Table 2, 'Nr-ara'her of chinook salmon examined at the Big VVhite 

 SalTion Hatchfry (apprcxirsately 30 miles above 

 Bonneville Dam) and mmber of injured fish ob??erved* 

 during the pioiod September 24-October 4, 1946. 



Total Dorsal fin Ventral fin Enoir cling 



Date examined ubrasicns abrasions abrasions 



ITo . ITo. Percent Mo. Percent No. Percer.-': 



9/24/46 547 r53 29.1 120 21. D 35 sTi 



9/26/46 1,207 264 21.8 200 16.6 50 4.1 



10/4/46 409 76 18.6 74 1^.1 17 4.2 



Totals 2,163 499 23.0 394 18.2 102 4.7 



* In addition to the injuries noted in the table, 37 fish or 1.7 percrnt had 

 open b odj'' wounds . 



Of the 499 fish with dorsal-fin injuries, 78.9 perocnt had the 

 accompanying ventral-fin injuries. All of the fish with encircling abra- 

 sions had both dorsal and ventral cuts. It is apparent in Figures 1 and 2 

 that these injuries v/ere caused by nets. 



Out of the total sample of 2,163 fish examined, 37 or 1.7 percent had 

 open body wounds. Two fish had open cuts in the peduncle area. The other 

 35 fish had cuts just bade of the head or crescent-shaped wounds on the 

 underside bet'/zeen the pectoral fins. No explanation is available of the 

 source of these injuries. 



Bonneville Hfatchery. Tanner Creek, v/hich flows through the hatchery 

 holding ponds, enipties Tn"'.::- the Coluribia River about a mile b-:low Bonne-vrille 

 Dam. As the fish enter Tanner Creek, most of them proceed upstream through 

 the raceway and directly into the hatchery holding ponds. A portion of the 

 later arrivals, hov/ever, remain in the raceway. 



The fish that have entered the holding ponds are collected for sorting 

 by the use of a 3 l/2 inc-h stretched-^iesh seine. Kales are separated from 

 females and placed in separate holding arens. At ths tine of spawning 

 operations, these fish are again collected by seining. 



"fthen the time arrives to ocllect spawn from the fish that have 

 remained in the racev/ay, the flow of vj-ater is decreesed to permit sein- 

 ing. Again the 3 l/2 inch seine is used for collecting the fish. It was 

 aonsicered impoosiblt for the fish to fiot dorsal, ventral, end encircling 

 abrasion;: in the net used because of the small size of the mesh. 



On September 20, the observer at Bonneville Hatchery reoorded only 

 dorsal-fin injuries, and it was found that these ocourred on 28.5 peroo:at 

 of the 56 fish examined on that day. 



?• 4 



