The haddpck's range in North American waters is divided by the Furldian and Laurentihn channels (both over 185 metres deep) into the "New England", "Nova Scotian" and "Newfoundland" regions. Marking experiments and comparisons of the age composition of stocks and of the growth rates show that there is practically no interchange between the first two. To the haddock, which are bottom-loving fish and never abundant below 185 metres (100 fathoms), the channels are barriers producing three divisions of the population corresponding to the divisions of the shallow water area. Seasonal migrations are shown in both the New England and Nova Scotian regions. Haddock withdraw in winter from areas north of l{alifax and large haddock migrate into the gulf of St. Lawrence each summer. In midwinter the catches are chiefly below 70 metres (40 fathoms); in spring and early summer haddock appear well inshore in shallow water; in late summer they withdraw to deeper water; in late autumn they are caught in a great range of depths leaving the shallor:ver parts as winter approaches. Both horizontal and vertical movements are correlated with temperatureshaddock avoiding those near OoC. and lloC. and preferring intermediate temperatures. Prior to maturity the haddock are relatively stationary becoming increasingly active in seasonal migration thereafter and changing their distribution-e.g., older haddock accumulate in the eastern part of the Nova Scotian region. The New England and Nova Scotian populations are groups of more or less distinct smaller units;
Below 5 °C. oysters do not change in fatness, as judged by the ratio, dry weight to space between the valves. Between 5 and 15° they get thin. Between 15 and 20° they fatten. Above 20° they may fatten slightly but spawning makes them thin. When the salinity drops below 20‰ no fattening takes place even at temperatures between 15 and 20°.
The evolution of the Biological Stations established by the Government of Canada at St. Andrews, N.B., and Nanaimo, B.C., in the summer of 1908 is outlined from small operations with limited facilities ashore and afloat manned seasonally by volunteer university scientists to modern well-equipped laboratories used by year-round scientific and technical staffs. The excellence of the work of the two stations depended on the independence and scientific integrity of the Biological Board (1912–37) and the Fisheries Research Board (1937–73) with memberships combining representatives of government and industry with a majority of university scientists. Under the Board the stations maintained a high level of efficiency and a good balance between short-and long-term and between fundamental and applied research. Programs were responsive to the needs of government and industry and made important contributions to fisheries management and development both domestic and international in both the Atlantic and the Pacific. It is hoped that the new regime may be modified to enable the stations to continue the level of excellence achieved under the Board.
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