306 
BULLETIN OF THE BUREAU OF FISHERIES 
The catches of the Killisnoo plant show large variations that may be partially 
caused by biological factors, such as the passage through the catch of dominant year 
Figure 45.— The catch of raw herring by the reduction plant at Killisnoo, on upper Chatham 
Strait, from 1883 to 1920, inclusive. The trend was obtained by the method of least squares 
(omitting 1883, because the guano plant was not installed until 1884, and omitting 1888, in 
which year the first company was reorganized) 
Figure 45. — Catch of raw herring in southeastern Alaska from 1910 to 1928, inclusive. Heavy 
line, total catch. Light line, amount converted into by-products. Broken line, amount 
pickled by the reduction companies since 1920 
groups. But it would be presuming to definitely ascribe any of the changes in the catch 
to biological factors without an intimate knowledge of the many other factors concerned. 
