CALIFORNIA FISH AND GAME 153 



NOTES ON THE CALIFORNIA TROUT INVESTIGATIONS 



The new experimental weir constructed on Waddell Creek last 

 summer for use in detailed studies of life history and habits of the 

 sea-run steelhead trout has proven very satisfactory to date. This was 

 specially constructed to count downstream as well as upstream migrat- 

 ing- fish and while it catches all the latter fish, during periods of high 

 floods only a portion of the former fish can be caught. So far during 

 the present season approximately four hundred silver salmon and two 

 hundred steelhead have been handled at the weir, and the steelhead run 

 is still in progress. For the same period several hundred cottoids and 

 some immature trout were taken while migrating downstream. The 

 new weir is proving to be a great asset in working on problems relating 

 to the conservation of steelhead trout. 



Environmental studies made in Sierran streams such as the Merced 

 River in Yosemite Valley have shown that this stream averaged about 

 103 pounds of food per acre of riffle area in the month of February. 

 Food samples from the same areas in August showed an average of 85 

 pounds per acre. These are significant figures. They indicate that 

 contrary to the usual belief that foods are scarce in streams in the 

 winter time, there is at least as much food at this season of the year 

 and there may be more than in the summer time. Further investiga- 

 tions will be necessary to verify these findings. 



Waddell Creek, a coastal stream near Santa Cruz, M^as found to 

 average 198 pounds of food per acre of riffle area over all seasons of 

 the year, or more than twice as much as was found in the Merced River. 

 Lagoons of coastal streams are very rich in food. Waddell Creek 

 Lagoon was found to average over 250 pounds per acre of bottom area. 

 In this connection it is interesting to note that while aquatic insects com- 

 pose the bulk of foods in coastal and Sierran streams, lagoon foods are 

 largely shrimps and isopods. These are organisms which can withstand 

 extreme changes in salinity and other environmental conditions and at 

 the same time find ample food for themselves in such areas. 



Plans are rapidly being developed for an intensive stream survey 

 of the better fishing areas in California next summer. Through funds 

 allotted by the Public Works Administration to the United States 

 Bureau of Fisheries it is planned to operate several four-man field 

 parties to carry on intensive biological investigations in both streams 

 and lakes. This work is to be done in cooperation with the Division of 

 Fish and Game and the National Forest Service as an integral part of 

 the program of the California Trout Investigations. The object of the 

 work is to gather such facts on the waters investigated as will assist 

 in the formulation of well-balanced stocking policies. Detailed plans 

 for the work will be published later. 



In brief, excellent progress is being made on the problems upon 

 which the staff of these investigations are working, and this is due, in 

 no small part, to the splendid cooperation extended to us by officials of 

 the Division of Fish and Game, sportsmen, wardens, fish hatchery 

 men, and others. — P. R. Needham, Associate Aquatic Biologist, U. S. 

 Bureau of Fisheries, Stanford University, California, February 16, 

 1934. 



