Creel returns of stocked rainbow trout Oncorhynchus mykiss are often below management objectives. In the Hoover Dam tailwater, Colorado River, predation by striped bass Morone saxatilis limits creel returns of stocked rainbow trout. On two occasions, we stocked large (33‐em) and small (21–25‐cm) rainbow trout into the tailwater to compare returns to the creel. Angler return rates for the two stockings were 47% and 22% for the large fish and 1 % and 2% for the small fish. Costs of large fish returned to the creel were US$6.02 and $12.86 per fish for the two stockings. Costs of small fish returned to the creel were $59.00 and $29.50 per fish for the two stockings. Annual survival of large rainbow trout did not increase compared with small fish. Stocking large rainbow trout is a cost‐effective option for the Hoover Dam tailwater and may improve creel returns in other waters where predation limits survival of stocked fish.

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We examined redd microhabitat characteristics of an adfluvial population of rainbow trout Oncorhynchus mykiss in Trail Creek, a third-order tributary to Deep Creek in the Kootenai River drainage, Idaho. We also monitored timing of spawning in relation to stream temperature and discharge. A total of 103 suspected redds were found; 51 of these were measured and checked for the presence of eggs. Thirty-four were actual redds (contained eggs), while 17 were test digs that did not contain eggs. Rainbow trout began spawning on 14 April 2005, 13 d after peak discharge (1.9 m 3 /s), as mean daily temperature exceeded 4.08C. Redds had a mean area of 1.19 m 2 (SD ¼ 0.62; range ¼ 0.27-2.40 m 2 ), a mean water depth at the pit head of 0.18 m (SD ¼ 0.08; range ¼ 0.05-0.38 m), and a mean water velocity at the pit head of 0.39 m/s (SD ¼ 0.15; range ¼ 0.08-0.67 m/s). Area, total length, and width were the only microhabitat variables that differed statistically between redds and test digs; the mean area of the test digs was 0.72 m 2 (SD ¼ 0.67; range ¼ 0.22-2.60 m 2 ). However, the ranges of microhabitat measurements for redds and test digs overlapped; therefore, distinguishing redds from test digs based solely on size, without verifying the presence of eggs, is unlikely. These data could be used to help guide spawning habitat enhancement projects or to create or quantify spawning habitat for adfluvial rainbow trout. The presence of an appreciable number of test digs indicates that redd counts should not be considered a surrogate for numbers of spawning adfluvial rainbow trout; additionally, our results have implications for the use of redd counts to monitor other adult salmonid populations.

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We recorded habitat variables including macrohabitat type (run or pool), substrate, cover type, stream depth, and light level periods for focal point observations of smallmouth bass Micropterus dolomieu while snorkeling along transects in the Buffalo River, Arkansas. We used logistic regression analysis to determine which habitat variables were important in discriminating between the presence of age‐0 (<100 mm) and older fish as an indication of microhabitat segregation. Runs and pools were occupied by both groups of smallmouth bass, though a higher proportion of age‐0 fish were observed in pools. Age‐0 smallmouth bass were not restricted to stream edges and runs as in some eastern United States streams. A fitted model for run microhabitats indicated that bedrock, silt, sand, gravel, aquatic macrophytes, boulders, and light period were significant predictors of an age‐0 smallmouth bass observation. Significant predictors in pool microhabitats included cobble, undercut banks, depth, and light. Thus, we found evidence of intraspecific microhabitat segregation in the Buffalo River. We conclude that Buffalo River smallmouth bass are habitat generalists and may not be a good indicator species of the effects of habitat alterations. Our evidence of intraspecific habitat segregation indicates the need to identify relations between habitat use and survival of age‐0 fish.