CONFERENCE ON SALMON PROBLEMS 



97 



they come to the place where the Baker 

 River, a major tributary, joins the river. 

 There there is an eddy in which they mill 

 around for a variable time depending upon 

 the definiteness of the current from the 

 Baker. But all of the sockeye turn into the 

 Baker instead of following up the Skagit, 

 although the angle between the two streams 

 is reentrant and they have to turn in some- 

 what the opposite direction from their previ- 

 ous course. In larger eddies not at stream 

 junctions salmon often mill around, head- 

 ing into the current of the eddy and leaving 

 it apparently when drawn into contact with 

 stronger downstream currents at the margin 

 of the eddy. 



Now, after studying the situation at the 

 junction of the Skagit and Baker as to 

 chemical, physical and other differences be- 

 tween the two streams, I demonstrated a 

 constant and consistent difference between 

 the two streams at the time of the sockeye 

 migration of something like two degrees 

 Fahrenheit. To leave no question as to the 

 consistency and accuracy of the tempera- 

 ture records, two recording instruments 

 were placed just above the junction where 

 the streams are perfectly free of possible 

 connection, and yet so near as to show con- 

 ditions where the waters mingled ; records 

 were obtained for 24 hours per day 

 throughout the entire period. Some fluc- 

 tuations in the stream are observable due 

 to warm days, melting snow or ice in gla- 

 ciers from the mountains which drain into 

 the two streams. But these temperature 

 fluctuations are slight and preserved that 

 consistent relation noted until about mid- 

 September, when strikingly enough the con- 

 dition was reversed and after that the tem- 

 perature on the Skagit River was steadily 

 lower than on the Baker. There is a small 

 sockeye run in the fall and those fish were 

 caught above the junction of the Baker and 

 in the Skagit. 



Attention must be directed to a change 

 which was brought about by the installa- 

 tion of a hydro-electric plant, a mile above 

 the junction of the two rivers, and a dam 

 by which was formed a lake eleven miles 

 long. Temperatures in that body of water 



became considerably altered. The surface 

 temperature was very much higher than the 

 water had ever been in the canyon pre- 

 viously. The river was fed by water taken 

 out for the plant and the temperature in 

 the tailrace was lower than ever before ; sub- 

 sequent to the construction of the dam the 

 temperature was four degrees lower in the 

 Baker than in the Skagit but the choice of 

 the salmon for the Baker River was not 

 modified by a drop of that extent. 



Going to a point a little higher up on the 

 Baker, I found a remarkable example of 

 the effect of the quality of the water. At a 

 point before you reach Baker Lake Sulphur 

 Creek runs into Baker River ; it was fed by 

 springs and melting snow on the side of 

 Mount Baker, and was distinctly colder 

 than the river itself. But the creek water 

 was highly impregnated with sulphur. 



Some years ago the fish went right past 

 that cold water and that seemed to contra- 

 dict my views with relation to temperature 

 influences. I had the opportunity of test- 

 ing the effect later. At a time some ten 

 years after I started my observations. Sul- 

 phur Creek was diverted from its course 

 well up on the mountain. The water from 

 the lava fields impregnated with sulphur 

 was turned into another stream which fed 

 a commercial power plant. After that Sul- 

 phur Creek was fed exclusively by large 

 springs below the lava and the water was 

 clear, cold and pure. 



I visited the place by routine two years 

 after this change was made. I found to 

 my astonishment that sockeye were enter- 

 ing Sulphur Creek and were attempting to 

 go up in considerable numbers. I studied 

 the stream continuously and found that 

 until a time some two weeks later when the 

 volume of that stream became very small, 

 the fish scrambled up as far as they could 

 or until they reached a long rapids which 

 large fish could not ascend. Later they 

 came up into small bays below these rapids, 

 swimming around and trying to make the 

 ascent; ultimately as the water fell still 

 further they went back to the Baker River 

 and up to Baker Lake. 



The quality of the water that I have re- 

 garded as a chemical factor, I believe influ- 



