Nutrients

Role of Nutrients in Fish Population Dynamics below Glen Canyon Dam The 2012-2014 rainbow trout population decline corresponded with a decline in condition for other large-bodied native fish like humpback chub, flannelmouth sucker, and bluehead sucker. These declines in fish population size and body condition occurred at the same time as a decline in drift biomass in the foodbase below Glen Canyon Dam. Primary production in the Colorado River is nutrient limited (soluble reactive phosphorous or SRP). Seasonal estimates of primary production just above the LCR are highly correlated with SRP measured at the Glen Canyon Dam. Primary production is linked to foodbase production, native fish condition, and rainbow trout condition and recruitment. [1]

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Updates https://www.usbr.gov/uc/progact/amp/twg/2017-01-26-twg-meeting/AR20_Yackulic.pdf https://www.usbr.gov/uc/progact/amp/twg/2017-01-26-twg-meeting/AR20_Yackulic.pdf https://www.usbr.gov/uc/progact/amp/twg/2017-01-26-twg-meeting/AR20_Yackulic.pdf https://www.usbr.gov/uc/progact/amp/twg/2017-01-26-twg-meeting/AR20_Yackulic.pdf https://www.usbr.gov/uc/progact/amp/twg/2017-01-26-twg-meeting/AR20_Yackulic.pdf https://www.usbr.gov/uc/progact/amp/twg/2017-01-26-twg-meeting/AR20_Yackulic.pdf https://www.usbr.gov/uc/progact/amp/twg/2017-01-26-twg-meeting/AR20_Yackulic.pdf

Links and Information Water Quality Page Algae and Aquatic Macrophytes Page Foodbase Page Trout Fishery Page Humpback Chub Page Nutrients Gages USGS 09380000 COLORADO RIVER AT LEES FERRY, AZ Papers and Presentations 2022 Effects of drought-related low phosphorous concentrations on the aquatic ecosystem downstream of Glen Canyon Dam, and potential to improve productivity via nutrient fertilization pH Regulates Phosphorus Cycling in the Colorado River pH Regulates Phosphorus Cycling in the Colorado River 2021 Nutrients, Primary Production, and the Colorado River Foodbase Flows and Phosphorus: the Influence of Lake Powell on Primary Production Dynamics in the Colorado River 2020 GCMRC 2019 Annual Reporting Meeting Overview – Part 2b 2018 Temperature and nutrients as ecosystem drivers in the Colorado River PPT, Lake Powell as a regulator of temperature and Lake Powell as a regulator of nutrients PPT 2017 The Role of Nutrients in Colorado River Ecosystem Dynamics 2011 Deegan et al. 2011. Effects of fish density and river fertilization on algal standing stocks, invertebrate communities, and fish production in an arctic river. Canadian Journal of Fisheries and Aquatic Sciences 1983 Evans and Paulson. 1983. The influence of Lake Powell on the suspended sediment-phosphorus dynamics of the Colorado River inflow to Lake Mead. Water Resources. Erin. XXXX. Nitrogen & Phosphorus Dynamics below Glen Canyon Dam. U.C. Davis Nutrient Supplementation Programs Corps Dworshak Nutrient Supplementation Study Aims To Boost Kokanee, Listed Bull Trout Dworshak Nutrient Supplementation Program EA Upper Columbia Nutrient Supplementation Project Dewatto River Nutrient Supplementation Study Redfish Lake Sockeye Salmon: Nutrient Supplementation as a Means of Restoration Kootenai River Ecosystem Restoration (Nutrient Restoration) Kootenai River Fisheries Recovery Investigations: Ecosystem Rehabilitation. Project Progress Report. 2003-2005 Annual Report Other Stuff Nutrients released from GCD and trout competition appear to have a bigger effect on growth than fall HFEs [2]