GCDAMP- Questions and Answers Page

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Library Book- Pic.jpg Research Questions and Information Needs Identified in the 2013-14 Glen Canyon Dam Adaptive Management Program Biennial Budget and Work Plan

  • Revision Date_140212


Num Project, Elements, and Sub-elements Project/Element summary (2012-13 BWP) Research Questions, Uncertainties, & Information Needs identified in the 2012-13 BWP Relevant Research Questions & Information Needs identified from: Project timeline: When will data obtained through this project be able to answer the relevent science questions? Project funding (FY) Reporting links NOTES
000 Project A. Sandbars and Sediment Storage Dynamics: Long-term Monitoring and Research at the Site, Reach, and Ecosystem Scales Project will evaluate the geomorphology of fine sediment deposits in and near the Colorado River. Supports the direct measurements of the volume of fine sediment, especially sand, that is stored on the bed of the Colorado River, in its eddies, or at higher elevation along the river's banks. Supports the direct measurement of the volume of fine sediment, especially sand, that is stored on the bed of the Colorado River, in its eddies, or at higher elevation along the river’s banks for the HFE protocol. Monitoring will include daily and annual observations of long-term sandbar monitoring sites by remote camera and conventional topographic survey, respectively. Also includes the analysis of system-wide airborne remote-sensing data to monitor a much larger set of sandbars every four years to assess sandbar size and abundance "Project will address the broad questions of:

(1) Will multiple high flows conducted over a period of years result in net increases in sandbar area and volume?; (2) With the available sand supply (i.e. tributary inputs), is the approach of using repeated floods to build sandbars sustainable?;and, (3) Will multiple high flows conducted over a period of 10 years result in net increases in campable area along the Colorado River?"

"How can erosion of sandbars after an HFE be minimized or offset? (IV: Dept. of Interior 2011a)

Do sandbars deposited by HFEs contribute to preservation of archaeological sites in the river corridor? (II: Mellis et al. 2007) Is sediment conservation more effective when an HFE is held in rapid response to sediment input from the Paria River? (IV: Dept. of Interior 2011a) What are the effects of ramping rates on sediment transport and sandbar stability? (USGS 2007b; SSQ RIN 4) What is the desired range of seasonal and annual flow dynamics associated with powerplant operations, BHBFs, and habitat maintenance flows, or other flows that meet GCDAMP goals and objectives? (USGS 2007b; RIN 7.4.1) What is the desired pattern of seasonal and annual flow dynamics associated with powerplant operations, BHBFs, HMFs, or other flows to meet GCDAMP Goals and Objectives? (USGS 2007b; RIN 7.4.2) What elements of ROD operations (upramp, downramp, maximum and minimum flow, modified low fluctuating flow (MLFF), habitat maintenance flow (HMF), and BHBF) are most/least critical to conserving new fine-sediment inputs, and stabilizing sediment deposits above the 25,000 cfs stage? (USGS 2007b; RIN 8.5.1) How do sandbar textures influence biological processes? (USGS 2007b; SIN 8.5.) What is the relationship between the fine-sediment budget and turbidity? (USGS 2007b; SIN 8.5.2) How can the ongoing fine sediment supply be managed to achieve sustainable habitats? (USGS 2007b; SIN 8.5.5)"

AMWG
000 Project Element A.1. Sandbar and Camping Beach Monitoring ($269,000) Track trends in the status of sandbars throughout Marble and Grand Canyons that are emergent above the water surface at 8,000 ft3/s.
000 Project Element A.1.1. Monitoring sandbars using topographic surveys and remote cameras Sandbar monitoring is conducted at a daily (using remote cameras) and annual (by conventional survey) interval in order to track local response to individual events in the context of a long-term record. Monitor selected high-elevation sandbars (~50) with conventional topographic surveys (volume and area; “long term sandbar time series”) yearly for annual status check on sandbar and camping beach condition. In addition, campable area is measured at a subset of 37 of these sites. Monitor selected high-elevation sandbars (~30) with remotely deployed digital camera (approximate size) for daily status check on sandbar condition at ~6-month intervals. "(1) What is the long-term net effect of dam operations, including high flows, on changes in high-elevation sandbar area and sand storage (i.e. the sand above the 8,000 ft3/s stage)? These changes are relevant to camping beaches, riparian vegetation, backwater habitat, and control the supply of bare sand that is redistributed by wind." "Given that sandbars are naturally dynamic and go through cycles of building and eroding, can a protocol of frequent high flows under sediment-enriched conditions be effective in sustaining these dynamic habitat features? (IV: Dept. of Interior 2011a)

Will multiple high flows conducted over a period of 10 years result in net increases in sandbar area and volume? (V: Dept. of Interior 2011b) What is the minimum duration for HFEs needed to build and maintain sandbars under sand enrichment? (II: Mellis et al. 2007) How do post HFE flows affect the persistence of sandbars and related backwater habitats? (II: Mellis et al. 2007) Is there a “flow-only” operation (i.e., a strategy for dam releases, including managing tributary inputs with BHBFs, without sediment augmentation) that will restore and maintain sandbar habitats over decadal time scales? (USGS 2007b; SSQ 3.1 / 4.1)"

000 Project Element A.1.2. Monitoring sandbars by remote sensing A larger collection of high-elevation sandbars (>1000 sites) are also monitored every four years using remote sensing (2002, 2005, 2009, and 2012 over-flights), in order to provide a synoptic view of the entire Colorado River for long-term trend of sandbar condition. Since 2002, how has the area of vegetation and sand coverage changed at the 1000+ eddy sandbars larger than about 250 m2 (inclusive of nearly every location that has had a camping beach in any campsite inventory since 1975).
000 Project Element A.1.3. Geomorphic attributes of camping beaches Track trends in specific camping beach attributes (i.e. spatial distribution of sand and other geomorphic units, the slope of the sandbar, and the distribution and density of vegetation) over time and in response to changes in flow regime. (7) How have changes in sandbar size, sandbar characteristics (e.g., slope, roughness), and vegetation cover affected the Marble and Grand Canyon camping beach resource? This builds on sandbar monitoring (Question 1) to address the recreation resource. "Will multiple high flows conducted over a period of 10 years result in net increases in campable area along the Colorado River? (V: Dept. of Interior 2011b)

How do varying flows positively or negatively affect campsite attributes that are important to visitor experience? (USGS 2007b; SSQ 3.9) How are sandbar textures related to recreational site stability? (USGS 2007b; SIN 8.5.10)"

000 Project Element A.1.4. Analysis of historical images at selected monitoring sites Extend the length of the monitoring record back in time for the long-term sandbar monitoring sites (Project A.1.1.) by incorporating data from air photos taken before 1990. Produce digital elevation models using digitally scanned 1984 stereo photographs. Many perceptions regarding the current condition of sandbars is based on limited observations of sandbars following the floods of 1983-86 (Schmidt and Grams, 2011). However, those observations are based largely on imprecise photo comparisons and are not quantitatively tied to the current sandbar monitoring program.
000 Project Element A.2. Sediment Storage Monitoring ($609,000)
000 Project Element A.2.1. Bathymetric and topographic mapping Track longterm trends in sand storage to provide a robust measure of whether or not management objectives for fine sediment conservation (HFEs) are being met. Track the location of changes in sand storage between the channel and eddies and between high- and low-elevation deposits. Monitor low-elevation fine sediment storage in 30 to 80-mile segments with combined bathymetric and topographic surveys (area and volume) every 3 to 10 years, depending on reach for long-term trend in fine sediment storage. "(2) What is the long-term net effect of dam operations, including high flows, on changes in low-elevation sand storage and bed sediment texture (the sand below the 8,000 ft3/s stage)? These changes are relevant to backwaters and other aquatic habitat, the foundation of eddy sandbars, and as the source of sediment that fuels transport and determines whether the use of high flows is sustainable." "When are there optimal times to conduct high flows in regard to sediment building, humpback chub survivability, and ecosystem response? (IV: Dept. of Interior 2011a)

Is sediment conservation more effective following a sediment enrichment period in the context of multi-year, multi-event experiments? (IV: Dept. of Interior 2011a) With the available sand supply that comes from tributary inputs, is the approach of using repeated floods to build sandbars sustainable? (V: Dept. of Interior 2011b) Can the decline in sediment resources since 1990 be reversed using “flow” options with remaining downstream sand supplies from tributaries (Paria and Little Colorado Rivers and lesser tributaries)? (III: USGS 2007a) What is the rate of change in eddy storage (erosion) during time intervals between BHBFs? (USGS 2007b; SSQ RIN 5) What is the longitudinal variability of fine-sediment inputs, by reach? (USGS 2007b; RIN 8.1.1) What is the temporal variability of fine-sediment inputs, by reach? (USGS 2007b; RIN 8.1.2) What fine sediment abundance and distribution, by reach, is desirable to support GCDAMP ecosystem goals? (Note: Definition of “desirable” will be derived from targets for other resources and managers goals. (USGS 2007b; RIN 8.1.3, 8.2.1, 8.3.1, 8.4.1, 8.5.6) What is the reach-scale variability of fine-sediment storage throughout the main channel? (USGS 2007b; RIN 8.5.2) What are the historic and ongoing longitudinal trends of fine-sediment storage, above 25,000 cfs? (USGS 2007b; RIN 8.5.5)"

000 Project Element A.2.2. Bed-material characterization Improve the method used to characterize bed texture using the backscattering data from the multibeam sonar surveys used to identify and map bed material by calibrating and validating with observations of bed material characteristics made by underwater video camera. "(5) What is the spatial distribution of bed sediment texture, and how does it affect primary production, fish habitat, and sediment transport modeling? This builds on low elevation sand monitoring (Question 2) to support sediment transport and biological prediction." "What are the limiting factors that regulate substrate availability and its distribution? (USGS 2007b; SIN 8.5.7)

What is the total area of different aquatic habitat types (cobble, gravel, sand, talus, etc,) in the CRE? (USGS 2007b; SIN 8.5.8)"

000 Project Element A.3. Investigating Eddy Sandbar Variability and the Interactions among Flow, Vegetation, and Geomorphology ($104,000) Even when there is a large supply of sand on the river bed, as was the case in 2008, sandbar response is highly variable. Investigate the dynamics of eddy sandbar deposition by coupling a large existing dataset of eddy sandbar behavior with metrics that describe site geometric and hydrodynamic characteristics. Look for statistical relations between observed eddy behavior and site characteristics. Develop a tool for predicting sandbar response to given flow events. "4) What are the causes of variability in sandbar response to controlled floods and other dam operations (i.e. why do sandbars respond differently from place to place to the same flow and sediment supply conditions?), and how does vegetation affect sandbar response? This builds on sandbar monitoring (Question 1) to support prediction of sandbar response."
000 Project Element A.4. Quantifying the correlation between bed and transport grain size ($244,000) Use both field measurements and modeling to partition the effects of bed grain size, areal sand coverage, and the spatial distribution of bed shear stress in order to provide a more reliable link between bed and transport grain size. This work will improve our understanding of the linkages between suspended-sediment observations and bed-sediment texture, which will provide greater understanding of the upstream extent of river that determines concentration and grain size at sediment gaging stations. Findings from this work will be used to improve models for suspended sediment transport and may provide improved methods for tracking the abundance of sand on the river bed using the suspended sediment monitoring network. Better understanding of temporal changes in bed texture will also be used to improve our ability to model and predict aquatic primary productivity. "(6) Can we relate changes in the spatial distribution of bed sediment texture to observed changes in suspended sand concentrations and grain size? This would enable use of the continuous record of suspended sediment to infer changes in bed sediment composition for use in modeling of sediment transport and primary production." "How do ongoing inputs of coarse-sediment from tributaries influence storage of fine sediment within pools, runs, and eddies throughout the CRE? (USGS 2007b; RIN 8.6.1)"
000 Project Element A.5. Geochemical Signatures of Pre-Dam Sediment ($56,000) Provide an additional measure to evaluate long-term trends of sediment abundance in Marble Canyon and the ability to detect mined pre-dam sediment in future high flows. "(3) What are the relative proportions of pre-dam sediment (sediment that entered the Colorado River before dam completion) and post-dam sediment (sediment from tributaries that has entered the Colorado River following dam completion) present in deposits formed by dam operations, including HFEs? Do the proportions of pre- and post dam fine sediment indicate depletion of non-renewable pre-dam fine sediment from storage or accumulation of tributary-derived post-dam fine sediment? This question is relevant to determining whether the use of HFEs is sustainable." "How do flows impact old high water zone terraces in the CRE (where the majority of archaeological sites occur), and what kinds of important information about the historical ecology and human history of the CRE are being lost due to ongoing erosion of the Holocene sedimentary deposits? (USGS 2007b; SSQ 2.2)

What is the pre- and post-dam range of grain-size in fine-sediment deposits, by reach? (USGS 2007b; RIN 8.5.3)"

Project Element A.6. Control Network and Survey Support ($37,000) An accurate geodetic control network is required to support nearly every aspect of this project as well as other GCMRC monitoring projects. The control network is the set of monumented and documented reference points (benchmarks) that exist along the river corridor and on the rim together with the collection of observations that determine the relative and absolute positions of those points. Those points serve as the basis for referencing all ground- and air-based monitoring observations. The purpose of the control network is to ensure that spatial data acquired on all projects are collected with accurate and repeatable spatial reference. This effort is nearing completion, and most segments of the river corridor now have a sufficient number of control points to support monitoring activities. In 2013 and 2014, field work will be required to complete this task in Glen Canyon (between the dam and Lees Ferry), RM 81 to RM 91, RM 98 to RM 119, RM 144 to RM 166, and RM 225 to 277.
000 Project B. Streamflow, Water Quality, and Sediment Transport in the Colorado River Ecosystem ($1,287,000) Ongoing measurement and interpretation of stage, discharge, water quality (water temperature, specific conductance, turbidity, and dissolved oxygen), suspended sediment, and bed sediment data at gaging stations in the Colorado River ecosystem (CRe) downstream from Glen Canyon Dam in Glen Canyon National Recreation Area and Grand Canyon National Park. These parameters are measured at USGS stream-flow gaging stations located on the Colorado River in Marble and Grand Canyons at river miles 0, 30, 61, 87, 166, and 225. The data collected by this project provide the fundamental stream flow, sediment transport, temperature, and water quality data that are used by other physical, ecological, and socio-cultural resource studies. One of the major products of this project has been the mass-balance sand budgets (e.g., Topping and others, 2010) used to trigger controlled floods and to evaluate the effects of all dam operations on the CRe. It is also proposed to continue the development and application of a one-dimensional sand routing model (Wright and others, 2010a). One task for this modeling component will be to extend the existing model, whose downstream boundary is river mile 87, through the central and western part of Grand Canyon to river mile 225. This is the measurement program for the HFE Protocol that describes the fate of new fine sediment once it enters the Colorado River. How do dam release temperatures, flows (average and fluctuating component), meteorology, canyon orientation and geometry, and reach morphology interact to determine mainstem and nearshore water temperatures throughout the CRe? (USGS 2007b; SSQ 5-1)
000 Project C. Water-Quality Monitoring of Lake Powell and Glen Canyon Dam Releases ($236,000) Describe the current quality of Glen Canyon Dam releases to the downstream ecosystem, as well as describe the current water-quality conditions and hydrologic processes in Lake Powell, which can be used to predict the quality of future releases from the dam. The water-quality monitoring program consists of monthly surveys of the reservoir forebay and tailwater, as well as quarterly surveys of the entire reservoir, including the Colorado, San Juan, and Escalante arms. The entire funding for this project is provided directly by the Bureau of Reclamation (no AMP funds).
000 Project Element C.1. Revisions to Existing Program Evaluations will be made of current chlorophyll preservations methods. One or more inflow monitoring stations will be reestablished to provide input data on inflow temperature and salinity. One or more weather stations will be established at remote pumpout stations in the upper part of the reservoir. Construct historical longitudinal profiles of the sediment deltas of the three major tributaries to evaluate rates and patterns of deposition under varying hydrologic regimes and reservoir levels.
000 Project Element C.2. Details of Current Program Monthly water quality surveys of the reservoir forebay and tailwater and quarterly surveys of the entire reservoir, including the Colorado, San Juan, and Escalante arms of the reservoir to the inflow areas. depth profile of temperature, specific conductance, dissolved oxygen, pH, redox potential, turbidity, and chlorophyll florescence. Major ionic constituents and nutrient concentrations are collected in the major strata. Dissolved organic carbon samples are collected at the forebay, tailwater, and tributary inflow sites. Biological samples for chlorophyll concentration, phytoplankton, and zooplankton are also collected at selected sites. "Which major ions should be measured? Where and how often? (USGS 2007b; RIN 7.2.1)

Which nutrients should be measured? Where and how often? (USGS 2007b; RIN 7.2.2) Which metals should be measured? Where and how often? (USGS 2007b; RIN 7.2.3) What are the waterborne pathogens that are a threat to human health? How should they be monitored? Where and how often? (USGS 2007b; RIN 7.2.4) Determine the status and trends of chemical and biological components of water quality in Lake Powell as a function of regional hydrologic conditions and their relation to downstream releases. (USGS 2007b; RIN 7.3.1.a) Determine stratification, convective mixing patterns, and behavior of advective currents in Lake Powell and their relation to GCD operations to predict seasonal patterns and trends in downstream releases. (USGS 2007b; RIN 7.3.1.b) How do the hydrodynamics and stratification of Lake Powell influence the food base or fisheries downstream? (USGS 2007b; SIN 7.2.1) Which water quality variables influence food base and fisheries in the CRE? (USGS 2007b; SIN 7.2.2)"

000 Project Element C.3. Reservoir Modeling The CE-QUAL-W2 model is used to synthesize data for periods in which regular monitoring was not conducted and to simulate the effects of various hypothetical operational, hydrological, and climatological scenarios on historical patterns. It is also used to provide predictions of future temperature and dissolved oxygen patterns in GCD releases. "How do dam release temperatures, flows (average and fluctuating component), meteorology, canyon orientation and geometry, and reach morphology interact to determine mainstem and nearshore water temperatures throughout the Colorado River ecosystem (CRE)? (I: Melis et al. 2006)

Will HFEs affect the water quality released from Glen Canyon Dam? (III: USGS 2007a) Develop simulation models for Lake Powell and the Colorado River to predict water quality conditions under various operating scenarios, supplant monitoring efforts, and elucidate understanding of the effects of dam operations, climate, and basin hydrology on Colorado River water quality. (USGS 2007b; RIN 7.3.1) How accurately can modeling predict reservoir dynamics and operational scenarios? (USGS 2007b; RIN 7.3.2) How do dam operations affect reservoir limnology? (USGS 2007b; RIN 7.3.3) Measure appropriate water quality parameters to determine the influence of these parameters on biological resources in the CRE. (USGS 2007b; SIN 7.3.1)"

000 Project D. Mainstem Humpback Chub Aggregation Studies and Metapopulation Dynamics Research projects intended to resolve critical uncertainties about humpback chub, their distirbution in the Colorado River (CRe), and their life history in the Little Colorado River and elsewhere. Sampling mainstem humpback chub (Gila cypha) aggregations has been conducted periodically over the last decade including in 2002 through 2004, 2006, 2010, and 2011. These monitoring efforts provided catch per unit effort indices, but abundance estimates were infrequently made. This project proposes to increase sampling during FY13-14, following on the results of a pilot study in FY12. The purpose of this work is to improve monitoring techniques and provide estimates of humpback chub abundance in several mainstem aggregations. Additionally, this project will improve our understanding of the impact of translocation efforts in humpback chub metapopulation dynamics. Collectively, the proposed research will yield a more rigorous aggregation monitoring program and will increase our understanding of the ecology of aggregations, including whether downstream reaches in Grand Canyon are capable of supporting self-sustaining populations of humpback chub. We also propose research on otolith microchemistry of juvenile humpback chub captured at aggregations or of areas such as during backwater seining to assess whether these aggregations are supported by emigration of juvenile fish from the LCR or local spawning and recruitment. Resolve key uncertainties regarding the dynamics and ecology of the mainstem population segments of humpback chub known as ‘aggregations." These surveys provide critical information on the relative abundance of humpback chub populations and also provide data used in generating survival estimates as well as abundance estimates with the Age-Structured Mark Recapture model.
000 "Project Element D.1. Improve aggregation sampling to develop more rigorous approaches to monitor

aggregations (includes ongoing monitoring) ($225,000)"

An addition of a second sampling trip during late spring or early summer. Because of concerns about potential impacts of increased sampling on aggregations, we propose sampling different aggregations in FY13 than in FY14. Thus, all aggregations will be sampled during the two year budget period. Investigate use of mark-recapture methods during FY12 at the Shinumo Inflow aggregation. A stratified random sampling design will be used for the second sampling trips in FY13 and FY14 to assess humpback chub relative abundance in other areas of the river (table 3). "What is the relationship between the “aggregations"" in the mainstem and LCR? Are mainstem aggregations ”sinks” of the LCR? Are aggregations real or due to sampling bias? (USGS 2007b; RIN 2.2.4)

What are the criteria for establishment of spawning aggregations (i.e., how does one determine if it is “established”)? (USGS 2007b; RIN 2.2.6) What is the appropriate role of HBC augmentation as a management strategy to establish mainstem spawning aggregations? (USGS 2007b; RIN 2.2.9)"

000 Project Element D.2.1. Natal origins of Humpback Chub, adult condition and reproductive potential Evaluate if existing mainstem water temperatures are warm enough for successful gamete development. Humpback chub have been reported to initiate spawning at about 16° C (Hamman, 1982). However, the ability of humpback chub females to produce viable gametes in the mainstem Colorado River at mainstem aggregations is unknown. Can the mainstem Colorado River, under current dam operations, support self-sustaining populations of humpback chub? "What are the factors limiting humpback chub (HBC) reproduction and rearing in the main channel of the Colorado River below Glen Canyon Dam? (III: USGS 2007a)

To what extent do temperature and fluctuations in flow limit spawning and incubation success for native fish? (USGS 2007b; SSQ 5.3) What is the relative importance of increased water temperature, shoreline stability, and food availability on the survival and growth of YoY and juvenile native fish? (USGS 2007b; SSQ 5.4) Do the potential benefits of improved rearing habitat (warmer, more stable, more backwater and vegetated shorelines, more food) outweigh negative impacts due to increases in nonnative fish abundance? (USGS 2007b; SSQ 5.6) What are the appropriate habitat conditions for HBC spawning? Where are these found? Can they be created in the mainstem? (USGS 2007b; RIN 2.2.5) Determine if implementation and operation of the TCD and/or steady flows represent a technically feasible, ecologically sustainable, and practical option for establishing mainstem spawning. (USGS 2007b; RIN 2.2.7)"

000 Project Element D.2.2. Egg maturation studies using Ultrasonic Imaging and Ovaprim® We will collect ultrasound images of captive reared fish at fish hatcheries and wild fish captured in the LCR to refine methods and techniques for using ultrasonic imagery to solve questions about stage of maturity of adult humpback chub in mainstem aggregations. Ultrasound images will then be collected from a small sample of adult fish from mainstem aggregations (<30) to evaluate the ability of female humpback chub to produce viable gametes in three mainstem aggregations. Fish will be non-lethally scanned with ultrasound to evaluate the status of gamete development . If females with developed eggs are encountered, a subset of these individuals (<10 fish) will be injected with Ovaprim®, a synthetic hormone used to artificially induce spawning in fish. Ultrasound and Ovaprim® methods will be developed and tested in the LCR in FY13, and if proven useful, will be used on humpback chub from mainstem aggregations in FY14.
000 Project E. Humpback Chub Early Life History in and Around the Little Colorado River "In FY13-14, we will:

(a) estimate growth, survival, and movement of juvenile humpback chub in the Little Colorado River (LCR) by marking young-of-year humpback chub (Gila cypha) each year in the LCR in July, (b) describe food web structure and assess the potential for food limitation within the LCR (above and below Chute Falls), and (c) conduct data analysis and modeling that will integrate findings from the above efforts and ongoing standardized monitoring to determine the relative roles of LCR hydrology, intraspecific and interspecific interactions, and mainstem conditions in humpback chub juvenile life history and adult recruitment."

"Resolve the key uncertainty regarding variability in survival, growth, and emigration rates of early life history stages of humpback chub in the Little Colorado River as well as the physical and biological drivers of this variation.

To what extent do survival and growth in the LCR aggregation vary annually and spatially (i.e., mainstem vs. LCR downstream of Chute Falls vs. LCR upstream of Chute Falls)? What are the drivers of observed variation in survival and growth? Specifically, to what extent are endogenous (e.g., intraspecific predation and competition for food) versus exogenous factors (e.g., interspecific competition and predation, mainstem conditions— including dam operations—and variation in LCR hydrology, etc.) responsible for temporal and spatial variation in survival and growth? To what extent does outmigration of humpback chub from the LCR vary over time?"

000 Project Element E.1. July Little Colorado Marking ($122,000) Determine the extent of juvenile humpback chub outmigration and the role that summer monsoon floods play in augmented outmigration. The additional marking trip in July is primarily motivated by a trend emerging from the NSE study. A proportion of the small number of fish marked in the LCR by NSE researchers during July show up in the Colorado River in later sampling periods. However, relatively few of the fish marked by the USFWS in the fall are subsequently found in the Colorado River. This suggests that large numbers of juveniles may be moving out of the LCR between July and the fall, consistent with H3. "To what extent do survival and growth in the LCR aggregation vary temporally (i.e., among years) and spatially (i.e., mainstem vs. LCR upstream of Chute Falls vs. LCR downstream of Chute Falls)?

What are the drivers of observed variation in survival and growth? Specifically, to what extent are endogenous (e.g., intraspecific predation and competition for food) versus exogenous factors (e.g., interspecific competition and predation, dam operations, variation in LCR hydrology, etc.) responsible for temporal and spatial variation in juvenile survival and growth? To what extent does outmigration of humpback chub from the LCR vary from year to year?"

"Understand the role of the Little Colorado River and the mainstem Colorado River in juvenile humpback chub survival rates and recruitment to the adult humpback chub population (VII: Dept. of Interior 2011d)

Determine the timing and quantity of YoY HBC dispersal (passive and active) from the LCR. (USGS 2007b; RIN 2.1.5)"

000 "Project Element E.2. Describing food web structure and the potential for food limitation within the LCR

($250,000)"

Develop quantitative food webs for two segments of the LCR— the reach upstream of Chute Falls and the reach downstream of Chute Falls using quantitative gut content analysis and stable isotope analysis. Developing quantitative food webs requires estimates of production (or supply) for each trophic level (i.e., algae production, detritus inputs during floods, invertebrate production, fish production), and also information on feeding habitats of higher trophic levels (that is, invertebrates and fish). In FY13, we will assess contaminant levels in food web compartments including common native fish other than humpback chub (i.e., suckers and speckled dace). If contaminant levels in these fish are elevated, we will submit an amendment to our USFWS permit and seek permission to take muscle plugs from humpback chub in FY14 to assess contaminant levels. Is the available foodbase or metals/other toxins limiting the humpback chub population in the LCR (see H2 and H6 below)?
000 Project Element E.3. Population modeling ($86,000) Develop integrated statistical models to estimate survival, growth and movement in the LCR and Colorado River portions of the LCR complex. This project will also develop models to test the roles of intraspecific interactions and hydrology in explaining observed juveniles abundance trends over the last decade. Use a multistate mark-recapture models to estimate survival, growth, and movement within the LCR complex. Develop deterministic models to evaluate the degree to which variation in juvenile abundances and sizes in the LCR can be attributed to LCR hydrology versus intraspecific or interspecific interactions. "Hypotheses for HBC at the LCR:

(H1) Survival of humpback chub eggs in the LCR is limited in years when snowmelt flooding is negligible or small because of poor spawning substrate conditions. (H2) Large snowmelt floods in the LCR stimulate production of the prey base through improvements in both the quantity and quality of food resources consumed by humpback chub, which leads to high juvenile humpback chub survival and low outmigration. (H3a) In years without large LCR snowmelt floods, more yearlings remain in the system and there are higher levels of cannibalism and competition than in years with large LCR snowmelt flood. (H3b)The lack of yearlings in the LCR in the following spawning season (2003 and 2007) led to especially large cohorts of young-of-year in those birth years because of reduced cannibalism and competition. (H4) Outmigration rates of juvenile humpback chub from the LCR are directly linked to the intensity of monsoon flooding in the summer and fall. (H5) The observed variation in humpback chub growth rates among locations and times is that growth rates are mainly driven by concomitant changes in water temperature. (H6) Humpback chub growth among locations and times is mainly driven by differences in the quantity and quality of prey available to juvenile humpback chub. The quality of food resources could be related to the nutritional quality of the organic matter and invertebrates eaten by chub (e.g., the amount of nitrogen and phosphorus they contain). Alternatively, concentrations of metals and other toxins in food resources could be a more important determinant of resource quality for chub than nutrient content. (H7) Interspecific and intraspecific competition for food resources is the main driver of humpback chub growth rates among locations and times."

To what extent are adult populations of native fish controlled by production of young fish from tributaries, spawning and incubation in the mainstem, survival of young-of-year (YoY) and juvenile stages in the mainstem, or by changes in growth and maturation in the adult population as influenced by mainstem conditions? (USGS 2007b; SSQ 1.1)
000 Project F. Monitoring of Native and Nonnative Fishes in the Mainstem Colorado River and the lower Little Colorado River Includes all of the long-term monitoring projects funded by the GCDAMP during the past few years. Two recent Environmental Assessments and an associated Biological Opinion, as well as the GCDAMP 2011-2012 Work plan and Budget, mandate monitoring the status and trends of adult humpback chub in the Little Colorado River (LCR) near the confluence, in the mainstem Colorado River (see Mainstem Humpback Chub Aggregation, Project D), and at areas where humpback chub have been translocated. The Biological Opinion defines triggers to determine when nonnative fish control will take place near the LCR. Triggers are related to the abundance of adult and juvenile humpback chub, survival rates of juvenile humpback chub, abundance of rainbow trout (Oncorhynchus mykiss) and brown trout (Salmo trutta), and river temperature. The following monitoring projects contribute data and information required by the Environmental Assessments and Biological Opinion to determine if elements and conditions of the trigger are met. Generate data that can be used to provide a baseline for observing status and trends in resources of interest, to assess the effectiveness of various management actions, and to inform managers as to the need to conduct management actions or the attainment of identified goals. These surveys provide critical information on the relative abundance of humpback chub populations and also provide data used in generating survival estimates as well as abundance estimates with the Age-Structured Mark Recapture model. Understanding the aquatic food base and its dynamics is essential to understanding the distribution, condition and abundance of fish populations in the CRe. "What are the measurable criteria that need to be met in order to remove jeopardy for HBC in the Colorado River ecosystem (CRE)? (USGS 2007b; RIN 2.2.3 )

What are the impacts of current recreational activities on mortality, recruitment and the population size of HBC? (USGS 2007b; RIN 2.2.11) What are the impacts of research activities on mortality, recruitment, and the population size of HBC? (USGS 2007b; RIN 2.2.12) What are the physical and biological characteristics of habitats that enhance recruitment of FMS, BS, and SD populations in the CRE? (USGS 2007b; RIN 2.6.3) What is the age structure, including relationship between age and size of FMS, BS, and SD in the CRE? (USGS 2007b; RIN 2.6.4) How are movement patterns for FMS, BS, and SD in the CRE affected by age, natal stream, and dam operations? (USGS 2007b; RIN 2.6.5) How is the rate of mortality for FMS, BS, and SD in the CRE related to individual body size? What are the sources of mortality for FMS, BS, and SD in the CRE? (USGS 2007b; RIN 2.6.6) How does temperature modification in the mainstem affect recruitment and mortality for FMS, BS, and SD originating from tributary spawning? (USGS 2007b; RIN 2.6.7)"

000 Project element F.1. System Wide Electrofishing ($217,000) Uses catch per unit effort indices to track relative status and trends of most common native and nonnative fish including sampling downstream from Diamond Creek. Provides trout relative abundance estimates which, in turn, may be used as part of the suite of triggers identifying when to implement mechanical removal of nonnative fish to protect humpback chub. "What are the population dynamics and trends of native and nonnative fish in the CRE?" "What are the population dynamics of those nonnative fish that are the major predators and competitors of native fish? (USGS 2007b; RIN 2.4.6)"
000 Project Element F.2. Glen Canyon Monitoring ($285,000) Inclusion of the following projects listed below:
000 Project Element F.2.1. Rainbow Trout Monitoring in Glen Canyon Monitor of basic fish population elements, including relative abundance, size composition, distribution, condition, and recruitment of native and nonnative fish in Glen Canyon. Conduct three trips in FY12 that each sample 36 random sites stratified longitudinally by river mile and by shoreline type. Sample 15 sites for warm water nonnative invasive fish where nonnative fish are most likely to be captured, including the slough at RM -12, warm spring inputs, and immediately downstream of the dam. How is the Lees Ferry rainbow trout population affected by GCD operations? "What Glen Canyon Dam operations (ramping rates, daily flow range, etc.) maximize trout fishing opportunities and catchability? (USGS 2007b; SSQ 3.6)

To what extent is there overlap in the Lees Ferry reach of RBT habitat and native fish habitat? (USGS 2007b; RIN 4.1.3)"

000 Project Element F.2.2. Rainbow Trout Early Life Stage Studies (RTELSS) Winter and early spring redd surveys provide information on the magnitude of spawn and the effects of flows on incubation mortality. Electrofishing of nearshore habitat in the summer and fall provides information on recruitment, survival, and growth of juvenile fish. Whereas the Rainbow Trout Monitoring in Glen Canyon Project (Project Element F.2.1.) monitors relative abundance of young-of-the-year rainbow trout in the fall, this project provides “initial response” information about survival rates of age-0 rainbow trout, and provides insight into how early rainbow trout life stages are affected by their density. How are early rainbow trout life stages are affected by their own density?
000 "Project Element F.3. Mainstem Monitoring of Native and Nonnative Fishes Near the LCR Confluence; Juvenile

Chub Monitoring (JCM) ($432,000)"

Estimate juvenile humpback chub survival rates, and rainbow trout and brown trout abundance near the confluence of the mainstem Colorado River and the LCR. Identify when to implement mechanical removal of nonnative fish to protect humpback chub as described in the 2011 Environmental Assessment for Non-Native Fish Control Downstream from Glen Canyon Dam and associated Biological Opinion. "What is the effect of HFEs on humpback chub and native fish populations located downstream from Glen Canyon Dam? (IV: Dept. of Interior 2011a)

What is the relative importance of increased water temperature, shoreline stability, and food availability on the survival and growth of YoY and juvenile native fish? (I: Melis et al. 2006) How important are backwaters and vegetated shoreline habitats to the overall growth and survival of YoY and juvenile native fish? Does the long-term benefit of increasing these habitats outweigh short-term potential costs (displacement and possibly mortality) associated with high flows? (I: Melis et al. 2006) Will increased water temperatures increase the incidence of Asian Tapeworm in humpback chub or the magnitude of infestation, and if so, what is the impact on survival and growth rates? (I: Melis et al. 2006) What is the importance of mainstem habitats to humpback chub recruitment relative to the LCR? (VI: Dept. of Interior 2011c) Do HFEs result in creation of nearshore habitats (i.e. backwaters) that can offer physical benefits to humpback chub and other native fishes? (II: Mellis et al. 2007) What are the effects of HFEs on aquatic food production? How do these effects impact native fishes? (II: Mellis et al. 2007) What effect do power plant releases (ramp rates, fluctuating and steady) have on listed or special status species (including HBC) in the Colorado River ecosystem? (III: USGS 2007a) How important are backwaters and vegetated shoreline habitats to the overall growth and survival of YoY and juvenile native fish? Does the long-term benefit of increasing these habitats outweigh short-term potential costs (displacement and possibly mortality of young humpback chub) associated with high flows? (USGS 2007b; SSQ 4.2) Will increased water temperatures increase the incidence of Asian tapeworm in humpback chub or the magnitude of infestation, and if so, what is the impact on survival and growth rates? (USGS 2007b; SSQ 5.5) What habitats and habitat characteristics, if any, will enhance survival, growth, and reproduction of native Grand Canyon fishes, especially HBC, in the mainstem Colorado River? (USGS 2007b; SSQ RIN 1)" "Quantify sources of mortality for humpback chub (HBC) 51 mm in rearing habitats in the Little Colorado River (LCR) and mainstem, and determine how these sources of mortality are related to dam operations. (USGS 2007b; RIN 2.1.2) What is the relationship between size of HBC and mortality in the LCR and the mainstem? What are the sources of mortality (i.e., predation, cannibalism, other) in the LCR and the mainstem? (USGS 2007b; RIN 2.1.3) How does flow rate and fluctuation affect habitat availability and utilization by fish and other organisms? (USGS 2007b; RIN 7.4.4) What are the desired ranges of spatial and temporal patterns of water temperatures for the CRE? (USGS 2007b; RIN 7.1.1) What are the most likely downstream temperature responses to a variety of scenarios involving a TCD on GCD? (USGS 2007b; RIN 7.1.2) What are the potential ecological effects of increasing mainstem water temperatures? (USGS 2007b; RIN 7.1.3)"

000 Project Element F.4. Little Colorado River Monitoring ($606,000) Provides data for use in the Age-Structured-Mark-Recapture Model (ASMR) as well as information required in the 2011 Biological Opinion. Required in the 2011 Biological Opinion.
000 Project Element F.4.1 Annual Spring and Fall Humpback Chub Abundance Estimates in the Lower 13.6 km of the Little Colorado River Ongoing project since 2000 provides annual estimates of abundance of adult humpback chub (> 150 mm and > 200 mm total length(TL)), and during some years provides abundance estimates of other native fishes. Identify when to implement mechanical removal of nonnative fish to protect humpback chub as described in the 2011 Environmental Assessment for Non-Native Fish Control Downstream from Glen Canyon Dam and associated Biological Opinion.
000 Project Element F.4.2. Monitoring Native and Nonnative Fishes in the Lower 1.2 km of the Little Colorado River Started by the Arizona Game and Fish Department in 1987, has operated continuously (except in 2000 and 2001). Produces annual assessments of the relative abundance (catch-per-unit effort) of all size classes of humpback chub, flannelmouth suckers, bluehead suckers, speckled dace, and a host of nonnative fish in the lower 1,200 m of the LCR. Provides independent comparisons to humpback chub abundance trends generated by the ASMR model. Same as above but provides a longer-term data set for humpback chub in the LCR. The statistical power of this portion of the monitoring program has not yet been assessed, but statistically significant differences in relative abundance are apparent in current data when compared to data collected in Project F.4.1.
000 TBD
000 TBD
000 TBD


UNDER CONSTRUCTION:

  • To be added: From Knowledge Assessment_"Assessing what we know and don't know_8-22-2011"- USGS
  1. The food web on which fish depend is very simple
  2. Availablitity of high-quality food resources limits fish populations- Black Flies and midges are the most important parts of the present food web.
  3. The mainstem Colorado River water temperature is typically well velow the termal optimum for native fishes, but recently has been warmer.
  4. Warming increases growth/ production of algae and invertebrates.
  5. Warming increases the growth rate of humpback chub.
  6. We don't understand the decline in RBT between 2001 and 2007.
  7. Rainbow and brown trout disproportionately prey on native fish.

WHAT WE DON'T KNOW--

  1. Will warmer mainstem temperatures alone allow for increased survival of humpback chub?
  2. Do trout have substantial population-level effects on humpback chub?
  3. What ages of HBC are most impacted, and by what mechanisms? Competition, predation...


RAFTING RELATED

  • Do rafting groups get told not to cave-in sandbars?

SEDIMENT RELATED

  • Sediment Retention:
  1. Q: How do intervening flows effect retention of sand bars? A
  2. Q: In order to retain sandbar life following an HFE, has riprap been considered as a possible action against erosion in the Grand Canyon?

A: The park system was created to conserve unimpaired the resources and values that the park was set aside to protect. Natural landscapes disturbed by natural phenomena will be allowed to recover naturally (where possible). Landscape and vegetation conditions altered by human activity may be manipulated where the park management plan provides for restoring the lands to a natural condition. This usually entails removing the man-made objects (like a fence, structure, or even a dam) to bring the area back to a natural state. If the use of man-made objects or non-native species proves worthy in restoring a landscape, it can be used to a limited degree, and as long as it is done on a temporary basis and does not impair the resources.

In addition, one needs to factor in wilderness management (which applies to the lands along the river). Because the beaches are within NPS proposed wilderness recommendation, They are required to manage the area as Wilderness; including the values of naturalness, primitive and unconfined recreation, solitude, and special values. No action can be taken that would diminish the area's wilderness eligibility until after Congress and the President have taken action. This aspect takes us back to the "as natural as possible" discussion and would be a prohibitive factor for such actions as rip-wrapping and other such man-made structures.

>>Also consider-- the cost of doing such work in the Grand Canyon may even exceed that of sediment augmentation. ---Riprap, HFE, Sandbars erosion

FISH RELATED

  • How often do native fish get handled?


DAM- General Overview

  • What resources have been improved because of the dam?
  • Was there more or less vegetation along the river after GC Dam was built?

Monitoring

  • How far back does the readings of the gauges go? Pre-dam?


Flow Regimes

  • Do steady flows produce more trout?
  • Do steady flows lead to increases in vegetation encroachment?
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