Idaho Streams Research Articles

Nitrogen and phosphorus uptake in two Idaho (USA) headwater wilderness streams.

Nitrate and phosphate solutions were released into two reaches of two central Idaho streams to determine within- and between-stream variability in uptake lengths, uptake rates, and mass transfer coefficients. Physical and biotic stream characteristics and periphyton nitrate-uptake rates in recirculating chambers were measured to determine their influence on nutrient dynamics. Phosphate uptake length did not differ among the four reaches. There were no within-stream differences in nitrate uptake lengths but they did differ between the two streams. Long nitrate uptake lengths likely were due to instream concentrations above saturation but also may have been influenced by differences in active surface area and algal abundance. Nitrate and phosphate uptake lengths were longer, and uptake rates higher, than most other published values. However, mass transfer coefficients were comparable to measurements in other streams. Mass transfer coefficients may be a better parameter for temporal and spatial comparisons of instream nutrient dynamics, and for determining the underlying causes of variability in uptake length.

Processing of native and exotic leaf litter in two Idaho (U.S.A.) streams

The Russian olive tree (Elaeagnus angustifolia L.) was brought to the western United States from Eurasia during the early to mid-1900s, and has since become a common member of many riparian communities in Idaho. We compared leaf chemistry and in-stream processing of Russian olive leaves (exotic) and various species of native leaves in one hardwater and one relatively softwater Idaho stream. Measurements using air-dried leaves showed that Russian olive contained the greatest concentration of nitrogen, approximately 1.6% of the dry mass, whereas the native species each contained less than 1.0% nitrogen. The C/N ratio of Russian olive was <30, whereas the natives each had C/N ratios greater than 40. Results from the hardwater stream indicated no difference in 30-day loss of AFDM between Russian olive and the native leaves (dogwood and aspen). In the relatively softwater stream, the Russian olive leaves were processed significantly slower than the native leaf species (cottonwood). The results indicate that a replacement of native riparian trees by exotics, such as Russian olive, may result in slower rates of leaf processing in Idaho streams but that the effect may vary among streams. When comparing the processing of native and exotic leaf litter, initial nitrogen concentrations and initial C/N ratios of the leaves did not appear to be accurate indicators of relative decay rates.

Enhanced Incubation Success for Kokanee Spawning in Groundwater Upwelling Sites in a Small Idaho Stream

Abstract Kokanee (Oncorhynchus nerka lacustrine sockeye salmon) spawned in groundwater upwelling in the North Fork of the Payette River, Idaho. Intragravel water temperatures in groundwater-influenced redds exceeded surface flow water temperature by 2.4–2.6°C. In redds without groundwater influence, intragravel and water column temperatures did not differ by more than 0.2°C. Although redds constructed in upwelling sites contained significantly more fine sediments (<0.83 mm) and were constructed in areas of significantly lower surface water velocities than redds not influenced by upwelling, preemergent survival of fry from redds in upwelling sites (84%) significantly exceeded that from redds in other areas (66%). Higher incubation temperatures at upwelling sites accelerated rates of development, protected embryos from freezing, and may increase survival of fry recruiting to Payette Lake.

Annual hysteresis in bed load rating curves

The relationship between flow and bed load transport measured for 10 years in six gravel‐bed streams in Idaho exhibits annual hysteresis. At a given flow rate, more bed load is carried by discharges preceding the first annual occurrence of a “threshold” rate, which is characteristic of each stream. Incorporating the effect of hysteresis leads to a small improvement in the fit of the bed load–flow regression. As the turning point for hysteresis, a constant threshold discharge is found to work better than the annual peak discharge. This bimodal hysteresis model is also found to out perform one with a more gradual transition, based on cumulative discharge. These results are interpreted to reflect a buildup of readily moved sediment supplies during the low‐flow periods from late summer to early spring, supplies which are then exhausted by rising springtime discharges up to the threshold. The threshold is greater than mean annual discharge and about one‐half bank‐full discharge.

Macroinvertebrate communities, secondary production, and life history patterns in two adjacent streams in Idaho, USA

We compared community attributes, secondary production, and life histories of macroinvertebrates in two adjacent streams with contrasting environmental characteristics. Environmental variables (measured as coefficients of variation) were up to an order of magnitude greater in Little Lost River (Lost River) than in Birch Creek. In particular, the flow regime was 12 x more variable in Lost River, a stream fed largely by surface runoff, than in Birch Creek, a groundwater-fed stream. Birch Creek accumulated more annual degree days, had higher ionic concentrations, and developed greater periphyton biomass than Lost River. Although, the mean density of macroinvertebrates was similar between the streams, species richness was higher and mean biomass was lower in Lost River. Annual macroinvertebrate production was dominated by Chironomidae and was 1.6 x higher in Lost River than Birch Creek. However, if Chironomidae are excluded, total annual production was 1.5 x greater in Birch Creek than in Lost River. Life cycles of some common taxa reflected the different environmental conditions in each stream. Our data support the idea that certain attributes of macroinvertebrate assemblages (density, biomass, and production) are structured by environmental factors regulating growth (e.g. water chemistry, thermal loading, periphyton), whereas other biotic attributes (e.g. species richness, assemblage composition, and life histories) are more influenced by thermal and flow regimes.

Macroinvertebrate community structure in relation to measures of lotic habitat heterogeneity

We examined the relationship between habitat heterogeneity and benthic macroinvertebrate assemblages in thirty-two 2nd to 6th order wilderness streams in central Idaho. Twenty-one environmental measures were evaluated for each stream with their heterogeneity expressed in terms of coefficients of variation (CV'S). Although the annual range in water temperature was greater in the larger (5th and 6th order) streams, most other habitat measures showed greater variation among smaller streams (2nd order) than larger streams. Mean habitat-CV's also were about 20% greater for smaller (2nd order) than larger (5th and 6th order) streams, suggesting a homogenizing influence of stream size on habitat heterogeneity. Multivariate analyses of the habitat measures clearly separated 5th and 6th order streams from ≤4th order streams, further indicating major environmental differences between larger and smaller stream systems. Multiple regression and canonical correspondence analysis revealed that some biotic properties, e.g. % shredders, were associated with stream size, reflecting longitudinal changes in food resource availability or annual variation in temperature, while others, e.g. Shannon's diversity, were more dependent on measures of within-reach habitat heterogeneity.

Physiological profiling of indigenous aquatic microbial communities to determine toxic effects of metals

Conventional bioassays for environmental assessment frequently rely on nonindigenous single species. We employed an assay in which whole environmental samples were distinguished by the ability of the native heterotrophic microbial communities to oxidize 95 different sole carbon sources generating a community-level physiological profile (CLPP). The average metabolic response (AMR) to the 95 variables defining the CLPP was used in laboratory bioassay studies with copper to construct dose–response curves over several different periods of exposure: 1 h (acute), 1 d, 2 d, and 4 d. The acute dose–response of Snake River bacterioplankton communities measured by AMR was compared to the dose–response of Photobacterium phosphoreum (used in the Microtox test) and a proprietary mixed consortia (used in the Polytox test). In laboratory bioassay studies, CLPP AMR exhibited acute dose–response behavior over a greater range in copper concentrations and with less variability (per dose) than Microtox and Polytox. The acute sensitivity of CLPP AMR to copper was roughly equal to Microtox and much greater than Polytox. After a longer exposure (1 d) to copper, Snake River communities became more sensitive to copper but no additional effect was observed when the exposure was increased to 2 and 4 d. Snake River communities pre-exposed to copper (1 mg/L) for 4 d prior to acute dose–response experiments showed no difference in AMR with respect to doses up to 10 mg/L, indicating the ability of the assay to detect adaptation. Several metal-contaminated streams in Idaho were used to field validate the CLPP approach for detecting impacts of metals in the environment. The response profiles of the bacterioplankton from two downstream sites receiving metal laden mine drainage were compared to those from reference sites upstream and further downstream of the location receiving the mine drainage. The AMR of the communities at the stream reference sites were greater than sites just below the mines. We ascribed this finding to acute physiological insult near the mines and subsequent recovery downstream. Multivariate analysis revealed differences in the pattern of carbon source utilization between chronically stressed (mine waters) and unstressed communities (reference stream sites). At the third site, treatment of mine drainage by an artificial wetland was assessed above and below the wetland; water exiting the treatment wetland had a higher AMR than water that was untreated. The CLPP approach has sufficient sensitivity to detect acute contaminant impact on physiological processes of the indigenous microbial community while providing data for evaluation of chronic stress-induced adaptations in microbial community structure.

Temperature patterns in small streams following wildfire

We examined the influence of a moderately severe wildfire on the thermal patterns in three small streams in central Idaho, USA, for an 11-month period beginning ten months after the fire. Two streams in unburned catchments served as reference sites. No differences were observed between the burned and reference streams in daily minimum temperatures or in the general thermal conditions during winter. During late summer and early autumn, when solar radiation was greatest, the burned streams displayed warmer temperatures than did the reference streams. During non-winter months, the burned streams experienced diel ranges in water temperature 2-3 x greater than those of the reference streams. Despite these differences, the number of degree-days accumulated among the streams was similar. In general, the wildfire altered the thermal stability of the burned streams, relative to the reference streams. Return to a pre-fire condition is expected to occur as riparian vegetation (shading) recovers along the burned streams.

Habitat utilization and diel behavior of juvenile bull trout (Salvelinus confluentus) at the onset of winter

Abstract— Underwater observations were used to describe habitat use and diel behavior of juvenile bull trout (Salvelinus confluentus) at the onset of winter (0.8°C) in a second‐order central Idaho stream. All fish observed during daytime counts were concealed beneath “home stones” (mean dimensions 32.3 by 21.9 cm) in primarily pool and run habitats. Focal point depths and velocities averaged 57.2 cm and 4.7 cm/s (home stone removed). Fish maintained stations over substrate with low percentages of fine (&lt; 2 mm, mean= 5.2%) sediment. Concealed bull trout were not evenly distributed across the stream channel. Significantly more home stones were distributed near the midline of the channel, compared to the channel margins. Fish size was positively correlated with home stone size. At night, bull trout exhibited a diel behavioral shift, some fish moved out of daytime concealment cover into the water column. At night, bull trout were observed feeding and resting, primarily in pool and run habitats. During both day and night, bull trout used riffles significantly less frequently than those habitats were available.

Use of Passive Integrated Transponder (PIT) Tags to Monitor Migration Timing of Snake River Chinook Salmon Smolts

Abstract Before 1989, there was little detailed knowledge of the migrational timing of wild smolts of Snake River spring and summer chinook salmon Oncorhynchus tshawytscha from individual streams. With the development of the passive integrated transponder (PIT) tag and methods for collecting and tagging parr, acquisition of information on migrational timing became feasible. We PIT-tagged wild chinook salmon parr in several streams in Idaho and Oregon each summer from 1988 through 1990. Each subsequent spring and summer, we detected surviving smolts on their migration through Lower Granite Dam. We also PIT-tagged hatchery-reared parr during fall or late winter and compared their migrations with those of wild fish. Migrational timing of wild smolts through Lower Granite Dam varied for fish from different streams and also differed from hatchery-reared fish. Generally, wild spring chinook salmon migrated later and over a more protracted period than their hatchery-reared counterparts. Wild summer chinook salmo...

Comparison of Day Snorkeling, Night Snorkeling, and Electrofishing to Estimate Bull Trout Abundance and Size Structure in a Second-Order Idaho Stream

Biologists lack sufficient information to develop protocols for sampling the abundance and size structure of bull trout Salvelinus confluentus. We compared summer estimates of the abundance and size structure of bull trout in a second-order central Idaho stream, derived by day snorkeling, night snorkeling, and electrofishing. We also examined the influence of water temperature and habitat type on day and night counts of bull trout. Electrofishing yielded the largest estimates of abundance of age- 1 and older bull trout. Day snorkeling counts accounted for a mean of 75% and night snorkeling counts a mean of 77% of the fish estimated by electrofishing. Numbers of age- 1 and older bull trout observed during day counts did not differ from numbers observed at night. Water temperatures during underwater surveys were 9–13.5°C. Counts were not influenced by temperatures in this range; however, statistical power of the tests was low. The three sampling techniques yielded similar estimates of the size structure of the bull trout population. When compared with electrofishing, underwater estimates recorded fewer small fish and overestimated the size of some fish. We detected no significant interaction between the type of snorkeling count (day or night) and fish densities observed in different habitat types. Densities of bull trout observed during both day and night were similar, regardless of the habitat type. Under the conditions of water temperature, conductivity, visibility, and habitat in which we sampled, day snorkeling surveys were suitable for estimating the relative abundance and size structure of the bull trout population. Our results conflict with those of other studies that suggest night snorkeling is more effective than day snorkeling for censuring bull trout. Explanations for this discrepancy may include differences in stream temperature and stream channel features.

Winter concealment by subyearling rainbow trout: space size selection and reduced concealment under surface ice and in turbid water conditions

The proportion of rainbow trout (Oncorhynchus mykiss) concealing themselves in simulated interstitial spaces was examined in the presence of surface ice, in turbid water, and in clear water. Tests were conducted in enclosures in a small Idaho stream with structures that provided five rectangular spaces varying in width and height, one circular space, and one triangular space. Space use was assessed each morning by trapping test fish inside the structures. Significantly more fish concealed themselves under clear water conditions than under either surface ice or turbid water conditions. Spaces narrower than the width of a test fish with extended pectoral fins and spaces taller than the height of a test fish with dorsal fin extended were used less than would be expected if space use was random. The frequency with which two or more fish occurred together in the same space was similar to that expected if fish occurred together at random. Fish rarely returned to the same space on consecutive nights.

Capture, Marking, and Enumeration of Juvenile Bull Trout and Cutthroat Trout in Small, Low-Conductivity Streams

Abstract Relative efficiencies of sampling methods were evaluated for bull trout Salvelinus confluentus and cutthroat trout Oncorhynchus clarki in small, high-gradient streams with low conductivities. We compared day and nighttime observations by snorkelers to enumerate bull trout and cutthroat trout, and at night we also used a bank observer. Methods were developed for capturing juvenile bull trout in areas where traditional methods such as electrofishing were ineffective. Juvenile salmonids were counted during the day and night in two reaches (200 m) of Trestle Creek, Idaho, in August 1991. In July 1992, juvenile salmonids were counted during the day and night in 10 reaches (75 m) of three Idaho streams: Trestle, Rattle, and Granite creeks. Night counts of juvenile bull trout exceeded day counts in all reach comparisons; differences were significant (P < 0.05) in 1992 but not in 1991. In contrast, summer day counts of cutthroat trout were significantly higher (P < 0.05) than night counts when reaches we...

Transport dynamics of fine particulate organic matter in two Idaho streams

Natural suspended fine particulate organic matter (FPOM, 53–102-µm diam) was labeled with 14C and reinjected to estimate transport distances in the water column and retention times within the sediments of two Idaho streams. Transport of labeled FPOM particles declined exponentially with downstream distance, yielding mean transport distances of 800 and 580 m in Smiley Creek in 1989 and 1990 at a mean water velocity of 0.27 m s−1 and mean depth of 0.34 m in both years, and a distance of 630 m in the upper Salmon River at a mean velocity of 0.29 m s−1 and a depth of 0.14 m. These travel distances are equivalent to vertical deposition velocities of 0.7–1.6 mm s−1, or ~7–12% of the temperature-corrected quiescent-water fall velocities of the FPOM particles. The estimated deposition flux of ~1.5 g (AFDM) m−2 d−1 would turn over the standing stock of 0.8 g m−2 in surficial sediments twice daily. Sampling of benthic FPOM 24 h after release indicated that ~99% of the 14C-labeled FPOM initially deposited in the 1,005-m study reach had been resuspended and exported; subsequent clearing was much slower. An advection-dispersion model satisfactorily simulated the deposition of 14C-labeled particles and their subsequent resuspension and export from the reach. Model-estimated retention times were 1.5–3 h for 99% of deposited sediments and 17 d for the remaining 1%. Thus, particles in surficial sediments exchange rapidly with the water column and migrate downstream several kilometers per day in alternating deposition and resuspension events. These results support the overall concept that conditions throughout a river system are strongly connected longitudinally and that OM introduced in headwater reaches can be transported large distances for later use or storage elsewhere in the river or for eventual export to estuaries.

Field Testing of New Monitoring Protocols to Assess Brown Trout Spawning Habitat in an Idaho Stream

Abstract The effects of nonpoint source pollution on salmonid incubation and embryo survival to emergence were evaluated on Rock Creek in south-central Idaho. New monitoring protocols were applied to evaluate effects ofsediments and associated pollutants on spawning and recruitment of brown trout Salmo trutta. According to these new protocols, incubation success in artificial egg pockets is measured in terms of intragravel dissolved oxygen (IGDO), percent fine sediment (<2.0 mm) in the substrate, and survival of embryos and alevins to emergence. Mean IGDO concentrations and saturation levels were significantly less (P < 0.05) at stations affected by agricultural pollutants than at a control station. Up to 40% of IGDO measurements were below 6.0 mg/L, the proposed water quality criterion for salmonid spawning in Idaho streams. Mean values for percent fine sediment were also higher at all impacted stations. Survival to emergence at the control station ranged from 18 to 83% and averaged 48%. Survival at impa...

Effects of Increasing Zinc Levels and Habitat Degradation on Macroinvertebrate Communities in Three North Idaho Streams

ABSTRACT A rapid bioassessment study was conducted on the South Fork of the Coeur d'Alene River and selected tributaries in northern Idaho. Species richness, Ephemeroptera-Plecoptera-Trichoptera (EPT) index, and species diversity showed strong negative correlations with habitat assessment scores (mean r2-.68); whereas regression coefficients for percent dominant taxon, modified Hilsenhoff's index, and EPT/Chironomidae abundance were generally lower (mean r2-.42) than the above. Zinc was negatively correlated with biotic metrics (r2-.23-.58). Values for EPT (r2-.60-.75) and species richness (r2-.54-.65) provided the highest correlation coefficients of the six metrics measured. Conductivity (r2-.18-.41) and pH (r2-.08-.21) showed the weakest correlations with biotic metrics. Streams affected by metal pollution also exhibited extreme habitat degradation due to activities involved in ore processing. As a result, macroinvertebrate communities may be severely impacted by habitat loss even where zinc concentrati...

PATTERNS OF PERIPHYTON CHLOROPHYLL ? IN AN AGRICULTURAL NONPOINT SOURCE IMPACTED STREAM

ABSTRACT: An agricultural nonpoint source polluted stream in northern Idaho was examined to determine seasonal and longitudinal patterns of periphyton chlorophyll α. Chlorophyll a was measured at eight sites along Lapwai Creek, a fifth order stream impacted by agricultural runoff containing nutrients and eroded soils. Seasonally, periphyton chlorophyll α was lowest in the spring (cumulative x̄= 60.4 mg m−2) and highest in the summer (cumulative x̄= 222 mg m−2). Winter concentrations were higher than expected (cumulative x̄= 168.6 mg m−2). The headwaters, flowing through an open grassy meadow, had the lowest concentrations of the study (two-year x̄= 49.7 mg m−2). Immediately below a small, eutrophic reservoir, periphyton chlorophyll α increased markedly (two-year x̄= 155.8 mg m−2) and remained high through a deep canyon (two year x̄= 135.5 mg m−2) and down to the mouth of the stream (two-year x̄= 172.3 mg−2). Periphyton chlorophyll α in Lapwai Creek was at least two times greater than values reported in the literature for comparable, undisturbed Idaho streams. We suggest that increased nutrient concentrations via agricultural nonpoint source pollution and increased light penetration from the removal of large, woody riparian vegetation have resulted in high periphyton chlorophyll α along the continuum of Lapwai Creek.

Seasonal Colonization Dynamics of Macroinvertebrates in an Idaho Stream

Field experiments were conducted to examine effects of macroinvertebrate removal frequency on community development on bricks with similar food resource levels (chlorophyll a levels and diatom composition). The experiments were conducted during summer and fall to examine effects of seasonal differences in animal abundances. For each experiment macroinvertebrates were removed from groups of bricks at intervals of 3, 9, or 27 days or were not removed for 54 days. Insect removal frequency had no significant effect on macroinvertebrate abundance in summer when overall animal abundance and richness were low. During fall, when overall abundance was 3× greater, there were significantly fewer animals on bricks with a 3-day removal interval. Baetis tricaudatus represented 65% of all invertebrates in summer, but declined in relative abundance to about 25% in fall. In contrast, the Chironomidae increased from 6% of the assemblage in summer to comprise over 30% in fall, suggesting that differences in the composition ...

Gold found in Idaho streams

Fine‐grained gold has been found in stream sediments in parts of central Idaho, indicating that minable, higher‐grade deposits of gold may be present in the near‐surface rocks in the area, according to three U.S. Geological Survey scientists.As part of a continuing USGS program to assess mineral resources in Idaho, the gold was found in sediments of several creeks south of Salmon in Lemhi County. George A. Desborough, a USGS geologist in Denver, Colo., and principal investigator on the project, said the sediment samples taken from Allison Lake, Mulky and Poison creeks were subjected to a laboratory tabletop mechanical panning technique that detected gold particles of a size too fine to be recognized by conventional hand panning.

The Effects of Fish Predation and Algal Biomass on Insect Community Structure in an Idaho Stream

ABSTRACT To determine the affect of fish predation and food resource levels on lotic macroinvertebrates, a 2 × 2 factorial experiment was conducted. Treatments consisted of varied densities of fish and algal biomass levels placed in cage enclosures. Treatment interaction affected total taxa densities. Fish levels had an negative impact on some taxa densities and biomass, while algal levels had a positive effect. Although richness and evenness were not affected by the treatments, several functional feeding group parameters were altered.