36 ILLINOIS AUDUBON BULLETIN 
Channelization Reduces Fish Population: 
by LONNIE WILLIAMSON 
Wildlife Management Institute 
Researchers in California have found that channelized sections of a 
stream support less fish life than unchannelized portions of the same 
stream, according to the Wildlife Management Institute. 
Reporting in the July 1976 edition of “California Fish and Game,” 
researchers said that channelized and unchannelized sections of Rush 
Creek, Modoc County, California were compared to determine the im- 
pact of channelization on fish populations, especially those of trout and 
the rare Modoc sucker. 
The researchers said, “Channelized sections contained fewer and 
smaller trout, as well as a lower biomass, than the unchannelized sec- 
tions. Modoc sucker numbers and biomass were also lower in the chan- 
nelized sections. Only Pit sculpin were consistently more numerous in the 
channelized sections. Overall, total fish biomass in the channelized sec- 
tions was less than one-third of that in the unchannelized sections. The 
biomass of invertebrates in the channelized sections was found to be less 
than one-third of that in the unchannelized sections. The invertebrate 
species composition of the two areas was also different.” 
(President’s Message continued from page 2) 
a scientific bent. One can study such things as bird behavior, 
migration, habitats, populations and songs. Amateur birders have 
made significant contributions to ornithology, the study of birds. For 
those with artistic or photographic talents, birds have always been 
popular. 
Many birds have learned to live with us. Now, many people are 
discovering that most of our birds can be interesting neighbors; they 
give us a closer tie with nature’s ways. Migrant birds tell us when 
Spring or Fall is coming; bird activity at feeders indicate coming 
weather conditions. A bird’s song, whether the thin melody of a 
White-throated Sparrow or the raucous harmony of a flock of 
Canada Geese is a reminder that nature composed a tune in some 
long-forgotten time. The way birds are made: their design, their 
color, their song, seems to indicate that they were intended to be 
something special. Many of us think they are. 
—Peter B. Dring 
P.O. Box 92 
Willow Springs, IL 60480 
