Did a Shifting Ecological Baseline Mask the Predatory Effect of Striped Bass on Delta Smelt?

Nobriga, Matthew L.; Smith, William E.

doi:10.15447/sfews.2020v18iss1art1

Cited by 12 publications

(20 citation statements)

References 84 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Seasonal shift in temperatures above 20 degrees causes a nonlinear increase in predation hazard and intensifies the risk for salmon seeking refuge in littoral habitats rates and decline in maximum swim speeds that lessen the smolts' quick-burst escape response (Lehman et al, 2017). Striped Bass has been the estuary's dominant piscine predator for about 140 years (Nobriga & Smith, 2020). This faculta-…”

Section: S Tudy Are Amentioning

confidence: 99%

Coldwater fish in a warm water world: Implications for predation of salmon smolts during estuary transit

Nobriga

Michel

Johnson

et al. 2021

Ecology and Evolution

View full text Add to dashboard Cite

1. Predator-prey systems face intensifying pressure from human exploitation and a warming climate with implications for where and how natural resource management can successfully intervene. We hypothesized young salmon migrating to the Pacific Ocean face a seasonally intensifying predator gauntlet when warming water temperature intensifies a multiple predator effect (MPE) from Striped Bass Morone saxatilis and Largemouth Bass Micropterus salmoides. We evaluated this hypothesis using data synthesis and simulation modeling.

show abstract

Section: S Tudy Are Amentioning

confidence: 99%

Coldwater fish in a warm water world: Implications for predation of salmon smolts during estuary transit

Nobriga

Michel

Johnson

et al. 2021

Ecology and Evolution

View full text Add to dashboard Cite

show abstract

“…This observation may be attributed to the sensitivity of the genetic method or differences in the season sampled or the sampling region. While these do not represent direct comparisons, our findings indicate that the predator-prey dynamics between these species is not well understood, an idea highlighted by (Nobriga and Smith 2020) who posit that the lack of historic data has prevented understanding the outsized role of Striped Bass may play as a predator in the estuary. Unfortunately, the small…”

Section: Accepted Articlementioning

confidence: 73%

“…Other piscivorous fish species-Largemouth Bass, Smallmouth Bass, White Catfish, Channel Catfish, and the native Sacramento Pikeminnowwere opportunistically collected and saved for analysis. As the targets of this sampling were predators consuming native fish greater than 50 mm fork length (FL), our sampling focused on predators greater than 200 mm FL (Nobriga and Smith 2020).…”

Section: Accepted Articlementioning

confidence: 99%

“…We sampled six species of predators: Striped Bass, Sacramento Pikeminnow Ptychocheilus grandis , Largemouth Bass Micropterus salmoides , Smallmouth Bass Micropterus dolomieu , Channel Catfish Ictalurus punctatus , and White Catfish Ameiurus catus . The primary target predator, nonnative Striped Bass, are hypothesized to be the primary predator consuming Delta Smelt in open water habitats (Nobriga and Smith 2020) and are among the most abundant predator in pelagic habitats, which are typically occupied by prey species of interest. Sacramento Pikeminnow serves as a comparative native piscivore targeting similarly sized prey (Moyle 2002).…”

mentioning

confidence: 99%

See 1 more Smart Citation

Enumerating Predation on Chinook Salmon, Delta Smelt, and Other San Francisco Estuary Fishes Using Genetics

Brandl

Schreier²,

Conrad³

et al. 2021

N American J Fish Manag

View full text Add to dashboard Cite

The establishment of non-native predator fish is a worldwide phenomenon often having adverse effects on native species. Trophic interactions are complex, and uncertainty is a common theme in discussions of non-native predator management. Several fishes of the San Francisco Estuary have experienced significant declines in recent decades due to multiple factors, including habitat alteration and predation. The role of predation as a direct cause of mortality remains an open question, as does whether habitat conditions play a role in promoting predation on species of concern. Recent studies using visual identification of prey have found little to no evidence of predation on ESA-listed species such as Delta Smelt Hypomesus transpacificus and juvenile Chinook Salmon Oncorhynchus tshawytscha. To increase the likelihood of detecting predation, this study employed a genetic approach. We combined this technique with habitat and water quality data to investigate the role habitat may be playing on incidence of predation. This study focused on detection of predation on Chinook Salmon and Delta Smelt, as well as 6 other native fishes, and 6 non-native fishes by Striped Bass Morone saxatilis, and other piscivores. Unlike previous studies in the region, the proportion of predators with no prey detected in their gut contents was high (47-81%). The study detected Delta Smelt in 1.3% of Striped Bassconsiderably higher than other contemporary predation studies in the Delta. In the month of April 2014, 6.6% of Striped Bass were positive for Chinook Salmon-substantially higher than recent visual diet studies in the Delta. Interestingly, native species comprised a relatively high proportion of Striped Bass prey (60%). Water temperature and conductivity were identified as significant predictors of Chinook Salmon presence in Striped Bass gut contents. This research

show abstract

“…The Delta environment has been radically transformed over the past 150 years, and multiple forces continue to drive change (San Francisco Estuary Institute 2014). Annual variations in streamflow, temperature, seasonal timing, pollution inputs, and salinity gradients-complicated, for example, by invasions of new species or a levee collapse-have made it difficult to establish baselines and detect trends (Nobriga and Smith 2020).…”

Section: The Nature Of the Problemmentioning

confidence: 99%

Preparing Scientists, Policymakers, and Managers for a Fast-Forward Future

Norgaard¹,

Wiens²,

Brandt³

et al. 2020

SFEWS

View full text Add to dashboard Cite

Ecosystems in the Sacramento–San Joaquin Delta are changing rapidly, as are ecosystems around the world. Extreme events are becoming more frequent and thresholds are likely to be crossed more often, creating greater uncertainty about future conditions. The accelerating speed of change means that ecological systems may not remain stable long enough for scientists to understand them, much less use their research findings to inform policy and management. Faced with these challenges, those involved in science, policy, and management must adapt and change and anticipate what the ecosystems may be like in the future. We highlight several ways of looking ahead—scenario analyses, horizon scanning, expert elicitation, and dynamic planning—and suggest that recent advances in distributional ecology, disturbance ecology, resilience thinking, and our increased understanding of coupled human–natural systems may provide fresh ways of thinking about more rapid change in the future. To accelerate forward-looking science, policy, and management in the Delta, we propose that the State of California create a Delta Science Visioning Process to fully and openly assess the challenges of more rapid change to science, policy, and management and propose appropriate solutions, through legislation, if needed.

show abstract

Did a Shifting Ecological Baseline Mask the Predatory Effect of Striped Bass on Delta Smelt?

Cited by 12 publications

References 84 publications

Coldwater fish in a warm water world: Implications for predation of salmon smolts during estuary transit

Coldwater fish in a warm water world: Implications for predation of salmon smolts during estuary transit

Enumerating Predation on Chinook Salmon, Delta Smelt, and Other San Francisco Estuary Fishes Using Genetics

Preparing Scientists, Policymakers, and Managers for a Fast-Forward Future

Contact Info

Product

Resources

About