The sun. [volume] (New York [N.Y.]) 1833-1916, 1908-03-29
sTUDY on Use HIsTORY.
ocean FisheFles meKhauStible by Man,
Say European INVESTIGATOR.

oeean Fisheries mexhaugtible by Maj
Say European INVESTIGATOR.
For Ave years ten steamers belonging b
eight different nations whose coasts an
washed by the Atlantic. the North Se'
and the Baltic have been engaged In inter
national oceanic research. The purpos,
has been 10 make u study Of the life history
Of fshes, with the expectation that II woulc
yield both practical and scientific results o
importance.
To learn the life story OF fshes the observ
era found II necessary to study the element
In which fishes live and the influences, sucl
a. water temperatures, ocean currents
minute organisms that are the food supply
Of many fahes and other things which az.
feet fab life. These scientific workers
have now completed q general survey
OF the most noteworthy features relating
70 fsh life In the seas Of north Europe,
from the Baltic 10 the North Sea, thence Ia
Iceland in the west and to s~pitzbergen in
the north.
Hundreds Of thousands OF fish and mill
ions Of fab egg have also been collected
while studying the wanderngs Of fish
aud the mode Of their occurrence. It Ia the
purpose here to mention a few Of the signia-
cant results Of the investigation.
II IL found that the eggs Of most food
fishes hoat In the sea, the herring being an
exception. The little eggs, about one
tWenty-fourth Of an inch in size, develop
In a few days or weeks into lArve, only
slightly larger; These remain floating, and
after a few weeks acquire a little Of the
structure and appearance Of the future
denizen Of the deep.
For q month or 30 they remain suspended
In the waste Of waters, some near the sur
face and some at considerable depth, and
then, II possible, they seek the bottom,
where by degrees they attain maturity.
A great step forward in the study Of fish
was the discovery Of means to determine
their age.
Il was found that the otoliths or cal
careous seoretions in the ear openings Of
plaico showed age rings similar 10 those
found on the stems Of trees and the horns
Of cattle. So 1t became possible 10 tell the
age Of each individual place. and later it
was proved that also many Of the bones
and also the scales show age rings, a fact
which now enables the observers TO tell with
certainty the g Of cod, paddock. saithe,
herring or sprat, as well as Of many other
species Of fish.
The age OF a fish up to II or is years is
easily ascertained by the scales, but after
that time the additional growth 10 so small
a. to be Of little service. Some Of the
largest specimens Of cod carried proof that
they were from 10 10 II years old. 1t is
inferred that many OF these cod have
spawned from eleven to twelve times in
their lives.
Another interesting question is the rate
Of growth Of fish. 1t is found that the rate
at which young cod grow varies according
TO their surroundings.
In the southern part Of the North Sea
theV grow very rapidly. attaining a length
OF nealry eight inches in the first year, but
In many places along the Norway coast the
average size Of a year old cod is only about
three inches. Some OF the largest cod
caught we're over forty-six inches in length
and more than 10 years old. The growth Of
haddock 10 about four inches the first year,
but the rate decreases as they approach
the higher ages.
Avery important part Of the work was the
investigation Of the baunts and wanderings
Of fish. This study was carried on chiefly
by marking thousands Of fsh by means Of
small wires. There are buttons at each
end Of the wires, and the time and place Of
turning each fab loose is marked or the
buttons.
Il was found that the larve Of the eel
are met only in the deep portion OF the
Atlantic, and far reaching conclusions were
from this fact as to the watderings
Of the full grown eel and its young, The
law vas deduced from the astonish-
ing wanderings Of many fish species that
they can never be seriously affected by
local conditions.
The observers believe they have proved
that the growth and prOductiveness of
ash is subject TO such mighty natural in
huences, such az climatic changes in the
regions which they frequent, that
hey may be regarded as independent Of
The interference or the fisheries Of a
II is certain that man has considerably
the number Of plaice. paddock
and cod in some waters, but not 10 such an
,Itent as 10 have more than a temporary
effect upon fishing interests. Man cannot
sXtermlnate them,
At what age does the individual fish
its best selling valuel This ques-
ion has not yet been solved, but DR.. Hort
n his recent writings on some Of the results
II these researches says that the study
II this question is well under way and
hat its solution is merely a matter Of carry
out the necessary work. The light
which he expects will be thrown uPon this
Iubiect he thinks will be the greatest
achievement Of these studies.
The work will probably be continued
or years to come. and the international
committee which is directing II has no
loubt that other splendid discoveries Of
10Th practical and theoretical interest will
70 the outcome.