THE ARTIFIOIAL PROPAGATION OF W
E FISH
19
The majority of marine hatcheries were built during the first wave
of enthusiasm for artificial propagation, and immediately dedicated to
the mass-production of fry. Newly-hatched larvae are comparatively
easy to produce ; conclusive evidence of their effect on the subsequent
yield of marketable fish is not. When forceful critioism waa levelled
at the value of artificial hatohing, retreat was inevitable-hatchery
enthusiasts had no strong defensive evidence to fall back on. Controversy arose ; doubts hardened into prejudice ; financial resources began
TABLE Iv. BASIO DATA FROM A LOOH F Y m EXPERIMENT ON TIIE PBACTICAL
VALUE OF PLAICE-FRY LIBERATIONS. (After Fulton, 1908)
-~
Mean catch
per hour
No. larvae
Duration of
No. of
(neorwt million)
h
min
taken
Year
liberated
$8hing
0-group plaice
1896 .
4
10
-
1114
111.4
1897 . . 21
2
30
60
24.0
1898 . . 19
12
30
1196
96.6
1899 . . 16
17
-
488
28.7
lQO0 . . 31
16
-
860
63.1
1901 . . 61
16
-
2784
174.0
TOTAL . 143
74
-
6491
87.7
1903 . . Nil
33
-
1231
37.3
1904 . . Nil
31
46
263
8.0
1906 . . Nil
29
46
3333
112.0
1906 . . Nil
30
26
606
16.6
1907 . . Nil
8
60
294
33.3
1908 . . Nil
31
46
961
30.3
TOTAL
. Nil
166
30
6677
39.7
to dry up. In matters of this sort, trustees of public money naturally
prefer to back certainties. It is little wonder that in conditions of
waning oonfidence, no further technical advances of importance were
made. Artificial propagation as a commercial proposition slowly lost
its appeal, and when the movement virtually expired in the 1960’6,
methods were substantially the same as in the 1880’s.
Any revival of general intereat in artificial propagation must be
preceded by systematic field experiments to eetablieh beyond doubt
that thia form of human intervention can profitably improve the l o d
field of food fish. This pre-requisite is well understood in Norway,
where Gunnar Dannevig (1963) hae been releasing 100-180 millions
Yolk-sac cod larvae into the heavily exploited Oslofjord every alternate
E FISH
19
The majority of marine hatcheries were built during the first wave
of enthusiasm for artificial propagation, and immediately dedicated to
the mass-production of fry. Newly-hatched larvae are comparatively
easy to produce ; conclusive evidence of their effect on the subsequent
yield of marketable fish is not. When forceful critioism waa levelled
at the value of artificial hatohing, retreat was inevitable-hatchery
enthusiasts had no strong defensive evidence to fall back on. Controversy arose ; doubts hardened into prejudice ; financial resources began
TABLE Iv. BASIO DATA FROM A LOOH F Y m EXPERIMENT ON TIIE PBACTICAL
VALUE OF PLAICE-FRY LIBERATIONS. (After Fulton, 1908)
-~
Mean catch
per hour
No. larvae
Duration of
No. of
(neorwt million)
h
min
taken
Year
liberated
$8hing
0-group plaice
1896 .
4
10
-
1114
111.4
1897 . . 21
2
30
60
24.0
1898 . . 19
12
30
1196
96.6
1899 . . 16
17
-
488
28.7
lQO0 . . 31
16
-
860
63.1
1901 . . 61
16
-
2784
174.0
TOTAL . 143
74
-
6491
87.7
1903 . . Nil
33
-
1231
37.3
1904 . . Nil
31
46
263
8.0
1906 . . Nil
29
46
3333
112.0
1906 . . Nil
30
26
606
16.6
1907 . . Nil
8
60
294
33.3
1908 . . Nil
31
46
961
30.3
TOTAL
. Nil
166
30
6677
39.7
to dry up. In matters of this sort, trustees of public money naturally
prefer to back certainties. It is little wonder that in conditions of
waning oonfidence, no further technical advances of importance were
made. Artificial propagation as a commercial proposition slowly lost
its appeal, and when the movement virtually expired in the 1960’6,
methods were substantially the same as in the 1880’s.
Any revival of general intereat in artificial propagation must be
preceded by systematic field experiments to eetablieh beyond doubt
that thia form of human intervention can profitably improve the l o d
field of food fish. This pre-requisite is well understood in Norway,
where Gunnar Dannevig (1963) hae been releasing 100-180 millions
Yolk-sac cod larvae into the heavily exploited Oslofjord every alternate