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Effects of Sublethal Copper Exposure on Escape Behavior and Growth of Rana pipiens Tadpoles

Description: This research is designed to test how sublethal exposure to copper affects tadpole predator-escape behavior and how quickly tadpoles recover. After exposure, tadpoles were separated. Escape behavior was recorded for two-thirds of exposed tadpoles while one-third of the exposed population was measured weekly to determine growth and recovery. Control tadpoles were consumed within 15 minutes whereas those exposed to higher concentrations were consumed at a slower rate, which does not support the h… more
Date: May 2002
Creator: Redick, Melinda
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
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Feeding Activity, Rate of Consumption, Daily Ration and Prey Selection of Major Predators in the John Day Pool : 1983, Annual Report.

Description: This report summarizes activities in 1983, the second of a five year study to determine the extent of predation by resident populations of native and introduced fishes on juvenile salmonids in John Day Reservoir. As in 1982, catches of northern squawfish (Ptychocheilus oregonensis) were highest in areas adjacent to dams; percent by weight of juvenile salmonids in the diet was up to 89.7% higher in these areas. Catches of walleyes (Stizostedion vitreum vitreum) were greatest outside restricted z… more
Date: February 1, 1985
Creator: Gray, Gerard A.; Administration, United States. Bonneville Power; Service, U.S. Fish and Wildlife & (U.S.), National Fishery Research Center
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Feeding Activity, Rate of Consumption, Daily Ration and Prey Selection of Major Predators in John Day Reservoir, 1984 : Annual Report.

Description: The extent of predation on juvenile salmonids in John Day Reservoir was determined. Salmonids were the single most important food item by weight for northern squawfish (Ptychocheilus oregonensis) in the restricted zones at McNary tailrace and John Day forebay during all sampling periods. Salmonids accounted for 18.1% of the weight in the diet of walleyes (Stizostedion vitreum vitreum) in 1984 which was at least twice that found in previous years. In smallmouth bass (Micropterus dolomieui) salmo… more
Date: July 1, 1986
Creator: Gray, Gerard A.; Administration, United States. Bonneville Power; Service, U.S. Fish and Wildlife & (U.S.), National Fishery Research Center
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Habitat Partitioning by a Riparian Cursorial Spider Guild, and Intraspecific Behaviors of the Wolf Spider Pardosa valens (LYCOSIDAE) and the Stonefly Hydroperla crosbyi (PERLODIDAE)

Description: Members of a guild of cursorial spiders (Pardosa spp. and Alopecosa spp.) spatially segregated among five discrete habitats, from a streamside cobble habitat grading laterally along a successional gradient to the leaf litter zone of a transition or climax riparian forest. Seasonal activity peaked in midsummer for all guild members. Spiders were active diurnally earlier in the streamside habitats, and levels of activity were positively correlated with light intensity. Guild members Pardosa trist… more
Date: May 1991
Creator: Moring, J. Bruce (James Bruce)
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
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Feeding Activity, Rate of Consumption, Daily Ration and Prey Selection of Major Predators in the John Day Pool. 1982 Annual Report.

Description: This study was initiated to determine the extent of predation by resident populations of native and introduced fish on juvenile salmonids in main stem Columbia River Reservoirs. The John Day Reservoir and tailrace was selected as the study area. First year objectives were: (1) determine whether native and introduced predators preyed on juvenile salmonids; (2) determine which species were major predators; and (3) locate areas where predation was most intense. Results indicated that juvenile salm… more
Date: March 1, 1984
Creator: Gray, Gerard A. & Administration, United States. Bonneville Power
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Feeding Activity, Rate of Consumption, Daily Ration and Prey Selection of Major Predators in John Day Reservoir, 1986 : Annual Report.

Description: This report summarizes activities in 1986 to determine the significance of predation on juvenile salmonids in John Day Reservoir. Salmonids were the single most important food item (by weight) for northern squawfish (Ptychocheilus oregonensis) at McNary tailrace during all sampling periods and at John Day forebay during July. Salmonids accounted for 23.7% of the diet of walleye (Stizostedion vitreum vitreum) in July 1986, which was higher than in previous years (although the sample size examine… more
Date: February 1, 1987
Creator: Poe, Thomas P.; Administration, United States. Bonneville Power; Service, U.S. Fish and Wildlife & (U.S.), National Fishery Research Center
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Development of a System Wide Predator Control Program: Stepwise Implementation of a Predation Index, Predator Control Fisheries, and Evaluation Plan in the Columbia River Basin; Section II: Evaluation; 1996 Annual Report.

Description: Predator control fisheries aimed at reducing predation on juvenile salmonids by northern squawfish (Ptychocheilus oregonensis) were implemented for the seventh consecutive year in the mainstream Columbia and Snake rivers.
Date: November 1, 1997
Creator: Young, Franklin R.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Effects of Marine Mammals on Columbia River Salmon Listed under the Endangered Species Act : Recovery Issues for Threatened and Endangered Snake River Salmon : Technical Report 3 of 11.

Description: Most research on the Columbia and Snake Rivers in recent years has been directed to downstream migrant salmon (Oncorhynchus spp.) losses at dams. Comparatively little attentions has been given to adult losses. Recently an estimated 378,4000 adult salmon and steelhead (O. mykiss) were unaccounted-for from Bonneville Dam to terminal areas upstream. It is now apparent that some of this loss was due to delayed mortality from wounded by marine mammals. This report reviews the recent literature to de… more
Date: June 1, 1993
Creator: Park, Donn L.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Feeding Activity, Rate of Consumption, Daily Ration and Prey Selection of Major Predators in John Day Reservoir, 1985: Annual Report.

Description: This report summarizes activities in 1985 to determine the extent of predation on juvenile salmonids in John Day Reservoir. To estimate consumption of juvenile salmonids we used the composition of the natural diet of predators and in the laboratory determined rate of gastric evacuation by predators. Salmonids were the single most important food item for northern squawfish (Ptychocheilus oregonensis) at McNary tailrace during all sampling periods and at John Day forebay during July. Salmonids ac… more
Date: October 1986
Creator: Palmer, Douglas E.; Hansel, Hal C.; Beyer, Jean M.; Vigg, Steven C.; Yasutake, William T.; Lofy, Peter T. et al.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Development of a Systemwide Program: Stepwise Implementation of a Predation Index, Predator Control Fisheries and Evaluation Plan in the Columbia River Basin, Volume 1, 1992 Annual Report.

Description: Results of the second year are reported of a basinwide program to harvest northern squawfish in an effort to reduce mortality due to squawfish predation on juvenile salmonids during their migration from natal streams to the ocean. Six papers are included in this report. They are entitled: feasibility investigation of a commercial longline fishery for northern squawfish in the Columbia River downstream from Bonneville dam; evaluation of the northern squawfish sport-reward fishery in the Columbia… more
Date: June 1, 1994
Creator: Ward, David L.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Development of a System-Wide Predator Control Program : Stepwise Implementation of a Predation Index Predator Control Fisheries and Evaluation Plan in the Columbia River Basin, 1990 Annual Report.

Description: The papers in this document report the results of studies to develop a Columbia River basin-wide program to control northern squawfish predation on juvenile salmonids. Our studies focus on (1) determining where in the basin northern squawfish predation is a problem, (2) conducting various fisheries for northern squawfish, and (3) testing a plan to evaluate how well fisheries are controlling northern squawfish populations. These studies were initiated as part of a basin-wide effort to reduce mor… more
Date: December 1, 1990
Creator: Nigro, Anthony A.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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