U.S. Bureau of Reclamation Offers Grant for Aquatic Ecosystem Health Monitoring Below Flaming Gorge Dam

Project Objectives
The overall and specific purposes of this work is to continue to monitor and evaluate the health and status of the aquatic ecosystem of the Green River downstream from Flaming Gorge Dam, within the context of evaluating the effects of the recently implemented daily double peak flow operations as well as more-typical dam operations, such as above power plant flows during high water years.

Project details

Sampling locations
Data will be collected from 9 locations in the Green River from Fontenelle Dam downstream to the Colorado state line at Swinging Bridge. These are the same locations sampled quarterly by Vinson since 1995 (Vinson et al. 2006). Sampling conducted downstream from Fontenelle Dam may be of particular importance for understanding possible effects of the daily double peak flow regime downstream from Flaming Gorge Dam, as a single peak or constant daily flows are released from Fontenelle Dam.

Data to be collected
Physical habitat – Stream discharge and water temperature data are collected by the U.S. Bureau of Reclamation (BOR) and the U.S. Geological Survey (USGS) at Flaming Gorge Dam (Station 092345000), Fontenelle Dam (Station 09211200), and at Green River, Wyoming (Station 09216500). These data will be obtained and incorporated into our analyses.

Benthic Biota – Epiphytic aquatic plants and benthic aquatic invertebrate samples will be collected seasonally (January, April, July, and September) following Vinson et al. (2006). Epiphytic aquatic plant standing stock will be estimated by collecting samples from ten D50 sized rocks at each riffle site. The attached plants will be removed from a small area (5.3 cm2) on the upper surface of each rock. Samples will be frozen and returned to the laboratory. In the laboratory, the samples are thawed, dried at 60 C, weighed, and then fired in a muffle furnace at 550 C for 2 hours to obtain ash-free dry mass (AFDM).

Benthic macroinvertebrate samples will be collected in riffle habitats with a Hess net (0.08 m2, 250 micron mesh) following Vinson et al. (2006). Eight samples are collected at each site and composited. When possible, samples will be collected below the 28 cms (800 cfs) minimum flow water line. In the laboratory, a minimum of 300 organisms will be removed and identified from each sample under a dissecting microscope. The remaining portion of each sample will then be searched for rarer organisms that were not collected during the sample splitting process. Aquatic invertebrates will be identified to the lowest taxonomic level possible based on organism maturity, except for Chironomidae, which will be identified to subfamily and some non-insect groups, primarily Annelida, which will be identified to Class or Order. Insects are most frequently identified to species or genus. Small, immature, or damaged specimens are generally identified to family. Species level identifications are based on identification keys, distributions records, and the author’s experience.

All identified invertebrates in each sample will be composited into a single museum-grade glass screw-top vial with a polypropylene lid and polypropylene liner. Sample labels will be written with fade proof permanent black carbon ink on waterproof paper. Information on each label includes the sampling location, sampling date and a unique catalog number. Vials will be filled with 70% ethanol. All samples will be retained in our collection and made available to others upon request and permission from the U.S. Bureau of Reclamation.

Data analysis and presentation
The primary objective of this work is to monitor the health of the Green River downstream from Flaming Gorge Dam and to understand how changes in dam operations affect this ecosystem. Reports will describe the work conducted that year and put that year’s data in a historical perspective. Reports will include data and information on streamflow, water temperature, and the occurrence and relative abundance of aquatic invertebrates and aquatic plant biomass at each sampling location. As in the past, all data will be quickly made available to the U.S. Bureau of Reclamation, Western Area Power Administration, and the Utah Division of Wildlife Resources, as well as other researchers to incorporate into modeling exercises or other analyses. Annual progress reports will be completed no later than March 31 of each year and we will provide a final project report on or before the expiration date of the agreement.

Project Objectives
The overall and specific purposes of this work is to continue to monitor and evaluate the health and status of the aquatic ecosystem of the Green River downstream from Flaming Gorge Dam, within the context of evaluating the effects of the recently implemented daily double peak flow operations as well as more-typical dam operations, such as above power plant flows during high water years.

Project details

Sampling locations
Data will be collected from 9 locations in the Green River from Fontenelle Dam downstream to the Colorado state line at Swinging Bridge. These are the same locations sampled quarterly by Vinson since 1995 (Vinson et al. 2006). Sampling conducted downstream from Fontenelle Dam may be of particular importance for understanding possible effects of the daily double peak flow regime downstream from Flaming Gorge Dam, as a single peak or constant daily flows are released from Fontenelle Dam.

Data to be collected
Physical habitat – Stream discharge and water temperature data are collected by the U.S. Bureau of Reclamation (BOR) and the U.S. Geological Survey (USGS) at Flaming Gorge Dam (Station 092345000), Fontenelle Dam (Station 09211200), and at Green River, Wyoming (Station 09216500). These data will be obtained and incorporated into our analyses.

Benthic Biota – Epiphytic aquatic plants and benthic aquatic invertebrate samples will be collected seasonally (January, April, July, and September) following Vinson et al. (2006). Epiphytic aquatic plant standing stock will be estimated by collecting samples from ten D50 sized rocks at each riffle site. The attached plants will be removed from a small area (5.3 cm2) on the upper surface of each rock. Samples will be frozen and returned to the laboratory. In the laboratory, the samples are thawed, dried at 60 C, weighed, and then fired in a muffle furnace at 550 C for 2 hours to obtain ash-free dry mass (AFDM).

Benthic macroinvertebrate samples will be collected in riffle habitats with a Hess net (0.08 m2, 250 micron mesh) following Vinson et al. (2006). Eight samples are collected at each site and composited. When possible, samples will be collected below the 28 cms (800 cfs) minimum flow water line. In the laboratory, a minimum of 300 organisms will be removed and identified from each sample under a dissecting microscope. The remaining portion of each sample will then be searched for rarer organisms that were not collected during the sample splitting process. Aquatic invertebrates will be identified to the lowest taxonomic level possible based on organism maturity, except for Chironomidae, which will be identified to subfamily and some non-insect groups, primarily Annelida, which will be identified to Class or Order. Insects are most frequently identified to species or genus. Small, immature, or damaged specimens are generally identified to family. Species level identifications are based on identification keys, distributions records, and the author’s experience.

All identified invertebrates in each sample will be composited into a single museum-grade glass screw-top vial with a polypropylene lid and polypropylene liner. Sample labels will be written with fade proof permanent black carbon ink on waterproof paper. Information on each label includes the sampling location, sampling date and a unique catalog number. Vials will be filled with 70% ethanol. All samples will be retained in our collection and made available to others upon request and permission from the U.S. Bureau of Reclamation.

Data analysis and presentation
The primary objective of this work is to monitor the health of the Green River downstream from Flaming Gorge Dam and to understand how changes in dam operations affect this ecosystem. Reports will describe the work conducted that year and put that year’s data in a historical perspective. Reports will include data and information on streamflow, water temperature, and the occurrence and relative abundance of aquatic invertebrates and aquatic plant biomass at each sampling location. As in the past, all data will be quickly made available to the U.S. Bureau of Reclamation, Western Area Power Administration, and the Utah Division of Wildlife Resources, as well as other researchers to incorporate into modeling exercises or other analyses. Annual progress reports will be completed no later than March 31 of each year and we will provide a final project report on or before the expiration date of the agreement.