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Effects Determinations for the California Red-legged Frog and other California Listed Species

2,4-D Acephate Acrolein Aldicarb Alachlor Aluminum Phosphide Atrazine Azinphos methyl Bensulide Bifenthrin
Bromacil Brodifacoum Bromadiolone Bromethalin Carbaryl Carbofuran Captan Chlorophacinone Chloropicrin Chlorpyrifos
Chlorothalonil Cholecalciferol Cyfluthrin and Beta-Cyfluthrin DCPA Deltamethrin Diazinon Dicofol Difenacoum Difethialone Diflubenzuron
Dimethoate Diuron Diphacinone Disulfoton Diquat Dibromide Endosulfan EPTC Esfenvalerate Fenamiphos Glyphosate
Hexazinone Imazapyr Iprodione Lambda-Cyhalothrin Linuron Magnesium Phosphide Malathion Mancozeb and Maneb Mancozeb Maneb
Metam sodium Methamidiphos Methidathion Metolachlor Methomyl Methoprene Methyl Bromide Methyl parathion Molinate Myclobutanil
Naled Norflurazon Oryzalin Oxamyl Oxydemeton Methyl Oxyfluorfen Paraquat Permethrin Pendimethalin Pentachloronitrobenzene (PCNB)
Phorate Phosmet Potassium Prometryn Prometryn Propargite Propanil Propyzamide Rotenone S-Metolachlor
Sodium Nitrates Simazine Strychnine Telone Tralomethrin Tribufos Thiobencarb Triclopyr Trifluralin Vinclozolin
Zinc Phosphide Warfarin Ziram              
Quick Resources

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Effects Determination for 2,4-D and the California Red-legged Frog and Alameda Whipsnake

Transmittal Letter (PDF) (2 pp, 125K) from Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division to Bryan Arroyo, Acting Assistant Director for Endangered Species, U.S. Fish and Wildlife Service (2/20/09)

Effects Memorandum (PDF) (2 pp, 104.53K) from Christine Hartless, Environmental Fate and Effects Division to Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division (2/20/09)

2,4-D Analysis (PDF) (184 pp, 2.08MB) Risks of 2,4-D Use to the Federally Threatened California Red-legged Frog and the Alameda Whipsnake (2/20/09)

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Effects Determination for Acephate and the Bay Checkerspot Butterfly, California Clapper Rail, California Fresh Water Shrimp, California Tiger Salamander, Salt Marsh Harvest Mouse, San Francisco Garter Snake, San Joaquin Kit Fox, and Valley Elderberry Longhorn Beetle

Transmittal Letter (PDF) (2 pp, 60K) from Anita Pease, Associate Director, Environmental Fate and Effects Division to Gary Frazer, Assistant Director for Endangered Species, U.S. Fish and Wildlife Service (12/19/2011)

Effects Memorandum (PDF) (3 pp, 74K) from Jean Holmes, Environmental Fate and Effects Division to Anita Pease, Associate Director, Environmental Fate and Effects Division (12/19/2011)

Acephate Analysis (PDF) (199 pp, 1.87MB) Beetle (Desmocerus californicus dimorphus), and California Tiger Salamander (Ambystoma californiense), Central California Distinct Population Segment and the Federally Endangered California Clapper Rail (Rallus longirostris obsoletus), California Freshwater Shrimp (Syncaris pacifica), California Tiger Salamander (Ambystoma californiense) Sonoma County Distinct Population Segment and Santa Barbara County Distinct Population Segment, Salt Marsh Harvest Mouse (Reithrodontomys raviventris), San Francisco Garter Snake (Thamnophis sirtalis tetrataenia), and San Joaquin Kit Fox (Vulpes macrotis mutica) (12/19/2011)

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Effects Determination for Acephate and the California Red-legged Frog

Transmittal Letter (PDF) (2 pp, 32.1K) from Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division to Bryan Arroyo, Acting Assistant Director for Endangered Species, U.S. Fish and Wildlife Service (7/20/07)

Effects Memorandum (PDF) (2 pp, 102.5K) from Donna Randall, Environmental Fate and Effects Division to Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division (07/19/07)

Acephate Analysis (PDF) (122 pp, 2.01MB) Risks of Acephate Use to the Federally Threatened California Red-legged Frog of appendices) (7/19/07)

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Effects Determination for Acrolein and the Alameda Whipsnake

Transmittal Memo (PDF) (2 pp, 43K) from Anita Pease, Associate Director, Environmental Fate and Effects Division to Gary Frazer, Assistant Director for Endangered Species, U.S. Fish and Wildlife Service (09/26/2010)

Effects Memo (PDF) (2 pp, 53K) from Thomas Steeger, Ph.D., Environmental Fate and Effects Division to Anita Pease, Associate Director, Environmental Fate and Effects Division (09/16/2011)

Acrolein Effects Determination (PDF) (89 pp, 818K) Risks of Acrolein Use to Federally Threatened Alameda Whipsnake (Masticophis lateralis euryxanthus) (09/16/2011)

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Effects Determination for Alachlor and the California Red-legged Frog and the Delta Smelt

Transmittal Letter (PDF) (2 pp, 58.27K) from Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division to Bryan Arroyo, Acting Assistant Director for Endangered Species, U.S. Fish and Wildlife Service (June 17, 2009)

Effects Memorandum (PDF) (2 pp, 58.2K from Melissa Panger, Environmental Fate and Effects Division to Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division (June 15, 2009)

Alachlor Analysis (PDF) (132 pp, 2.21MB) Potential Risks of Alachlor Use to the Federally Threatened California Red-legged Frog (Rana aurora draytonii) and Delta Smelt (Hypomesus transpacificus) (June 15, 2009)

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Effects Determination for Aldicarb for the Valley Elderberry Longhorn Beetle and the San Joaquin Kit Fox

Transmittal Letter (PDF) (2 pp, 58K) from Steven Bradbury Ph.D, Director, Office of Pesticide Programs to Gary Frazer, Assistant Director for Endangered Species, U.S. Fish and Wildlife Service (03/30/2012)

Effects Memorandum (PDF) (2 pp, 199K) from Jean Holmes, DVM, Environmental Fate and Effects Division to Anita Pease, Associate Director, Environmental Fate and Effects Division (03/28/2012)

Aldicarb Analysis (PDF) (85 pp, 750K) Risks of Aldicarb Use to the Federally Threatened Valley Elderberry Longhorn Beetle (Desmocerus californicus dimorphus) and the Federally Endangered San Joaquin Kit Fox (Vulpes macrotis mutic) (03/28/2012)

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Effects Determination for Aldicarb and the California Red-legged Frog

Transmittal Letter (PDF) (3 pp, 33.4K) from Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division to Bryan Arroyo, Acting Assistant Director for Endangered Species, U.S. Fish and Wildlife Service (7/19/07)

Effects Memorandum (PDF) (2 pp, 96K) from Donna Randall, Environmental Fate and Effects Division to Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division (7/17/07)

Aldicarb Analysis (PDF) (118 pp, 1.92MB) Risks of Aldicarb Use to the Federally Threatened California Red-legged Frog (7/17/07)

Submission from Bayer CropScience (PDF) (139 pp, 8.1MB) Report on the Effects Determination for the California Red-Legged Frog Potentially Exposed to Aldicarb (5/8/07)

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Effects Determination for Aluminum Phosphide and the Alameda Whipsnake, San Francisco Garter Snake, San Joaquin Kit Fox and the California Tiger Salamander

Transmittal Letter (PDF) (2 pp, 53K) from Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division to Gary Frazer, Assistant Director for Endangered Species, U.S. Fish and Wildlife Service (12/30/2010)

Effects Memorandum (PDF) (2 pp, 42K) Edward Odenkirchen, ERB1, Environmental Fate and Effects Division to Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division (12/29/2010)

Aluminum and Magnesium Phosphides Assessment (PDF) (51 pp, 663K) Risks of Aluminum and Magnesium Phosphides Uses to the
Alameda Whipsnake, San Francisco Garter Snake, San Joaquin Kit Fox, and California Tiger Salamander (12/29/2010)

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Effects Determination for Atrazine and the California Red-legged Frog and the Delta Smelt

Transmittal Letter (PDF) (2 pp, 127.84K) from Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division to Bryan Arroyo, Acting Assistant Director for Endangered Species, U.S. Fish and Wildlife Service (2/20/09)

Effects Memorandum (PDF) (2 pp, 77.87K) from Stephanie Syslo, Environmental Fate and Effects Division to Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division (2/19/09)

Atrazine Analysis (PDF) (136 pp, 1.60MB) Risks of Atrazine Use to the Federally Threatened California Red-legged Frog and the Delta Smelt (2/19/09)

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Effects Determination for Azinphos methyl and the San Francisco Garter Snake, San Joaquin Kit Fox, Valley Elderberry Longhorn Beetle, California Clapper Rail, California Tiger Salamander, and Bay Checkerspot Butterfly SFBAY

Transmittal Letter (PDF) (2 pp, 46K) from Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division to Gary Frazer, Assistant Director for Endangered Species, U.S. Fish and Wildlife Service (3/30/2011)

Effects Memorandum and Analysis (inclusive of appendices and attachments) (PDF) (19 pp, 947K) from Melissa Panger, Ph.D.,Senior Biologist, Environmental Fate and Effects Division to Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division (3/2/2011)

Effects Determination for Azinphos methyl and the California Red-legged Frog

Transmittal Letter (PDF) (2 pp, 33K) from Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division to Bryan Arroyo, Acting Assistant Director for Endangered Species, U.S. Fish and Wildlife Service (7/19/07)

Effects Memorandum (PDF) (2 pp, 75K) from Stephanie Syslo, Environmental Fate and Effects Division to Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division (7/17/07)

Azinphos methyl Analysis (PDF) (116 pp, 2.40MB) Risks of Azinphos methyl Use to the Federally Threatened California Red-legged Frog (7/17/07)

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Effects Determination for Bensulide and the Bay Checkerspot Butterfly, California Clapper Rail, California Freshwater Shrimp, California Tiger Salamander, Delta Smelt, San Francisco Garter Snake, Tidewater Goby, and Valley Elderberry Longhorn Beetle

Transmittal Letter (PDF) (2 pp, 54K) from Steven Bradbury, Director, Office of Pesticide Programs to Gary Frazer, Assistant Director for Endangered Species, U.S. Fish and Wildlife Service (06/29/2012)

Effects Memorandum (PDF) (3 pp, 55K) from Edward Odenkirchen, Senior Science Advisor, Environmental Fate and Effects Division to Anita Pease, Associate Director, Environmental Fate and Effects Division (06/28/2012)

Bensulide Analysis (PDF) (163 pp, 1.36MB): Risks of Bensulide Use to the Federally Threatened Bay Checkerspot Butterfly (Euphydryas editha bayensis), Delta Smelt (Hypomesus transpacificus), California Tiger Salamander (Ambystoma californiense) Central California Distinct Population Segment, and Valley Elderberry Longhorn Beetle (Desmocerus californicus dimorphus), And the Federally Endangered California Clapper Rail (Rallus longirostris obsoletus), California Freshwater Shrimp (Syncaris pacifica), California Tiger Salamander (Ambystoma californiense) Sonoma County Distinct Population Segment and Santa Barbara County Distinct Population Segment, San Francisco Garter Snake (Thamnophis sirtalis tetrataenia), and Tidewater Goby (Eucyclogobius newberryi) Pesticide Effects Determinations (06/28/2012)

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Effects Determination for Bensulide and the California Red-legged Frog

Transmittal Letter (PDF) (2 pp, 31.50K) from Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division to Bryan Arroyo, Acting Assistant Director for Endangered Species, U.S. Fish and Wildlife Service (10/22/07)

Effects Memorandum (PDF) (2 pp, 106K) from Donna Randall, Environmental Fate and Effects Division to Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division (10/18/07)

Bensulide Analysis (PDF) (98 pp, 4.67MB) Risks of Bensulide Use to the Federally Threatened California Red-legged Frog (10/18/07)

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Effects Determination for Bifenthrin and the Bay Checkerspot Butterfly, Valley Elderberry Longhorn Beetle, California Tiger Salamander, Delta Smelt, California Clapper Rail, California Freshwater Shrimp, San Francisco Garter Snake, and Tidewater Goby

Transmittal Letter (PDF) (2 pp, 59K) from Donald Brady, Director, Environmental Fate and Effects Division to Gary Frazer, Assistant Director for Endangered Species, U.S. Fish and Wildlife Service (12/27/2012)

Effects Memorandum (PDF) (3 pp, 64K) from Mah T. Shamim, Ph.D., Environmental Fate and Effects Division to Anita Pease, Associate Director, Environmental Fate and Effects Division (12/27/2012)

Bifenthrin Analysis (PDF) (265 pp, 3.27MB) Risks of Bifenthrin Use to Federally Threatened Bay Checkerspot Butterfly (Euphydryas editha bayensis), Valley Elderberry Longhorn Beetle (Desmocerus californicus dimorphus), California Tiger Salamander (Ambystoma californiense), Central California Distinct Population Segment, and Delta Smelt (Hypomesus transpacificus), And the Federally Endangered California Clapper Rail (Rallus longirostris obsoletus), California Freshwater Shrimp (Syncaris pacificus), California Tiger Salamander (Ambystoma californiense) Sonoma County Distinct Population Segment and Santa Barbara County Distinct Population Segment, San Francisco Garter Snake (Thamnophis sirtalis tetrataenia), and Tidewater Goby (Eucyclogobius newberryi) (12/27/2012)

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Effects Determination for Brodifacoum and the Alameda Whipsnake, Salt Marsh Harvest Mouse, and San Joaquin Kit Fox

Transmittal Letter (PDF) (2 pp, 58K) from Steven Bradbury Ph.D, Director, Office of Pesticide Programs to Gary Frazer, Assistant Director for Endangered Species, U.S. Fish and Wildlife Service (03/30/2012)

Effects Memorandum (PDF) (2 pp, 37K) from Mah T. Shamim, Ph.D, Environmental Fate and Effects Division to Anita Pease, Associate Director, Environmental Fate and Effects Division (03/30/2012)

Brodifacoum Analysis (PDF) (135 pp, 1.66 MB) Risks of Brodifacoum Use to the Federally Threatened Alameda Whipsnake (Masticophis lateralis euryxanthus), and the Federally Endangered Salt Marsh Harvest Mouse (Reithrodontomys raviventris), and San Joaquin Kit Fox (Vulpes macrotis mutica) (03/30/2012)

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Effects Determination for Bromacil and the California Red-legged Frog

Transmittal Letter (PDF) (2 pp, 31K) from Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division to Bryan Arroyo, Acting Assistant Director for Endangered Species, U.S. Fish and Wildlife Service (10/22/07)

Effects Memorandum (PDF) (2 pp, 82K) from Thomas Steeger, PhD, Senior Biologist, Environmental Fate and Effects Division to Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division (10/19/07)

Bromacil Analysis (PDF) (118 pp, 1.70MB) Risks of Bromacil Use to the Federally Threatened California Red-legged Frog (10/19/07)

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Effects Determination for Bromadiolone and the Alameda Whipsnake, Salt Marsh Harvest Mouse, and San Joaquin Kit Fox

Transmittal Letter (PDF) (2 pp, 135K) from Anita Pease, Associate Director, Environmental Fate and Effects Division to Gary Frazer, Assistant Director for Endangered Species, U.S. Fish and Wildlife Service (09/30/2011)

Effects Memorandum (PDF) (2 pp, 433K) from Edward Odenkirchen, Environmental Fate and Effects Division to Anita Pease, Associate Director, Environmental Fate and Effects Division (09/28/2011)

Bromadiolone Effects Determination (PDF) (98 pp, 1.23MB) Risks of Bromadiolone Use to the Federally Threatened Alameda Whipsnake, the Federally Endangered Salt Marsh Harvest Mouse, and the Federally Endangered San Joaquin Kit Fox (09/28/2011)

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Effects Determination for Risk of Bromethalin to the Alameda Whipsnake and the Salt Marsh harvest Mouse

Bromethalin SF Bay Transmittal Letter (PDF) (2pp, 55K) from Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division to Gary Frazer, Assistant Director for Endangered Species, U.S. Fish and Wildlife Service (3/30/2011)

Bromethalin SF Bay Species Assessment (PDF) (88 pp, 1,435K) Risks of Bromethalin Use to the Alameda Whipsnake and Salt Marsh Harvest Mouse (3/25/2011)

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Effects Determination for Carbaryl and the Delta Smelt

Transmittal Letter (PDF) (2 pp, 510K) from Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division to Gary Frazer, Assistant Director for Endangered Species, U.S. Fish and Wildlife Service (6/30/2010)

Effects Memorandum (PDF) (1 pg, 32K) from Thomas Steeger, Environmental Fate and Effects Division to Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division (6/28/2010)

Carbaryl Analysis (PDF) (117 pp, 1.20MB): Risks of Carbaryl Use to Federally Threatened Delta Smelt (Hypomesus transpacificus) (6/28/2010)

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Effects Determination for Carbaryl and the California Red-legged Frog

Transmittal Letter (PDF) (2 pp, 33K) from Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division to Bryan Arroyo, Acting Assistant Director for Endangered Species, U.S. Fish and Wildlife Service (10/22/07)

Effects Memorandum (PDF) (2 pp, 59.3K) from Thomas Steeger, PhD, Senior Biologist, Environmental Fate and Effects Division to Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division (10/19/07)

Carbaryl Analysis (PDF) (160 pp, 1.74MB) Risks of Carbaryl Use to the Federally Threatened California Red-legged Frog (10/19/07)

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Effects Determination for Carbofuran and the Delta Smelt, San Francisco Garter Snake, San Joaquin Kit Fox, and Valley Elderberry Longhorn Beetle

Determination of No Effect (PDF) (2 pp, 38K) from Thomas Steeger, PhD, Senior Biologist, Environmental Fate and Effects Division to Arthur-Jean B.Williams, Associate Director, Environmental Fate and Effects Division (12/21/10)

Effects Determination for Captan and the California Red-legged Frog

Transmittal Letter (PDF) (2 pp, 30.99K) from Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division to Bryan Arroyo, Acting Assistant Director for Endangered Species, U.S. Fish and Wildlife Service (10/22/07)

Effects Memorandum (PDF) (2 pp, 98.71K) from Christine Hartless, Biologist, Environmental Fate and Effects Division to Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division (10/18/07)

Captan Analysis (PDF) (127 pp, 3.11MB) Risks of Captan Use to the Federally Threatened California Red-legged Frog (10/18/07)

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Effects Determination for Chloropicrin and the California Red-legged Frog

Transmittal Letter (PDF) (2 pp, 32.1K) from Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division to Bryan Arroyo, Acting Assistant Director for Endangered Species, U.S. Fish and Wildlife Service (7/19/07)

Effects Memorandum (PDF) (2 pp, 57.6K) from Mah Shamim, Ph.D., Environmental Fate and Effects Division to Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division (07/18/07)

Chloropicrin Analysis (PDF) (190 pp, 7.18MB): Risks of Chloropicrin Use to the Federally Threatened California Red-legged Frog (inclusive of appendices) (7/19/07)

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Effects Determination for Chlorophacinone and the Alameda Whipsnake, California Tiger Salamander, Salt Marsh Harvest Mouse, and San Joaquin Kit Fox

Transmittal Letter (PDF) (2 pp, 50.71KB) from Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division to Gary Frazer, Assistant Director for Endangered Species, U.S. Fish and Wildlife Service (06/30/2011)

Effects Memorandum (PDF) (2 pp, 44.78KB) from Christine Hartless, Environmental Fate and Effects Division to Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division (06/29/2011)

Chlorophacinone Analysis (PDF) (111 pp, 878.36KB) Risks of Chlorophacinone Use to the Alameda Whipsnake, California Tiger Salamander, Salt Marsh Harvest Mouse, and San Joaquin Kit Fox (06/29/2011)

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Effects Determination for Chlorpyrifos and the California red-legged frog, Delta smelt, California tiger salamander, San Francisco garter snake, California clapper rail, Salt marsh harvest mouse, Bay checkerspot butterfly, Valley elderberry longhorn beetle, San Joaquin kit fox and California freshwater shrimp

Transmittal Letter (PDF) (2 pp, 59.79K) from Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division to Gary Frazer, Assistant Director for Endangered Species, U.S. Fish and Wildlife Service (10/20/09)

Effects Memorandum (PDF) (2 pp, 62.66KB) from Stephanie Syslo, Environmental Fate and Effects Division to Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division (October 16, 2009)

Chlorpyrifos Analysis (PDF) (179 pp, 1.79MB) Risks of Chlorpyrifos Use to the Federally Threatened California Red-legged Frog (October 16, 2009)

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Effects Determinations for Chlorothalonil (PC Code 081901) Relative to the Bay Checkerspot Butterfly, California Tiger Salamander, Delta Smelt, California Clapper Rail, California Freshwater Shrimp, San Francisco Garter Snake, and Tidewater Goby and Designated Critical Habitat for the Bay Checkerspot Butterfly, California Tiger Salamander, Delta Smelt, and Tidewater Goby

Transmittal Memorandum (PDF) (2 pp, 56K) from Donald Brady, Environmental Fate and Effects Division to Gary Frazer, Assistant Director for Endangered Species, U.S. Fish and Wildlife Service (12/27/2012)

Effects Memorandum (PDF) (4 pp, 72K) from Melissa Panger, Environmental Fate and Effects Division to Donald Brady, Division Director, Environmental Fate and Effects Division (12/27/2012)

Chlorothalonil Analysis (PDF) (220 pp, 2.36MB) Risks of Chlorothalonil Use to Federally Threatened Bay Checkerspot Butterfly (Euphydryas editha bayensis), California Tiger Salamander (Ambystoma californiense), Central California Distinct Population Segment, and Delta Smelt (Hypomesus transpacificus, And the Federally Endangered California Clapper Rail (Rallus longirostris obsoletus), California Freshwater Shrimp (Syncaris pacifica), California Tiger Salamander (Ambystoma californiense) Sonoma County Distinct Population Segment and Santa Barbara County Distinct Population Segment, San Francisco Garter Snake (Thamnophis sirtalis tetrataenia), and Tidewater Goby (Eucyclogobius newberryi) (12/27/2012)

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Effects Determination for Chlorothalonil and the California Red-legged Frog

Transmittal Letter (PDF) (2 pp, 33K) from Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division to Bryan Arroyo, Acting Assistant Director for Endangered Species, U.S. Fish and Wildlife Service (10/22/07)

Effects Memorandum (PDF) (2 pp, 62.2K) from Stephanie Syslo, Environmental Fate and Effects Division to Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division (10/19/07)

Chlorothalonil Analysis (PDF) (140 pp, 2.43MB) Risks of Chlorothalonil Use to the Federally Threatened California Red-legged Frog (10/19/07)

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Effects Determination for Cholecalciferol and the Salt Marsh Harvest Mouse

Transmittal Letter (PDF) (2 pp, 580K) from Anita Pease, Associate Director, Environmental Fate and Effects Division to Gary Frazer, Assistant Director for Endangered Species, U.S. Fish and Wildlife Service (12/28/11)

Effects Memorandum (PDF) (2 pp, 215K) from Thomas Steeger, Senior Science Advisor, Environmental Fate and Effects Division to Anita Pease, Associate Director, Environmental Fate and Effects Division (12/28/2011)

Cholecalciferol Analysis (PDF) (58 pp, 6.40MB) Risks of Cholecalciferol Use to the Federally Threatened Bay Salt Marsh Harvest Mouse (Reithrodontomys raviventris) (12/28/11)

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Effects Determination for Cyfluthrin and Beta-Cyfluthrin and the Federally Threatened Bay Checkerspot Butterfly (Euphydryas editha bayensis), Valley Elderberry Longhorn Beetle (Desmocerus californicus dimorphus), California Tiger Salamander (Ambystoma californiense), Central California Distinct Population Segment, and Delta Smelt (Hypomesus transpacificus), and the Federally Endangered California Clapper Rail (Rallus longirostris obsoletus), California Freshwater Shrimp (Syncaris pacificus), California Tiger Salamander (Ambystoma californiense) Sonoma County Distinct Population Segment and Santa Barbara County Distinct Population Segment, San Francisco Garter Snake (Thamnophis sirtalis tetrataenia), and Tidewater Goby (Eucyclogobius newberryi)

Transmittal Memo (PDF) (2 pp, 272K) from Donald Brady, Director, Environmental Fate and Effects Division to Gary Frazer, Assistant Director for Endangered Species, U.S. Fish and Wildlife Service (03/28/2013)

Effects Memorandum (PDF) (2 pp, 199K) from Melissa Panger, Environmental Fate and Effects Division to Anita Pease, Associate Director, Environmental Fate and Effects Division (03/28/2013)

Cyfluthrin and Beta-Cyfluthrin Analysis (PDF) (164 pp, 1.76MB) Risks of Cyfluthrin and Beta-Cyfluthrin Use to Federally Threatened Bay Checkerspot Butterfly (Euphydryas editha bayensis), Valley Elderberry Longhorn Beetle (Desmocerus californicus dimorphus), California Tiger Salamander (Ambystoma californiense), Central California Distinct Population Segment, and Delta Smelt (Hypomesus transpacificus), and the Federally Endangered California Clapper Rail (Rallus longirostris obsoletus), California Freshwater Shrimp (Syncaris pacificus), California Tiger Salamander (Ambystoma californiense) Sonoma County Distinct Population Segment and Santa Barbara County Distinct Population Segment, San Francisco Garter Snake (Thamnophis sirtalis tetrataenia), and Tidewater Goby (Eucyclogobius newberryi) (03/28/2013)

Effects Determination for DCPA and the California Red-legged Frog

Transmittal Letter (PDF) (2 pp, 121K) from Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division to Bryan Arroyo, Acting Assistant Director for Endangered Species, U.S. Fish and Wildlife Service (2/20/09)

Effects Memorandum (PDF) (2 pp, 80K) from Jean Holmes, Environmental Fate and Effects Division to Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division (2/19/09)

DCPA Analysis (PDF) (176 pp, 1.59MB) Risks of DCPA Use to the Federally Threatened California Red-legged Frog (2/19/09)

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Effects Determination for Deltamethrin and the Bay Checkerspot Butterfly, Valley Elderberry Longhorn Beetle, California Tiger Salamander, Delta Smelt, California Clapper Rail, California Freshwater Shrimp, San Francisco Garter Snake, and Tidewater Goby

Transmittal Letter (PDF) (2 pp, 246K) from Donald Brady, Director, Environmental Fate and Effects Division to Gary Frazer, Assistant Director for Endangered Species, U.S. Fish and Wildlife Service (03/28/2013)

Effects Memorandum (PDF) (3 pp, 314K) from Mah T. Shamim, Ph.D., Environmental Fate and Effects Division to Anita Pease, Associate Director, Environmental Fate and Effects Division (03/28/2013)

Deltamethrin Analysis (PDF) (224 pp, 3.12MB) Risks of Deltamethrin Use to Federally Threatened Bay Checkerspot Butterfly (Euphydryas editha bayensis), Valley Elderberry Longhorn Beetle (Desmocerus californicus dimorphus), California Tiger Salamander (Ambystoma californiense), Central California Distinct Population Segment, and Delta Smelt (Hypomesus transpacificus), And the Federally Endangered California Clapper Rail (Rallus longirostris obsoletus), California Freshwater Shrimp (Syncaris pacificus), California Tiger Salamander (Ambystoma californiense) Sonoma County Distinct Population Segment and Santa Barbara County Distinct Population Segment, San Francisco Garter Snake (Thamnophis sirtalis tetrataenia), and Tidewater Goby (Eucyclogobius newberryi) (03/28/2013)

Effects Determinations for Diazinon relative to the Delta Smelt and Tidewater Goby

Transmittal Letter (PDF) (2 pp, 56K) from Steven Bradbury Ph.D, Director, Office of Pesticide Programs to Gary Frazer, Assistant Director for Endangered Species, U.S. Fish and Wildlife Service (03/30/2012)

Effects Determinations Memo (PDF) (2 pp, 41K) from Thomas Steeger, Environmental Fate and Effects Division to Anita Pease, Associate Director, Environmental Fate and Effects Division (03/28/2012)

Main Effects Determination Chapter (PDF) (163 pp, 2.06MB) Risks of Diazinon Use to Federally Threatened Delta Smelt (Hypomesus transpacificus) and the Federally Endangered Tidewater Goby (Eucyclogobius newberryi) (03/28/2012)

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Effects Determination for Diazinon and the California Red-legged Frog

Transmittal Letter (PDF) (2 pp, 32.1K) from Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division to Bryan Arroyo, Acting Assistant Director for Endangered Species, U.S. Fish and Wildlife Service (7/18/07)

Effects Memorandum (PDF) (2 pp, 80.1K) from Thomas Steeger, Ph.D., Senior Biologist, Environmental Fate and Effects Division to Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division (07/17/07)

Diazinon Analysis (PDF) (162 pp, 1.77MB) Risks of Diazinon Use to the Federally Threatened California Red-legged Frog (7/17/07)

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Effects Determination for Dicofol and the California Red-legged Frog

Transmittal Letter (PDF) (2 pp, 64K) from Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division to Bryan Arroyo, Acting Assistant Director for Endangered Species, U.S. Fish and Wildlife Service (June 17, 2009)

Effects Memorandum (PDF) (1pp, 55K) from Thomas Steeger, Ph.D., Environmental Fate and Effects Division to Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division (June 15, 2009)

Dicofol Analysis (PDF) (147 pp, 1.24MB) Risks of Dicofol Use to the Federally Threatened California Red-legged Frog (June 15, 2009)

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Effects Determination for Difenacoum for the Alameda Whipsnake, the Salt Marsh Harvest Mouse, and the San Joaquin Kit Fox

Transmittal Letter (PDF) (2 pp, 55K) from Steven Bradbury Ph.D, Director, Office of Pesticide Programs to Gary Frazer, Assistant Director for Endangered Species, U.S. Fish and Wildlife Service (03/30/2012)

Effects Memorandum (PDF) (2 pp, 42K) from Stephanie Syslo, Environmental Scientist, Environmental Fate and Effects Division to Anita Pease, Associate Director, Environmental Fate and Effects Division (03/28/2012)

Difenacoum Analysis (PDF) (88 pp, 935K) Risks of Difenacoum Use To the Federally Threatened Alameda Whipsnake (Masticophis lateralis euryxanthus), the Federally Endangered Salt Marsh Harvest Mouse (Reithrodontomys raviventris), and the Federally Endangered San Joaquin Kit Fox (Vulpes macrotis mutica) (03/28/2012)

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Effects Determination for Difethialone and the Alameda Whipsnake, Salt Marsh Harvest Mouse, and San Joaquin Kit Fox

Transmittal Letter (PDF) (2 pp, 56K) from Anita Pease, Associate Director, Environmental Fate and Effects Division to Gary Frazer, Assistant Director for Endangered Species, U.S. Fish and Wildlife Service (09/30/2011)

Effects Memorandum (PDF) (2 pp, 40K) from Mah T. Shamim, Ph.D, Environmental Fate and Effects Division to Anita Pease, Associate Director, Environmental Fate and Effects Division (09/30/2011)

Difethialone Effects Determination (PDF) (106 pp, 3.71MB) Risks of Difethialone Use to the Federally Threatened Alameda Whipsnake (Masticophis lateralis euryxanthus), and the Federally Endangered Salt Marsh Harvest Mouse (Reithrodontomys raviventris), and San Joaquin Kit Fox (Vulpes macrotis mutica) (09/30/2011)

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Effects Determination for Diflubenzuron and the California Red-legged Frog

Transmittal Letter (PDF) (2 pp,56.05K) from Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division to Gary Frazer, Assistant Director for Endangered Species, U.S. Fish and Wildlife Service (October 20, 2009)

Effects Memorandum (PDF) (2 pp, 349K) from Edward Odenkirchen, Ph.D., Environmental Fate and Effects Division to Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division (October 19, 2009)

Diflubenzuron Analysis (PDF) (120 pp, 999.50K) Risks of Diflubenzuron Use to the Federally Threatened California Red-legged Frog (October 19, 2009)

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Effects Determination for Dimethoate and the California Red-legged Frog

Input from Cheminova (PDF) - Letter from Paul Whatling, Director of Regulatory Science, Cheminova, Inc., to Mr. Kelly Ballard, Office of Pesticide Programs, U.S. Environmental Protection Agency (July 31, 2012) (3 pp, 515K)

Input from Cheminova (PDF) - Cheminova's Comments on EPA's Dimethoate Effects Determination for the California Red-legged Frog (July 27, 2012) (143 pp, 27MB)

Input from Cheminova (PDF) - Refined Effects Determination for California Red-legged Frog Potentially Exposed to Dimethoate (July 27, 2012) (421 pp, 79.57MB)

Input from Cheminova (PDF) - Cheminova's Comments on EPA's Dimethoate Effects Determination for the California Red-legged Frog (July 8, 2009) (41 pp, 484K

Transmittal Letter (PDF) (2 pp, 33.3K) from Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division to Bryan Arroyo, Acting Assistant Director for Endangered Species, U.S. Fish and Wildlife Service (2/15/08)

Effects Memorandum (PDF) (1 p, 194K) from Thomas Steeger, Ph.D., Senior Biologist, Environmental Fate and Effects Division to Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division (1/31/08)

Dimethoate Analysis (PDF) (137 pp, 1.27MB) Risks of Dimethoate Use to the Federally Threatened California Red-legged Frog (1/31/08)

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Effects Determination for Diphacinone and the Alameda Whipsnake, California Tiger Salamander, Salt Marsh Harvest Mouse, and San Joaquin Kit Fox

Transmittal Letter (PDF) (2 pp, 49.04KB) from Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division to Gary Frazer, Assistant Director for Endangered Species, U.S. Fish and Wildlife Service (06/30/2011)

Effects Memorandum (PDF) (2 pp, 153KB) from Jean Holmes, Environmental Fate and Effects Division to Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division (6/21/2011)

Diphacinone Assessment (PDF) (94 pp, 6807KB) Risks of Diphacinone Use to the Federally Threatened Alameda Whipsnake (Masticophis lateralis euryxanthus), California Tiger Salamander (Ambystoma californiense), and the Federally Endangered Salt Marsh Harvest Mouse, California Tiger Salamander (Ambystoma californiense) Sonoma County Distinct Population Segment and Santa Barbara County Distinct Population Segment, and San Joaquin Kit Fox (Vulpes macrotis mutica) (6/21/2011)

Effects Determination for Disulfoton (PC Code 032501) Relative to the Bay Checkerspot Butterfly, Valley Elderberry Longhorn Beetle, California Tiger Salamander, California Clapper Rail, California Freshwater Shrimp, San Francisco Garter Snake, Delta Smelt, and Tidewater Goby.

Effects Memorandum (PDF) (6 pp, 177K) from Rosanna Louie-Juzwiak, Environmental Fate and Effects Division to Anita Pease, Associate Director, Environmental Fate and Effects Division (9/17/2012)

Effects Determination for Disulfoton and the California Red-legged Frog

Transmittal Letter (PDF) (2 pp, 132K) from Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division to Bryan Arroyo, Acting Assistant Director for Endangered Species, U.S. Fish and Wildlife Service (6/20/08)

Effects Memorandum (PDF) (2 pp, 70.69K) from Tom Bailey, Environmental Fate and Effects Division to Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division (6/20/08)

Disulfoton Analysis (PDF) (121 pp, 1.90MB) Potential Risks of Disulfoton Use to the Federally Threatened California Red-legged Frog (6/20/08)

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Effects Determination for Diquat Dibromide and the Delta Smelt

Transmittal Letter (PDF) (2 pp, 55K) from Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division to Gary Frazer, Assistant Director for Endangered Species, U.S. Fish and Wildlife Service (12/23/2010)

Effects Memorandum (PDF) (2 pp, 441K) from Christine Hartless, Environmental Fate and Effects Division to Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division (12/17/2010)

Diquat Dibromide Assessment (PDF) (95 pp, 947K): Risks of Diquat Dibromide Use to the Federally Listed Delta Smelt (12/17/2010)

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Effects Determination for Diuron and the California Red-legged Frog

Transmittal Letter (PDF) (2 pp, 121K) from Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division to Bryan Arroyo, Acting Assistant Director for Endangered Species, U.S. Fish and Wildlife Service (2/20/09)

Effects Memorandum (PDF) (2 pp, 69K) from Jean Holmes, DVM, MPH, Environmental Fate and Effects Division to Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division (2/18/09)

CRLF ESA Diuron (PDF) (135 pp, 1,609K) Risks of Diuron Use to the Federally Threatened California Red-legged Frog (2/18/09)

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Effects Determination for Endosulfan and the California Red-legged Frog and the San Francisco Bay Species

Transmittal Letter (PDF) (2 pp, 85K) from Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division to Bryan Arroyo, Acting Assistant Director for Endangered Species, U.S. Fish and Wildlife Service (June 19, 2009)

Effects Memorandum (PDF) (2 pp, 526K) from Mah Shamim, Environmental Fate and Effects Division to Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division (June 18, 2009)

Endosulfan Analysis (PDF) (242 pp, 2.76MB) Risks of Endosulfan Use to the Federally Threatened California Red-legged FrEog and SFBAY species (June 18, 2009)

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Effects Determination for EPTC and the Delta Smelt

Transmittal Letter (PDF) (2 pp, 60K) from Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division to Gary Frazer, Assistant Director for Endangered Species, U.S. Fish and Wildlife Service (03/31/2010)

Effects Memorandum (PDF) (2 pp, 35K) from Melissa Panger, Environmental Fate and Effects Division to Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division (03/29/2010)

EPTC Analysis (PDF) (121 pp, 1.43MB): Risks of EPTC Use to the Federally Threatened Delta Smelt (03/29/2010)

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Effects Determination for EPTC and the California Red-legged Frog

Transmittal Letter (PDF) (2 pp, 131K) from Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division to Bryan Arroyo, Acting Assistant Director for Endangered Species, U.S. Fish and Wildlife Service (6/20/08)

Effects Memorandum (PDF) (2 pp, 80.45K) from Tom Bailey, Environmental Fate and Effects Division to Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division (6/20/08)

EPTC (S-Ethyl dipropylthiocarbamate) Analysis (PDF) (127 pp, 184MB) Risks of EPTC Use to the Federally Threatened California Red-legged Frog (6/20/08)

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Effects Determination for Esfenvalerate and the California Red-legged Frog

Transmittal Letter (PDF) (2 pp, 33.2K) from Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division to Bryan Arroyo, Acting Assistant Director for Endangered Species, U.S. Fish and Wildlife Service (2/20/08)

Effects Memorandum (PDF) (2 pp, 89K) from Shannon Borges, Environmental Fate and Effects Division to Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division (2/19/08)

Esfenvalerate Analysis (PDF) (139 pp,  2.67MB) Risks of Esfenvalerate Use to the Federally Threatened California Red-legged Frog (2/19/08)

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Effects Determination for Fenamiphos and the California red-legged frog and other listed species

Effects Memorandum (PDF) (3 pp, 128K) from Thomas Steeger, Ph.D, Senior Scientist, Environmental Fate and Effects Division to Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division (2/9/09)

Effects Determination for Glyphosate and the California Red-legged Frog

Transmittal Letter (PDF) (2 pp, 129K) from Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division to Bryan Arroyo, Acting Assistant Director for Endangered Species, U.S. Fish and Wildlife Service (10-17-08)

Effects Memorandum (PDF) (2 pp, 87.01K) from Donna Randall, Environmental Fate and Effects Division to Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division (10/17/08)

Glyphosate Analysis (PDF) (180 pp, 276MB) Risks of Glyphosate Use to the Federally Threatened California Red-legged Frog (10/17/08)

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Effects Determination for Hexazinone and the California Red-legged Frog

Transmittal Letter (PDF) (2 pp, 32.9K) from Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division to Bryan Arroyo, Acting Assistant Director for Endangered Species, U.S. Fish and Wildlife Service (2/20/08)

Effects Memorandum (PDF) (2 pp, 74.8K) from Mah Shamim Ph.D., Chief, Environmental Risk Branch 5, Environmental Fate and Effects Division to Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division (2/20/08)

Hexazinone Analysis (PDF) (146 pp, 3.47MB) Risks of Hexazinone Use to the Federally Threatened California Red-legged Frog (2/20/08)

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Effects Determination for Imazapyr and the California Red-legged Frog

Transmittal Letter (PDF) (2 pp, 32.2K) from Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division to Bryan Arroyo, Acting Assistant Director for Endangered Species, U.S. Fish and Wildlife Service (7/19/07)

Effects Memorandum (PDF) (2 pp, 65.3K) from Anita Pease, Biologist, Environmental Fate and Effects Division to Arthur-Jean B. Williams, Associate Director, Environmental Ffate and Effects Division (7/17/07)

Imazapyr Analysis (PDF) (164 pp, 3.13MB) Risks of Imazapyr Use to the Federally Threatened California Red-legged Frog (7/17/07)

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Effects Determination for Iprodione and the California Red-legged Frog

Transmittal Letter (PDF) (2 pp, 57.77K) from Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division to Gary Frazer, Assistant Director for Endangered Species, U.S. Fish and Wildlife Service (10/20/09)

Effects Memorandum (PDF) (1 p, 43K) from Thomas Steeger, Senior Biologist, Environmental Fate and Effects Division to Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division (10/16/09)

Iprodione Analysis (PDF) (156 pp, 1.42MB) Risks of Iprodione Use to the Federally Threatened California Red-legged Frog (10/16/09)

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Effects Determination for Lambda-Cyhalothrin and the Bay Checkerspot Butterfly, Valley Elderberry Longhorn Beetle, California Tiger Salamander, California Clapper Rail, California Freshwater Shrimp, San Francisco Garter Snake, Delta Smelt, and Tidewater Goby

Transmittal Memo (PDF) (2 pp, 72K) from Donald Brady, Ph. D, Division Director for Environmental Fate and Effects Division, Office of Pesticide Programs to Gary Frazer, Assistant Director for Endangered Species, U. S. Fish and Wildlife Service (09/27/2012)

Effects Memorandum (PDF) (4 pp, 404K) from Edward Odenkirchen, Environmental Fate and Effects Division to Anita Pease, Assistant Division Director, Environmental Fate and Effects Division (09/24/2012)

Lambda-Cyhalothrin Analysis (PDF) (280 pp, 3MB) Risks of Lambda-Cyhalothrin Use to Federally Threatened Bay Checkerspot Butterfly (Euphydryas editha bayensis), Valley Elderberry Longhorn Beetle (Desmocerus californicus dimorphus), California Tiger Salamander (Ambystoma californiense) Central California Distinct Population Segment, and Delta Smelt (Hypomesus transpacificus) and the Federally Endangered California Clapper Rail (Rallus longirostris obsoletus), California Freshwater Shrimp (Syncaris pacificus), California Tiger Salamander (Ambystoma californiense) Sonoma County Distinct Population Segment and Santa Barbara County Distinct Population Segment, San Francisco Garter Snake (Thamnophis sirtalis tetrataenia), and Tidewater Goby (Euclyogobius newberryi) (09/30/2012)

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Effects Determination for Linuron and the California Red-legged Frog

Transmittal Letter (PDF) (2 pp, 126K) from Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division to Bryan Arroyo, Acting Assistant Director for Endangered Species, U.S. Fish and Wildlife Service (6/20/08)

Effects Memorandum (PDF) (2 pp, 78K) from Donna Randall, Environmental Fate and Effects Division to Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division (6/19/08)

Linuron Analysis (PDF) (113 pp, 1.24MB) Risks of Linuron Use to the Federally Threatened California Red-legged Frog (6/19/08)

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Effects Determination for Magnesium Phosphide and the Alameda Whipsnake, San Francisco Garter Snake, San Joaquin Kit Fox and the California Tiger Salamander

Transmittal Letter (PDF) (2 pp, 53K) from Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division to Gary Frazer, Assistant Director for Endangered Species, U.S. Fish and Wildlife Service (12/30/2010)

Effects Memorandum (PDF) (2 pp, 42K) Edward Odenkirchen, ERB1, Environmental Fate and Effects Division to Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division (12/29/2010)

Aluminum and Magnesium Phosphides Assessment (PDF) (51 pp, 663K) Risks of Aluminum and Magnesium Phosphides Uses to the
Alameda Whipsnake, San Francisco Garter Snake, San Joaquin Kit Fox, and California Tiger Salamander (12/29/2010)

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Effects Determination for Malathion and the Delta Smelt and California Tiger Salamander

Transmittal Letter (PDF) (2 pp, 59K) from Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division to Gary Frazer, Assistant Director for Endangered Species, U.S. Fish and Wildlife Service (09/30/2010)

Effects Memorandum (PDF) (2 pp, 42K) from Edward Odenkirchen, Environmental Fate and Effects Division to Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division (09/29/2010)

Malathion Analysis (PDF) (201 pp, 1101K) Risks of Malathion Use to the Federally Threatened Delta Smelt (Hypomesus transpacificus) and California Tiger Salamander (Ambystoma californiense), Central California Distinct Population Segment, and the Federally Endangered California Tiger Salamander, Santa Barbara County and Sonoma County Distinct Population Segments (09/29/2010)

Effects Determination for Malathion and the California Red-legged Frog

Transmittal Letter (PDF) (2 pp, 33K) from Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division to Bryan Arroyo, Acting Assistant Director for Endangered Species, U.S. Fish and Wildlife Service (10/22/07)

Effects Memorandum (PDF) (2pp, 50K) from Edward Odenkirchen, Senior Biologist, Environmental Fate and Effects Division to Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division (10/19/07)

Malathion Analysis (PDF) (272 pp, 6.80MB) Risks of Malathion Use to the Federally Threatened California Red-legged Frog (10/19/07)

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Effects Determination for Mancozeb and the California Tiger Salamander Ambystoma californiense

Transmittal Letter (PDF) (2 pp, 48KB) from Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division to Gary Frazer, Assistant Director for Endangered Species, U.S. Fish and Wildlife Service (06/30/2011)

Mancozeb Effects Memorandum (PDF) (2 pp, 34KB) from Mah Shamim, Environmental Fate and Effects Division to Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division (06/29/2011)

Mancozeb Analysis (PDF) (134 pp, 1.78MB) Risks of Mancozeb Use to the Federally Threatened California Tiger Salamander (Ambystoma californiense), Central California Distinct Population Segment and Federally Endangered California Tiger Salamander, Sonoma County and Santa Barbara County Distinct Population Segments (06/29/2011)

Effects Determination for Mancozeb and Maneb and the California Red-legged Frog

Transmittal Letter (PDF) (2 pp, 48.69KB) from Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division to Bryan Arroyo, Acting Assistant Director for Endangered Species, U.S. Fish and Wildlife Service (10/22/07)

Effects Memorandum (PDF) (2 pp,36.57KB) from Jean Holmes, DVM, MPH, Environmental Fate and Effects Division to Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division (10/18/07)

Mancozeb and Maneb Analysis (PDF) (143 pp, 3.95MB) Risks of Mancozeb and Maneb Use to the Federally Threatened California Red-legged Frog (10/17/07)

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Effects Determination for Maneb and the California Tiger Salamander (the Sonoma county, the Santa Barbara county, and the Central California Distinct Population Segments)

Transmittal Letter (PDF) (2 pp, 52.12KB) from Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division to Gary Frazer, Assistant Director for Endangered Species, U.S. Fish and Wildlife Service (06/30/2010)

Effects Memorandum (PDF) (2 pp, 40.27KB) from Mah Shamim, Environmental Fate and Effects Division to Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division (06/22/2011)

Maneb Analysis (inclusive of attachment) (PDF) (16 pp, 215.26KB) Risks of Maneb Use to Federally Threatened California Tiger Salamander (Ambystoma californiense) (Central California Distinct Population Segment) and Federally Endangered Sonoma County and Santa Barbara County Distinct Population Segments of California Tiger Salamander (06/22/2011)

Effects Determination for Metam Sodium and the California Tiger Salamander

Transmittal Letter (PDF) (2 pp, 48K) from Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division to Gary Frazer, Assistant Director for Endangered Species, U.S. Fish and Wildlife Service (12/30/2010)

Effects Memorandum (PDF) (2 pp, 33K) from Mah Shamim, Chief ERB5, Environmental Fate and Effects Division to Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division (12/29/2010)

Metam Sodium Assessment (PDF) (139 pp, 1.30MB) Risks of Metam Sodium Use to the Federally Threatened California Tiger Salamander (Ambystoma californiense) (Central California Distinct Population Segment) and Federally Endangered Sonoma County and Santa Barbara County Distinct Population Segments of California Tiger Salamander (12/29/2010)

Effects Determination for Metam sodium and the California Red-legged Frog

Transmittal Letter (PDF) (3 pp, 32.6K) from Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division to Bryan Arroyo, Acting Assistant Director for Endangered Species, U.S. Fish and Wildlife Service (7/20/07)

Effects Memorandum (PDF) (2 pp, 76.3K) from Mah Shamim, Ph.D., Environmental Fate and Effects Division to Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division (07/19/07)

Metam sodium Analysis (PDF) (237 pp, 7.74MB) Risks of Metam sodium Use to the Federally Threatened California Red-legged Frog (inclusive of appendices) (7/19/07)

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Effects Determination for Methamidophos and the Bay Checkerspot Butterfly, California Clapper Rail, California Fresh Water Shrimp, California Tiger Salamander, Delta Smelt, San Francisco Garter Snake, Tidewater Goby, Valley Elderberry Longhorn Beetle, and other Listed Species

Effects Memorandum (PDF) (6 pp, 249K) from Jean Holmes, Environmental Fate and Effects Division to Anita Pease, Associate Director, Environmental Fate and Effects Division (5/22/2012)

Effects Determination for Methamidiphos and the California Red-legged Frog

Transmittal Letter (PDF) (3 pp, 33.2K) from Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division to Bryan Arroyo, Acting Assistant Director for Endangered Species, U.S. Fish and Wildlife Service (7/19/07)

Effects Memorandum (PDF) (2 pp, 83.8K) from Donna Randall, Environmental Fate and Effects Division to Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division (07/19/07)

Methamidophos Analysis (PDF) (101 pp, 1.78MB) Risks of Methamidophos Use to the Federally Threatened California Red-legged Frog (7/18/07)

Submission from Bayer CropScience (PDF) (98 pp, 3.97MB) Report on the Effects Determination for the California Red-Legged Frog Potentially Exposed to Methamidophos (5/14/07)

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Effects Determination for Methidathion (PC Code 100301) Relative to the Bay Checkerspot Butterfly, Valley Elderberry Longhorn Beetle, California Tiger Salamander, California Clapper Rail, California Freshwater Shrimp, San Francisco Garter Snake, Delta Smelt, and Tidewater Goby.

Effects Memorandum (PDF) (5 pp, 681K) from Rosanna Louie-Juzwiak, Environmental Fate and Effects Division to Donald Brady, Ph.D., Director, Environmental Fate and Effects Division (6/28/2013)

Effects Determination for Methidathion and the California Red-legged Frog


Transmittal Letter (PDF) (2pp, 121K) from Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division to Bryan Arroyo, Acting Assistant Director for Endangered Species, U.S. Fish and Wildlife Service (2/20/09)

Effects Memorandum (PDF) (2 pp, 72.50K) from Stephanie Syslo, Environmental Fate and Effects Division to Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division (2/18/09)

Methidathion Analysis (PDF) (127 pp, 1.66MB) Risks of Methidathion Use to the Federally Threatened California Red-legged Frog (2/18/09)

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Effects Determination for Methomyl and the Bay Checkerspot Butterfly, Valley Elderberry Longhorn Beetle, California Clapper Rail, California Freshwater Shrimp, California Tiger Salamander, San Francisco Garter Snake, Delta Smelt, and Tidewater Goby

Transmittal Memo (PDF) (2 pp, 65KB) from Donald Brady Ph.D., Division Director for Environmental Fate and Effects Division, Office of Pesticide Programs to Gary Frazer, Assistant Director for Endangered Species, U.S. Fish and Wildlife Service (09/27/2012)

Effects Memorandum (PDF) (3 pp, 1,038K) from Melissa Panger, Senior Scientist, Environmental Fate and Effects Division to Anita Pease, Associate Director, Environmental Fate and Effects Division (09/28/2012)

Methomyl Analysis (PDF) (186 pp, 2.13MB) Risks of Methomyl Use to Federally Threatened Bay Checkerspot Butterfly (Euphydryas editha bayensis), Valley Elderberry Longhorn Beetle (Desmocerus californicus dimorphus), California Tiger Salamander (Ambystoma californiense), Central California Distinct Population Segment, and Delta Smelt (Hypomesus transpacificus), And the Federally Endangered California Clapper Rail (Rallus longirostris obsoletus), California Freshwater Shrimp (Syncaris pacificus), California Tiger Salamander (Ambystoma californiense) Sonoma County Distinct Population Segment and Santa Barbara County Distinct Population Segment, San Francisco Garter Snake (Thamnophis sirtalis tetrataenia), and Tidewater Goby (Eucyclogobius newberryi) (09/28/2012)

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Effects Determination for Methomyl and the California Red-legged Frog

Transmittal Letter (PDF) (2 pp, 33.1K) from Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division to Bryan Arroyo, Acting Assistant Director for Endangered Species, U.S. Fish and Wildlife Service (7/19/07)

Effects Memorandum (PDF) (2 pp, 66.8K) from Melissa Panger, Ph.D., Environmental Fate and Effects Division to Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division (07/18/07)

Methomyl Analysis (PDF) (264 pp, 8.84MB) Risks of Methomyl Use to the Federally Threatened California Red-legged Frog (inclusive of appendices) (7/18/07)

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Effects Determination for Methoprene and the California Tiger Salamander

Transmittal Letter (PDF) (2 pp, 149K) f rom Keith Matthews Director, Biopesticides and Pollution Prevention Division to Gary Frazer, Assistant Director for Endangered Species, U.S. Fish and Wildlife Services (12/28/2011)

Effects Memorandum (PDF) (2 pp, 156K) from Mike Rexrode, Biopesticide and Pollution Prevention Division (BPPD), to Anita Pease, Associated Director, Environmental Fate and effects Division (EFED) (12/28/2011)

S-methoprene Analysis (PDF) (94 pp, 10.75MB) Risks of S-methoprene Use to Federally Listed California Tiger salamander (CTS) (Ambystoma californiense)

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Effects Determination for Methoprene and the California Red-legged Frog

Transmittal Letter (PDF) (2 pp, 30.6K) from Janet Anderson, Ph.D., Director, Biopesticides and Pollution Prevention Division to Bryan Arroyo, Acting Assistant Director for Endangered Species, U.S. Fish and Wildlife Service (2/20/08)

Methoprene Analysis (PDF) (80 pp, 924K) Risks of Methoprene Use to the Federally Threatened California Red-legged Frog (2/20/08)

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Effects Determination for Methyl Bromide and the California Tiger Salamander

Transmittal Letter (PDF) (2 pp, 51K) from Anita Pease, Associate Director, Environmental Fate and Effects Division to Gary Frazer, Assistant Director for Endangered Species, U.S. Fish and Wildlife Service (12/28/2011)

Effects Memorandum (PDF) (2 pp, 52K) from Mah Shamim, Environmental Fate and Effects Division to Anita Pease, Associate Director, Environmental Fate and Effects Division (12/28/2011)

Methyl Bromide Analysis (PDF) (182 pp, 1.96MB) Risks of Methyl Bromide Use to Federally Threatened California Tiger Salamander (Ambystoma californiense) (Central California Distinct Population Segment) and Federally Endangered Sonoma County and Santa Barbara County Distinct Population Segments of California Tiger Salamander (12/28/2011)

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Effects Determination for Methyl parathion and the California Red-legged Frog

Transmittal Letter (PDF) (2 pp, 33.5K) from Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division to Bryan Arroyo, Acting Assistant Director for Endangered Species, U.S. Fish and Wildlife Service (2/20/08)

Effects Memorandum (PDF) (2 pp, 60.2K) from Thomas Steeger, Ph.D., Senior Biologist, Environmental Fate and Effects Division to Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division (2/20/08)

Methyl parathion Analysis (PDF) (96 pp, 2.94MB) Risks of Methyl parathion Use to the Federally Threatened California Red-legged Frog (2/20/08)

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Effects Determination for Metolachlor/S-Metolachlor and the Delta Smelt and California Tiger Salamander

Transmittal Letter (PDF) (2 pp, 546K) from Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division to Gary Frazer, Assistant Director for Endangered Species, U.S. Fish and Wildlife Service (06/30/2010)

Effects Memorandum (PDF) (2 pp, 52.84K) from Ed Odenkirchen, Environmental Fate and Effects Division to Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division (06/29/2010)

Metolachlor/S-Metolachlor Analysis (PDF) (143 pp, 1.43MB) Risks of Metolachlor and S-Metolachlor Use to Federally Threatened Delta Smelt (Hypomesus transpacificus) and California Tiger Salamander (Ambystoma californiense) (Central California Distinct Population Segment) and Federally Endangered Sonoma County and Santa Barbara County Distinct Population Segments of California Tiger Salamander (06/29/2010)

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Effects Determination for Metolachlor and the California Red-legged Frog

Transmittal Letter (PDF) (2 pp, 77.2K) from Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division to Bryan Arroyo, Acting Assistant Director for Endangered Species, U.S. Fish and Wildlife Service (7/17/07) 
 
Effects Memorandum (PDF) (1 p, 56.6K) from Paige Doelling-Brown, Ph.D., Senior Biologist, Environmental Fate and Effects Division to Arthur-Jean B. Williams, Associate Director, Environmental fate and Effects Division (7/16/07)

Metolachlor Analysis (PDF) (97 pp, 2.81MB) Risks of Metolachlor Use to the Federally Threatened California Red-legged Frog (7/16/07)

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Effects Determination for Molinate and the California Red-legged Frog and other Listed Species

Effects Memorandum (PDF) (3 pp, 103K) from Donna Randall, ERB 2, Environmental Fate and Effects Division to Arthur-Jean B.Williams, Associate Director, Environmental Fate and Effects Division (6/16/09)

Effects Determination for Myclobutanil and the California Red-legged Frog

Transmittal Letter (PDF) (2 pp, 66K) from Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division to Bryan Arroyo, Acting Assistant Director for Endangered Species, U.S. Fish and Wildlife Service (June 19, 2009)

Myclobutanil CRLF Effects Determination Memorandum (PDF) (2 pp, 324K) from Stephanie Syslo, Environmental Fate and Effects Division to Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division (June 17, 2009)

Myclobutanil CRLF Effects Determination (PDF) (135 pp, 1.28MB) Risks of Myclobutanil Use to the Federally Threatened California Red-legged Frog (June 17, 2009)

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Effects Determination for Naled and the Bay Checkerspot Butterfly, Valley Elderberry Longhorn Beetle, California Clapper Rail, San Francisco Garter Snake, and San Joaquin Kit Fox

Transmittal Letter (PDF) (2 pp, 531K) from Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division to Gary Frazer, Assistant Director for Endangered Species, U.S. Fish and Wildlife Service (6/30/2010)

Effects Memorandum (PDF) (3 pp, 664K) from Jean Holmes, Environmental Fate and Effects Division to Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division (06/30/2010)

Naled Analysis (PDF) (231 pp, 2.13MB): Risks of Naled Use to Federally Threatened Bay Checkerspot Butterfly (Euphydryas editha bayensis), and Valley Elderberry Longhorn Beetle (Desmocerus californicus dimorphus), and the Federally Endangered California Clapper Rail (Rallus longirostris obsoletus), San Francisco Garter Snake (Thamnophis sirtalis tetrataenia), and San Joaquin Kit Fox (Vulpes macrotis mutica) (06/30/2010)

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Effects Determination for Naled and the California Red-legged Frog

Transmittal Letter (PDF) (2 pp, 33.3K) from Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division to Bryan Arroyo, Acting Assistant Director for Endangered Species, U.S. Fish and Wildlife Service (2/20/08)

Effects Memorandum (PDF)
(2 pp, 84K) from Donna Randall, Environmental Fate and Effects Division to Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division (2/19/08)

Naled Analysis (PDF) (117 pp, 1.10MB) Risks of Naled Use to the Federally Threatened California Red-legged Frog (2/19/08)

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Effects Determination for Norflurazon and the California Red-legged Frog

Transmittal Letter (PDF) (2 pp, 121K) from Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division to Bryan Arroyo, Acting Assistant Director for Endangered Species, U.S. Fish and Wildlife Service (2/20/2009)

Effects Memorandum (PDF) (1 p, 63.31K) from Thomas Steeger, Ph.D, Senior Scientist, Environmental Fate and Effects Division to Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division (02/18/2009)

Norflurazon Analysis (PDF) (97 pp, 1.12MB) Risks of Norflurazon Use to the Federally Threatened California Red-legged Frog (02/18/2009)

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Effects Determination for Oryzalin and the California Tiger Salamander

Transmittal Letter (PDF) (2 pp, 58K) from Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division to Gary Frazer, Assistant Director for Endangered Species, U.S. Fish and Wildlife Service (09/30/2010)

Effects Memorandum (PDF) (2 pp, 33K) from Edward Odenkirchen, Environmental Fate and Effects Division to Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division (09/30/2010)

Oryzalin Analysis (PDF) (137 pp, 1397K) Risks of Oryzalin Use to the Federally Threatened and Endangered California Tiger Salamander (Ambystoma californiense) (09/30/2010)

Effects Determination for Oryzalin and the California Red-legged Frog

Transmittal Letter (PDF) (2 pp, 131.58K) from Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division to Bryan Arroyo, Acting Assistant Director for Endangered Species, U.S. Fish and Wildlife Service (6/20/08)

Effects Memorandum (PDF) (2 pp, 73K) from Ed Odenkirchen, Environmental Fate and Effects Division to Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division (6/19/08)

Oryzalin Analysis (PDF) (133 pp, 1.46MB) Risks of Oryzalin Use to the Federally Threatened California Red-legged Frog (6/19/08)

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Effects Determination for Oxamyl and the California red-legged frog


Transmittal Letter (PDF) (2 pp, 121K) from Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division to Bryan Arroyo, Acting Assistant Director for Endangered Species, U.S. Fish and Wildlife Service (2/20/09)

Effects Memorandum (PDF) (1 p, 60.72K) from Anita Pease, Environmental Fate and Effects Division to Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division (2/12/09)

Oxamyl Analysis (PDF) (117 pp, 930K) Risks of Oxamyl Use to the Federally Threatened California Red-legged Frog (2/12/09)

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Effects Determination for Oxydemeton Methyl and the Federally Threatened Bay Checkerspot Butterfly (Euphydryas editha bayensis), Valley Elderberry Longhorn Beetle (Desmocerus californicus dimorphus),California Tiger Salamander (Ambystoma californiense), Central California Distinct Population Segment, and Delta Smelt (Hypomesus transpacificus), and the Federally Endangered California Clapper Rail (Rallus longirostris obsoletus), California Freshwater Shrimp (Syncaris pacificus), California Tiger Salamander (Ambystoma californiense) Sonoma County Distinct Population Segment and Santa Barbara County Distinct Population Segment, San Francisco Garter Snake (Thamnophis sirtalis tetrataenia), and Tidewater Goby (Eucyclogobius newberryi)

Transmittal Memo (PDF) (2 pp, 197K) from Donald Brady, Director for Environmental Fate and Effects Division, Office of Pesticide Programs to Gary Frazer, Assistant Director for Endangered Species, U.S. Fish and Wildlife Service (06/27/2013)

Effects Memorandum (PDF) (5 pp, 706K) from Edward Odenkirchen, Environmental Fate and Effects Division to Anita Pease, Associate Director, Environmental Fate and Effects Division (06/27/2013)

Effects Determination for Oxydemeton Methyl and the California Red-legged Frog

Transmittal Letter (PDF) (2 pp, 33K) from Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division to Bryan Arroyo, Acting Assistant Director for Endangered Species, U.S. Fish and Wildlife Service (10/22/07)

Effects Memorandum (PDF) (2 pp, 116K) from Donna Randall, Environmental Fate and Effects Division to Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division (10/18/07)

Oxydemeton Methyl Analysis (PDF) (113 pp, 2.12MB) Risks of Oxydemeton Methyl Use to the Federally Threatened California Red-legged Frog (10/18/07)

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Effects Determination for Oxyfluorfen and the California Red-legged Frog

Transmittal Letter (PDF) (2 pp, 129K) from Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division to Bryan Arroyo, Acting Assistant Director for Endangered Species, U.S. Fish and Wildlife Service (10/17/08)

Effects Memorandum (PDF) (2 pp, 89K) from Christine Hartless, Environmental Fate and Effects Division to Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division (10/16/08)

Oxyfluorfen Analysis (PDF) (165 pp, 3.85MB) Risks of Oxyfluorfen Use to the Federally Threatened California Red-legged Frog (10/16/08)

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Effects Determination for Paraquat and the California Red-legged Frog

Transmittal Letter (PDF) (2 pp, 65K) from Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division to Bryan Arroyo, Acting Assistant Director for Endangered Species, U.S. Fish and Wildlife Service (June 19, 2009)

Effects Memorandum (PDF) (2 pp, 52.31K) from Jean Holmes, Environmental Fate and Effects Division to Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division (June 10, 2009)

Paraquat Analysis (PDF) (131 pp, 1.14MB) Risks of Paraquat Use to the Federally Threatened California Red-legged Frog (June 10, 2009)

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Effects Determination for Pendimethalin and the Bay Checkerspot Butterfly

Transmittal Letter (PDF) (2 pp, 56K) from Donald Brady, Director, Environmental Fate and Effects Division to Gary Frazer, Assistant Director for Endangered Species, U.S. Fish and Wildlife Service (12/27/2012)

Effects Memorandum (PDF) (2 pp, 36K) from Stephanie Syslo, Environmental Fate and Effects Division to Anita Pease, Associate Director, Environmental Fate and Effects Division (12/19/2012)

Pendimethalin (PDF) (80 pp, 853K) Risks of Pendimethalin Use to Federally Threatened Bay Checkerspot Butterfly (Euphydryas editha bayensis) (12/31/2012)

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Effects Determination for Pendimethalin and the California Red-legged Frog

Transmittal Letter (PDF) (2 pp, 67K) from Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division to Bryan Arroyo, Acting Assistant Director for Endangered Species, U.S. Fish and Wildlife Service (June 17, 2009)

Effects Memorandum (PDF) (2 pp, 51.08K) from Biologist Jean Holmes - who went through section 7 training and signed the memo, Environmental Fate and Effects Division to Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division (June 16, 2009)

Pendimethalin Analysis (PDF) (123 pp, 1.19MB) Risks of Pendimethalin Use to the Federally Threatened California Red-legged Frog (June 16, 2009)

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Effects Determination for Permethrin and the Valley Elderberry Longhorn Beetle

Transmittal Letter (PDF) (2 pp, 49K) from Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division to Gary Frazer, Assistant Director for Endangered Species, U.S. Fish and Wildlife Service (09/30/2010)

Effects Memorandum (PDF) (2 pp, 34K) from Mah T. Shamim, Ph.D., Environmental Fate and Effects Division to Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division (09/30/2010)

Permethrin Analysis (PDF) (98 pp, 732K) Risks of Permethrin Use to Federally Threatened Valley Elderberry Longhorn Beetle (Desmocerus californicus dimorphus) (09/30/2010)

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Effects Determination for Permethrin and the California Red-legged Frog, Bay Checkerspot Butterfly, California Clapper Rail, Salt Marsh Harvest Mouse, and San Francisco Garter Snake

Permethrin Transmittal Letter (PDF) (2 pp, 134K) from Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division to Bryan Arroyo, Acting Assistant Director for Endangered Species, U.S. Fish and Wildlife Service (10/20/08)

Permethrin Effects Memorandum (PDF) (2 pp, 122K) from Mah Shamim, Environmental Fate and Effects Division to Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division (10/20/08)

Permethrin Analysis (PDF) (293 pp, 2.46MB) Risks of Permethrin Use to the Federally Threatened California Red-legged Frog, and Bay Checkerspot Butterfly, and the Federally Endangered California Clapper Rail, Salt Marsh Harvest Mouse, and San Francisco Garter Snake (10/20/08)

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Effects Determination for Pentachloronitrobenzene (PCNB) and the Bay Checkerspot Butterfly, California Clapper Rail, California Fresh Water Shrimp, California Tiger Salamander, San Francisco Garter Snake, Delta Smelt, and Tidewater Goby

Transmittal Letter (PDF) (2 pp, 60K) from Steven Bradbury Ph.D, Director, Office of Pesticide Programs to Gary Frazer, Assistant Director for Endangered Species, U.S. Fish and Wildlife Service (06/29/2012)

Effects Memorandum (PDF) (2 pp, 57K) from Thomas Steeger, Environmental Fate and Effects Division to Anita Pease, Associate Director, Environmental Fate and Effects Division (06/27/2012)

Pentachloronitrobenzene Analysis (PDF) (153 pp, 1.54MB): Risks of Pentachloronitrobenzene Use to the Federally Threatened Bay Checkerspot Butterfly (Euphydryas editha bayensis), California Tiger Salamander (Ambystoma californiense) Central California Distinct Population Segment, and Delta Smelt (Hypomesus transpacificus) And the Federally Endangered California Clapper Rail (Rallus longirostris obsoletus), California Freshwater Shrimp (Syncaris pacificus), California Tiger Salamander (Ambystoma californiense) Sonoma County Distinct Population Segment and Santa Barbara County Distinct Population Segment, San Francisco Garter Snake (Thamnophis sirtalis tetrataenia), and Tidewater Goby ((Eucyclogobius newberryi) (06/28/2012)

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Effects Determination for Phorate and the California Red-legged Frog, Valley Elderberry Longhorn Beetle, Bay Checkerspot Butterfly, and San Joaquin Kit Fox

Transmittal Letter (PDF) (2 pp, 134K) from Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division to Bryan Arroyo, Acting Assistant Director for Endangered Species, U.S. Fish and Wildlife Service (10/20/08)

Effects Memorandum (PDF) (2 pp, 95K) from Tom Bailey, Environmental Fate and Effects Division to Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division (10/10/08)

Phorate Analysis (PDF) (127 pp, 2.42MB) Risks of Phorate Use to the Federally Threatened California Red-legged Frog, Valley Elderberry Longhorn Beetle, Bay Checkerspot Butterfly, and Endangered San Joaquin Kit Fox (10/10/08)

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Effects Determination for Phosmet and the California Tiger Salamander

Transmittal Letter (PDF) (2 pp, 59K) from Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division to Gary Frazer, Assistant Director for Endangered Species, U.S. Fish and Wildlife Service (03/31/2010)

Effects Memo (PDF) (2 pp, 245K) from Melissa Panger, Ph.D., Environmental Fate and Effects Division to Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division (03/29/2010)

Phosmet Effects Determination (PDF) (116 pp, 1.08MB): Risks of Phosmet Use to the Federally Threatened and Endangered California Tiger Salamander (03/29/2010)

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Effects Determination for Phosmet and the California Red-legged Frog

Transmittal Letter (PDF) (2 pp, 130.16K) from Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division to Bryan Arroyo, Acting Assistant Director for Endangered Species, U.S. Fish and Wildlife Service (6/20/08)

Effects Memorandum (PDF) (1 p, 67.70K) from Thomas Steeger, Ph.D., Environmental Fate and Effects Division to Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division (6/18/08)

Phosmet Analysis (PDF) (106 pp, 1.21MB) Risks of Phosmet Use to the Federally Threatened California Red-legged Frog (6/18/08)

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Effects Determination for Potassium and Sodium Nitrates and the Alameda Whipsnake, San Francisco Garter Snake, and San Joaquin Kit Fox

Effects Memorandum and Analysis (3/30/2010)

Effects Determination for Prometryn and the California Red-legged Frog

Transmittal Letter (PDF) (2 pp, 59K) from Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division to Bryan Arroyo, Acting Assistant Director for Endangered Species, U.S. Fish and Wildlife Service (June 19, 2009)

Effects Memorandum (PDF) (2 pp, 112K) from Stephanie Syslo, Risk Assessment Process Leader, Environmental Fate and Effects Division to Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division (June 17, 2009)

Prometryn Analysis (PDF) (128 pp, 1.25MB) Risks of Prometryn Use to the Federally Threatened California Red-legged Frog (June 17, 2009)

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Effects Determination for Propanil and the California Red-legged Frog

Transmittal Letter (PDF) (2 pp, 54K) from Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division to Gary Frazer, Assistant Director for Endangered Species, U.S. Fish and Wildlife Service (10/20/09)

Effects Memorandum (PDF) (2 pp, 46K) from Jean Holmes, Environmental Fate and Effects Division to Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division (October 15, 2009)

Propanil Analysis (PDF) (119 pp, 1.22MB) Risks of Propanil Use to the Federally Threatened California Red-legged Frog (October 15, 2009)

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Effects Determination for Propargite and the California Red-legged Frog

Transmittal Letter (PDF) (2 pp, 131K) from Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division to Bryan Arroyo, Acting Assistant Director for Endangered Species, U.S. Fish and Wildlife Service (6/20/08)

Effects Memorandum (PDF) (4 pp, 299K) from Christine Hartless, PhD, Environmental Fate and Effects Division to Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division (6/16/08)

Propargite Analysis (PDF) (137 pp, 1.51MB) Risks of Propargite Use to the Federally Threatened California Red-legged Frog (6/16/08)

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Effects Determination for Propyzamide and the California Red-legged Frog

Transmittal Letter (PDF) (2 pp, 33.3K) from Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division to Bryan Arroyo, Acting Assistant Director for Endangered Species, U.S. Fish and Wildlife Service (2/20/08)

Effects Memorandum (PDF) (1 p, 59.6K) from Thomas Steeger, Ph.D, Senior Biologist, Environmental Fate and Effects Division to Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division (2/7/08)

Propyzamide Analysis (PDF) (123 pp, 3.46MB) Risks of Propyzamide Use to the Federally Threatened California Red-legged Frog (2/7/08)

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Effects Determination for Rotenone and the California Red-legged Frog

Transmittal Letter (PDF) (2 pp, 131K) from Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division to Bryan Arroyo, Acting Assistant Director for Endangered Species, U.S. Fish and Wildlife Service (10/17/08)

Effects Memorandum (PDF) (2 pp, 75K) from Thomas Steeger, Senior Biologist, Environmental Fate and Effects Division to Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division (10/16/08)

Rotenone Analysis (PDF) (88 pp, 1.14MB) Risks of Rotenone Use to the Federally Threatened California Red-legged Frog (10/16/08)

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Effects Determination for Simazine and the Delta Smelt

Transmittal Letter (PDF) (2 pp, 512K) from Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division to Gary Frazer, Assistant Director for Endangered Species, U.S. Fish and Wildlife Service (06/30/2010)

Effects Memorandum (PDF) (2 pp, 53K) from Anita Pease, Environmental Fate and Effects Division to Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division (06/30/2010)

Simazine Analysis (PDF) (105 pp, 1.51MB): Risks of Simazine Use to Federally Threatened Delta Smelt (Hypomesus transpacificus) (06/30/2010)

Effects Determination for Potassium and Sodium Nitrates and the Alameda Whipsnake, San Francisco Garter Snake, and San Joaquin Kit Fox

Effects Memorandum and Analysis (3/30/2010)

Effects Determination for Simazine and the California Red-legged Frog

Transmittal Letter (PDF) (2 pp, 32K) from Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division to Bryan Arroyo, Acting Assistant Director for Endangered Species, U.S. Fish and Wildlife Service (10/22/07)

Effects Memorandum (PDF) (2 pp, 66.6K) from Anita Pease, Senior Biologist, Environmental Fate and Effects Division to Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division (10/17/07)

Simazine Analysis (PDF) (147 pp, 2.41MB) Risks of Simazine Use to the Federally Threatened California Red-legged Frog (10/17/07)

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Effects Determination for Strychnine and the California Red-legged Frog, the California Tiger Salamander, and the San Joaquin Kit Fox

Transmittal Letter (PDF) (2 pp, 58K) from Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division to Gary Frazer, Assistant Director for Endangered Species, U.S. Fish and Wildlife Service (10/20/09)

Effects Memorandum (PDF) (2 pp, 67.31K) from Stephanie Syslo, Environmental. Scientist/RAPL, Environmental Fate and Effects Division to Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division (10/19/09)

Strychnine Analysis (PDF) (71 pp, 556.04K) Risks of Strychnine Use to the Federally Threatened California Red-legged Frog, the Federally Threatened and Federally Endangered California Tiger Salamander, and the Federally Endangered San Joaquin Kit Fox (10/19/09)

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Effects Determination for Telone and the California Red-legged Frog

Transmittal Letter (PDF) (2 pp, 99.89K) from Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division to Bryan Arroyo, Acting Assistant Director for Endangered Species, U.S. Fish and Wildlife Service (6/20/08)

Effects Memorandum (PDF) (3 pp, 134K) from Shannon Borges, Biopesticides and Pollution Prevention Division to Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division (6/20/08)

Telone Analysis (PDF) (129 pp, 1.55MB) Risks of Telone Use to the Federally Threatened California Red-legged Frog (6/20/08)

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Effects Determination for Tralomethrin Relative to the Bay Checkerspot Butterfly, Valley Elderberry Longhorn Beetle, California Tiger Salamander, California Clapper Rail, California Freshwater Shrimp, San Francisco Garter Snake, Delta Smelt, and Tidewater Goby

Transmittal Letter (PDF) (2 pp, 201K) from Donald Brady, Director for Environmental Fate and Effects Division, Office of Pesticide Programs  to Gary Frazer, Assistant Director for Endangered Species, U.S. Fish and Wildlife Service (06/27/13)

Effects Memorandum (PDF) (17 pp, 2.60MB) from Mah T. Shamim, Ph.D., Environmental Fate and Effects Division to Anita Pease, Associate Director, Environmental Fate and Effects Division (06/27/13)

Effects Determination for Thiobencarb and the California Red-legged Frog and the Delta Smelt

Transmittal Letter (PDF) (2 pp, 58.61K) from Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division to Gary Frazer, Assistant Director for Endangered Species, U.S. Fish and Wildlife Service (10/20/09)

Effects Memorandum (PDF) (2 pp, 55K) from Jean Holmes, Environmental Fate and Effects Division to Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division (10/19/09)

Thiobencarb Analysis (PDF) (168 pp, 1.50MB) Potential Risks of Thiobencarb Use to the Federally Threatened California Red-legged Frog (Rana aurora draytonii) and Delta Smelt (Hypomesus transpacificus) (10/19/09)

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Effects Determination for Tribufos and the California Red-legged Frog

Transmittal Letter (PDF) (2 pp, 126K) from Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division to Bryan Arroyo, Acting Assistant Director for Endangered Species, U.S. Fish and Wildlife Service (10/17/08)

Effects Memorandum (PDF) (2 pp, 79K) from Melissa Panger and Megan Thynge, Environmental Fate and Effects Division to Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division (10/17/08)

Tribufos Analysis (PDF) (112 pp, 1.09 MB) Risks of Tribufos Use to the Federally Threatened California Red-legged Frog (10/17/08)

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Effects Determination for Triclopyr and the California Red-legged Frog

Transmittal Letter (PDF) (2 pp, 57.47K) from Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division to Gary Frazer, Assistant Director for Endangered Species, U.S. Fish and Wildlife Service (10/20/09)

Effects Memorandum (PDF) (2 pp, 49.57K) from Jean Holmes, Environmental Fate and Effects Division to Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division (October 19, 2009)

Triclopyr Analysis (PDF) (147 pp, 1.34MB) Risks of Triclopyr Use to the Federally Threatened California Red-legged Frog (October 19, 2009)

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Effects Determination for Trifluralin and the California Red-legged Frog, Delta Smelt, San Francisco Garter Snake and San Joaquin Kit Fox

Transmittal Letter (PDF) (2 pp, 57.30K) from Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division to Gary Frazer, Assistant Director for Endangered Species, U.S. Fish and Wildlife Service (10/20/09)

Effects Memorandum (PDF) (2 pp, 53.60K) from Christine Hartless, Environmental Fate and Effects Division to Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division (10/16/2009)

Trifluralin Analysis (PDF) (164 pp, 1.01MB): Risks of Trifluralin Use to the Federally Listed California Red-legged Frog, Delta Smelt, San Francisco Garter Snake and San Joaquin Kit Fox (10/16/2009)

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Effects Determination for Vinclozolin and the California Red-legged Frog

Transmittal Letter (PDF) (2 pp, 56K) from Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division to Gary Frazer, Assistant Director for Endangered Species, U.S. Fish and Wildlife Service (10/20/09)

Effects Memorandum (PDF) (1 p, 40.87K) from Thomas Steeger, Senior Biologist, Environmental Fate and Effects Division to Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division (10/14/09)

Vinclozolin Analysis (PDF) (98 pp, 676K) Risks of Vinclozolin Use to the Federally Threatened California Red-legged Frog (10/14/09)

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Effects Determination for Warfarin and the Alameda Whipsnake and the Salt Marsh Harvest Mouse

Transmittal Letter (PDF) (2 pp, 47K) from Anita Pease, Associate Director, Environmental Fate and Effects Division to Gary Frazer, Assistant Director for Endangered Species, U.S. Fish and Wildlife Service (12/27/2011)

Effects Memorandum (PDF) (2 pp, 39K) from Stephanie Syslo, Environmental Fate and Effects Division to Anita Pease, Associate Director, Environmental Fate and Effects Division (12/27/2011)

Warfarin Analysis (PDF) (74 pp, 612K) Risks of Warfarin Use to the Federally Threatened Alameda Whipsnake (Masticophis lateralis euryxanthus) and the Federally Endangered Salt Marsh Harvest Mouse (Reithrodontomys raviventris) (12/272011)

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Effects Determination for Zinc Phosphide and the Alameda Whipsnake and Salt Marsh Harvest Mouse

Transmittal Letter (PDF) (2 pp, 59K) from Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division to Gary Frazer, Assistant Director for Endangered Species, U.S. Fish and Wildlife Service (3/31/2011)

Effects Memorandum (PDF) (2 pp, 41K) from Edward Odenkirchen, Environmental Fate and Effects Division to Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division (3/30/2011)

Zinc Phosphide Assessment (PDF) (66 pp, 650K) Risks of Zinc Phosphide Use to the Federally Listed Alameda Whipsnake and Salt Marsh Harvest Mouse (3/30/2011)

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Effects Determination for Ziram and the California Red-legged Frog

Transmittal Letter (PDF) (2 pp, 124.25K) from Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division to Bryan Arroyo, Acting Assistant Director for Endangered Species, U.S. Fish and Wildlife Service (10/17/08)

Effects Memorandum (PDF) (2 pp, 56K) from Mah Shamim, Environmental Fate and Effects Division to Arthur-Jean B. Williams, Associate Director, Environmental Fate and Effects Division (10/16/08)

Ziram Analysis (PDF) (134 pp, 1.59MB) Risks of Ziram Use to the Federally Threatened California Red-legged Frog (10/16/08)

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