Table 1. -Numbers of fish taken in 1962-63 in the Elokomin River and Herman Creek, by time and area of sampling 

 and species collected 



We made one collection of predators with 

 electrofishing gear in Herman Creek in the 

 outlet channel on the morning after release 

 of the salmon. By this time all but a few 

 salmon had moved into the Columbia River 

 during the night. Fish observed or collected 

 in the outlet channel included the hatchery 

 chinook salmon fry; prickly sculpins, C. asper; 

 reticulate sculpin, C. perplexiis; and one rain- 

 bow trout, Salmo gairdneri. 



Laboratory Procedure 



The collected fish were preserved in For- 

 malin. Data recorded were total length of 

 sculpins, fork length of other fishes, and 

 stomach contents ; for specimens collected in 

 1962 in the Elokomin River and Herman Creek, 

 the lateral gape of mouth (length measured 

 by calipers with l-ounded fingers 3 mm. in di- 

 ameter) was recorded. 



Numbers of salmon in stomachs of preda- 



tors were counted. When remains of salmon 

 were present, I assumed that they were eaten 

 within a 24-hour period. Supplementary field 

 studies indicated that a sculpin could digest 

 a salmon 60 mm. long in a 24- to 28-hour period. 

 Lengths and species of salmon recovered from 

 stomachs of predators were recorded when pos- 

 sible. Of 235 prey fish recovered from sculpins 

 in the Elokomin River, 155 were chinook 

 salmon, 2 were coho salmon, and 78 could not 

 be identified. Prey species of salmon other 

 than chinook were not observed in Herman 

 Creek. The incidence refers to percentage of 

 predators containing salmon; rate refers to 

 occurence of a salmon per stomach; and in- 

 tensity refers to incidence and rate. 



SPECIES AND HABITAT 



IN THE LOWER ELOKOMIN RIVER 



In addition to chinook salmon fry (pre- 

 sumed to be of hatchery origin), the species 



