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• 951. [Image] Proceedings of second conference of engineers of the Reclamation service, with accompanying papers.

  	Conference was held at El Paso, Tex., November 14 to 18, 1904, and adjourned to Washington, D.C., where it was continued from January 9 to 14, 1905;
  	Citation × Citation Citation Abstract Copy Title: Proceedings of second conference of engineers of the Reclamation service, with accompanying papers. Author: Newell, Frederick Haynes, 1862-1932 Year: 1905, 2008, 2005 Conference was held at El Paso, Tex., November 14 to 18, 1904, and adjourned to Washington, D.C., where it was continued from January 9 to 14, 1905; Title: Proceedings of second conference of engineers of the Reclamation service, with accompanying papers. Author: Newell, Frederick Haynes, 1862-1932 Year: 1905, 2008, 2005 Conference was held at El Paso, Tex., November 14 to 18, 1904, and adjourned to Washington, D.C., where it was continued from January 9 to 14, 1905; Close

• 952. [Image] Handbook for developing watershed plans to restore and protect our waters

  	Draft; Title from title screen (viewed on Mar. 17, 2006); "October 2005."; "EPA 841-B-05-005."; Includes bibliographical references
  	Citation × Citation Citation Abstract Copy Title: Handbook for developing watershed plans to restore and protect our waters Author: United States Environmental Protection Agency, Office of Water Year: 2005, 2008, 2006 Draft; Title from title screen (viewed on Mar. 17, 2006); "October 2005."; "EPA 841-B-05-005."; Includes bibliographical references Title: Handbook for developing watershed plans to restore and protect our waters Author: United States Environmental Protection Agency, Office of Water Year: 2005, 2008, 2006 Draft; Title from title screen (viewed on Mar. 17, 2006); "October 2005."; "EPA 841-B-05-005."; Includes bibliographical references Close

• 953. [Image] Draft upper Klamath River management plan environmental impact statement and resource management plan amendments. Volume 2 - Appendices

  	"BLM/OR/WA/PL-02/038+1792"--P. [2] of cover; Cover title; Includes bibliographical references (v. 2, p. 219-228) and index
  	Citation × Citation Citation Abstract Copy Title: Draft upper Klamath River management plan environmental impact statement and resource management plan amendments. Volume 2 - Appendices Author: United States. Bureau of Land Management. Klamath Falls Resource Area Office Year: 2003, 2004 "BLM/OR/WA/PL-02/038+1792"--P. [2] of cover; Cover title; Includes bibliographical references (v. 2, p. 219-228) and index Title: Draft upper Klamath River management plan environmental impact statement and resource management plan amendments. Volume 2 - Appendices Author: United States. Bureau of Land Management. Klamath Falls Resource Area Office Year: 2003, 2004 "BLM/OR/WA/PL-02/038+1792"--P. [2] of cover; Cover title; Includes bibliographical references (v. 2, p. 219-228) and index Close

• 954. [Image] Recovery plan for the native fishes of the Warner Basin and Alkali Subbasin : Warner sucker (threatened) Catostomus warnerensis, Hutton tui chub (threatened) Gila bicolor ssp. Foskett speckled dace (threatened) Rhinichthys osculus ssp

  	"April 1998"--P. [4] of cover; Includes bibliographical references (p. 57-66)
  	Citation × Citation Citation Abstract Copy Title: Recovery plan for the native fishes of the Warner Basin and Alkali Subbasin : Warner sucker (threatened) Catostomus warnerensis, Hutton tui chub (threatened) Gila bicolor ssp. Foskett speckled dace (threatened) Rhinichthys osculus ssp Author: U.S. Fish and Wildlife Service. Oregon State Office Year: 1998, 2004 "April 1998"--P. [4] of cover; Includes bibliographical references (p. 57-66) Title: Recovery plan for the native fishes of the Warner Basin and Alkali Subbasin : Warner sucker (threatened) Catostomus warnerensis, Hutton tui chub (threatened) Gila bicolor ssp. Foskett speckled dace (threatened) Rhinichthys osculus ssp Author: U.S. Fish and Wildlife Service. Oregon State Office Year: 1998, 2004 "April 1998"--P. [4] of cover; Includes bibliographical references (p. 57-66) Close

• 955. [Image] Federal Register - Policy for Evaluation of Conservation Efforts When Making Listing Decisions

  	We, the Fish and Wildlife Service (FWS) and the National Marine Fisheries Service (NMFS) (the Services), announce a final policy for the evaluation of conservation efforts when making listing decisions ...
  	Citation × Citation Citation Abstract Copy Title: Federal Register - Policy for Evaluation of Conservation Efforts When Making Listing Decisions Year: 2003, 2008, 2005 We, the Fish and Wildlife Service (FWS) and the National Marine Fisheries Service (NMFS) (the Services), announce a final policy for the evaluation of conservation efforts when making listing decisions (PECE) under the Endangered Species Act of 1973, as amended (Act). While the Act requires us to take into account all conservation efforts being made to protect a species, the policy identifies criteria we will use in determining whether formalized conservation efforts that have yet to be implemented or to show effectiveness contribute to making listing a species as threatened or endangered unnecessary. The policy applies to conservation efforts identified in conservation agreements, conservation plans, management plans, or similar documents developed by Federal agencies, State and local governments, Tribal governments, businesses, organizations, and individuals Title: Federal Register - Policy for Evaluation of Conservation Efforts When Making Listing Decisions Year: 2003, 2008, 2005 We, the Fish and Wildlife Service (FWS) and the National Marine Fisheries Service (NMFS) (the Services), announce a final policy for the evaluation of conservation efforts when making listing decisions (PECE) under the Endangered Species Act of 1973, as amended (Act). While the Act requires us to take into account all conservation efforts being made to protect a species, the policy identifies criteria we will use in determining whether formalized conservation efforts that have yet to be implemented or to show effectiveness contribute to making listing a species as threatened or endangered unnecessary. The policy applies to conservation efforts identified in conservation agreements, conservation plans, management plans, or similar documents developed by Federal agencies, State and local governments, Tribal governments, businesses, organizations, and individuals Close

• 956. [Image] Water quality conditions in Upper Klamath and Agency Lakes, Oregon, 2005

  	Agency Lakes. Oregon. 2005 M.Wood By Gene R. Hoilman, Mary K. Lindenberg, and Tamara Abstract During June-October 2005, water quality data were collected from Upper Klamath and Agency Lakes In Oregon, ...
  	Citation × Citation Citation Abstract Copy Title: Water quality conditions in Upper Klamath and Agency Lakes, Oregon, 2005 Author: Hoilman, Gene R Year: 2008 Agency Lakes. Oregon. 2005 M.Wood By Gene R. Hoilman, Mary K. Lindenberg, and Tamara Abstract During June-October 2005, water quality data were collected from Upper Klamath and Agency Lakes In Oregon, and meteorological data were collected around and within Upper Klamath Lake. Data recorded at two continuous water quality monitors In Agency Lake showed similar temperature patterns throughout the field season, but data recorded at the northern site showed more day-to-day variability for dissolved oxygen concentration and saturation after late June and more day-to-day variability for pH and specific conductance values after mid-July. Data recorded from the northern and southern parts of Agency Lake showed more comparable day-to-day variability in dissolved oxygen concentrations and pH from September through the end of the monitoring period. For Upper Klamath Lake, seasonal (late July through early August) lows of dissolved oxygen concentrations and saturation were coincident with a seasonal low of pH values and seasonal highs of ammonia and orthophosphate concentrations, specific conductance values, and water temperatures. Patterns in these parameters, excluding water temperature, were associated with bloom dynamics of the cyanobacterium (blue-green alga) Aphanizomenonflos-aquae in Upper Klamath Lake. In Upper Klamath Lake, water temperature in excess of 28 degrees Celsius (a high stress threshold for Upper Klamath Lake suckers) was recorded only once at one site during the field season. Large areas of Upper Klamath Lake had periods of dissolved oxygen concentration of less than 4 milligrams per liter and pH value greater than 9.7, but these conditions were not persistent throughout days at most sites. Dissolved oxygen concentrations in Upper Klamath Lake on time scales of days and months appeared to be influenced, in part, by bathymetry and prevailing current flow patterns. Diel patterns of water column stratification were evident, even at the deepest sites. This diel pattern of stratification was attributable to diel wind speed patterns and the shallow nature of most of Upper Klamath Lake. Timing of the daily extreme values of dissolved oxygen concentration, pH, and water temperature was less distinct with increased water column depth. Chlorophyll a concentrations varied spatially and temporally throughout Upper Klamath Lake. Location greatly affected algal concentrations, in turn affecting nutrient and dissolved oxygen concentrations—some of the highest chlorophyll a concentrations were associated with the lowest dissolved oxygen concentrations and the highest un-ionized ammonia concentrations. The occurrence of the low dissolved oxygen and high un-ionized ammonia concentrations coincided with a decline in algae resulting from cell death, as rn.easu.red by concentrations of chlorophyll a. Dissolved oxygen production, rates in. experim.en.ts were as high as 1.47 milligrams of oxygen per liter per hour, and consumption rates were as much as -0.73 milligrams of oxygen per liter per hour. Dissolved oxygen, consumption rates measured in. this study were comparable to those measured in a 2002 Upper Klamath Lake study, and a higher rate of dissolved oxygen consumption was recorded in. dark bottles positioned higher in the water column. Data, though, inconclusive, indicated that a decreasing trend of dissolved oxygen productivity through July could have contributed to the decreasing dissolved oxygen concentrations and percent saturation recorded in Upper Klamath Lake during this time. Phytoplankton self-shading was evident from, a general inverse relation between depth of photic zone and chlorophyll a concentrations. This shading caused net dissolved oxygen consumption during daylight hours in lower parts of the water column that would otherwise have been in the photic zone. Meteorological data collected in and around Upper Klamath Lake showed that winds were likely to come from a broad range of westerly directions in the northern one-third of the lake, but tended to come from a narrow range of northwesterly directions over the main body of the lake farther south. Title: Water quality conditions in Upper Klamath and Agency Lakes, Oregon, 2005 Author: Hoilman, Gene R Year: 2008 Agency Lakes. Oregon. 2005 M.Wood By Gene R. Hoilman, Mary K. Lindenberg, and Tamara Abstract During June-October 2005, water quality data were collected from Upper Klamath and Agency Lakes In Oregon, and meteorological data were collected around and within Upper Klamath Lake. Data recorded at two continuous water quality monitors In Agency Lake showed similar temperature patterns throughout the field season, but data recorded at the northern site showed more day-to-day variability for dissolved oxygen concentration and saturation after late June and more day-to-day variability for pH and specific conductance values after mid-July. Data recorded from the northern and southern parts of Agency Lake showed more comparable day-to-day variability in dissolved oxygen concentrations and pH from September through the end of the monitoring period. For Upper Klamath Lake, seasonal (late July through early August) lows of dissolved oxygen concentrations and saturation were coincident with a seasonal low of pH values and seasonal highs of ammonia and orthophosphate concentrations, specific conductance values, and water temperatures. Patterns in these parameters, excluding water temperature, were associated with bloom dynamics of the cyanobacterium (blue-green alga) Aphanizomenonflos-aquae in Upper Klamath Lake. In Upper Klamath Lake, water temperature in excess of 28 degrees Celsius (a high stress threshold for Upper Klamath Lake suckers) was recorded only once at one site during the field season. Large areas of Upper Klamath Lake had periods of dissolved oxygen concentration of less than 4 milligrams per liter and pH value greater than 9.7, but these conditions were not persistent throughout days at most sites. Dissolved oxygen concentrations in Upper Klamath Lake on time scales of days and months appeared to be influenced, in part, by bathymetry and prevailing current flow patterns. Diel patterns of water column stratification were evident, even at the deepest sites. This diel pattern of stratification was attributable to diel wind speed patterns and the shallow nature of most of Upper Klamath Lake. Timing of the daily extreme values of dissolved oxygen concentration, pH, and water temperature was less distinct with increased water column depth. Chlorophyll a concentrations varied spatially and temporally throughout Upper Klamath Lake. Location greatly affected algal concentrations, in turn affecting nutrient and dissolved oxygen concentrations—some of the highest chlorophyll a concentrations were associated with the lowest dissolved oxygen concentrations and the highest un-ionized ammonia concentrations. The occurrence of the low dissolved oxygen and high un-ionized ammonia concentrations coincided with a decline in algae resulting from cell death, as rn.easu.red by concentrations of chlorophyll a. Dissolved oxygen production, rates in. experim.en.ts were as high as 1.47 milligrams of oxygen per liter per hour, and consumption rates were as much as -0.73 milligrams of oxygen per liter per hour. Dissolved oxygen, consumption rates measured in. this study were comparable to those measured in a 2002 Upper Klamath Lake study, and a higher rate of dissolved oxygen consumption was recorded in. dark bottles positioned higher in the water column. Data, though, inconclusive, indicated that a decreasing trend of dissolved oxygen productivity through July could have contributed to the decreasing dissolved oxygen concentrations and percent saturation recorded in Upper Klamath Lake during this time. Phytoplankton self-shading was evident from, a general inverse relation between depth of photic zone and chlorophyll a concentrations. This shading caused net dissolved oxygen consumption during daylight hours in lower parts of the water column that would otherwise have been in the photic zone. Meteorological data collected in and around Upper Klamath Lake showed that winds were likely to come from a broad range of westerly directions in the northern one-third of the lake, but tended to come from a narrow range of northwesterly directions over the main body of the lake farther south. Close

• 957. [Image] Macroecology, paleoecology, and ecological integrity of terrestrial species and communities of the interior Columbia River basin and northern portions of the Klamath and Great Basins

  	This report presents information on biogeography and broad-scale ecology (macroecology) of selected fungi, lichens, bryophytes, vascular plants, invertebrates, and vertebrates of the interior Columbia ...
  	Citation × Citation Citation Abstract Copy Title: Macroecology, paleoecology, and ecological integrity of terrestrial species and communities of the interior Columbia River basin and northern portions of the Klamath and Great Basins Author: U.S. Department of Agriculture. Forest Service. Pacific Northwest Research Station; U.S.Department of the Interior. Bureau of Land Management. Year: 1998, 2006, 2005 This report presents information on biogeography and broad-scale ecology (macroecology) of selected fungi, lichens, bryophytes, vascular plants, invertebrates, and vertebrates of the interior Columbia River basin and adjacent areas. Rare plants include many endemics associated with local conditions. Potential plant and invertebrate bioindicators are identified. Species ecological functions differ among communities and variously affect ecosystem diversity and productivity. Species of alpine and subalpine communities are identified that may be at risk from climate change. Maps of terrestrial ecological integrity are presented. Keywords: Macroecology, paleoecology, ecological integrity, terrestrial communities, ecosystems, wildlife, fungi, lichens, bryophytes, vascular plants, invertebrates, arthropods, mollusks, amphibians, reptiles, birds, mammals, endemism, interior Columbia River basin, Klamath Basin, Great Basin. Title: Macroecology, paleoecology, and ecological integrity of terrestrial species and communities of the interior Columbia River basin and northern portions of the Klamath and Great Basins Author: U.S. Department of Agriculture. Forest Service. Pacific Northwest Research Station; U.S.Department of the Interior. Bureau of Land Management. Year: 1998, 2006, 2005 This report presents information on biogeography and broad-scale ecology (macroecology) of selected fungi, lichens, bryophytes, vascular plants, invertebrates, and vertebrates of the interior Columbia River basin and adjacent areas. Rare plants include many endemics associated with local conditions. Potential plant and invertebrate bioindicators are identified. Species ecological functions differ among communities and variously affect ecosystem diversity and productivity. Species of alpine and subalpine communities are identified that may be at risk from climate change. Maps of terrestrial ecological integrity are presented. Keywords: Macroecology, paleoecology, ecological integrity, terrestrial communities, ecosystems, wildlife, fungi, lichens, bryophytes, vascular plants, invertebrates, arthropods, mollusks, amphibians, reptiles, birds, mammals, endemism, interior Columbia River basin, Klamath Basin, Great Basin. Close

• 958. [Image] Biological assessment of Klamath Project's continuing operations on the endangered Lost River sucker and shortnose sucker

  	BIOLOGICAL ASSESSMENT OF KLAMATH PROJECT'S CONTINUING OPERATIONS ON THE ENDANGERED LOST RIVER SUCKER AND SHORTNOSE SUCKER U.S. Bureau of Reclamation Mid-Pacific Region Klamath Basin Area Office Klamath ...
  	Citation × Citation Citation Abstract Copy Title: Biological assessment of Klamath Project's continuing operations on the endangered Lost River sucker and shortnose sucker Author: United States. Bureau of Reclamation Year: 2001, 2005 BIOLOGICAL ASSESSMENT OF KLAMATH PROJECT'S CONTINUING OPERATIONS ON THE ENDANGERED LOST RIVER SUCKER AND SHORTNOSE SUCKER U.S. Bureau of Reclamation Mid-Pacific Region Klamath Basin Area Office Klamath Falls, Oregon February 13,2001 TABLE OF CONTENTS 1.0 INTRODUCTION 2 2.0 DESCRIPTION OF THE ACTION 3 3.0 DESCRIPTION OF HISTORIC OPERATIONS 6 4.0 ENDANGERED SPECIES POTENTIALLY AFFECTED BY THE KLAMATH PROJECT 16 5.0 ENVIRONMENTAL BASELINE 60 6.0 EFFECTS OF KLAMATH PROJECT ON BALD EAGLES 60 7.0 EFFECTS OF KLAMATH PROJECT ENDANGERED SUCKERS 63 8.0 PROPOSED CRITICAL HABITAT FOR ENDANGERED SUCKERS 82 9.0 CUMULATIVE EFFECTS 84 10.0 DETERMINATION OF EFFECTS 89 11.0 LITERATURE CITED 90 12.0 PERSONAL COMMUNICATIONS 100 13.0 APPENDIX 1 - ESA CONSULTATION REVIEW 101 Title: Biological assessment of Klamath Project's continuing operations on the endangered Lost River sucker and shortnose sucker Author: United States. Bureau of Reclamation Year: 2001, 2005 BIOLOGICAL ASSESSMENT OF KLAMATH PROJECT'S CONTINUING OPERATIONS ON THE ENDANGERED LOST RIVER SUCKER AND SHORTNOSE SUCKER U.S. Bureau of Reclamation Mid-Pacific Region Klamath Basin Area Office Klamath Falls, Oregon February 13,2001 TABLE OF CONTENTS 1.0 INTRODUCTION 2 2.0 DESCRIPTION OF THE ACTION 3 3.0 DESCRIPTION OF HISTORIC OPERATIONS 6 4.0 ENDANGERED SPECIES POTENTIALLY AFFECTED BY THE KLAMATH PROJECT 16 5.0 ENVIRONMENTAL BASELINE 60 6.0 EFFECTS OF KLAMATH PROJECT ON BALD EAGLES 60 7.0 EFFECTS OF KLAMATH PROJECT ENDANGERED SUCKERS 63 8.0 PROPOSED CRITICAL HABITAT FOR ENDANGERED SUCKERS 82 9.0 CUMULATIVE EFFECTS 84 10.0 DETERMINATION OF EFFECTS 89 11.0 LITERATURE CITED 90 12.0 PERSONAL COMMUNICATIONS 100 13.0 APPENDIX 1 - ESA CONSULTATION REVIEW 101 Close

• 959. [Image] The Chemical and biological impact of Klamath Marsh on the Williamson River, Oregon

  	A comparative study of the Williamson River (before and after passage through Klamath Marsh) and the Sprague River (which is a major tributary of the Williamson River) in South Central Oregon has provided ...
  	Citation × Citation Citation Abstract Copy Title: The Chemical and biological impact of Klamath Marsh on the Williamson River, Oregon Author: Perdue, Edward M. Year: 1981, 2005 A comparative study of the Williamson River (before and after passage through Klamath Marsh) and the Sprague River (which is a major tributary of the Williamson River) in South Central Oregon has provided substantial insight into the effects of a marsh environment on the transport of iron and aquatic humus in river water. In the Sprague River and in the pre-marsh Williamson River, iron is transported primarily as 0.80 ym suspended particulate material. In Klamath Marsh, this coarse particulate material is "weathered11, yielding iron-aquatic humus "complexes'1. Thus, most iron and aquatic humus in the post-marsh Williamson River are in the 0.025 ?m size fraction. Presumably, other trace metals would be similarly affected. Klamath Marsh serves as an important source of biologically derived solutes such as amino acids and sugars. Fractionation studies have shown that amino acids are almost exclusively humic-bound in the Will-iamson River system, while sugars may be present as either polysacchar-ides (PS) or humic-bound saccharides (HS). The PS/HS ratio may reflect the relative importance of autochthonous and allochthonous sources of sugars. Major solute composition strongly indicates that ground waters flowing into the pre-marsh Williamson River and the Sprague River are derived from a different source than are ground waters which enter the post-marsh Williamson River from Big Springs, Spring Creek, and from unidentified springs below Klamath Marsh. Nutrient concentrations (H4SiO4, NO3, PO43) are significantly higher in spring waters than elsewhere in the system. While nitrate levels (3-11 ?m) were somewhat low, phosphate levels (1-3 ?m) were quite high throughout the Williamson River system. There was some evidence for nitrogen limitation of algal growth in the pre-marsh Williamson River. While Fragilaria construens was dominant throughout the Williamson River system, several Navicula spp. were restricted to the pre-marsh Williamson River and several Fragilaria spp. and Nitzschia, spp. were found only in the post-marsh Williamson River. In Upper Klamath Lake, Stephanodiscus astrea minuta, Fragilaria construens, and Aphanizomenon flos-aquae appeared in succession, with nuisance blooms of the latter organism occurring July-November. The cessation of flow of humic-rich water from Klamath Marsh during the summer months drastically decreased the flux of aquatic humus, iron, amino acids, and other marsh-derived solutes in the post-marsh Williamson River. At the time of cessation of flow from Klamath Marsh, nuisance blooms of Aphanizomenon flos-aquae appeared in Upper Klamath Lake. Furthermore, when flow from the marsh was re-established with the first major winter rains in November or December, Aphanizomenon flos-aquae abruptly ceased to grow in Upper Klamath Lake. Further studies are planned to determine whether this correlation is causal or coincidental. Title: The Chemical and biological impact of Klamath Marsh on the Williamson River, Oregon Author: Perdue, Edward M. Year: 1981, 2005 A comparative study of the Williamson River (before and after passage through Klamath Marsh) and the Sprague River (which is a major tributary of the Williamson River) in South Central Oregon has provided substantial insight into the effects of a marsh environment on the transport of iron and aquatic humus in river water. In the Sprague River and in the pre-marsh Williamson River, iron is transported primarily as 0.80 ym suspended particulate material. In Klamath Marsh, this coarse particulate material is "weathered11, yielding iron-aquatic humus "complexes'1. Thus, most iron and aquatic humus in the post-marsh Williamson River are in the 0.025 ?m size fraction. Presumably, other trace metals would be similarly affected. Klamath Marsh serves as an important source of biologically derived solutes such as amino acids and sugars. Fractionation studies have shown that amino acids are almost exclusively humic-bound in the Will-iamson River system, while sugars may be present as either polysacchar-ides (PS) or humic-bound saccharides (HS). The PS/HS ratio may reflect the relative importance of autochthonous and allochthonous sources of sugars. Major solute composition strongly indicates that ground waters flowing into the pre-marsh Williamson River and the Sprague River are derived from a different source than are ground waters which enter the post-marsh Williamson River from Big Springs, Spring Creek, and from unidentified springs below Klamath Marsh. Nutrient concentrations (H4SiO4, NO3, PO43) are significantly higher in spring waters than elsewhere in the system. While nitrate levels (3-11 ?m) were somewhat low, phosphate levels (1-3 ?m) were quite high throughout the Williamson River system. There was some evidence for nitrogen limitation of algal growth in the pre-marsh Williamson River. While Fragilaria construens was dominant throughout the Williamson River system, several Navicula spp. were restricted to the pre-marsh Williamson River and several Fragilaria spp. and Nitzschia, spp. were found only in the post-marsh Williamson River. In Upper Klamath Lake, Stephanodiscus astrea minuta, Fragilaria construens, and Aphanizomenon flos-aquae appeared in succession, with nuisance blooms of the latter organism occurring July-November. The cessation of flow of humic-rich water from Klamath Marsh during the summer months drastically decreased the flux of aquatic humus, iron, amino acids, and other marsh-derived solutes in the post-marsh Williamson River. At the time of cessation of flow from Klamath Marsh, nuisance blooms of Aphanizomenon flos-aquae appeared in Upper Klamath Lake. Furthermore, when flow from the marsh was re-established with the first major winter rains in November or December, Aphanizomenon flos-aquae abruptly ceased to grow in Upper Klamath Lake. Further studies are planned to determine whether this correlation is causal or coincidental. Close

• 960. [Image] Histopathological changes in gills of Lost River suckers (Deltistes luxatus) exposed to elevated ammonia and elevated pH

  	Lease, Hilary M., Histopathological Changes in Gills of Lost River Suckers (Deltistes luxatus) Exposed to Elevated Ammonia and Elevated pH, M.S., Department of Zoology and Physiology, December, 2000. ...
  	Citation × Citation Citation Abstract Copy Title: Histopathological changes in gills of Lost River suckers (Deltistes luxatus) exposed to elevated ammonia and elevated pH Author: Lease, Hilary Marian Year: 2000, 2008, 2005 Lease, Hilary M., Histopathological Changes in Gills of Lost River Suckers (Deltistes luxatus) Exposed to Elevated Ammonia and Elevated pH, M.S., Department of Zoology and Physiology, December, 2000. The Lost River sucker {Deltistes luxatus) is a federally listed, endangered fish species endemic to Upper Klamath Lake?a large, shallow hypereutrophic lake in southern Oregon. Sucker population declines in the lake over the past few decades are thought to be partly attributable to extreme water quality conditions, including elevated ammonia concentrations and elevated pH, that occur during summer cyanobacterial blooms. I analyzed structural changes in gills of larval Lost River suckers after they were exposed to elevated pH and elevated ammonia concentrations in chronic toxicity tests conducted in the laboratory. Histopathological changes in sucker lamellae were observed at ammonia concentrations that did not significantly decrease survival, growth, whole-body ion content, or swimming performance. Structural changes that I evaluated included O2 diffusion distance, lamellar thickness, hyperplasic and hypertrophic mucous cells, and infiltration of white blood cells into the lymphatic space. The increases in diffusion distance and lamellar thickness were statistically significant (P < 0.05). These gill changes are indicative of potentially compromised respiratory and ionoregulatory capacity. Because in this species gill structural changes appear to be a more sensitive indicator of stress in eutrophic water quality conditions than are the more traditional sublethal indices, gill histopathology might be useful for monitoring the health of Lost River suckers in Upper Klamath Lake. Title: Histopathological changes in gills of Lost River suckers (Deltistes luxatus) exposed to elevated ammonia and elevated pH Author: Lease, Hilary Marian Year: 2000, 2008, 2005 Lease, Hilary M., Histopathological Changes in Gills of Lost River Suckers (Deltistes luxatus) Exposed to Elevated Ammonia and Elevated pH, M.S., Department of Zoology and Physiology, December, 2000. The Lost River sucker {Deltistes luxatus) is a federally listed, endangered fish species endemic to Upper Klamath Lake?a large, shallow hypereutrophic lake in southern Oregon. Sucker population declines in the lake over the past few decades are thought to be partly attributable to extreme water quality conditions, including elevated ammonia concentrations and elevated pH, that occur during summer cyanobacterial blooms. I analyzed structural changes in gills of larval Lost River suckers after they were exposed to elevated pH and elevated ammonia concentrations in chronic toxicity tests conducted in the laboratory. Histopathological changes in sucker lamellae were observed at ammonia concentrations that did not significantly decrease survival, growth, whole-body ion content, or swimming performance. Structural changes that I evaluated included O2 diffusion distance, lamellar thickness, hyperplasic and hypertrophic mucous cells, and infiltration of white blood cells into the lymphatic space. The increases in diffusion distance and lamellar thickness were statistically significant (P < 0.05). These gill changes are indicative of potentially compromised respiratory and ionoregulatory capacity. Because in this species gill structural changes appear to be a more sensitive indicator of stress in eutrophic water quality conditions than are the more traditional sublethal indices, gill histopathology might be useful for monitoring the health of Lost River suckers in Upper Klamath Lake. Close