Columbia River Research Articles

Detecting aquatic and terrestrial biodiversity in a tropical estuary using environmental DNA

AbstractEstuaries are characterized by a tidal regime and are strongly influenced by hydrodynamics and host diverse and highly dynamic habitats, from fresh, brackish, or saltwater to terrestrial, whose biodiversity is especially difficult to monitor. Here, we investigated the potential of environmental DNA (eDNA) metabarcoding, with three primer sets targeting different regions of the mitochondrial DNA 12S ribosomal RNA gene, to detect vertebrate diversity in the estuary of the Don Diego River in Colombia. With eDNA, we detected not only aquatic organisms, including fishes, amphibians, and reptiles, but also a large diversity of terrestrial, arboreal, and flying vertebrates, including mammals and birds, living in the estuary surroundings. Further, the eDNA signal remained relatively localized along the watercourse. A transect from the deep outer section of the estuary, across the river mouth toward the inner section of the river, showed marked taxonomic turnover from typical marine to freshwater fishes, while eDNA of terrestrial and arboreal species was mainly found in the inner section of the estuary. Our results indicate that eDNA enables the detection of a large diversity of vertebrates and could become an important tool for biodiversity monitoring in estuaries, where water integrates information across the ecosystem.Abstract in Spanish is available with online material.

Assessment of Methods to Control Invasive Reed Canarygrass (Phalaris arundinacea) in Tidal Freshwater Wetlands

Reed canarygrass (Phalaris arundinacea) is invasive in temperate freshwater wetlands throughout the United States and Canada and presents challenges to restoring tidal freshwater wetlands. Methods for the prevention or elimination of reed canarygrass in palustrine wetlands are generally well established, typically involving herbicide application, mechanical treatments, prolonged inundation, or establishment of competitive plant species. These methods are often not suitable for the unique conditions in tidal wetlands and alternative strategies remain poorly understood. Prolonging inundation of tidal wetlands requires a loss of habitat forming processes, connectivity, and other functions. Treatments such as mowing, discing, or fire are not feasible in the perpetually wet conditions of tidal wetlands. Restoration practitioners aiming to design self-sustaining wetlands in the lower Columbia River estuary and the U.S. Pacific Coast have found that reed canarygrass is widespread and quick to establish post-restoration creating a management burden and impacting restoration goals. Here we report the results of a comprehensive effort to develop methods for control in tidal wetlands through systematic review of the scientific literature, interviews with experienced practitioners, and field observations at nine Pacific Northwest sites. The review framework evaluated key environmental conditions affecting reed canarygrass, control methods, and practical considerations. Findings support an integrated long-term control strategy at the largest possible scale to establish effective and self-sustaining control. Appropriate and practical strategies for tidal freshwater wetlands include implementing control pre-restoration to suppress existing populations; topographic modification such as scrape-downs and mounds to support competitiveness of desired vegetation communities; seeding or planting strong native competitors; limiting nutrient availability; and periodic, targeted control to limit reinvasion. These strategies are supported by the study, but long-term results are generally not available. Formal field experiments are recommended by the authors to better evaluate factors that influence reed canarygrass control in tidal freshwater wetlands.

An experimental evaluation of the efficacy of imaging flow cytometry (FlowCam) for detecting invasive Dreissened and Corbiculid bivalve veligers

Hassett W, Zimmerman J, Rollwagen-Bollens G, Bollens SM, Counihan TD. 2021. An experimental evaluation of the efficacy of imaging flow cytometry (FlowCam) for detecting invasive Dreissened and Corbiculid bivalve veligers. Lake Reserv Manage. 37:406–417. Zebra (Dreissena polymorpha) and quagga (D. bugensis) mussels, first introduced from central Asia into the Great Lakes of North America in the late 1980s, have crossed the continental divide and more recently spread across western North America. At the same time, several new technologies have been developed for the early detection of dreissenids, including the FlowCam, a digital imaging-in-flow instrument, intended to detect dreissenid planktonic larvae (veligers). However, the efficacy of this technology has rarely been tested. We experimentally evaluated the FlowCam’s ability to capture identifiable images of quagga mussel veligers under 2 different types of conditions: (i) deionized water, and (ii) Columbia River Basin water (CRBW), including natural sediment and native plankton. We further evaluated the FlowCam’s ability to distinguish between dreissenid veligers and corbiculid veligers (Asian clam, Corbicula fluminea). We interpret our results to indicate that the FlowCam can consistently detect dreissenid veligers across a range of veliger densities. Moreover, the presence of other plankton and detritus only slightly affected dreissenid detection by the FlowCam. However, the orientation of individual bivalve veligers as they were imaged by the FlowCam precluded specific identification of a substantial proportion (24.8%) of veligers as either dreissenid or corbiculid. We suggest that the FlowCam is an important detection tool best utilized as part of a multifaceted approach, including traditional microscopy and possibly environmental DNA.

High-precision measurement of U-Pu-Np-Am concentrations and isotope ratios in environmental reference materials by mass spectrometry

We report results of precise and sensitive mass spectrometric measurements of uranium, plutonium, neptunium, and americium concentrations and isotope ratios in a variety of environmental reference materials. Most of our work has been done on NIST SRM 4350b, River Sediment, but we also present results for NIST SRM 4354, Lake Sediment; NIST SRMs 4355 and 4355a, Peruvian Soil; NIST SRM 4357, Ocean Sediment; NIST SRM 1648a, Urban Particulate Material; NIST SRM 1649b, Urban Dust; IAEA CRM 385, Ocean Sediment; USGS BCR-2, Columbia River Basalt; and USGS BHVO-2, Hawaiian Volcanic Observatory Basalt. These materials reflect a wide range in long-lived actinide concentrations (e.g. 1E4 to 1E10 atoms 239Pu/g) and isotope ratios. Measurements were performed in a clean laboratory by isotope dilution, multi-collector thermal ionization and multi-collector inductively coupled plasma mass spectrometry. In general, our results are in agreement with, but lower the uncertainty of, literature or certificate values for these reference materials. Our uranium results for the basalts also confirm previously reported high-precision mass spectrometric results from our laboratory. In many cases our measurements of U-Pu-Np-Am nuclides appear to be novel.Extensive results for NIST SRM 4350b, River Sediment, indicate that this material is heterogeneous for Pu-Np-Am concentrations and isotope ratios at a sample size of 5 g or lower. Pu–Np isotope ratios and a241Pu-241Am model age of 1954 reflect a mix of plutonium production operations at the nearby Hanford, Washington site, and global atmospheric fallout from nuclear weapons testing. Results for the oceanic sediment materials (NIST SRM 4357 and IAEA 385) collected near Sellafield, U.K. vary but are also indicative of local anthropogenic sources of varying Pu isotopic composition and a mean 241Pu-241Am model age of 1964. Large environmental fractionation between Pu and Np is observed for the ocean, river, and lake sediment reference materials. Novel measurements for the two air particulate SRMs indicate high U, Pu and Np concentrations for these collections in 1976–1977 with an anomalous regional fallout Pu isotopic signature. Results for BHVO-2 and other Hawaiian basalts indicate that those which erupted before or during the period of abundant atmospheric nuclear weapons testing (1950–1970) contain significant levels of Pu (on the order of 1E7 atoms 239Pu/g) with a global fallout Pu isotopic composition, compared to more recent eruptions which incorporated less Pu. Hence, Hawaiian basalts may provide an integrated temporal record of anthropogenic actinide fallout deposition from the atmosphere since eruption.

Phenology and Fraser River sockeye salmon marine survival

Inspired by the pioneering work of Dr. Bill Peterson who demonstrated the utility of ocean indicators at predicting survival of coho and chinook salmon in the Columbia River, we investigated whether the phenology of primary productivity could explain variable marine survival of Fraser River sockeye salmon. Building on a study that had found a strong correlation between satellite-derived spring chlorophyll concentrations in Queen Charlotte Sound (British Columbia) and smolt survival, we hypothesized that smolt migration phenology could help to explain interannual survival differences among years. Applying a new migration model to 18 years of smolt migration data from Chilko Lake demonstrated that interannual differences in smolt migration timing were organized in up to 3 pulses of abundance with a general trend by the largest peak toward earlier peak migration dates over the time series (1998–2016). Analysis of satellite-derived fluorescence line height data within Queen Charlotte Sound identified 4 productivity domains through which most young sockeye salmon would migrate. Each domain had distinct seasonal productivity patterns. With these data, we were unable to demonstrate significant correlations between spring bloom dates in these domains and smolt marine survival, or between smolt migration timing and marine survival. Having separate survival estimates for each pulse and phenological indicators of the sockeye salmon prey base might improve our ability to test the hypothesis that phenology matters to sockeye salmon in the Queen Charlotte Sound region.

Observational case study of a persistent cold pool and gap flow in the Columbia River Basin

AbstractPersistent cold pools form as layers of cold stagnant air within topographical depressions mainly during wintertime when the near-surface air cools and/or the air aloft warms and daytime surface heating is insufficient to mix out the stable layer. An area often affected by persistent cold pools is the Columbia River Basin in the Pacific Northwest, when a high-pressure system east of the Cascade Range promotes radiative cooling and easterly flow. The only major outflow for the easterly flow is through the narrow Columbia River Gorge which cuts through the north-south oriented Cascade Range and often experiences very strong gap flows. Observations collected during the Second Wind Forecast Improvement Project (WFIP2) are used to study a persistent cold pool in the Columbia River Basin between 10-19 Jan 2017 which was associated with a strong gap flow. We used data from various remote sensing and in situ instruments and a optimal estimation physical retrieval to obtain thermodynamic profiles to address the temporal and spatial characteristics of the cold pool and gap flow and to investigate the physical processes involved during formation, maintenance and decay. While large-scale temperature advection occurred during all phases, we found that the cold pool vertical structure was modulated by the existence of low-level clouds and that turbulent shear-induced mixing and downslope wind storms likely played a role during its decay.

Chronology of Missoula Flood Deposits at the Coyote Canyon Mammoth Site, Washington State, USA

Late Pleistocene outburst megafloods, mostly from glacial Lake Missoula, hydraulically ponded behind downstream constrictions in the Columbia River in southeastern Washington State, USA. Optically stimulated luminescence (OSL) ages for flood deposits from the Coyote Canyon Mammoth Site, located in a high (315–320 m asl) distal portion of the transient lake, indicate that at least seven floods ponded high enough to inundate the area during the period 20.9 ± 2.6 ka to 16.3 ± 2.8 ka. This is consistent with a radiocarbon age of about 17.4 ± 0.2 ka cal BP from the middle of the flood sequence. OSL ages from loess deposits overlying a paleosol at the top of the flood sequence range from 14.0 ± 2.3 ka to 10.9 ± 2.0 ka, suggesting a hiatus of about 2.3 thousand years. These datasets are consistent with current understanding that multiple late Pleistocene megafloods occurred between 20 ka and 14 ka and that earlier floods produced higher flood stages than later ones. The lack of flood deposits in the Coyote Canyon area younger than 16 ka supports the hypothesis that younger megafloods did not hydraulically pond in the Pasco Basin above about 230 m asl.

Liver biomarkers response of the neotropical fish Aequidens metae to environmental stressors associated with the oil industry

The Acacias River in Colombia receives large volumes of industrial effluents mostly derived from the oil industry. To contribute to the study of the possible effects of industrial wastewaters on the aquatic environment and particularly on fish populations, a native neotropical fish, Aequidens metae was used as a sentinel species. Wild specimens of A. metae were caught at three different places of the Acacias River taking as reference the point of discharge of an oil industry effluent; upstream, downstream, and at the vicinity of the discharge pipe. A fourth sampling site was chosen as a reference site away from urban settlements. Samplings were performed twice, during the rainy and dry seasons. After anesthesia animals were weighted and measured, and humanely sacrificed. Livers were extracted, frozen on site and transported to the laboratory. Condition indices were calculated. Total protein content and the detoxification 7-ethoxyresorufin-O-deethylase (EROD) enzyme activity were estimated. Histopathological alterations were also evaluated. Water quality was estimated through the measurement of several variables. Results obtained evidenced that the highest induction in EROD activity and the strongest histological alterations in liver of the monitored fish appeared during the dry seasons at the discharge site and downstream to this point.

Exploring the operational impacts of climate change and glacier loss in the upper Columbia River Basin, Canada

AbstractThe mountainous watersheds of western Canada are generally thought to be in a state of transition from snow‐dominated to hybrid regimes. In stream networks that are regulated, the effects of this transition on streamflow can have compelling operational consequences. Seasonal magnitude changes may impact spill‐risk management, while changes in the composition of summer runoff may increase its variability and reduce the forecasting capabilities of state variables like peak snow water equivalent. Though glacier loss can have a considerable impact on summer runoff, few studies explicitly model the ongoing glacier recession in conjunction with other primary hydrological processes. In this study, we incorporate glacier dynamics from a previous run of the Regional Glaciation Model into the University of British Columbia Watershed Model via the Raven modelling framework. We use this modelling system to explore potential changes under Representative Concentration Pathways 4.5 and 8.5 to the hydrology of the Mica Basin, a regulated watershed containing the headwaters of the Columbia River. Our results project statistically significant increases in spring flow in future eras, which may force lower reservoir drafting in late winter, creating potential for energy shortfalls in early spring. We project the coefficient of variation of summer runoff generally goes unchanged in future eras as does the summer runoff forecasting capability of April 1st SWE. Hence, despite modelled glacier loss and reduced snowmelt contribution, our study does not reject the null hypothesis that the predictability of the Mica Basin's summer runoff is unchanged in future eras. We explore these results in detail because they superficially appear to contrast the conventional conceptualization that reduced snowmelt negatively affects the predictive powers of snowpack and glacier loss increases the variability of runoff. We argue that our results' apparent discordance from convention displays the complexities inherent in isolating the effects of changes to a single water balance component when other components are also non‐stationary and highlights the benefits of using modelling to more explicitly explore such implications.

Ancient anthropogenic soils and activity areas of the Colombian Andean region: A geoarchaeological approach

AbstractThe Monte Azul archaeological site is located in the inter‐Andean Aburrá Valley of the upper Medellín River in Colombia and it is dated from the Middle Ceramic period to the Republican period. In this study area, it is common to find evidence of disturbed soils that is related to ancient use and erosion. In Monte Azul, the pedogenesis is associated with the presence of fast‐weathering eolian volcanic ash deposits, extreme acidity, low base saturation, strong leaching, high precipitation, and high temperature; hence, some of these tropical conditions are responsible for the low conservation of the archaeological record. Consequently, we used a geoarchaeological approach with paleoenvironmental, sedimentary, geochemical, and soil micromorphological proxies as integral units of analysis to understand site formation processes. Micromorphological and paleobotanical records indicate soil use dynamics and changes in paleoenvironmental conditions from humid conditions to small and persistent clearings around a domestic unit. This approach sheds light on the development of possible pre‐Hispanic activity areas and cultivation techniques related to the ancient use of the Ferrería pottery style in the Central Mountain Range of Colombia.

Reach‐scale stream temperature response to large wood placement

Climate change models indicate that stream temperatures within much of the Columbia River Basin will increase significantly in the next 50 years leading to inhospitable conditions for salmonid fishes in several stream reaches. Restoration measures such as riparian planting, maintaining instream flows, and large wood (LW) placement are thought to ameliorate the impacts of climate change on stream temperatures. While LW placement is known to improve habitat complexity, it is unclear whether it will also help reduce summer stream temperatures. To help understand the influence of LW placement on stream temperatures, we monitored nine interior Columbia River Basin LW projects using an extensive posttreatment study design. We mapped stream bottom temperatures, topography, and physical habitat in paired treatment (LW placement) and control reaches to compare water temperatures and cool‐water patches between reaches. We found no difference in the mean or the variance in overall reach temperatures or thalweg temperatures between treatment and control reaches. Mapping found variation in water temperatures of less than 0.5°C within reaches, making mapping of cool‐water patches impractical and further emphasized the lack of temperature differences. Our results indicate that LW placement projects in the interior Columbia River Basin do not appear to be decreasing reach‐scale summer water temperatures or creating cool water refugia for fishes. Moreover, the current configuration and implementation of LW placement projects, which typically focus on placing wood on banks and channel margins, are unlikely to ameliorate the effects of climate change on stream temperatures.

Dietary tetradecylthioacetic acid supplementation during the fall prevents an increase in body lipid levels but does not influence precocious male maturation rate in juvenile spring Chinook salmon

Precocious maturation of male fish as two-year-olds occurs at significant rates in spring Chinook salmon hatchery programmes in the Columbia River Basin, representing a loss of production. Precocious maturation is thought to occur due to elevated lipid and other energy reserves in hatchery fish during critical periods for the regulation of gonadal development. To determine whether modification of lipid reserves affects precocious maturation rates in juvenile spring Chinook salmon, we administered feed supplemented with tetradecylthioacetic acid (TTA; a supplement that upregulates lipid oxidation) during the fall critical period one year prior to maturation of precocious individuals. Maturation status was determined the following spring from plasma 11-ketotestosterone levels. TTA administration reduced body lipid levels relative to controls but did not reduce precocious maturation rate. Fish growth was reduced during the TTA feeding period but recovered after fish were returned to a standard diet. No differences in the effect of TTA were found between male and female fish. Our results show that TTA can be used to manipulate body lipid levels in juvenile Chinook salmon but provide no support for a major role of fall body lipid levels in regulating precocious maturation in juvenile male spring Chinook salmon under hatchery conditions.

Studies on Neotropical crickets: A new Anurogryllina genus (Orthoptera: Gryllidae: Gryllinae).

Andeogryllus n. gen. including two new species from the inter-Andean slopes and valleys of the Magdalena and Cauca rivers of Colombia are described. This new genus is similar to Zebragryllus in their habitus, differed by not have white stripes on the body or antennae and by a modified pseudoepiphallic sclerite. The genus Atsigryllus (Atsigryllae group) is located in the subtribe Anurogryllina, highlighting the secondary reduction of the median lobe. An updated key is provided for the genera of the subtribe Anurogryllina and the species of the new genus.

Tui Chub (Siphateles bicolor) are Native to the Columbia River Basin in Washington State

Although many modern authorities hold that Tui chub (Siphateles bicolor) are native to the Columbia River basin, they are uncommon in most of the basin today, and others have called their native status into question. Here we provide evidence that the species is indigenous to lakes and streams in the Columbia River basin of Washington State, based on multiple lines of testimony. Evidence includes: 1) no record of introductions by federal or state fish and wildlife management agencies; 2) over 100 museum specimens collected from 1881 to 1930; 3) records of abundance in the tens of thousands in area lakes prior to modern management efforts in the 1940s; and 4) 62 diagnostic bones recovered from four archaeological sites dating before 1850.

Fish Communities in the Tidal Freshwater Wetlands of the Lower Columbia River

Fish Communities in the Tidal Freshwater Wetlands of the Lower Columbia River

Implications of the Thermodynamic Response of Soil Mineralization, Respiration, and Nitrification on Soil Organic Matter Retention.

Considerable research has shown that modifications in global temperature regimes can lead to changes in the interactions between soil respiration and the sequestration of C and N into soil organic matter (SOM). We hypothesized that despite the interconnected nature of respiration, net N mineralization, and nitrification processes, there would be differences in their thermodynamic responses that would affect the composition of inorganic soil N and the potential for retention of N in SOM. To test this hypothesis, soil respiration, N mineralization and nitrification responses were evaluated during constant temperature incubations at seven temperatures (4–42°C) in tilled and no-till soils from two major agroecological zones in Oregon; Willamette Valley, and Pendleton located in the Columbia River Basin. We observed (1) significant thermodynamic differences between the three processes in all soils, (2) a distinctly different thermodynamic profile in Willamette vs. Pendleton, and (3) a dynamic response of Topt (optimal temperature for activity), and Tsmax (temperature of greatest rate response to temperature), and temperature sensitivity (Δ) over the incubation time course, resulting in shifts in the thermodynamic profiles that could not be adequately explained by changes in process rates. We found that differences in contributions of ammonia oxidizing archaea and bacteria to nitrification activity across temperature helped to explain the thermodynamic differences of this process between Willamette and Pendleton soils. A two-pool model of SOM utilization demonstrated that the dynamic thermodynamic response of respiration in the soils was due to shifts in utilization of labile and less-labile pools of C; and that the respiration response by Pendleton soils was more dependent upon contributions from the less-labile C pool resulting in higher Topt and Tsmax than Willamette soils. Interestingly, modeling of N mineralization using the two-pool model suggested that only the less-labile pool of SOM was contributing to N mineralization at most temperatures in all soils. The difference in labile and less-labile SOM pool utilization between respiration and N mineralization may suggest that these processes may not be as interconnected as previously thought.

Ingestion of PIT Tags by Hatchery‐Reared Juvenile Steelhead and Subsequent Detection at Main‐Stem Dams in the Columbia River Basin

AbstractDuring the past 30 years, millions of hatchery‐reared Pacific salmon Oncorhynchus spp. have been implanted with PIT tags to estimate their survival and track their migration through the extensive system of hydroelectric dams in the Columbia River basin. The mark–recapture models that are used for these analyses assume that the tags are not lost, making it important to understand retention rates for PIT tags and the fate of shed tags. To understand the potential fate of shed PIT tags in a production hatchery, we distributed 12‐mm PIT tags in two traditional cement raceways and the two circular tanks of a partial reuse aquaculture system (PRAS) containing juvenile summer steelhead O. mykiss. We then monitored the detection of these PIT tags at the time that the fish were released as smolts and at main‐stem dams during their migration. The probability that a loose PIT tag was inside a steelhead smolt at release ranged from 0.200 to 0.519 across the raceways and tanks, confirming that the fish consumed tags during hatchery rearing. Detections at six dams—including one located 1,208 km from the release site—and up to 36 d after smolt release confirmed that some ingested tags remained in the steelhead during their migration. The estimates of apparent survival for smolts with ingested and implanted PIT tags suggested that some ingested tags were being excreted during migration through the Columbia River basin. The results highlight the need to reevaluate assumptions about the fate of shed PIT tags in steelhead production hatcheries and ensure that biologists and managers have reliable estimates of tag retention.

Calcium concentrations in the lower Columbia River, USA, are generally sufficient to support invasive bivalve spread

AbstractDissolved calcium concentration [Ca2+] is thought to be a major factor limiting the establishment and thus the spread of invasive bivalves such as zebra (Dreissena polymorpha) and quagga (Dreissena bugensis) mussels. We measured [Ca2+] in 168 water samples collected along ~100 river‐km of the lower Columbia River, USA, between June 2018 and March 2020. We found [Ca2+] to range from 13 to 18 mg L−1 during summer/fall and 5 to 22 mg L−1 during the winter/spring. Previous research indicates that [Ca2+] < 12 mg L−1 are likely to limit the establishment and spread of invasive bivalves. Thus, our results indicate that there is sufficient Ca2+ in most locations in the lower Columbia River to support the establishment of invasive dreissenid mussels, which could join the already widespread and abundant Asian clam (Corbicula fluminea) as the newest invader to an already heavily invaded Columbia River ecosystem. These new data provide important measurements from a heretofore undersampled region of the Columbia River and have important implications for the spread of invasive bivalves and, by extension, the conservation and management of native species and ecosystems.

Environmentally triggered shifts in steelhead migration behavior and consequences for survival in the mid-Columbia River.

The majority of Columbia River summer-run steelhead encounter high river temperatures (near or > 20°C) during their spawning migration. While some steelhead pass through the mid-Columbia River in a matter of days, others use tributary habitats as temperature refuges for periods that can last months. Using PIT tag detection data from adult return years 2004-2016, we fit 3-component mixture models to differentiate between "fast", "slow", and "overwintering" migration behaviors in five aggregated population groups. Fast fish migrated straight through the reach on average in ~7-9 days while slow fish delayed their migration for weeks to months, and overwintering fish generally took ~150-250 days. We then fit covariate models to examine what factors contributed to the probability of migration delay during summer months (slow or overwintering behaviors), and to explore how migration delay related to mortality. Finally, to account for the impact of extended residence times in the reach for fish that delayed, we compared patterns in estimated average daily rates of mortality between migration behaviors and across population groups. Results suggest that migration delay was primarily triggered by high river temperatures but temperature thresholds for delay were lowest just before the seasonal peak in river temperatures. While all populations groups demonstrated these general patterns, we documented substantial variability in temperature thresholds and length of average delays across population groups. Although migration delay was related to higher reach mortality, it was also related to lower average daily mortality rates due to the proportional increase in reach passage duration being larger than the associated increase in mortality. Lower daily mortality rates suggest that migration delay could help mitigate the impacts of harsh migration conditions, presumably through the use of thermal refuges, despite prolonged exposure to local fisheries. Future studies tracking individual populations from their migration through reproduction could help illuminate the full extent of the tradeoffs between different migration behaviors.

Passage and Survival of Juvenile Salmonid Smolts through Dams in the Columbia and Snake Rivers, 2010–2018

AbstractMinimizing the mortality and migration time of juvenile salmon (smolts) that pass through dams is a long‐standing objective in the pursuit of salmon recovery in the Columbia River basin. We compiled and analyzed 40 acoustic tag studies of juvenile salmonid that were performed between 2010 and 2018 at seven of the eight hydroelectric projects in the Federal Columbia River Power System. We found that the use of nonturbine routes decreased monotonically moving downstream from the Snake River to the main‐stem Columbia River dams and associated mortality differed substantially between the dams in the two rivers. Spillways were the predominant passage route at the main‐stem Columbia River dams. In contrast, passage was more common through the surface weirs and juvenile bypass systems at the dams in the Snake River, which generally provided higher survival. The observed stocks exhibited variable passage behaviors and mortalities, and the estimated probability that an individual would pass through all eight dams in the system without using a turbine route was 0.31, 0.47, and 0.60 for subyearling Chinook Salmon Oncorhynchus tshawytscha, yearling Chinook Salmon, and steelhead O. mykiss, respectively. Although subyearling Chinook Salmon were generally more likely to pass through a turbine route, they also experienced less turbine‐associated mortality than did the other stocks, especially steelhead. Notably, the proportion of smolts that passed through the spillway relative to the proportion of water through the spillway was lowest at Bonneville Dam, the largest and lowermost dam in the system. Bonneville Dam also stood out as having the highest proportion of smolts passing through turbines, but it was among the locations with the lowest rates of turbine‐associated mortality.