and in other localities does agree with Dr. Tully's results. How was 

 the absence of a gradient accounted for in Bristol Channel ? It was 

 explained that in shallow water the opposition of strong tidal currents 

 may create these effects. 



Dr. Deacon stressed the importance of Tidly's work ; the biologists 

 ask important and difficult questions which he thought it not yet possible 

 to answer dogmaticalh'. Tully's methods would very soon acquire the 

 strongest importance in marine biology, and would be applied also to 

 oceanic currents from one region to another. 



SUMMARY OF DISCUSSION FOLLOWING ON JOINT SESSION 

 ■ OF OCEANOGRAPHY WITH BOTANY, ZOOLOGY. 

 AND METEOROLOGY 



Dr. Foerster opened by declaring that a challenge had been sent out 

 by the papers of Drs. Spilhaus, Tully, and Deacon to the biological 

 oceanographers to improve their methods in quantitative fish and 

 plankton recording, and to make thereby full use of the physical data 

 available for correlation. Mr. Powell commented that it might be difficult 

 for fish observations to be sustained during a movement through the 

 water at 20 knots. 



Dr. Johnson stated that high-speed nets were being perfected at 

 California Fish and Game and at Scripps Institutions. The stratifrcation 

 of occurrence of fish and plankton provided a difficulty, since there is a 

 lack of comparable regularity in distribution as against the physical 

 data. Dr. Miller pointed to the use of under-water listening-devices, and 

 Dr. Johnson to the use for detection of outward sound. 



Dr. Clements indicated some of the problems in which the biological, 

 oceanographers look to the physicochemical workers. We have not yet 

 reached the desired goal of complete correlation, and, as Dr. Deacon 

 had pointed out, we have still quite a long way to go before the physical 

 oceanographer is able to supply all the information the biologist needs. 

 Dr. Johnson hoped that the physical oceanographers would take to 

 heart the dictum that the real justification for physical oceanography is 

 in the assistance rendered to biology. Dr. Deacon confessed that it was 

 as yet difficult to cite an example of direct benefit to fisheries from the 

 work of the physical oceanographers. However, several speakers referred 

 to the use of echo-sounding in fish detection off the Norwegian coasts. 

 During his work with the " Discovery " expedition Dr. Deacon had, 

 however, come up against definite clearly stated problems in which the 

 aid of the physical oceanographer was sought. He laid stress on the 

 need for careful formulation of problems. He instanced the field of 

 whale research, where a definite fluctuation in abundance of whales from 

 year to year was correlated with variations in the supply of euphausids, , 

 which in turn was correlated with physical conditions. He begged the 

 biologists to be very patient for a while yet with the physical school. 



Speaking for the meteorologists. Dr. Spilhaus deplored the fact that 

 none of the American weather ships make oceanographic observations. 

 This was shortsighted even from the meteorologists' point of view. For. 

 instance, oceanic atmospheric energy exchange data would be very: 

 relevant in meteorology. Dr. TuUy spoke of the project to record hydro- 

 graphic sections off the west coast of Canada. It was obvious that more, 

 joint meetings were required between the two sciences. M. 



289 



10 — Pac. Congress 



