BioLO(;icAL Survey — Erie-Xiagaka Watershed 23 



The temperatures recorded in Table 4 were taken at the following places: 



North Branch Wiscoy just above railroad crossing near the village of Bliss. This 

 must have been close to the lower limit of distribution of brook trout but brown 

 trout ranged a much greater distance downstream. 



Trout brook, just above highway bridge at Pike Five Corners. Both brook and 

 brown trout were present here. 



Wiscoy, main stream immediately below Bliss. Brook trout were not seen at this 

 point but brown trout were very abundant. 



Wiscoy, main stream at Pike Five Corners a distance of approximately 4.5 miles 

 below Bliss. Brown trout were found here but were more numerous at Bliss. 



In all three streams there was much colder water to be found 

 above the points of observation, and it may be said that brook 

 trout were more numerous in those sections having colder water. 

 Nevertheless it is interesting to note that brook trout in some num- 

 bers remained in temperatures as high as 75.5° F., and that browns 

 extended downstream into water having a still higher temperature, 

 the highest observed in this case being 81° F. 



The great difference between the upper AViscoy and the Fish 

 creek watersheds (Table 3) is to be found in the latitude and the 

 forest conditions. The Wiscoy flows through an open cultivated 

 region while the East Branch of Fish creek has its origin in an area 

 of approximately 70 square miles nearly all of which is covered by 

 forest and is a little farther to the north where the winters are more 

 severe. The maximum summer temperatures range two or three 

 degrees loAver; the forest cover tends to keep the ground and the 

 air immediately over the streams a little colder on hottest days and 

 consequently the water temperatures are held down to a greater 

 degree on such days than on moderately warm days. 



A Quantitative Study of the Fish Population in Streams. — 



During the latter part of June, attempts were made to study the 

 fish population of selected trout streams. The excessive rain, how- 

 ever, interfered with the plans to such an extent that it was ])0ssible 

 to carry out the program in but one case, Peg Mill brook located 

 near Groton, N. Y. 



The object of this study was to throw light upon a number of 

 questions, including the following : 



1. Total quantity of fish per unit area of stream. 



2. Ratio of trout to minnow population. 



3. Relative number of individuals belonging to each age group 

 represented. 



4. Rate of growth of wild trout. 



The procedure consisted in first measuring the stream, evaluat- 

 ing food and pool conditions and then, so far as possible, draining 

 the section to be studied by diverting the water to another channel. 

 Finally all fish were collected, weighed, measured and ages 

 determined. 



Only a very brief statement of results from the study of Peg 

 Mill brook can be given at this time. 



Average width of stream, 7.3 feet ; length of drained section, 

 1002 feet. Area of drained section 7348 square feet or .168-]- acres. 



