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Results

Although the sampling technique permits estimation of numbers and biomass in the sample sites, the associated statistical bounds were often large. Rather than comparing imprecise population estimates, it seems more meaningful to compare the size distribution of fish actually captured at each site. Since collection techniques were comparable from 1987 to 1996, relative numbers in different years can also be compared. The 1986 data, which were collected in the same sites, but by a different method (collection of total kill) would be expected to yield slightly higher numbers as compared with subsequent years. The 1984 data is the least comparable, since the sites sampled did not exactly correspond (areas were larger but included some deeper pools where electrofishing was less effective) and at the lower (detox) site many small, non-game fish were not measured.

In interpreting data for the large cyprinoid fishes (Sacramento sucker, Sacramento squawfish, and hardhead), keep in mind that these fish travel in shoals which move from pool to pool in the creek. Getting many large ones (or no large ones) on a given sampling date is partly a function of whether or not a shoal chanced to be in the sampling site, particularly when the creek population is low. (Hardhead data for the detox site provides an excellent example.)

Data and descriptions are presented for individual species:

Family	Common Name	Sci Name	Description	Data
Salmonidae	Steelhead Rainbow Trout	Oncorhynchus mykiss	Description	DATA
	*Brown Trout	Salmo trutta	Description	DATA
Cyprinidae	Hardhead	Mylopharodon conocephalus	Description	DATA
	Sacramento Squawfish	Ptychocheilus grandis	Description	DATA
	California Roach	Hesperoleucas symmetricus	Description	DATA
Catostomidae	Sacramento Sucker	Catostomus occidentalis	Description	DATA
Centrarchidae	*Green Sunfish	Lepomis cyanellus	Description	DATA
	*Smallmouth Bass	Micropterus dolomieui	Description	DATA
Cottidae	Riffle Sculpin	Cottus gulosus	Description	DATA

* Introduced species.

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Results Last Updated September 21, 1996