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Key Points: Question: Is dialysis facility staffing associated with access to waitlisting and kidney transplant among adolescents and young adults receiving dialysis? Findings: In this cohort of individuals aged 12 to 30 years receiving maintenance dialysis, treatment at facilities with the highest (vs lowest) quartile of patient to social worker ratios was associated with 5% lower incidence of waitlisting. Treatment at facilities with the highest (vs lowest) quartile of patient to nurse or patient to social worker ratios was associated with a 14% to 15% lower incidence of transplant. Meaning: Higher staffing ratios at dialysis facilities were associated with lower access to waitlisting and transplant for adolescents and young adults. Importance: Patient to staff ratios vary across US dialysis facilities and have been associated with patient outcomes in older adults. Objective: To determine whether patient to nurse or patient to social worker staff ratios are associated with access to kidney transplant for adolescents and young adults. Design, Setting, and Participants: Retrospective cohort study including patients aged 12 to 30 years who started dialysis between 2005 and 2019 at 8490 US facilities according to the US Renal Data System, the national end-stage kidney disease registry. Exposures: Time-updated quartile of patient to nurse and patient to social worker ratios at dialysis facilities. Main Outcomes and Measures: Fine-Gray models were used to relate the exposure to the incidence of waitlisting and kidney transplant, accounting for the competing risk of death. Subgroup analysis by age at dialysis initiation (<22 vs ≥22 years) was performed. Follow-up was censored in January 2020. Results: A total of 54 141 participants were included (median age, 25 years [IQR, 21-28]; 54.4% male; 4.3% of Asian race, 35.3% of non-Hispanic Black race). The median patient to staff ratios were 14.4 patients per nurse (IQR, 10.3-18.9) and 91.0 patients per social worker (IQR, 65.2-115.0). During a median follow-up of 2.6 years, 39.9% of patients (n = 21 598) received a transplant. In adjusted analysis, the highest (vs lowest) quartile of patient to nurse ratios was associated with 14% lower incidence of transplant (subhazard ratio [SHR], 0.86 [95% CI, 0.82-0.91]). The highest (vs lowest) quartile of patient to social worker ratios was associated with lower incidence of waitlisting (SHR, 0.95 [95% CI, 0.91-0.99]) and transplant (SHR, 0.85 [95% CI, 0.81-0.89]). For both staff ratios, there was an interaction with age at dialysis initiation, such that the association was more pronounced in patients starting dialysis at younger than 22 years (SHR, 0.71 [95% CI, 0.65-0.78] for the highest vs lowest quartile for nursing; SHR, 0.74 [95% CI, 0.68-0.80] for social work) compared with those 22 years and older (SHR, 1.00 [95% CI, 0.94-1.06] for nursing; SHR, 0.96 [95% CI, 0.91-1.02] for social work) for the outcome of transplant. Conclusions and Relevance: Adolescents and young adults receiving care at dialysis facilities with higher patient to staff ratios had reduced access to waitlisting and transplant, particularly if they were younger than 22 years of age at dialysis initiation. This cohort study aims to determine whether patient to nurse or patient to social worker staff ratios are associated with access to kidney transplant for adolescents and young adults. [ABSTRACT FROM AUTHOR]

Anadromous fishes rely on abundant prey in the ocean to grow large quickly, but prey limitation leads to interspecific competition. When species interactions are difficult to observe, growth can be studied to detect otherwise cryptic signals of competition. We describe a previously undocumented 2-year cycle in the lengths of adult natural-origin steelhead (Oncorhynchus mykiss) returning to spawn in the Snake River Basin. Returning steelhead were 38 mm shorter on odd return years, not accounting for sex, stock, and years of ocean residence. The well-known cycle in abundance of pink salmon (Oncorhynchus gorbuscha) from eastern Kamchatka and North America had statistically significant negative effects on returning steelhead lengths that depended on sex and the number of years of ocean residence. These results suggest that competition for limited resources occurs well after initial ocean entry and that interactions during later stages of ocean residence can be influential. Interspecific competition has implications for future returns of steelhead from the ocean, especially as metabolic demands for steelhead increase as the ocean warms. [ABSTRACT FROM AUTHOR]

Objective: We sought to evaluate the risk of preterm labor and hypertensive disorders in adolescent pregnancies with and without diabetes. Methods: We evaluated 1,843,139 adolescents (≤20 years old) with labor and delivery admissions in the national Kids' Inpatient Database (KID) in years 2006, 2009, 2012, 2016, and 2019. International classification of disease codes was used to identify diabetes and medical factors affecting pregnancy. Weighted logistic regression was used to evaluate the association between diabetes and complications. Results: Among admissions, 0.2% had type 1 diabetes (T1D), 0.2% had type 2 diabetes (T2D), and 0.7% had gestational diabetes (GDM); 10.1% of admissions were complicated by hypertensive disorders and 5.8% by preterm labor. Compared to adolescents without diabetes, those with diabetes had a higher prevalence of hypertensive disorders (T1D: 35.4%, T2D: 37.8%, GDM: 24.9%, None: 9.9%; p < 0.001) and preterm labor (T1D: 21.5%, T2D: 16.8%, GDM: 6.8%, none: 5.7%; p < 0.001). In adjusted models, odds of hypertensive disorders were higher in later study years (2019 vs. 2006 OR 1.85, 95% CI 1.77–1.94), among those with T1D (OR 4.32, 95% CI 3.94–4.74), with T2D (OR 4.18, 95% CI 3.79–4.61), and with GDM (OR 1.99, 95% CI 1.89–2.10). Adjusted odds of preterm labor were higher among those with T1D (OR 4.53, 95% CI 4.09–5.02), with T2D (OR 3.35, 95% CI 2.96–3.78), and with GDM (OR 1.18, 95% CI 1.08–1.28); disparities were seen by race/ethnicity, insurance, and income. Conclusions: Diabetes, which is increasing among adolescents, is a significant risk factor for preterm labor and hypertensive disorders. Though the absolute number of adolescent pregnancies is decreasing, rates of hypertensive disorders have increased. Appropriate interventions are needed to ensure healthy outcomes for adolescents who are pregnant. [ABSTRACT FROM AUTHOR]

Snorkel surveys are widely used for monitoring fish populations because they are a versatile and cost-effective technique. However, snorkel surveys provide instantaneous measurements that might not describe continuous processes, such as the emigration of juvenile anadromous salmonids. A model capable of assessing the level of potential production of emigrating juvenile steelhead (anadromous Oncorhynchus mykiss) from watersheds in Idaho on the basis of snorkel surveys would be useful. Our objective was to determine the relationship between abundance of emigrants estimated from rotary screw traps (RSTs) and parr densities from snorkel surveys. We analyzed over 1,000 snorkel surveys and 70 year-watershed combinations of emigrant estimates. Density was positively related to emigrant abundance. The most reasonable model included a common slope among watersheds, a common year effect, and varying intercepts, supporting a hypothesis that some watersheds produce more emigrating juveniles at similar observed densities. This model explained 82.7% of the variation observed in emigrant abundance. Uncertainty was greater among watersheds than within a watershed. The model can be used to translate mean densities observed in snorkel surveys to abundance of steelhead emigrants and thus to infer the effects of a habitat restoration program or other management actions. This work is important as a step toward understanding juvenile emigrant abundance in watersheds without RSTs and to aid understanding of steelhead emigrant productivity in Idaho watersheds. [ABSTRACT FROM AUTHOR]

Objective: The potential influence (i.e., impact rate) of catch‐and‐release fisheries on wild steelhead Oncorhynchus mykiss is poorly understood and is a function of the abundance of wild fish, how many fish are encountered by anglers (i.e., encounter rate), and the mortality of fish that are caught and released. In Idaho, estimates of wild steelhead encounter rates have been derived using the number of wild and hatchery steelhead passing Lower Granite Dam, the number of hatchery steelhead harvested, and the number of hatchery steelhead caught and released. The method includes assumptions that hatchery and wild steelhead have equal encounter rates and catch‐and‐release mortality is 5% for wild steelhead. Here, we investigated wild and hatchery steelhead encounter rates by anglers, estimated catch‐and‐release mortality, and concatenated both aspects to examine how existing recreational steelhead fisheries influence wild steelhead mortality. Methods: We sampled, tagged, and released 1,251 spawn‐year 2020 (SY2020) and 1,956 spawn‐year 2021 (SY2021) adult steelhead at Lower Granite Dam with T‐bar anchor tags and passive integrated transponder (PIT) tags to estimate steelhead encounter rates and catch‐and‐release mortality. Differences in survival of caught steelhead and those not reported as caught were evaluated using detections at various locations (e.g., PIT arrays, weirs). Result: Estimated encounter rates were 43.7% (95% credible interval; 28.2%, 100.0%) for wild fish and 46.7% (29.6%, 100.0%) for adipose‐clipped fish in SY2020. In SY2021, encounter rates were 47.2% (32.4%, 100.0%) for wild fish and 52.3% (37.1%, 100.0%) for adipose‐clipped fish. Based on detections of caught fish and those not reported as caught, catch‐and‐release mortality of wild steelhead was estimated to be 1.6% (0.0%, 5.2%). Wild steelhead impact rates were 0.7% (0.0%, 2.7%) in SY2020 and 0.7% (0.0%, 2.8%) in SY2021. Conclusion: Estimated rates of impact on wild steelhead were consistent and low across years despite major differences in the structure of the fisheries. Our results suggest assuming that encounter rates are equal between hatchery and wild steelhead, and that steelhead catch‐and‐release mortality is 5%, will likely lead to a conservative estimate of the wild steelhead impact occurring from catch‐and‐release fisheries. Impact statementWith wild steelhead numbers declining in many parts of North America, a dilemma between providing angling opportunity and wild steelhead conservation can develop. We show that encounter rate plays a larger role than mortality regarding catch‐and‐release angling on overall impact rates. Our method provides a direct, reliable estimate of encounter rates across multiple scales. [ABSTRACT FROM AUTHOR]

The ability to predict the likelihood of a live birth after single fresh embryo transfer is an important part of fertility treatment. While past studies have examined the likelihood of live birth based on the number of oocytes retrieved and cleavage-stage embryos available, the odds of a live birth based on the number of supernumerary blastocysts cryopreserved following a fresh embryo transfer has not been rigorously studied. We performed a retrospective analysis, stratified by age, on patients undergoing their first fresh autologous single day 5 blastocyst transfer to assess relationship between the likelihood of a live birth and number of supernumerary blastocysts cryopreserved. In patients aged <35 years and 35–39 years old, the likelihood of a live birth increased linearly between 1 and 6 supplementary blastocysts and non-linearly if 10 or more blastocysts were cryopreserved. When aged 40 years and above, the likelihood of a live birth increased linearly up to 4 cryopreserved blastocysts and then non-linearly if 10 or more blastocysts were cryopreserved. The present study demonstrated a non-linear relationship between the number of supernumerary blastocysts cryopreserved and the likelihood of a live birth after single blastocyst transfer in the first autologous fresh IVF/ICSI cycle across different age groups. [ABSTRACT FROM AUTHOR]

Many population metrics for wild steelhead Oncorhynchus mykiss are unquantified due to complex early life history strategies and a lack of juvenile age data. Juvenile steelhead can rear in freshwater systems for up to 7 years, with overlapping size distributions among age‐classes. As logistics for sampling and aging fish can be challenging, there are benefits to utilizing age–length keys (ALKs). We examined the potential benefits of applying ALKs to unaged juvenile steelhead from a rotary screw trap and to determine whether stratifying trapping data by season could improve accuracy in assigning ages to unaged fish. Additionally, we examined the effects of reducing samples of aged fish using a uniform sampling design in which there was a fixed number of aged fish across all length intervals of the size distributions. Using a leave‐one‐out cross validation method with aged fish, we found that ALKs assigned unbiased ages to unaged fish. When including fish with assigned ages from ALKs, results of mean length‐at‐age and brood year abundance estimates between using proportional‐sampled aged fish and uniform‐sampled aged fish were comparable. Typically, absolute differences in estimated brood year abundances were improved if age‐assigned fish were included, and mean absolute error did not exceed 0.4 years for any of the methods examined. Although seasons had a significant effect on mean length at age, overall brood year estimates of juvenile abundance derived from stratifying data by season did not notably differ from pooling summer and fall seasons together, likely because there was a higher portion of juveniles emigrating in the fall compared to the summer. Age–length keys can benefit trapping operations and aid in filling data gaps in age‐based movement and survival for steelhead by being able to accurately assign ages to unaged fish and include more data for population analyses. [ABSTRACT FROM AUTHOR]

Management of hatchery and wild stocks of steelhead Oncorhynchus mykiss within the same watershed requires careful consideration when management objectives include the use of the hatchery stock to meet fishery objectives while maintaining the genetic integrity of coexisting wild stocks. This scenario can be further complicated when management objectives for the hatchery stock include supplementation of natural production. The lower Clearwater River in Idaho provided an ideal location to evaluate hatchery steelhead genetic influence within a drainage with separate wild steelhead and supplementation management emphasis areas. We collected 813 genetic samples from wild juvenile steelhead from two sample years in 10 tributaries to the lower Clearwater River to explore genetic structure and assess hatchery influence. Overall, levels of genetic diversity of wild groups were comparable with those observed elsewhere in the Snake River basin. Estimates of effective population size of sample tributaries ranged from 22 to 198 spawners, with a median of 84. All but two tributaries had >50 spawners, and evidence of natural gene flow from other stocks was observed. Results of the study display three zones of hatchery influence in the lower Clearwater River: (1) no influence in lower tributaries with wild steelhead emphasis, (2) moderate influence in wild steelhead tributaries in close proximity to the hatchery facility, and (3) significant influence in hatchery‐supplementation tributaries. Interestingly, a number of wild steelhead reporting groups from elsewhere in the Snake River basin were observed in the assignments of study fish, suggesting movement of wild steelhead among larger drainage areas. Techniques outlined in this study can be used to monitor future hatchery influence in the Clearwater River drainage, track historic versus contemporary genetic influence in the drainage, and apply to other watersheds with hatchery and wild steelhead management objectives. [ABSTRACT FROM AUTHOR]

Habitat fragmentation threatens the persistence of fish populations, and road crossings (e.g., culverts) are particularly problematic because they are globally ubiquitous and can block access to critical habitats. Barrier removal or modifications that allow upstream access can result in expanded distributions, increased abundances, and gene flow among historically isolated populations. Actions that promote connectivity, gene flow, and the potential expression of multiple life history forms (e.g., anadromy in Pacific salmon Oncorhynchus spp.) are thought to buffer against extinction and are increasingly important given the high rates of imperilment for many fish species. We collected genetic samples from juvenile O. mykiss (anadromous steelhead and resident Rainbow Trout) prior to and following the modification of a culvert that served as a historical barrier to upstream movement and tested for changes in genetic composition through time. Prior to culvert modification, levels of genetic diversity were low and genetic differentiation with reference collections of anadromous steelhead was high. After treatment, we observed increased levels of genetic diversity, larger estimates of effective population size, and decreased genetic differentiation with steelhead, indicating an influx of individuals from a downstream population. Using an inexpensive genetic‐based monitoring approach, we show that culvert modification can result in the rapid reestablishment of connectivity between historically isolated populations. [ABSTRACT FROM AUTHOR]

Mountain Whitefish Prosopium williamsoni have failed to garner the same level of attention as other members of the salmonid family in terms of scientific investigations, especially with regard to habitat associations and population status. Consequently, we used snorkel survey data from 1985 to 2019 to relate a suite of environmental factors to Mountain Whitefish occupancy and abundance and to estimate population growth rates in central Idaho. Mountain Whitefish population growth rates in the majority of subbasins in central Idaho appear to be stable or increasing over the past several decades, but more so in the Salmon River basin than in the Clearwater River basin. Mountain Whitefish occupancy and abundance were higher in stream reaches that were lower in elevation and gradient and larger in size, with an occupancy rate of <0.10 in stream reaches that were <6 m average wetted width but >0.50 in stream reaches that were ≥9 m average wetted width. Road density was positively associated with the occupancy and abundance of Mountain Whitefish, contrasting previous studies that generally report negative associations between road density and salmonid population metrics. While this relationship may simply be correlative in nature, in the relatively sterile lotic environment of central Idaho, such anthropogenic disturbance may inadvertently result in nutrient enrichment, potentially benefitting the forage base of Mountain Whitefish. We also observed that conductivity positively influenced Mountain Whitefish abundance, likely stemming from its direct effect on stream productivity. Although the status of Mountain Whitefish in central Idaho appears generally stable, the paucity of studies reporting on the status of this species highlights the need for additional research devoted to a better understanding of trends in Mountain Whitefish abundance across their range. [ABSTRACT FROM AUTHOR]

Age information is central to assessment and management of fish populations. Age information must be reliable to have value, which depends on its quality. Quality assurance (QA) and quality control (QC) are processes often applied to some aspects of producing age information (e.g., annulus validation). However, we advocate for a more holistic approach which leverages QA/QC measures across all phases of the age information-generating process. Systematic implementation of QA/QC measures in a repetitive process is common in the manufacturing industry where it is known as a quality management system (QMS) but this framework is not well described in the fisheries literature. We designed and implemented a QMS that incorporates QA/QC measures across all phases of fish age information development: Collection, Interpretation, and Distribution. These measures are guided by six principles: Train, Simplify, Validate, Compare, Record, and Improve. In our QMS, the Train, Simplify, and Validate principles are largely guidance for QA measures, while Compare, Record, and Improve guide QC measures. We provide examples of common errors (or sources of error) in each phase, and how the guiding principles in our QMS address these errors. This is a QMS crafted as a holistic approach to managing the quality of fish age information; however, it has broad application as a conceptual framework for other repetitive processes in fisheries. • Fish age information development can be broken down into three phases: Collection, Interpretation, and Distribution. • Most traditional literature pertaining to quality and fish age information is focused on the interpretation of fish ages. • Implementing a QMS ensures all three phases of age information development are covered by QA/QC processes. • We describe the six principles that guide our QMS: Train, Simplify, Validate, Compare, Record, and Improve. [ABSTRACT FROM AUTHOR]

Background: Insulin pump use in type 1 diabetes management has significantly increased in recent years, but we have few data on its impact on inpatient admissions for acute diabetes complications. Methods: We used the 2006, 2009, 2012, and 2019 Kids' Inpatient Database to identify all-cause type 1 diabetes hospital admissions in those with and without documented insulin pump use and insulin pump failure. We described differences in (1) prevalence of acute diabetes complications, (2) severity of illness during hospitalization and disposition after discharge, and (3) length of stay (LOS) and inpatient costs. Results: We identified 228 474 all-cause admissions. Insulin pump use was documented in 7% of admissions, of which 20% were due to pump failure. The prevalence of diabetic ketoacidosis (DKA) was 47% in pump nonusers, 39% in pump users, and 60% in those with pump failure. Admissions for hyperglycemia without DKA, hypoglycemia, sepsis, and soft tissue infections were rare and similar across all groups. Admissions with pump failure had a higher proportion of admissions classified as major severity of illness (14.7%) but had the lowest LOS (1.60 days, 95% CI 1.55-1.65) and healthcare costs ($13 078, 95% CI $12 549-$13 608). Conclusions: Despite the increased prevalence of insulin pump in the United States, a minority of pediatric admissions documented insulin pump use, which may represent undercoding. DKA admission rates were lower among insulin pump users compared to pump nonusers. Improved accuracy in coding practices and other approaches to identify insulin pump users in administrative data are needed, as are interventions to mitigate risk for DKA. [ABSTRACT FROM AUTHOR]

Accurate age information is a critical component in fisheries monitoring, management, and research. The ability to assign accurate ages to fish by using nonlethal structures is vital in calculating cohort productivity for fish species with low abundances and variable life histories. A common nonlethal method to assign ages is by interpretation of patterns in scales. Validation of ages is not easily obtained for free‐ranging fishes; however, the development of genetic "tags" has expanded age validation opportunities. In this study, we used parental‐based genetic tagging to validate ages determined from scales collected from juvenile and adult steelhead Oncorhynchus mykiss in two streams within the Snake River basin. Juvenile scale ages were in agreement with 93% of the known ages. Adult scale ages were in agreement with 89% of the known ages. Although overall bias in juvenile ages was very low, we saw a slight positive bias in younger fish (young of the year and age 1) and a small negative bias in older juveniles (ages 2–4). A small negative bias in ages of adults was a consequence of errors in freshwater age. The errors observed did not significantly bias age compositions because the 90% confidence intervals about the age proportions based on scales contained the known proportions; therefore, scale analysis is an acceptable method for assigning ages to Snake River steelhead. We discuss the value of validated known‐age scales as a reference collection, and as an illustrative use, we constructed a circulus count guide to aid technicians in identifying missing annuli and distinguishing true from false annuli. To demonstrate the use of the circulus guidelines, we reanalyzed samples with age discrepancies, applying the circulus count data and the known age to identify mistakes. [ABSTRACT FROM AUTHOR]

Background and Objectives: Diabetic ketoacidosis (DKA) rates in the United States are rising. Prior studies suggest higher rates in younger populations, but no studies have evaluated national trends in pediatric populations and differences by subgroups. As such, we sought to examine national trends in pediatric DKA.Methods: We used the 2006, 2009, 2012, and 2016 Kids' Inpatient Database to identify pediatric DKA admissions among a nationally representative sample of admissions of youth ≤20 years old. We estimate DKA admission per 10 000 admissions and per 10 000 population, charges, length of stay (LOS), and trends over time among all hospitalizations and by demographic subgroups. Regression models were used to evaluate differences in DKA rates within subgroups overtime.Results: Between 2006 and 2016, there were 149 535 admissions for DKA. Unadjusted DKA rate per admission increased from 120.5 (95% CI, 115.9-125.2) in 2006 to 217.7 (95% CI, 208.3-227.5) in 2016. The mean charge per admission increased from $14 548 (95% CI, $13 971-$15 125) in 2006 to $20 997 (95% CI, $19 973-$22 022) in 2016, whereas mean LOS decreased from 2.51 (95% CI, 2.45-2.57) to 2.28 (95% CI, 2.23-2.33) days. Higher DKA rates occurred among 18- to 20-year-old females, Black youth, without private insurance, with lower incomes, and from nonurban areas. Young adults, men, those without private insurance, and from nonurban areas had greater increases in DKA rates across time.Conclusions: Pediatric DKA admissions have risen by 40% in the United States and vulnerable subgroups remain at highest risk. Further studies should characterize the challenges experienced by these groups to inform interventions to mitigate their DKA risk and to address the rising DKA rates nationally. [ABSTRACT FROM AUTHOR]

In a cohort of 1817 children with type 1 diabetes (T1D), short-term hyperglycemia was associated with transient albuminuria (11 % during new-onset T1D without diabetic ketoacidosis (DKA), 12 % during/after DKA, 6 % during routine screening). Our findings have implications regarding future risk of diabetic kidney disease and further investigation is needed. • Albuminuria is a key risk factor for progression to diabetic kidney disease. • Transient albuminuria occurred often at new onset T1D and during/after DKA • Short-term severe prolonged hyperglycemia may induce transient renal tubular dysfunction [ABSTRACT FROM AUTHOR]

While the influenza vaccine is recommended for all pregnant women, influenza vaccine coverage among this high-risk population remains inadequate. Factors associated with vaccine coverage among pregnant women, including insurance status, are poorly understood. In a cross-sectional study of the National Health Interview Survey (NHIS) data from 2012 to 2018, we evaluated predictors of self-reported influenza vaccine coverage in pregnant women. Among 1,942 pregnant women surveyed, 39% reported receiving the influenza vaccine in accordance with national recommendations. Influenza vaccine coverage increased by 8 percentage points from 2012 to 2018. Only 15% of uninsured pregnant women received the influenza vaccine, compared to 41% of those with insurance (design-corrected F-test, p-value < 0.001). In the multivariate Poisson regression analysis, significant predictors of influenza vaccine coverage were health insurance (prevalence ratio [PR] 1.90, 95% confidence interval [CI] 1.23–2.93), ratio of household income to federal poverty level (FPL) threshold greater than 400% (PR 1.54, 95% CI 1.20–1.96), graduate school education (PR 1.52, 95% CI 1.04–2.23), and the 2015–2018 survey year period (PR 1.27, 95% CI 1.08–1.49). While previous literature focuses heavily on demographics, our research underscores the need to further explore modifiable factors that impact vaccine uptake during pregnancy, particularly the interplay between health insurance and access to care. [ABSTRACT FROM AUTHOR]

Managing fisheries for species of conservation concern, such as steelhead Oncorhynchus mykiss fisheries in Idaho where wild steelhead are incidentally caught and released, requires a tradeoff between providing opportunity for anglers to fish for hatchery‐origin steelhead and managing conservation risk for wild steelhead. Understanding population‐level effects of catch‐and‐release fishing is critical for effectively balancing this tradeoff. We used an integrated population model to evaluate population‐level effects of incidental catch‐and‐release mortality on steelhead in Idaho and assessed the effectiveness of alternative management strategies for meeting fishery and population objectives. When simulated catch‐and‐release mortality or encounter rates were low, fishery, abundance, and conservation risk objectives were easily met by implementing fisheries annually, regardless of adult abundance. However, when simulated catch‐and‐release mortality rates were high, management strategies that required the population to surpass minimum thresholds for pre‐season abundance were more likely to meet goals for minimizing conservation risk but limited fishing opportunity substantially. Results of this study provide managers with a framework that can be used to manage fisheries to meet fishery goals in the form of hatchery steelhead harvest while maintaining sustainable populations and minimizing risk to wild steelhead. The results also suggest that when implemented properly, it is possible to meet fisheries and conservation objectives simultaneously. [ABSTRACT FROM AUTHOR]

Estimated parameters include the intercept HT ht , random year effects HT ht , and covariate effects HT ht . Like Faulkner et al. (2019), we modeled all interannual variation in freshwater and marine factors on survival as random year effects: HT ht . [Extracted from the article]

Stream habitat restoration is an important tool for fisheries management in impaired lotic systems. Although small‐scale benefits of stream habitat restoration are commonly investigated, it is difficult to demonstrate population effects. The Pahsimeroi River Chinook salmon Oncorhynchus tshawytscha population was previously restricted to the lower portion of the river by multiple irrigation structures. To address fish passage issues, a combination of restoration projects was initiated including barrier removals, instream flow enhancements and installation of fish screens on diversions. The largest barrier was removed in 2009, more than doubling the amount of accessible linear habitat. We hypothesized restoration efforts would expand the distribution of spawning salmon in the Pahsimeroi River watershed, leading to a broader distribution of juveniles. We also hypothesized a broader juvenile distribution would have population effects by reducing the prevalence of density‐dependent growth and survival. Redds were documented in newly accessible habitat immediately following barrier removal and accounted for a median of 42% of all redds in the Pahsimeroi River watershed during 2009–2015. Snorkel surveys also documented juvenile rearing in newly accessible habitat. Juvenile productivity increased from a median of 64 smolts/female spawner for brood years 2002–2008 to 99 smolts/female spawner for brood years 2009–2014. Overall, results suggested increased habitat accessibility in the Pahsimeroi River broadened the distribution of spawning adult and rearing juvenile salmon and reduced the effects of density‐dependent survival. Large‐scale stream restoration efforts can have a population effect. Despite the large‐scale effort and response, habitat restoration alone is likely not sufficient to restore this population. [ABSTRACT FROM AUTHOR]

Diversity in steelhead Oncorhynchus mykiss (anadromous Rainbow Trout) is often characterized by varying time spent in freshwater and saltwater environments. However, ontogenetic shifts are not often highlighted as an important diversity characteristic in salmonids. Larger water bodies can play a key role in population stability by buffering limited resources in smaller tributary systems. Based on freshwater and saltwater ages of adult steelhead in Fish Creek, Idaho, there were 12 different life history trajectories observed. Juvenile abundance varied from 12,083 (SE = 1,225.7) to 62,463 (SE = 1,753.8), with ages ranging from young of the year (age 0) to 4 years. Adult abundance fluctuated from 17 (SE < 0.1) to 499 (SE = 67.1), and total age of adults varied from 3 to 7 years. Diversity was most evident in juvenile movement and rearing strategies. We observed four types of movement and rearing pathways in which juveniles either directly migrated to the ocean from Fish Creek or resided for up to three winters in main‐stem river habitat in the Clearwater River basin prior to ocean migration. Most juveniles emigrated in the fall at age 2, and most ocean‐emigrating smolts were age 3. Subsequently, most juveniles resided for at least one additional winter period before ocean migration. Juvenile diversity was also reflected in adult ages; the mean proportion that spent 3 years in freshwater was 0.55 (SE = 0.03), and the mean proportion that spent 2 years in freshwater was 0.41 (SE = 0.03). Adult sex ratio was female biased (mean ± SE = 0.66 ± 0.02), with a higher proportion of females (0.89 ± 0.03) than males (0.65 ± 0.05) residing in the ocean for at least 2 years. Density‐dependent mechanisms were evident in juvenile rearing habitat in Fish Creek for cohorts of high female abundance. Population productivity potentials can be met when tributary and main‐stem rearing habitat can be utilized, and this will be essential in attaining recovery goals. [ABSTRACT FROM AUTHOR]

We analyzed and compared productivity and survival rates of populations of stream‐type Chinook Salmon Oncorhynchus tshawytscha from the upper and middle ranges of their distribution in the Columbia River basin. These two groups of populations undergo vastly different exposures during migration through the Federal Columbia River Power System (FCRPS). Declines of the Snake River populations, listed as threatened under the U.S. Endangered Species Act, have been associated with the development and operation of the FCRPS. In contrast, John Day River stream‐type Chinook Salmon populations, which were less affected by the FCRPS, have declined to a lesser extent and are not listed. Smolt‐to‐adult survival rates (SARs) accounted for a majority of the variation in life cycle survival rates of Snake River Chinook Salmon. Productivity declined to 13% and 44% of historical productivity levels for Snake River and John Day River populations, respectively. A synthesis of previous studies contrasting anthropogenic impacts between the two regions supports the conclusion that FCRPS impacts explain the large difference in population productivity. Our results suggest that SARs of 4% would result in an expected productivity of up to 70% of historical levels (a SAR level consistent with regional restoration objectives). The SARs have been shown to be highly influenced by conditions within the FCRPS (e.g., water velocity and passage through dam powerhouses). Marine conditions also influence SARs; however, meaningful management actions are only available to affect conditions within the FCRPS. Given the importance of SARs to overall life cycle productivity, recovery and restoration strategies need to prioritize actions that have potential to substantially increase SARs by addressing the significant impacts of main‐stem dams. This study highlights the importance of considering river management options in the face of increasingly variable and warming ocean conditions. [ABSTRACT FROM AUTHOR]

The "shifting baseline syndrome" (SBS) is the paradigm whereby recent species abundances and environmental conditions are accepted as reflecting historical conditions. This leads to false impressions of the past, inaccurate baselines, and unrealistic recovery goals. Idaho biologists have counted Chinook salmon redds for >60 consecutive years, generating an invaluable database; however, inaccurate historical baselines compromise the utility of even such high-quality, long-term databases. To develop an accurate baseline, we integrated archival (1951–1964), maximum redd counts with contemporary (1995–2017), continuous counts and spawn timing datasets to estimate historical (1950s–1960s) wild Chinook salmon production potential. Current salmon populations average 3% of 1950s–1960s abundances, which may have been 30% of precommercial fishery (1880s) populations. Notably, the SBS has influenced contemporary managers as reflected in minimum viable abundance, sustainable escapement, and adequate seeding objectives equaling 10.4%, 17.9%, and 20.4%, respectively, of 1950s–1960s potential. Our approach provides a framework for utilizing archival and contemporary data to reconstruct historical baselines and repress SBS. Contrasting contemporary goals with maximum production potential provides new reference points and perspectives for managers to consider. [ABSTRACT FROM AUTHOR]

Steelhead Oncorhynchus mykiss exhibit significant variation in life histories. Dworshak National Fish Hatchery (NFH)‐stock steelhead exhibit a life history that is unique compared to other Columbia River basin hatchery summer steelhead stocks, as it is dominated by older and larger‐length fish relative to conspecifics. We evaluated changes within the Dworshak NFH stock's ocean age composition and length at age from run years 1978 to 2016 using samples collected from the commercial gill‐net fishery, the sport fishery, and the hatchery trap. In addition, we analyzed the genetic composition of the stock by comparing samples collected in 1969 from the wild founding stock to samples from recent returns. We found that Dworshak NFH steelhead became younger across the study, with fewer of the oldest, three‐ocean fish (i.e., rearing in the ocean for 3 years) and increases in the proportion of the population returning as one‐ocean fish (i.e., rearing in the ocean for 1 year). Length at ocean age decreased for all ocean ages; however, the decrease was not significant in one‐ocean fish. In general, samples collected from gill nets and the sport fishery contained fish with older ocean ages and larger sizes at age compared to samples collected from the hatchery trap. Neutral genetic diversity, as measured from a panel of single‐nucleotide polymorphic markers, showed no changes between the sample of fish representing the original founders and the present‐day population. Life history shifts observed in Dworshak NFH‐stock steelhead were likely influenced by a variety of factors, including gear selectivity and changing ocean conditions. Decreases in ocean age composition and length at age have implications for both fishery and broodstock management as well as generating concern that similar trends may be occurring within wild steelhead stocks. [ABSTRACT FROM AUTHOR]

Steelhead Oncorhynchus mykiss is a species that is of high economic value that supports popular sport fisheries across the Pacific Northwest. The Clearwater River in Idaho provides a trophy steelhead fishery, and it is home to both wild‐ and hatchery‐origin steelhead. To manage the fishery effectively, information is needed about the spatial and temporal overlap of wild and hatchery steelhead in the Clearwater River, as well as the activity of anglers. We conducted a radiotelemetry study to describe the distribution of steelhead and their final fate in the Clearwater River, and creel surveys were used to describe the distribution of anglers. In total, 289 wild (Potlatch River and Lochsa River) and hatchery (from Dworshak National Fish Hatchery and South Fork Clearwater River) steelhead were radio‐tagged at Lower Granite Dam, 51 river kilometers (rkm) downstream from the mouth of the Clearwater River. Fish were monitored upon their entry into the Clearwater River by using mobile tracking surveys (boat and vehicle) and stationary antennas. The majority of wild and hatchery steelhead arrived in the Clearwater River in the fall with the exception of those from the Lochsa River, which arrived in the fall and following spring. Average daily movement of the fish was minimal (range = 0.3–4.7 km/d) and dependent on water temperature and flow. The fates of wild and hatchery steelhead varied. Fish returned to spawning grounds, were harvested by anglers (hatchery fish only), or had unknown fates. Both wild and hatchery steelhead returned at high rates to their natal tributaries and release locations. No straying was observed in either group; however, occasions when steelhead have overshot their natal tributaries and release locations were documented. Spatial and temporal overlap of the distributions of wild and hatchery steelhead was minimal. The distribution of anglers overlapped with that of hatchery steelhead in the fall, winter, and spring. The distributional overlap of anglers and wild steelhead was minimal and largely occurred in September in the lower Clearwater River. This suggests that the Clearwater River has a highly compartmentalized fishery and that current fishing regulations in the Clearwater River are providing for a diversity of angling opportunities while conserving wild steelhead and offering harvest of hatchery fish. The results from this study have important implications for the conservation and management of wild and hatchery steelhead. [ABSTRACT FROM AUTHOR]

Our aim was to determine factors that influence time to removal of tunneled hemodialysis catheter (THC), probability of repeat vascular access creation, and time to repeat vascular access. The Optum Clinformatics Data Mart claims database was queried from 2011 to 2017 for patients who initiated hemodialysis with a THC. Time from initial arteriovenous fistula (AVF)/graft (AVG) to THC removal and time to repeat AVF/AVG were analyzed using Cox proportional hazards. The likelihood of repeat AVF/AVG was analyzed using logistic regression. A total of 8941 vascular access met the inclusion criteria: 6913 (77%) AVF and 2028 (23%) AVG. Median follow-up was 595 days among AVF patients (range, 1-2543 days) and 579 days among AVG patients (range, 1-2529 days). Patients undergoing AVF were younger, more likely to be male, of white race, and obese. Patients undergoing AVF were also slightly less likely to have diabetes, cardiac arrhythmia, congestive heart failure, and peripheral vascular disease than patients undergoing AVG. At 90 days and at 180 days after index access creation, significantly more patients who underwent index AVG had their THC removed compared with patients who underwent index AVF. By day 365, 78% of patients in both AVF and AVG had their THC removed. A total of 2550 (28.5%) patients underwent a repeat vascular access creation during the follow-up period: 30% of index AVF and 24% of index AVG. At 90 days, 180 days, and 365 days, significantly more patients in the index AVF group underwent a repeat vascular access creation than those in the index AVG group. Multivariate analysis demonstrated a significant interaction between vascular access type and age ≥70 years (P <.001) for time to THC removal, likelihood of repeat vascular access, and time to repeat vascular access. In the age <70 group, patients who underwent AVG were 60% more likely to have a shorter time to THC, had a 50.4% lower odds of repeat vascular access, and were 47% more likely to have a longer time to repeat vascular access compared with patients who underwent index AVF. In the age ≥70 group, patients who underwent AVG were 98% more likely to have a shorter time to THC removal, had 69.7% lower odds of repeat vascular access, and were 66% more likely to have a longer time to repeat vascular access. Creation of AVG vs AVF significantly decreases the time to THC removal in dialysis-dependent patients, with a larger difference in patients aged ≥70 vs <70. Initial AVG was associated with lower odds of repeat vascular access and longer time to repeat vascular access. These results suggest that the dictum of "fistula first" is not appropriate for all patient populations and supports judicious use of AVG in achieving the more recent shift toward "catheter last." [ABSTRACT FROM AUTHOR]