Table 2. — Summary of analysis of variance data for tests conducted under 

 ideal field conditions, Harris River, 1956-57 



Test 



Between observers 



Between counts 



l.LiTl n.s. 



5.178 2 



2.230 n.s. 



1.57li n.s. 



1.250 n.s. 

 0,021 n.s. 

 2.049 n.s. 

 0.505 n.s. 



N.s. means not significant. 



Statistically significant at the 5-percent level. 



Results indicate that under ideal conditions, 

 variability in riffle counts was low between 

 different observers and between successive 

 counts by the same observer. 



Resxilts of Second Set of Tests 



Test IIA.--Five observers counted live pink 

 salmon in the Harris River intertidal zone 

 (containing both pools and riffles), first in 

 an upstreann direction and then in the same 

 area in a downstream direction. Results are 

 given in table 3. 



Analysis of variance of these data shows 

 no significant difference (95 percent) either 

 between observers or between counts. 



Test IIB.-- Three observers counted live 

 pink salnnon in Harris River from the 13-foot 

 tide level to the Fisheries Research Institute 



terminus (about 8,000 feet; such a ternninus 

 nnarks the end of a survey area and is usually 

 located upstream from greatest abundance of 

 spawners). The counting area was divided into 

 three sections and subdivided into pools and 

 riffles (some variability may have occurred be- 

 cause of an observer's idea of what constituted 

 a pool and what a riffle, but these were fairly 

 well defined). Results are given in table 4. 



In this test variability be twee nob servers was 

 generally high and was higher in estimates of 

 numbers of salmon in pools than on riffles. Very 

 high variation in counts of salmon in pools in 

 section 2 (C.V, almost 100 percent) is an indica- 

 tion of what we can expect from pool estinnates. 



Test lie. --The observers who conducted 

 test IIB counted live pink salnnon in the same 

 portion of the Harris River again on Septem- 

 ber 11, 1957. Results are shown in table 5. 



Table 3. — Test IIA conducted in Harris River intertidal zone, 

 September 10, 1957 



^ standard deviation. 



2 Coefficient of variation (in percent). 



