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Watershed Sciences Faculty Publications

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Articles 31 - 60 of 160

Full-Text Articles in Life Sciences

Marine Reserves Shape Seascapes On Scales Visible From Space, Elizabeth M. P. Madin, Alastair R. Harborne, Aaron M. T. Harmer, Osmar J. Luiz, Trisha Brooke Atwood, Brian J. Sullivan, Joshua S. Madin Apr 2019

Marine Reserves Shape Seascapes On Scales Visible From Space, Elizabeth M. P. Madin, Alastair R. Harborne, Aaron M. T. Harmer, Osmar J. Luiz, Trisha Brooke Atwood, Brian J. Sullivan, Joshua S. Madin

Watershed Sciences Faculty Publications

Marine reserves can effectively restore harvested populations, and ‘mega-reserves’ increasingly protect large tracts of ocean. However, no method exists of monitoring ecological responses at this large scale. Herbivory is a key mechanism structuring ecosystems, and this consumer–resource interaction's strength on coral reefs can indicate ecosystem health. We screened 1372, and measured features of 214, reefs throughout Australia's Great Barrier Reef using high-resolution satellite imagery, combined with remote underwater videography and assays on a subset, to quantify the prevalence, size and potential causes of ‘grazing halos’. Halos are known to be seascape-scale footprints of herbivory and other ecological interactions. Here we …


The Power Of Environmental Observatories For Advancing Multidisciplinary Research, Outreach, And Decision Support: The Case Of The Minnesota River Basin, K. B. Gran, C. Dolph, A. Baker, M. Bevis, S. J. Cho, J. A. Czuba, B. Dalzell, M. Danesh-Yazdi, A. T. Hansen, Sara A. Kelly, Z. Lang, J. Schwenk, Patrick Belmont, J. C. Finlay, P. Kumar, S. Rabotyagov, G. Roehrig, Peter Wilcock, E. Foufoula-Georgiou Apr 2019

The Power Of Environmental Observatories For Advancing Multidisciplinary Research, Outreach, And Decision Support: The Case Of The Minnesota River Basin, K. B. Gran, C. Dolph, A. Baker, M. Bevis, S. J. Cho, J. A. Czuba, B. Dalzell, M. Danesh-Yazdi, A. T. Hansen, Sara A. Kelly, Z. Lang, J. Schwenk, Patrick Belmont, J. C. Finlay, P. Kumar, S. Rabotyagov, G. Roehrig, Peter Wilcock, E. Foufoula-Georgiou

Watershed Sciences Faculty Publications

Observatory‐scale data collection efforts allow unprecedented opportunities for integrative, multidisciplinary investigations in large, complex watersheds, which can affect management decisions and policy. Through the National Science Foundation‐funded REACH (REsilience under Accelerated CHange) project, in collaboration with the Intensively Managed Landscapes‐Critical Zone Observatory, we have collected a series of multidisciplinary data sets throughout the Minnesota River Basin in south‐central Minnesota, USA, a 43,400‐km2 tributary to the Upper Mississippi River. Postglacial incision within the Minnesota River valley created an erosional landscape highly responsive to hydrologic change, allowing for transdisciplinary research into the complex cascade of environmental changes that occur due to hydrology …


Guidelines For Reporting And Archiving 210pb Sediment Chronologies To Improve Fidelity And Extend Data Lifecycle, Colin J. Courtney Mustaphi, Janice Brahney, Marco A. Aquino-Lopez, Simon Goring, Kiersten Orton, Alexandra Noronha, John Czaplewski, Quinn Asena, Sarah Paton, Johnny Panga Brushworth Apr 2019

Guidelines For Reporting And Archiving 210pb Sediment Chronologies To Improve Fidelity And Extend Data Lifecycle, Colin J. Courtney Mustaphi, Janice Brahney, Marco A. Aquino-Lopez, Simon Goring, Kiersten Orton, Alexandra Noronha, John Czaplewski, Quinn Asena, Sarah Paton, Johnny Panga Brushworth

Watershed Sciences Faculty Publications

Radiometric dating methods are essential for developing geochronologies to study Late Quaternary environmental change and 210Pb dating is commonly used to produce age-depth models from recent (within 150 years) sediments and other geoarchives. The past two centuries are marked by rapid environmental socio-ecological changes frequently attributed to anthropogenic land-use activities, modified biogeochemical cycles, and climate change. Consequently, historical reconstructions over this recent time interval have high societal value because analyses of these datasets provide understanding of the consequences of environmental modifications, critical ecosystem thresholds, and to define desirable ranges of variation for management, restoration, and conservation. For this information …


Mountain Lakes: Eyes On Global Environmental Change, K. A. Moser, J. S. Baron, Janice Brahney, I. A. Oleksy, J. E. Saros, E. J. Hundey, S. A. Sadro, J. Kopáček, R. Sommaruga, M. J. Kainz, A. L. Strecker, S. Chandra, D. M. Walters, D. L. Preston, Et Al. Apr 2019

Mountain Lakes: Eyes On Global Environmental Change, K. A. Moser, J. S. Baron, Janice Brahney, I. A. Oleksy, J. E. Saros, E. J. Hundey, S. A. Sadro, J. Kopáček, R. Sommaruga, M. J. Kainz, A. L. Strecker, S. Chandra, D. M. Walters, D. L. Preston, Et Al.

Watershed Sciences Faculty Publications

Mountain lakes are often situated in protected natural areas, a feature that leads to their role as sentinels of global environmental change. Despite variations in latitude, mountain lakes share many features, including their location in catchments with steep topographic gradients, cold temperatures, high incident solar and ultraviolet radiation (UVR), and prolonged ice and snow cover. These characteristics, in turn, affect mountain lake ecosystem structure, diversity, and productivity. The lakes themselves are mostly small, and up until recently, have been characterized as oligotrophic. This paper provides a review and update of the growing body of research that shows that sediments in …


Increased Dust Deposition In New Zealand Related To Twentieth Century Australian Land Use, Janice Brahney, Ashley P. Ballantyne, Marcus Vandergoes, Troy Baisden, Jason C. Neff Apr 2019

Increased Dust Deposition In New Zealand Related To Twentieth Century Australian Land Use, Janice Brahney, Ashley P. Ballantyne, Marcus Vandergoes, Troy Baisden, Jason C. Neff

Watershed Sciences Faculty Publications

Mineral aerosols (dust) generated in the dryland regions of Australia have the potential to reach New Zealand through atmospheric transport. Although a large portion of dust in New Zealand originates in Australia, little is known about how dust deposition has varied over time in New Zealand or what may have caused this variation. We used geochemical dust proxies to examine the recent history of dust deposition to two alpine lakes in Kahurangi National Park, South Island, New Zealand. Geochemical indicators suggest that dust deposition began to increase around 1900, with the greatest deposition rates occurring from ~1920 to ~1990. In …


Modelling Braided River Morphodynamics Using A Particle Travel Length Framework, Alan Kasprak, James Brasington, Konrad Hafen, Richard D. Williams, Joseph Michael Wheaton Mar 2019

Modelling Braided River Morphodynamics Using A Particle Travel Length Framework, Alan Kasprak, James Brasington, Konrad Hafen, Richard D. Williams, Joseph Michael Wheaton

Watershed Sciences Faculty Publications

Numerical models that predict channel evolution are an essential tool for investigating processes that occur over timescales which render field observation intractable. The current generation of morphodynamic models, however, either oversimplify the relevant physical processes or, in the case of more physically complete codes based on computational fluid dynamics (CFD), have computational overheads that severely restrict the space–time scope of their application. Here we present a new, open-source, hybrid approach that seeks to reconcile these modelling philosophies. This framework combines steady-state, two-dimensional CFD hydraulics with a rule-based sediment transport algorithm to predict particle mobility and transport paths which are used …


Simulation Model For Collaborative Decision Making On Sediment Source Reduction In An Intensively Managed Watershed, Se Jong Cho, Peter Wilcock, Patrick Belmont, Karen B. Gran, Benjamin F. Hobbs Feb 2019

Simulation Model For Collaborative Decision Making On Sediment Source Reduction In An Intensively Managed Watershed, Se Jong Cho, Peter Wilcock, Patrick Belmont, Karen B. Gran, Benjamin F. Hobbs

Watershed Sciences Faculty Publications

We developed a watershed sediment source and delivery model for use in evaluating conservation trade‐offs in southern Minnesota, where sediment loading has been identified as a priority and there is substantial public investment in cleaner water. The model was developed in a stakeholder process and links user‐specified management options to reductions in sediment loading at the outlet of a 2,880‐km2 intensively farmed watershed. The simulation model was formulated to allocate total sediment load among sources, which provides robustness to the model by constraining the relative magnitude of sediment loads and their reduction. A novel topographic filtering approach was used to …


Emerging Reservoir Delta‐Backwaters: Biophysical Dynamics And Riparian Biodiversity, Malia A. Volke, W. Carter Johnson, Mark D. Dixon, Michael L. Scott Feb 2019

Emerging Reservoir Delta‐Backwaters: Biophysical Dynamics And Riparian Biodiversity, Malia A. Volke, W. Carter Johnson, Mark D. Dixon, Michael L. Scott

Watershed Sciences Faculty Publications

Deltas and backwater‐affected bottomlands are forming along tributary and mainstem confluences in reservoirs worldwide. Emergence of prograding deltas, along with related upstream hydrogeomorphic changes to river bottomlands in the backwater fluctuation zones of reservoirs, signals the development of new and dynamic riparian and wetland habitats. This study was conducted along the regulated Missouri River, USA, to examine delta‐backwater formation and describe vegetation response to its development and dynamics. Our research focused specifically on the delta‐backwater forming at the confluence of the White River tributary and Lake Francis Case reservoir. Objectives of the research were to: (1) describe and analyze the …


Timescale Dependence In River Channel Migration Measurements, Mitchell Donovan, Patrick Belmont Jan 2019

Timescale Dependence In River Channel Migration Measurements, Mitchell Donovan, Patrick Belmont

Watershed Sciences Faculty Publications

Accurately measuring river meander migration over time is critical for sediment budgets and understanding how rivers respond to changes in hydrology or sediment supply. However, estimates of meander migration rates or streambank contributions to sediment budgets using repeat aerial imagery, maps, or topographic data will be underestimated without proper accounting for channel reversal. Furthermore, comparing channel planform adjustment measured over dissimilar timescales are biased because short‐ and long‐term measurements are disproportionately affected by temporary rate variability, long‐term hiatuses, and channel reversals. We evaluate the role of timescale dependence for the Root River, a single threaded meandering sand‐ and gravel‐bedded river …


Assessment Of The Effects Of Climate Change On Evapotranspiration With An Improved Elasticity Method In A Nonhumid Area, Lei Tian, Jiming Jin, Pute Wu, Guo-Yue Niu Dec 2018

Assessment Of The Effects Of Climate Change On Evapotranspiration With An Improved Elasticity Method In A Nonhumid Area, Lei Tian, Jiming Jin, Pute Wu, Guo-Yue Niu

Watershed Sciences Faculty Publications

Climatic elasticity is a crucial metric to assess the hydrological influence of climate change. Based on the Budyko equation, this study performed an analytical derivation of the climatic elasticity of evapotranspiration (ET). With this derived elasticity, it is possible to quantitatively separate the impacts of precipitation, air temperature, net radiation, relative humidity, and wind speed on ET in a watershed. This method was applied in the Wuding River Watershed (WRW), located in the center of the Yellow River Watershed of China. The estimated rate of change in ET caused by climatic variables is −10.69 mm/decade, which is close to the …


Quantifying The Impact Of Climate Change And Human Activities On Streamflow In A Semi-Arid Watershed With The Budyko Equation Incorporating Dynamic Vegetation Information, Lei Tian, Jiming Jin, Pute Wu, Guo-Yue Niu Dec 2018

Quantifying The Impact Of Climate Change And Human Activities On Streamflow In A Semi-Arid Watershed With The Budyko Equation Incorporating Dynamic Vegetation Information, Lei Tian, Jiming Jin, Pute Wu, Guo-Yue Niu

Watershed Sciences Faculty Publications

Understanding hydrological responses to climate change and land use and land cover change (LULCC) is important for water resource planning and management, especially for water-limited areas. The annual streamflow of the Wuding River Watershed (WRW), the largest sediment source of the Yellow River in China, has decreased significantly over the past 50 years at a rate of 5.2 mm/decade. Using the Budyko equation, this study investigated this decrease with the contributions from climate change and LULCC caused by human activities, which have intensified since 1999 due to China’s Grain for Green Project (GFGP). The Budyko parameter that represents watershed characteristics …


Riparian Research And Management: Past, Present, Future: Volume 1, Steven W. Carothers, Hisham El Waer, Helen C. Fairley, Deborah M. Finch, Suzanne C. Fouty, Jonathan M. Friedman, Jennifer K. Frey, Stanley V. Gregory, Robert H. Hamre, Annie Henry, Osvel Hinojosa-Huerta, Elaine E. Johnson, R. Roy Johnson, Kenneth J. Kingsley, Mary Anne Mcleod, Eric Mellink, Katie Merewether, Duncan T. Patten, John S. Richardson, Anne Sands, Michael L. Scott, Bo Shelby, Anna A. Sher, D. Max Smith, John T. Stanley, Frederick J. Swanson, Raymond M. Turner, Robert H. Webb, William E. Werner Nov 2018

Riparian Research And Management: Past, Present, Future: Volume 1, Steven W. Carothers, Hisham El Waer, Helen C. Fairley, Deborah M. Finch, Suzanne C. Fouty, Jonathan M. Friedman, Jennifer K. Frey, Stanley V. Gregory, Robert H. Hamre, Annie Henry, Osvel Hinojosa-Huerta, Elaine E. Johnson, R. Roy Johnson, Kenneth J. Kingsley, Mary Anne Mcleod, Eric Mellink, Katie Merewether, Duncan T. Patten, John S. Richardson, Anne Sands, Michael L. Scott, Bo Shelby, Anna A. Sher, D. Max Smith, John T. Stanley, Frederick J. Swanson, Raymond M. Turner, Robert H. Webb, William E. Werner

Watershed Sciences Faculty Publications

Fifty years ago, riparian habitats were not recognized for their extensive and critical contributions to wildlife and the ecosystem function of watersheds. This changed as riparian values were identified and documented, and the science of riparian ecology developed steadily. Papers in this volume range from the more mesic northwestern United States to the arid Southwest and Mexico. More than two dozen authors—most with decades of experience—review the origins of riparian science in the western United States, document what is currently known about riparian ecosystems, and project future needs. Topics are widespread and include: interactions with fire, climate change, and declining …


Landscape Heterogeneity Strengthens The Relationship Between Β-Diversity And Ecosystem Function, Edd Hammill, Charles P. Hawkins, Hamish S. Greig, Pavel Kratina, Johathan B. Shurin, Trisha Brooke Atwood Oct 2018

Landscape Heterogeneity Strengthens The Relationship Between Β-Diversity And Ecosystem Function, Edd Hammill, Charles P. Hawkins, Hamish S. Greig, Pavel Kratina, Johathan B. Shurin, Trisha Brooke Atwood

Watershed Sciences Faculty Publications

Consensus has emerged in the literature that increased biodiversity enhances the capacity of ecosystems to perform multiple functions. However, most biodiversity/ecosystem function studies focus on a single ecosystem, or on landscapes of homogenous ecosystems. Here, we investigate how increased landscape‐level environmental dissimilarity may affect the relationship between different metrics of diversity (α, β, or γ) and ecosystem function. We produced a suite of simulated landscapes, each of which contained four experimental outdoor aquatic mesocosms. Differences in temperature and nutrient conditions of the mesocosms allowed us to simulate landscapes containing a range of within‐landscape environmental heterogeneities. We found that the variation …


Relationships Between Borders, Management Agencies, And The Likelihood Of Watershed Impairment, Josh Epperly, Andrew Witt, Jeffrey Haight, Susan E. Washko, Trisha Brooke Atwood, Janice Brahney, Soren Brothers, Edd Hammill Sep 2018

Relationships Between Borders, Management Agencies, And The Likelihood Of Watershed Impairment, Josh Epperly, Andrew Witt, Jeffrey Haight, Susan E. Washko, Trisha Brooke Atwood, Janice Brahney, Soren Brothers, Edd Hammill

Watershed Sciences Faculty Publications

In the United States, the Clean Water Act (CWA) establishes water quality standards important for maintaining healthy freshwater ecosystems. Within the CWA framework, states define their own water quality criteria, leading to a potential fragmentation of standards between states. This fragmentation can influence the management of shared water resources and produce spillover effects of pollutants crossing state lines and other political boundaries. We used numerical simulations to test the null prediction of no difference in impairment between watersheds that cross political boundaries (i.e. state lines, national or coastal borders, hereafter termed “transboundary”) and watersheds that cross no boundaries (hereafter “internal”). …


Conservation Of Aquatic Biodiversity In The Context Of Multiple-Use Management On National Forest System Lands, Brett B. Roper, James M. Capurso, Yvette Paroz, Michael K. Young Sep 2018

Conservation Of Aquatic Biodiversity In The Context Of Multiple-Use Management On National Forest System Lands, Brett B. Roper, James M. Capurso, Yvette Paroz, Michael K. Young

Watershed Sciences Faculty Publications

The U.S. Department of Agriculture Forest Service (USFS) manages 193 million acres of public lands across 43 states and Puerto Rico. The original intent behind reserving lands managed by the USFS was to improve and protect forests, secure favorable conditions for water flows, and furnish a continuous supply of timber for the nation. Through time national forests have evolved, so they are managed for a broad array of uses. Differing expectations have led to conflicts between aquatic conservation and other aspects of the USFS’ mandate. In the 1990s, these conflicting goals came to a head with the listing of the …


Effects Of Eutrophication On Birds In Three Bays Of Great Salt Lake: A Comparative Analysis With Utah Dwr Waterbird Survey Data, Wayne A. Wurtsbaugh Aug 2018

Effects Of Eutrophication On Birds In Three Bays Of Great Salt Lake: A Comparative Analysis With Utah Dwr Waterbird Survey Data, Wayne A. Wurtsbaugh

Watershed Sciences Faculty Publications

Farmington Bay and Bear River support massive numbers of migratory birds. Because of Farmington Bay’s high nutrient loading and hypereutrophic condition, the Utah DWQ has proposed to list it as impaired under EPA’s and Utah’s 303d criteria. There is concern, however, that changing nutrient loading might influence invertebrate prey of birds, but it is not known if this would be a positive or negative effect. Bear River Bay is far less eutrophic, but has a similar shallow morphometry, and thus presents an ideal comparative opportunity to assess the influence of eutrophication on birds.

From 2007‐2011 the Utah Division of Wildlife …


Low-Tech Riparian And Wet Meadow Restoration Increases Vegetation Productivity And Resilience Across Semiarid Rangelands, Nicholas L. Silverman, Brady W. Allred, John Patrick Donnelly, Teresa B. Chapman, Jeremy D. Maestas, Joseph Michael Wheaton, Jeff White, David E. Naugle Aug 2018

Low-Tech Riparian And Wet Meadow Restoration Increases Vegetation Productivity And Resilience Across Semiarid Rangelands, Nicholas L. Silverman, Brady W. Allred, John Patrick Donnelly, Teresa B. Chapman, Jeremy D. Maestas, Joseph Michael Wheaton, Jeff White, David E. Naugle

Watershed Sciences Faculty Publications

Restoration of riparian and wet meadow ecosystems in semiarid rangelands of the western United States is a high priority given their ecological and hydrological importance in the region. However, traditional restoration approaches are often intensive and costly, limiting the extent over which they can be applied. Practitioners are increasingly trying new restoration techniques that are more cost‐effective, less intensive, and can more practically scale up to the scope of degradation. Unfortunately, practitioners typically lack resources to undertake outcome‐based evaluations necessary to judge the efficacy of these techniques. In this study, we use freely available, satellite remote sensing to explore changes …


Predators Shape Sedimentary Organic Carbon Storage In A Coral Reef Ecosystem, Trisha Brooke Atwood, Elizabeth M. P. Madin, Alastair R. Harborne, Edd Hammill, Osmar J. Luiz, Quinn R. Ollivier, Chris M. Roelfsema, Peter I. Macreadie, Catherine E. Lovelock Aug 2018

Predators Shape Sedimentary Organic Carbon Storage In A Coral Reef Ecosystem, Trisha Brooke Atwood, Elizabeth M. P. Madin, Alastair R. Harborne, Edd Hammill, Osmar J. Luiz, Quinn R. Ollivier, Chris M. Roelfsema, Peter I. Macreadie, Catherine E. Lovelock

Watershed Sciences Faculty Publications

Trophic cascade theory predicts that predator effects should extend to influence carbon cycling in ecosystems. Yet, there has been little empirical evidence in natural ecosystems to support this hypothesis. Here, we use a naturally-occurring trophic cascade to provide evidence that predators help protect sedimentary organic carbon stocks in coral reef ecosystems. Our results show that predation risk altered the behavior of herbivorous fish, whereby it constrained grazing to areas close to the refuge of the patch reefs. Macroalgae growing in “riskier” areas further away from the reef were released from grazing pressure, which subsequently promoted carbon accumulation in the sediments …


Empirical Correspondence Between Trophic Transfer Efficiency In Freshwater Food Webs And The Slope Of Their Size Spectra, Thomas Mehner, Betty Lischke, Kristin Scharnweber, Katrin Attermeyer, Soren Brothers, Ursula Gaedke, Sabine Hilt, Sandra Brucet Jun 2018

Empirical Correspondence Between Trophic Transfer Efficiency In Freshwater Food Webs And The Slope Of Their Size Spectra, Thomas Mehner, Betty Lischke, Kristin Scharnweber, Katrin Attermeyer, Soren Brothers, Ursula Gaedke, Sabine Hilt, Sandra Brucet

Watershed Sciences Faculty Publications

The density of organisms declines with size, because larger organisms need more energy than smaller ones and energetic losses occur when larger organisms feed on smaller ones. A potential expression of density-size distributions are Normalized Biomass Size Spectra (NBSS), which plot the logarithm of biomass independent of taxonomy within bins of logarithmic organismal size, divided by the bin width. Theoretically, the NBSS slope of multi-trophic communities is exactly 1.0 if the trophic transfer efficiency (TTE, ratio of production rates between adjacent trophic levels) is 10% and the predator-prey mass ratio (PPMR) is fixed at 104 . Here we provide evidence …


High Interspecific Variation In Nutrient Excretion Within A Guild Of Closely Related Caddisfly Species, Jared A. Balik, Brad W. Taylor, Susan E. Washko, Scott A. Wissinger May 2018

High Interspecific Variation In Nutrient Excretion Within A Guild Of Closely Related Caddisfly Species, Jared A. Balik, Brad W. Taylor, Susan E. Washko, Scott A. Wissinger

Watershed Sciences Faculty Publications

Understanding the amount of variation in functional traits between closely related species within guilds is critical for understanding links between community composition and ecosystem processes. Nutrient excretion is an important link between animals and their environments, and aquatic invertebrate communities can supply a considerable proportion of ecosystem nutrient demand via excretion. We quantified nitrogen (N) and phosphorus (P) excretion rates of 10 species of larval caddisflies that inhabit high‐elevation ponds and wetlands to determine the magnitude of variation in nutrient excretion within this guild. We found considerable interspecific variation in biomass‐specific excretion of nitrogen (eightfold differences), phosphorus (sevenfold differences), and …


The Relationship Between Measures Of Annual Livestock Disturbance In Western Riparian Areas And Stream Conditions Important To Trout, Salmon, And Char, Lindsey M. Goss, Brett B. Roper Apr 2018

The Relationship Between Measures Of Annual Livestock Disturbance In Western Riparian Areas And Stream Conditions Important To Trout, Salmon, And Char, Lindsey M. Goss, Brett B. Roper

Watershed Sciences Faculty Publications

Managing livestock disturbance in riparian zones in a manner that provides economic returns to ranchers while protecting streams is an important aspect of rangeland management on public lands in the western United States. Attempts to balance economic and ecologic outcomes have been made more difficult due to the presence of several salmonid species that are protected under the Endangered Species Act. One approach to proper management of livestock use near streams has been to define the allowable limits of disturbance using 2 metrics, streambank alteration and stubble height. We evaluated 153 stream reaches within the Interior Columbia Basin to determine …


Alluvial Substrate Mapping By Automated Texture Segmentation Of Recreational-Grade Side Scan Sonar Imagery, Daniel Hamill, Daniel Buscombe, Joseph Michael Wheaton Mar 2018

Alluvial Substrate Mapping By Automated Texture Segmentation Of Recreational-Grade Side Scan Sonar Imagery, Daniel Hamill, Daniel Buscombe, Joseph Michael Wheaton

Watershed Sciences Faculty Publications

Side scan sonar in low-cost ‘fishfinder’ systems has become popular in aquatic ecology and sedimentology for imaging submerged riverbed sediment at coverages and resolutions sufficient to relate bed texture to grain-size. Traditional methods to map bed texture (i.e. physical samples) are relatively high-cost and low spatial coverage compared to sonar, which can continuously image several kilometers of channel in a few hours. Towards a goal of automating the classification of bed habitat features, we investigate relationships between substrates and statistical descriptors of bed textures in side scan sonar echograms of alluvial deposits. We develop a method for automated segmentation of …


Benthic Meiofaunal Community Response To The Cascading Effects Of Herbivory Within An Algal Halo System Of The Great Barrier Reef, Quinn R. Ollivier, Edward Hammill, David J. Booth, Elizabeth M.P. Madin, Charles Hinchliffe, Alastair R. Harborne, Catherine E. Lovelock, Peter I. Macreadie, Trisha Brooke Atwood Mar 2018

Benthic Meiofaunal Community Response To The Cascading Effects Of Herbivory Within An Algal Halo System Of The Great Barrier Reef, Quinn R. Ollivier, Edward Hammill, David J. Booth, Elizabeth M.P. Madin, Charles Hinchliffe, Alastair R. Harborne, Catherine E. Lovelock, Peter I. Macreadie, Trisha Brooke Atwood

Watershed Sciences Faculty Publications

Benthic fauna play a crucial role in organic matter decomposition and nutrient cycling at the sediment-water boundary in aquatic ecosystems. In terrestrial systems, grazing herbivores have been shown to influence below-ground communities through alterations to plant distribution and composition, however whether similar cascading effects occur in aquatic systems is unknown. Here, we assess the relationship between benthic invertebrates and above-ground fish grazing across the ‘grazing halos’ of Heron Island lagoon, Australia. Grazing halos, which occur around patch reefs globally, are caused by removal of seagrass or benthic macroalgae by herbivorous fish that results in distinct bands of unvegetated sediments surrounding …


Cosmopolitan Species As Models For Ecophysiological Responses To Global Change: The Common Reed Phragmites Australis, Franziska Eller, Hana Skálová, Joshua S. Caplan, Ganesh P. Bhattarai, Melissa K. Burger, James T. Cronin, Wen-Yong Guo, Xiao Guo, Eric L. G. Hazelton, Karin M. Kettenring, Carla Lambertini, Melissa K. Mccormick, Laura A. Meyerson, Thomas J. Mozdzer, Petr Pyšek, Et Al. Nov 2017

Cosmopolitan Species As Models For Ecophysiological Responses To Global Change: The Common Reed Phragmites Australis, Franziska Eller, Hana Skálová, Joshua S. Caplan, Ganesh P. Bhattarai, Melissa K. Burger, James T. Cronin, Wen-Yong Guo, Xiao Guo, Eric L. G. Hazelton, Karin M. Kettenring, Carla Lambertini, Melissa K. Mccormick, Laura A. Meyerson, Thomas J. Mozdzer, Petr Pyšek, Et Al.

Watershed Sciences Faculty Publications

Phragmites australis is a cosmopolitan grass and often the dominant species in the ecosystems it inhabits. Due to high intraspecific diversity and phenotypic plasticity, P. australis has an extensive ecological amplitude and a great capacity to acclimate to adverse environmental conditions; it can therefore offer valuable insights into plant responses to global change. Here we review the ecology and ecophysiology of prominent P. australis lineages and their responses to multiple forms of global change. Key findings of our review are that: (1) P. australis lineages are well-adapted to regions of their phylogeographic origin and therefore respond differently to changes in …


Effects Of Changes In Alternative Prey Densities On Predation Of Drifting Lake Sturgeon Larvae (Acipenser Fulvescens), Justin Waraniak, Shaley Valentine, Kim Scribner Sep 2017

Effects Of Changes In Alternative Prey Densities On Predation Of Drifting Lake Sturgeon Larvae (Acipenser Fulvescens), Justin Waraniak, Shaley Valentine, Kim Scribner

Watershed Sciences Faculty Publications

Predator–prey interactions including prey switching, predator swamping, and size-selectivity are important in maintaining multi-species systems. In fishes, early life stages are often recruitment bottlenecks due to high mortality partially caused by predation. High mortality is of particular concern for threatened species such as lake sturgeon (Acipenser fulvescens). Effects of different relative prey densities were examined using two predatory fishes [rock bass (Ambloplites rupestris) and hornyhead chub (Nocomis biguttatus)] and two density treatments of three prey [lake sturgeon, mayflies (Family: Heptageniidae), and suckers (Family: Catostomidae)]. Treatments consisted of prey introduced to predators in a series …


Growth Of Endangered Humpback Chub In Relation To Temperature And Discharge In The Lower Colorado River, W. E. Pine Iii, K. Limburg, B. Gerig, Colton Finch, D. Chagaris, L. Coggins, D. Speas, D. A. Hendrickson Jun 2017

Growth Of Endangered Humpback Chub In Relation To Temperature And Discharge In The Lower Colorado River, W. E. Pine Iii, K. Limburg, B. Gerig, Colton Finch, D. Chagaris, L. Coggins, D. Speas, D. A. Hendrickson

Watershed Sciences Faculty Publications

Assessments of growth can provide information needed to understand how fish populations respond to changing environmental conditions and management actions, including ecosystem experimentation. We estimated growth rates and parameter uncertainty from otoliths of endangered Humpback Chub Gila cypha from the Colorado River in Grand Canyon, Arizona. We then compared growth of Humpback Chub , age 2 that were 1) occupying the mainstem Colorado River during a period of variable discharge and cooler water temperatures (1980–1998; epoch 1), 2) occupying the Colorado River during a period of moderate discharge variability and warmer water (2001–2011; epoch 2), and 3) occupying the unregulated …


Characterizing Growth And Condition Of Endangered Humpback Chub In The Lower Colorado River, William E. Pine Iii, Brandon S. Gerig, Colton Finch Jun 2017

Characterizing Growth And Condition Of Endangered Humpback Chub In The Lower Colorado River, William E. Pine Iii, Brandon S. Gerig, Colton Finch

Watershed Sciences Faculty Publications

This paper is a preface to the two papers that follow in this issue. The two papers (by Pine et al. and Hayes et al.) use long-term fish sampling data from ongoing Humpback Chub monitoring efforts and archival otolith samples (from museums) collected in the lower Colorado and Little Colorado Rivers during periods of both cold- and warm-water conditions to assess whether Humpback Chub growth characteristics may have responded to changes in water temperature. Growth patterns are often of interest to resource managers because growth integrates a large range of environmental and ecological factors, including habitat conditions. Together, these papers …


Body Condition Of Endangered Humpback Chub In Relation To Temperature And Discharge In The Lower Colorado River, Forest P. Hayes, Michael J. Dodrill, Brandon S. Gerig, Colton Finch, William E. Pine Iii Jun 2017

Body Condition Of Endangered Humpback Chub In Relation To Temperature And Discharge In The Lower Colorado River, Forest P. Hayes, Michael J. Dodrill, Brandon S. Gerig, Colton Finch, William E. Pine Iii

Watershed Sciences Faculty Publications

Determining the population status of endangered Humpback Chub Gila cypha is a major component of the adaptive management program designed to inform operation of Glen Canyon Dam upstream from Grand Canyon, Arizona. In recent decades, resource managers have identified a portfolio of management actions (with intermittent implementation) to promote population recovery of Humpback Chub, including nonnative fish removal, changes in water release volumes and discharge ramping schedules, and reductions in hydropower peaking operations. The Humpback Chub population in Grand Canyon has increased over this same period, causal factors for which are unclear. We took advantage of unusual hydrology in the …


Brine Shrimp Grazing And Fecal Production Increase Sedimentation To The Deep Brine Layer (Monimolimnion) Of Great Salt Lake, Utah, Piotr Maszczyk, Wayne A. Wurtsbaugh May 2017

Brine Shrimp Grazing And Fecal Production Increase Sedimentation To The Deep Brine Layer (Monimolimnion) Of Great Salt Lake, Utah, Piotr Maszczyk, Wayne A. Wurtsbaugh

Watershed Sciences Faculty Publications

Great Salt Lake (Utah) has a monimolimnion with high concentrations of salts, particulate matter, nutrients, and mercury. To test the importance of brine shrimp (Artemia franciscana) grazing on particulate matter flux, we created salinity gradients in 160-cm high columns, reflecting the lake’s gradient. Two experiments were performed in replicated columns with or without Artemia. Sediment traps were positioned at the bottoms of the mixolimnion (95 cm), chemolimnion (105 cm), or monimolimnion (140 cm). We hypothesized that because of the high salt densities of the monimolimnia, greater accumulation of sediments would be in the lower chemocline, than in …


Accounting For Spatial And Temporal Variation In Macroinvertebrate Community Abundances When Measuring The Food Supply Of Stream Salmonids, Nicholas Weber, Nicolaas Bouwes, Chris Jordan Apr 2017

Accounting For Spatial And Temporal Variation In Macroinvertebrate Community Abundances When Measuring The Food Supply Of Stream Salmonids, Nicholas Weber, Nicolaas Bouwes, Chris Jordan

Watershed Sciences Faculty Publications

The goal of salmonid habitat monitoring programs is to measure habitat attributes linked to salmonid productivity based on protocols that have sufficient precision to detect environmental variation at relevant spatial and temporal scales. Benthic macroinvertebrate community composition often is evaluated as part of habitat monitoring and assessment protocols, despite a lack of direct relationships between benthic composition and salmonid production. Macroinvertebrate drift provides a direct measure of the food resources available to stream salmonids, but drift is rarely evaluated as part of habitat monitoring protocols. This reluctance may stem from the complex spatial and temporal variability inherent in macroinvertebrate drift …