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Deemer BR, Yackulic CB, Hall RO, Dodrill MJ, Kennedy TA, Muehlbauer JD, Topping DJ, Voichick N, Yard MD. Experimental reductions in subdaily flow fluctuations increased gross primary productivity for 425 river kilometers downstream. PNAS NEXUS 2022; 1:pgac094. [PMID: 36741441 PMCID: PMC9896909 DOI: 10.1093/pnasnexus/pgac094] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2022] [Accepted: 06/17/2022] [Indexed: 02/07/2023]
Abstract
Aquatic primary production is the foundation of many river food webs. Dams change the physical template of rivers, often driving food webs toward greater reliance on aquatic primary production. Nonetheless, the effects of regulated flow regimes on primary production are poorly understood. Load following is a common dam flow management strategy that involves subdaily changes in water releases proportional to fluctuations in electrical power demand. This flow regime causes an artificial tide, wetting and drying channel margins and altering river depth and water clarity, all processes that are likely to affect primary production. In collaboration with dam operators, we designed an experimental flow regime whose goal was to mitigate negative effects of load following on ecosystem processes. The experimental flow contrasted steady-low flows on weekends with load following flows on weekdays. Here, we quantify the effect of this experimental flow on springtime gross primary production (GPP) 90-to-425 km downstream of Glen Canyon Dam on the Colorado River, AZ, USA. GPP during steady-low flows was 41% higher than during load following flows, mostly owing to nonlinear reductions in sediment-driven turbidity. The experimental flow increased weekly GPP even after controlling for variation in weekly mean discharge, demonstrating a negative effect of load following on GPP. We estimate that this environmental flow increased springtime carbon fixation by 0.27 g C m-2 d-1, which is ecologically meaningful considering median C fixation in 356 US rivers of 0.44 g C m-2 d-1 and the fact that native fish populations in this river are food-limited.
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Affiliation(s)
| | - Charles B Yackulic
- Southwest Biological Science Center, U.S. Geological Survey, Flagstaff, AZ 86001, USA
| | - Robert O Hall
- Flathead Lake Biological Station, University of Montana, Polson, MT 59860, USA
| | - Michael J Dodrill
- Southwest Biological Science Center, U.S. Geological Survey, Flagstaff, AZ 86001, USA,Columbia River Research Lab, U.S. Geological Survey, Cook, WA 98605, USA
| | - Theodore A Kennedy
- Southwest Biological Science Center, U.S. Geological Survey, Flagstaff, AZ 86001, USA
| | - Jeffrey D Muehlbauer
- Southwest Biological Science Center, U.S. Geological Survey, Flagstaff, AZ 86001, USA,Alaska Cooperative Fish and Wildlife Research Unit, U.S. Geological Survey, Fairbanks, AK 99775 , USA
| | - David J Topping
- Southwest Biological Science Center, U.S. Geological Survey, Flagstaff, AZ 86001, USA
| | - Nicholas Voichick
- Southwest Biological Science Center, U.S. Geological Survey, Flagstaff, AZ 86001, USA
| | - Michael D Yard
- Southwest Biological Science Center, U.S. Geological Survey, Flagstaff, AZ 86001, USA
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Dempsey BL, Roden JW, Bidwell JR. Predator-avoidance of larval black-bellied salamanders ( Desmognathus quadramaculatus) in response to cues from native and nonnative salmonids. ETHOL ECOL EVOL 2021. [DOI: 10.1080/03949370.2021.1988720] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
- Brian L. Dempsey
- Biological Sciences, East Tennessee State University, Johnson City, USA
| | - John W. Roden
- Biological Sciences, East Tennessee State University, Johnson City, USA
| | - Joseph R. Bidwell
- Biological Sciences, East Tennessee State University, Johnson City, USA
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3
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Gibeau P, Palen WJ. Impacts of run‐of‐river hydropower on coho salmon (
Oncorhynchus kisutch
): the role of density‐dependent survival. Ecosphere 2021. [DOI: 10.1002/ecs2.3684] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- Pascale Gibeau
- Earth to Ocean Research Group Department of Biological Sciences Simon Fraser University Burnaby British Columbia V5A 1S6 Canada
| | - Wendy J. Palen
- Earth to Ocean Research Group Department of Biological Sciences Simon Fraser University Burnaby British Columbia V5A 1S6 Canada
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Abernethy EF, Muehlbauer JD, Kennedy TA, Tonkin JD, Van Driesche R, Lytle DA. Hydropeaking intensity and dam proximity limit aquatic invertebrate diversity in the Colorado River Basin. Ecosphere 2021. [DOI: 10.1002/ecs2.3559] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Affiliation(s)
- Erin F. Abernethy
- Department of Integrative Biology Oregon State University Corvallis Oregon97331USA
| | - Jeffrey D. Muehlbauer
- US Geological Survey Southwest Biological Science Center Grand Canyon Monitoring and Research Center Flagstaff Arizona86001USA
| | - Theodore A. Kennedy
- US Geological Survey Southwest Biological Science Center Grand Canyon Monitoring and Research Center Flagstaff Arizona86001USA
| | - Jonathan D. Tonkin
- School of Biological Sciences University of Canterbury Christchurch8140New Zealand
| | - Richard Van Driesche
- Department of Integrative Biology Oregon State University Corvallis Oregon97331USA
| | - David A. Lytle
- Department of Integrative Biology Oregon State University Corvallis Oregon97331USA
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Ruhi A, Dong X, McDaniel CH, Batzer DP, Sabo JL. Detrimental effects of a novel flow regime on the functional trajectory of an aquatic invertebrate metacommunity. GLOBAL CHANGE BIOLOGY 2018; 24:3749-3765. [PMID: 29665147 DOI: 10.1111/gcb.14133] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2017] [Revised: 02/15/2018] [Accepted: 02/23/2018] [Indexed: 06/08/2023]
Abstract
Novel flow regimes resulting from dam operations and overallocation of freshwater resources are an emerging consequence of global change. Yet, anticipating how freshwater biodiversity will respond to surging flow regime alteration requires overcoming two challenges in environmental flow science: shifting from local to riverscape-level understanding of biodiversity dynamics, and from static to time-varying characterizations of the flow regime. Here, we used time-series methods (wavelets and multivariate autoregressive models) to quantify flow-regime alteration and to link time-varying flow regimes to the dynamics of multiple local communities potentially connected by dispersal (i.e., a metacommunity). We studied the Chattahoochee River below Buford dam (Georgia, U.S.A.), and asked how flow regime alteration by a large hydropower dam may control the long-term functional trajectory of the downstream invertebrate metacommunity. We found that seasonal variation in hydropeaking synchronized temporal fluctuations in trait abundance among the flow-altered sites. Three biological trait states describing adaptation to fast flows benefitted from flow management for hydropower, but did not compensate for declines in 16 "loser" traits. Accordingly, metacommunity-wide functional diversity responded negatively to hydropeaking intensity, and stochastic simulations showed that the risk of functional diversity collapse within the next 4 years would decrease by 17% if hydropeaking was ameliorated, or by 9% if it was applied every other season. Finally, an analysis of 97 reference and 23 dam-affected river sites across the U.S. Southeast suggested that flow variation at extraneous, human-relevant scales (12-hr, 24-hr, 1-week) is relatively common in rivers affected by hydropower dams. This study advances the notion that novel flow regimes are widespread, and simplify the functional structure of riverine communities by filtering out taxa with nonadaptive traits and by spatially synchronizing their dynamics. This is relevant in the light of ongoing and future hydrologic alteration due to climate non-stationarity and the new wave of dams planned globally.
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Affiliation(s)
- Albert Ruhi
- Department of Environmental Science, Policy, and Management, University of California, Berkeley, Berkeley, CA, USA
- National Socio-Environmental Synthesis Center (SESYNC), University of Maryland, Annapolis, MD, USA
| | - Xiaoli Dong
- Nicholas School of the Environment, Duke University, Durham, NC, USA
| | - Courtney H McDaniel
- Department of Environmental Science and Ecology, The College at Brockport, State University of New York, Brockport, NY, USA
| | - Darold P Batzer
- Department of Entomology, University of Georgia, Athens, GA, USA
| | - John L Sabo
- School of Life Sciences, Arizona State University, Tempe, AZ, USA
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Kennedy TA, Muehlbauer JD, Yackulic CB, Lytle DA, Miller SW, Dibble KL, Kortenhoeven EW, Metcalfe AN, Baxter CV. Flow Management for Hydropower Extirpates Aquatic Insects, Undermining River Food Webs. Bioscience 2016. [DOI: 10.1093/biosci/biw059] [Citation(s) in RCA: 118] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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