Dynamics of endangered sucker populations in Clear Lake Reservoir, California

Hewitt, David A.; Hayes, Brian S.; Harris, Alta C.; Janney, Eric C.; Kelsey, Caylen M.; Perry, Russell W.; Burdick, Summer M.

doi:10.3133/ofr20211043

Cited by 5 publications

(12 citation statements)

References 6 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, the annual variation in survival for LRS and SNS in Upper Klamath Lake is minor compared to the highly variable estimates (0.41–0.95) for these species in Clear Lake, Oregon (Hewitt et al. 2021). Avian predators are present in Upper Klamath Lake, and the smaller SNS are more susceptible to predation than are LRS (Evans et al.…”

Section: Discussionmentioning

confidence: 89%

Water and Endangered Fish in the Klamath River Basin: Do Upper Klamath Lake Surface Elevation and Water Quality Affect Adult Lost River and Shortnose Sucker Survival?

Krause

Janney

Burdick

et al. 2022

N American J Fish Manag

Self Cite

View full text Add to dashboard Cite

In the western United States, water allocation decisions often incorporate the needs of endangered fish. In the Klamath River basin, an understanding of temporal variation in annual survival rates of Shortnose Suckers Chasmistes brevirostris and Lost River Suckers Deltistes luxatus and their relation to environmental drivers is critical to water management and sucker recovery. Extinction risk is high for these fish because most individuals in the populations are approaching their maximum life span and recruitment of new fish into the adult populations has never exceeded mortality losses in the past 22 years. We used a time series of mark–recapture data from the years 1999–2021 to analyze the relationship between lake level, water quality covariates, and survival of adult Shortnose Suckers and two spawning populations of Lost River Suckers in Upper Klamath Lake, Oregon. We compared competing model hypotheses in a maximum likelihood framework using Akaike's information criterion and then ran the top environmental covariates in a Bayesian framework to estimate how much of the variation in survival was explained by these covariates as compared to random variation. The complementary analyses found almost unequivocal support for our base model without environmental covariates. Estimated adult sucker survival was high across the time series and consistent with sucker life history (mean annual survival = 0.82–0.91). This suggests that adult suckers were generally robust to interannual variation in lake levels as well as consistently poor water quality within the years of our data set. Recovery time is limited, as a declining survival trend for adult suckers in recent years may be due to the onset of senescence. The successful recovery of suckers in Upper Klamath Lake may rely on shifting research from the causes of adult mortality and its relationship with lake surface elevation to the causes of poor recruitment into adult populations.

show abstract

Section: Discussionmentioning

confidence: 89%

Water and Endangered Fish in the Klamath River Basin: Do Upper Klamath Lake Surface Elevation and Water Quality Affect Adult Lost River and Shortnose Sucker Survival?

Krause

Janney

Burdick

et al. 2022

N American J Fish Manag

Self Cite

View full text Add to dashboard Cite

show abstract

“…Avian predation is also one of the largest known causes of adult sucker mortality in the UKB. For instance, despite annual avian predation rate estimates of just 1-7%, annual estimates of total mortality (i.e., 1survival) for adult suckers during 2009-2018 were just 6-26% in Upper Klamath Lake and were 5-55% in Clear Lake Reservoir (depending on the sucker species; Hewitt et al 2018Hewitt et al , 2021. Thus, avian predation represented a relatively large proportion of all sources of adult sucker mortality in some years.…”

Section: Discussionmentioning

confidence: 99%

“…2015; Hewitt et al. 2018, 2021). Passive integrated transponder tags link species, size, age‐class (adult, juvenile), release/recapture location, and other demographic information to individual fish.…”

mentioning

confidence: 99%

“…Some of the spawning populations may now consist of fewer than 10,000 individuals (Childress et al 2019). Numerous factors have been identified as limiting the recovery of sucker populations, including habitat loss, poor water quality, low water levels, and a lack of juvenile recruitment into spawning populations (Janney et al 2008;USFWS 2012;Burdick et al 2015Burdick et al , 2020Hewitt et al 2018Hewitt et al , 2021. Recent data also suggest that impacts from colonial waterbirds may be limiting sucker survival based on the number and percentage of PIT tags implanted into suckers that were subsequently recovered on bird colonies in the UKB during 2009-2014 (Evans et al 2016).…”

mentioning

confidence: 99%

“…To monitor the behavior and survival of LRS and SNS, fish have been PIT-tagged in Upper Klamath Lake and Clear Lake Reservoir for over two decades (Janney et al 2008;Hewitt and Hayes 2013;Burdick et al 2015;Hewitt et al 2018Hewitt et al , 2021. Passive integrated transponder tags link species, size, age-class (adult, juvenile), release/recapture location, and other demographic information to individual fish.…”

mentioning

confidence: 99%

See 2 more Smart Citations

Avian Predation on Juvenile and Adult Lost River and Shortnose Suckers: An UpdatedMulti‐PredatorSpecies Evaluation

Evans

Payton

Banet

et al. 2022

N American J Fish Manag

Self Cite

View full text Add to dashboard Cite

Previous research suggests that predation by piscivorous colonial waterbirds may negatively influence the survival of Lost River Suckers (LRS) Deltistes luxatus and Shortnose Suckers (SNS) Chasmistes brevirostris in the Upper Klamath Basin (UKB), USA. However, estimates of predation from past studies, which were based on suckers with PIT tags, represent minimum estimates of sucker mortality because analyses did not account for the proportion of tags that were consumed by birds and deposited beyond their breeding colony. To address this uncertainty, we fed PIT‐tagged suckers to American white pelicans Pelecanus erythrorhynchos to estimate deposition probabilities. A hierarchical Bayesian model was then used to estimate predation rates (percentage of available tagged fish that were consumed) on juvenile suckers that were released as part of the Sucker Assisted Rearing Program (SARP) and on wild juvenile and adult LRS and SNS during 2009–2020. Pelican deposition probabilities were estimated to be 0.47 (95% credible interval = 0.36–0.60), indicating that for every 100 tags consumed, 47 tags on average were deposited on breeding colonies by birds. Deposition‐corrected estimates of predation rates were approximately two times greater than those previously reported and ranged annually from 4.3% (95% credible interval = 2.9–6.7%) to 8.5% (6.3–12.7%) on SARP juvenile suckers, from 4.3% (0.9–13.2%) to 10.5% (3.8–24.5%) on wild juvenile suckers, and from 0.1% (<0.1–0.3%) to 7.2% (2.8–16.4%) on adult suckers, depending on species and location. Results suggest that predation by colonial waterbirds, although not the original cause of sucker declines, was a substantial source of sucker mortality in some years. Future studies should consider models that jointly estimate both predation and survival and models that include environmental factors that potentially influence sucker susceptibility to avian predators in the UKB.

show abstract

Growth, survival, and cohort formation of juvenile Lost River (Deltistes luxatus) and shortnose suckers (Chasmistes brevirostris) in Upper Klamath Lake, Oregon, and Clear Lake Reservoir, California—2020 monitoring report

Martin¹,

Kelsey²,

Burdick³

et al. 2022

Open-File Report

View full text Add to dashboard Cite

Dynamics of endangered sucker populations in Clear Lake Reservoir, California

Cited by 5 publications

References 6 publications

Water and Endangered Fish in the Klamath River Basin: Do Upper Klamath Lake Surface Elevation and Water Quality Affect Adult Lost River and Shortnose Sucker Survival?

Water and Endangered Fish in the Klamath River Basin: Do Upper Klamath Lake Surface Elevation and Water Quality Affect Adult Lost River and Shortnose Sucker Survival?

Avian Predation on Juvenile and Adult Lost River and Shortnose Suckers: An UpdatedMulti‐PredatorSpecies Evaluation

Growth, survival, and cohort formation of juvenile Lost River (Deltistes luxatus) and shortnose suckers (Chasmistes brevirostris) in Upper Klamath Lake, Oregon, and Clear Lake Reservoir, California—2020 monitoring report

Contact Info

Product

Resources

About