REPORT ON OCEANOGRAPHY 109 



Because of the complexity of these problems, a dynamic model of 

 Puget Sound and Hood Canal was built in 1950. In this scale model 

 the tides and tidal currents can, be duplicated and studied in detail 

 and in addition the effects of variable river discharge in salt water in- 

 trusion can be tested. Some of the results of these investigations are 

 being reported elsewhere (Rattray, in press). Besides serving as a val- 

 uable research tool, the model is used as a teaching aid to demonstrate 

 the nature of tides and tidal currents and also to develop in the stu- 

 dents an understanding and appreciation of the local environment. The 

 facilities are frequently used by fisheries investigators and pollution 

 engineers to aid them in their studies. To supplement the model and 

 to make available to both research investigators and students a means 

 to study the nature and behavior of waves and tides under conditions 

 much simpler than those in the Puget Sound Model, a tank with trans- 

 parent sides 5 meters long and 2 meters wide and 0.5 meters deep has 

 recently been completed. 



Among the unique features available to the Department are Lakes 

 Washington and Union that are connected to Puget Sound through a 

 system of canals and locks. The penetration of salt water tln-ough the 

 locks into Lake Union was in fact the topic that first turned the atten- 

 tion of Dr. Thompson to Oceanographic chemistry some 40 years ago. 

 With increased use of the locks and limited supplies of fresh water run- 

 off, during recent years there has been some penetration of salt into 

 Lake Washington so that the average chlorinity has risen from about 

 3 p.p.m. to about 55 p.p.m. Although this increase may appear to be 

 rather minor, the lake is large and it represents an intrusion of some 

 250,000 tons of sea salts. Mr. Gunter Seckel, under the direction of 

 Dr. Rattray, has been investigating the physical processes involved in 

 the mixing and movements of the fresh and salt water. 



Under the leadership of Dr. C. A. Barnes, the Department has con- 

 tinued an active interest in Arctic oceanography. Faculty and staff 

 members have participated each summer in surveys in the Arctic on 

 board U.S. Naval Vessels. 



Many of the programs in Marine Biology described in previous re- 

 ports are being continued by the faculty of the Department of Zoology 

 at the Friday Harbor Laboratories and in space made available to them 

 in the Department of Oceanography. Projects carried on by faculty and 

 staff of the Department of Oceanography have so far been relatively 

 limited. In addition to the Bonneville Power Administration work, 

 mentioned above. Dr. Frolander has begun a program of plankton 

 sampling. During 1952-53 this was supplemented by the work of Dr. 



