Geology topics

Research about Boise River basin

Source-linked reports with geographic coverage including Boise River basin.

3 recordsLinked to original sources

USGS2020

Thermal heterogeneity, migration, and consequences for spawning potential of female bull trout in a river-reservoir system

The likelihood that fish will initiate spawning, spawn successfully, or skip spawning in a given year is conditioned in part on availability of energy reserves. We evaluated the consequences of spatial heterogeneity in thermal conditions on the energy accumulation and spawning potential of migratory bull trout ( Salvelinus confluentus ) in a regulated river–reservoir system. Based on existing data, we identified a portfolio of thermal exposures and migratory patterns and then estimated their influence on energy reserves of female bull trout with a bioenergetics model. Spawning by females was assumed to be possible if postspawning energy reserves equaled or exceeded 4 kJ/g. Given this assumption, results suggested up to 70% of the simulated fish could spawn each year. Fish that moved seasonally between a cold river segment and a warmer reservoir downstream had a greater growth rate and higher propensity to spawn in a given year (range: 40%–70%) compared with fish that resided solely in the cold river segment (25%–40%). On average, fish that spawned lost 30% of their energy content relative to their prespawn energy. In contrast, fish that skipped spawning accumulated, on average, 16% energy gains that could be used toward future gamete production. Skipped spawning occurred when water temperatures were relatively low or high, and if upstream migration occurred relatively late (mid-July or later) or early (early-May or earlier). Overall, our modeling effort suggests the configuration of thermal exposures, and the ability of bull trout to exploit this spatially and temporally variable thermal conditions can strongly influence energy reserves and likelihood of successful spawning.

Idaho↗

USGS2013

Characterizing the thermal suitability of instream habitat for salmonids: A cautionary example from the Rocky Mountains

Understanding a species’ thermal niche is becoming increasingly important for management and conservation within the context of global climate change, yet there have been surprisingly few efforts to compare assessments of a species’ thermal niche across methods. To address this uncertainty, we evaluated the differences in model performance and interpretations of a species’ thermal niche when using different measures of stream temperature and surrogates for stream temperature. Specifically, we used a logistic regression modeling framework with three different indicators of stream thermal conditions (elevation, air temperature, and stream temperature) referenced to a common set of Brook Trout Salvelinus fontinalis distribution data from the Boise River basin, Idaho. We hypothesized that stream temperature predictions that were contemporaneous with fish distribution data would have stronger predictive performance than composite measures of stream temperature or any surrogates for stream temperature. Across the different indicators of thermal conditions, the highest measure of accuracy was found for the model based on stream temperature predictions that were contemporaneous with fish distribution data (percent correctly classified = 71%). We found considerable differences in inferences across models, with up to 43% disagreement in the amount of stream habitat that was predicted to be suitable. The differences in performance between models support the growing efforts in many areas to develop accurate stream temperature models for investigations of species’ thermal niches.

Idaho↗

USGS1999

Streamflow gains and losses in the lower Boise River basin, Idaho, 1996-97

Information on streamflow gains and losses in the lower Boise River Basin is needed by the Idaho Department of Water Resources to determine recharge to and discharge from the ground- water system. A method was developed to select canal and creek reaches such that a minimum of two reaches were measured in each of 12 different areas that share a set of common environmental characteristics. After a large number of environmental characteristics were evaluated, soil type, land use, and canal density were selected to define the 12 areas. Seepage runs were made on 39 irrigation canal and creek reaches in the lower Boise River Basin in June-July and September 1996. During the June-July seepage runs, irrigation canals gained and lost water, whereas in September, most reaches lost. No substantial differences were noted in the median and spread of flow gains and losses within the 12 areas; therefore, no direct relation could be defined between seepage and environmental areas. Seepage runs were made on three reaches of the lower Boise River in November 1996 to identify flow gains and losses after the irrigation season. The two upstream reaches had net gains, whereas the most downstream reach, near the confluence with the Snake River, had a net loss. The total gain to the river from the three reaches was 90.71 cubic feet per second. Because of potential flooding in March 1997, water was diverted from the Boise River into the New York Canal to reduce flows in the river. This allowed a seepage run on the canal when there were no irrigation diversions or return flows. Subsequently, two seepage runs were made in March when flows near Diversion Dam were about 440 and 860 cubic feet per second. Both gains and losses were measured along the canal, but losses were dominant. Total loss from the canal during the first seepage run was -54 cubic feet per second; during the second, -143 cubic feet per second. Sixteen wells near the canal were measured weekly from the last week in February through mid-June. Generally, water levels decreased from February to mid-April and then increased through June. Paired wells near the canal indicated downward movement of water, probably recharge from canal losses. Study results indicate that additional seepage runs are needed on irrigation canals and creeks, the Boise River, and the New York Canal. Piezometers installed at different depths are needed to better define vertical ground-water movement and gradients. Additional work is needed to determine how seepage in canals and streams relates to environmental characteristics.

Idaho↗