Changes in solar radiation, water temperature, periphyton accumulation, and allochthonous inputs and storage were measured after we removed patches of deciduous, second‐growth riparian vegetation bordering two small streams in southeast Alaska that produce coho salmon Oncorhynchus kisutch. Solar radiation and leaf litter input were measured at the water surface at random locations dispersed through six alternating closed‐ and open‐canopy stream sections. Water temperature, periphyton, and stored organic samples were collected near the downstream end of each section. Solar radiation intensity was measured with digital daylight integrators and pyronometers, periphyton biomass and chlorophyll a were measured on red clay tile substrates, allochthonous input was measured with leaf litter baskets, and benthic organic matter was measured with a Hess sampler. Average intensity of solar radiation that reached the water surface of open‐canopy sections was significantly higher than in closed‐canopy sections of two streams measured during daylight hours in summer 1988 and of one stream measured day and night in summer 1989. Average daily water temperature was similar in the two canopy types in summer 1988, but was higher in open‐ than in closed‐canopy sections in 1989. Accumulation of periphyton biomass was significantly higher in open‐ than in closed‐canopy sections of the two streams studied in the summer of 1988 and of the one stream sampled in 1989. Accrual of periphyton biomass on tiles placed in the stream for 30‐d colonization periods during the summer months of 1989 was also significantly higher in the open than closed sections. Accumulation of chlorophyll a was significantly higher in the open‐ than in closed‐canopy sections of the two streams in 1988 but did not differ significantly between canopy types in 1989. Thirty‐day accrual of chlorophyll a was greater in open‐ than in closed‐canopy sections of the one stream studied in 1989. Allochthonous input to the streams decreased after canopy removal, but the amount of organic material stored in the substrate did not differ significantly between open‐ and closed‐canopy sections. Weather was predominantly overcast and rainy in summer 1988 and mostly sunny with infrequent rain in 1989. We speculate that advective heat transfer and high stream discharge from frequent rains moderated the effect of canopy removal and increased solar radiation on water temperatures in open‐canopy stream sections in 1988. In 1989, solar radiation was a significant factor in regulating water temperature, especially when streamflows were low. Using a model, we predicted that water temperatures would change little in a 160‐m open‐canopy reach of Eleven Creek during any weather condition when flows were high. With low flows, however, stream temperatures in open sections of Eleven Creek were predicted to exceed the optimum for growth of juvenile coho salmon in about 20 m during clear sunny weather and in about 50 m when cloudy and overcast.

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Hook‐and‐line gear is commonly used for monitoring the size and abundance of resident fish populations in southwest Alaska. The selectivity of the gear, however, may contribute to bias in the catch, making it difficult to detect changes in population structure over time. This study assessed the potential bias in sampling a population of rainbow trout Oncorhynchus mykiss with angling gear. A bidirectional weir was operated on Gertrude Creek from 1997 to 1999 to intercept the annual upstream spring migration of rainbow trout into the stream. Captured fish were measured and tagged to establish a population of marked individuals with a known length distribution above the weir. The marked population was then sampled with angling gear on three occasions during each of three summers. A variety of terminal tackle was used, and types were selected to maximize the catch of rainbow trout. Size selectivity was evaluated by use of an exact Kolmogorov–Smirnov (KS) test of the hypothesis that the length distribution of all marked fish was equivalent to that of the subset of marked fish recaptured by anglers during a single recapture event. Test results were not significant for any of the recapture events, providing strong evidence that length selectivity did not exist for fish within the size range of the marked population. An exact KS test was also used to test length distribution equality between the marked population and all fish captured during an angling event. All of these KS tests were significant, suggesting that the marked group was a size‐biased subset of the rainbow trout population in the drainage. The results of this study support the use of angling gear as a potentially viable sampling method for monitoring the size composition of rainbow trout in small southwest Alaskan streams.