disasters to the suspended sponges al
several places and the comparative I'M
munity of those on the bottom caused
return to the earlier method OF planning
on cement disks and other bodies placed on
the bottom Cuttings were fastened ol-
rious material attached to the disks, ana
experiments were begun In growing sponges
of special shapes to meet the marke. oe.
mands. Several attempts were mace 10
transport live sponges by express, packed
in boxes and it was found that with proper
care in packing they could be carried sue
cessfully on journeys not exceeding three
days in duration. With proper precautions
and the use of ice 1t is believed posslple
to carry live sponges from Florida to Cali
fornia. Further experiments Will De maze.
Potomac Pollution.
Considerable work has been done during
the year to dete. mine the effects upon fishes
of certain industrial wastes commonly dis
charged into streems in the Potomac drain
age basin. The principal species expert
mented with were large-mouth black bass
and yellow perch. typical fishes OF the 20
tomac system. To support fish life the
water must have a slightly alkaline reac-
ton and in dealing with acid pollutions the
results of the experiments are affected by
the alkalinitY of the water used as Oh
luent. In the present experiments the lat
ter was in all cases Potomac service water,
tested for alkalinity at frequent Intervals
rno degree OF az. alton also affects the re-
suits City sewage and wastes OF various
kinds from paper ana pulp mills, tanner,es
and gasworks were experimented WITH under
various conditions of dilution and aera-
ton The gas works wastes were gener-
ally fatal. in extreme dilution. while most
of the other materials lost their toxic quail
ties when mixed with greater or less guam
titles of Potomac water. especially When
thoroughly aerated. The results Of this
work will have an important bearing upon
legislative and other projects for the I'M
provement of streams. The report Will De
published by the United States geological
survey as part of a water-supply and 1rrl-
CATION paper. entitled The Potomac River
Basin"