Mean daily vrater temperatures in Carp Greek during the periods 

 of operation of the vreir varied from 39.0 de;^-rees T. to 73.0 degrees 

 F. in 19h7, from 3^.0 decrees F. to 72.0 degrees F. in l^UO, and 

 frcsn 37.5 degrees F. to 79.5 degrees F. in 1914? (Figure 15-17; 

 Appendix C). Due to the small size o£ the creel: and the extremely 

 sl'iallov; character of its source, Carp Lalce, these teinperatiores 

 fluctuated vadely, reflecting closely even moderate changes in 

 vreather. 



In 19'l7j fror.1 April 21 until I.'ay 15, vfater ter.peratures were 

 predominantly below 50 degrees F, and the run during that period 

 ivas, on the average, light (Figure 15). At riean temperature levels 

 of hi degrees F., or lovrar, virtually no nigratorj'- activity occurred 

 (April 21-23 and liar/ 9). On Hay 16 the mean daily vmter ter.perature 

 rose above 50 degrees F. and, except for the period I.^ay 28-31, re- 

 mained well above that temperature for the balance of the run. Con- 

 currently, the greatest migratory activity began. The most pro- 

 nounced interruption in the run occurred during the period liay 23-31 

 vrhen the mean victor temperat^'ores fell to a lov/ of Iiij..5 degrees F, 



In 19U8, from April 7-lU, mean water te:"peratures were at or 

 belov; 1|0.5 degrees F. llo migrators^ activity occurred. A brief 

 rise on April 15 and 16 to the nid-forties brouj^ht in the first 

 migrants (Figure 16), A brief recession to near UO-degree levels 

 follov:ed, which interrupted the rim, A continuous, light run began 

 on April 22 as the v/ater temperature rose rapidly towards 50 degrees 

 F, On April 26 the v/ater temperature rose and remained above 50 

 degTees F. At the same tir,ie, the major upstream movement began. 

 A recession in water temperatures to a low of Iili.5 de^Tees F. between 

 Vsiy 8 and 12 interrupted the major upstream movement. On Hay 23 and 

 June 1-5, the mean water temperature rose above 65 degrees F. and 

 migratory activity v/as depressed. Cooling of the virater between these 

 tv/o periods, and folloTri.nc the second, v/as accompanied by increased 

 activity. 



In I9J4.9, from April 6 to 9, mean daily T/ater tem.peratui'es fluc- 

 tuated at or below UO.O degrees F. (Fi^gure 17). One sea lamprey 

 entered the trap on the last day of tliis period. A brief rise to 

 $3 degrees F. (April 10-15) brought in the first mirrants of the 

 run, A brief recession (April 16-1?) to a low of 37.5 degrees F, 

 interrupted the run. The run resined on April 13 with rising 

 temperatures and was thereafter continuous, though light, until 

 the miean daily water temperatures rose, and remained above 50 

 degrees F. on and after April 27. Folloiving this rise the major 

 upstreara movement took place. Two general temperature recessions to, 

 or below, the 50-degree level occurred during Hay 9-16 and I.Iay 26-29. 

 Recessions in m.igrator;;'' activity corresponded to these periods. On 

 June 3 and h and during June 12-11;, the mean water temperature rose 

 above 65 degrees F, A very noticeable decline in migratory activity 

 accompanied this condition. Cooling of tlie water to m.e.-=ns below 65 

 degrees F. between these two periods, and follovring the second one, 

 was accom^panied by an increase in upstream movement. 



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