TBE ARTIFIULkL PROPAGATION OF MABINE BISE
15
a few years ago by the Commission, indicated that the value of the
cod now annually taken on new grounds is at least sevgrd times
greater than the entire yearly expenditure of the Commission for
fish-oultural work, and is increasing each season.” Similar praise
regarding the effectiveness of cod hatching appeared in the U.S.
Commissioner’s reports for 1903 and 1906, and, as late m 1929, s t a b -
merits were being made to the effect that winter flounder became more
abundant after planting hatchery-reared larvae.
Dannevig (191Ob), in a report on the utility of sea-fish hatching,
referred to the decline in the cod fisheries of Southern Norway since
the middle of the nineteenth century, and the difficulty he had in
obtaining ripening fish for his hatchery ponds during the first few years
of work. The situation changed during 1891 and subsequent years,
after hatchery output was substantially increased. Dannevig was
unanimously supported by public organizations-parish
councils,
commercial societies and private fishermen. They all agreed that sn
imusual number of small cod made their appearance wherever fiy
were planted. and further, that the fish were usually of a oolour differing
from that of the looal raoe.
Hjort and Dahl (1900) were the leading critios of the marine
hatchery movement. They were convinced that reported changes in
the annual yield of Norwegian cod fisheries represented natural
variations in the approach of the fish to the shore, and pointed out that
whilst the Norwegian take had increased after the establishment of
a hatchery at Flodevigen, so had the Danish and Swedish catch.
They could not agree that the Norwegian effort to propagate cod waa
influenoing the whole of the Skagerrak.
B. Experimental evidence
An attempt was made in Norway, between 1903 and 1906, to resolve
this dispute by experiment. Capt. Dannevig and Knut Dahl, representing both factions, conducted annual surveys for 0-group cod fky
with a 40-m seine net in two Skagerrak fiords, before and after brood
liberations from the Flodevigen hatchery. Table I is a summary of
basic data, taken from Dahl and Dannevig (1906) by Fulton (1908).
Dannevig took the view that liberations were generally effective,
whilst Dahl waa quick to emphasize the importance of natural
fluctuations (Hellefjord, 1903-4).
Both collaborators made extra observations to support their own
Particular convictions. Dannevig, for instance, compared variations
in the abundance of other fish fry during the experimental period, BS
Well as studying another area (Stendalsfjord). These extra resultaJ m
15
a few years ago by the Commission, indicated that the value of the
cod now annually taken on new grounds is at least sevgrd times
greater than the entire yearly expenditure of the Commission for
fish-oultural work, and is increasing each season.” Similar praise
regarding the effectiveness of cod hatching appeared in the U.S.
Commissioner’s reports for 1903 and 1906, and, as late m 1929, s t a b -
merits were being made to the effect that winter flounder became more
abundant after planting hatchery-reared larvae.
Dannevig (191Ob), in a report on the utility of sea-fish hatching,
referred to the decline in the cod fisheries of Southern Norway since
the middle of the nineteenth century, and the difficulty he had in
obtaining ripening fish for his hatchery ponds during the first few years
of work. The situation changed during 1891 and subsequent years,
after hatchery output was substantially increased. Dannevig was
unanimously supported by public organizations-parish
councils,
commercial societies and private fishermen. They all agreed that sn
imusual number of small cod made their appearance wherever fiy
were planted. and further, that the fish were usually of a oolour differing
from that of the looal raoe.
Hjort and Dahl (1900) were the leading critios of the marine
hatchery movement. They were convinced that reported changes in
the annual yield of Norwegian cod fisheries represented natural
variations in the approach of the fish to the shore, and pointed out that
whilst the Norwegian take had increased after the establishment of
a hatchery at Flodevigen, so had the Danish and Swedish catch.
They could not agree that the Norwegian effort to propagate cod waa
influenoing the whole of the Skagerrak.
B. Experimental evidence
An attempt was made in Norway, between 1903 and 1906, to resolve
this dispute by experiment. Capt. Dannevig and Knut Dahl, representing both factions, conducted annual surveys for 0-group cod fky
with a 40-m seine net in two Skagerrak fiords, before and after brood
liberations from the Flodevigen hatchery. Table I is a summary of
basic data, taken from Dahl and Dannevig (1906) by Fulton (1908).
Dannevig took the view that liberations were generally effective,
whilst Dahl waa quick to emphasize the importance of natural
fluctuations (Hellefjord, 1903-4).
Both collaborators made extra observations to support their own
Particular convictions. Dannevig, for instance, compared variations
in the abundance of other fish fry during the experimental period, BS
Well as studying another area (Stendalsfjord). These extra resultaJ m