28 EIGHTH PACIFIC SCIENCE CONGRESS 



soundings, temperatures and water samples down to 3500 metres, and 

 carrying out investigations into morphology and submarine geology 

 with the help of samplers and seismic methods. Magnetic observations, 

 plankton hauls and bird observations were also made. 



Observations on the ascent and descent of the sound scattering 

 layer at sunset and dawn were plotted against light intensity measured 

 by a Secchi disc. They suggested that the migrations depended only 

 on light intensity with no regard to temperature gradients. The rate 

 of descent averaged 14 feet per minute; the ascents were more variable, 

 small groups of scatterers appearing to rise ahead of others, and the 

 rate varied from 9 to 3 feet per minute. In 40°N I48°E photographs, 

 were taken of a a short-tailed albatross (Diomedia albatrus) which had 

 been considered extinct for the past 15 years. 



A bottom sample was obtained from a depth of 5744 fathoms in 

 the Mariana's Trench. It has been described by the British Museum 

 (Natural History) as "dark brown ooze containing many remains of 

 diatoms and radiolaria." 



CANADIAN PACIFIC OCEANOGRAPHY SINCE 1949 

 By John P. Tully 



Since the last Pacific Science Congress, Canada has made consider- 

 able progress in oceanography. The nature and scope of our problems 

 have been recognized. The plans for research and education have been 

 established. The oceanographic resources have been organized. It will 

 be sufficient to show you the high-lights of our problems, work, and 

 organizations, and refer you to the bibliography for the details. 



Canada fronts on the Pacific, the Arctic and the Atlantic Oceans, 

 which are completely different in character, climate, and behavior. We 

 do not have the resources to conduct complete programs in all three 

 at the same time, but we have managed to get the essential work done. 

 If the total Canadian effort were concentrated in any one of these 

 oceans, it would be one of the world's major programs. However, the 

 development of our fisheries, industries, and sovereignty has made in- 

 creasing demands for information, particularly in the coastal approaches. 



A short description of the principal oceanographic features of these 

 three oceans will help you to appreciate the magnitude and diversity 

 of the Canadian problems. 



The Canadian Arctic is completely ice-bound from November to 

 June each year. As the ice in Hudson's Strait and Baffin Bay breaks up, 

 it is carried southward, by the Labrador Current, to meet the Gulf 



