74 SALMON AND TROUT TN ALASKA. 



far beyond the receiving bays, and if currents are a prominent 

 factor fish enterino; Behni Canal should all travel to the Unuk. 



The influence of flood water on schools near a river's mouth may 

 be due in part to an increased temperature of the water as well as to 

 an augmented volume. It is well known that in dry seasons, when 

 the streams are low, even though a sufficient depth for a practicable 

 ascent may remain, schools tarry in the bays much longer than in 

 rain}^ seasons. But as this is marked only in the case of small streams, 

 the main factor must be the volume or quantity of water. 



ASCENT OF STREAMS. 



The speed of the salmons' ascent of rivers is perhaps modified 

 by various conditions. In short streams of Southeast Alaska large 

 fish are not noted in the rivers except wliile passing difficult falls. 

 In the Naha they seem to make the distance from tide water to the 

 lakes traveling at night, hence not observed. At Dorr Falls, on the 

 Naha, humpbacks which were constantly jumping at the fall through- 

 out the day made no attempts at night. This lack of movement 

 at night can not hold for waters of other character. 



Observations on the Karluk indicated that about ten days were 

 consumed in making the ascent there, a rate of 2 to 3 miles per day, 

 the main movement occurring after 4 o'clock p. m. 



Rutter estimated that the spring run of king salmon in the Sacra- 

 mento ascend from the ocean to their spa^vning beds at the average 

 rate of 10 miles per day. If some of this time is lost in the ebb and 

 flow of tides in the bay, the rate in the river is in excess of this. 

 The fall run, he determined, ascended the river at the rate of 4 or 5 

 miles per day. Earlier observers supposed the fall fish to travel 

 the faster." Sockeyes are reported to reach the Quesnel Dam, 500 

 miles up the Eraser, about the middle of August; in 1906 the first 

 arrived July 26. These are perhaps the fish entering the river in 

 May and June, and if so they travel at a rate between 5 and 10 

 miles per day up a rapid river — ascending in that time to an altitude 

 of 2,250 feet. The run continues at this point until September, 

 perhaps including a part of the heavy July run at the mouth of the 

 river. This would indicate that the rate of ascent is more nearly 

 the liigher figure, or that it is about ecjual to that of the early 

 Sacramento fish. The variation between this movement and that 

 in the Karluk is notable. Does it indicate any knowledge on the 

 part of the fish as to the extent of the journey that is to be performed i 



No observations are recorded regarding the movement of the coho 

 or of the steelhead. The coho probably ascends rapidly when travel- 

 ing for such points as the Wallowa and Baker Lake regions. The 

 time occupied by schools of fish in the brackish water before entering 



o Report Commissioners of Fisheries, California, 1876-77, p. 10. 



