Brent Topping
Brent is the Quality Management System (QMS) Manager for the NW-PI Region. He, and the USGS QMS Team, lead USGS laboratories through implementation of a new Bureau-wide QMS. Brent works closely with Southwest Region laboratories and their staff on the implementation of 10 Core Elements, including documentation, procedures, methods, quality controls, sample management and quality assessment
Science and Products
Filter Total Items: 25
Quantifying the benthic source of nutrients to the water column of Upper Klamath Lake, Oregon Quantifying the benthic source of nutrients to the water column of Upper Klamath Lake, Oregon
Executive Summary Five sampling trips were coordinated in April, May and August 2006, and May and July 2007 to sample the water column and benthos of Upper Klamath Lake, OR (Fig. 1; Table 1), before, during and after the annual cyanophyte bloom of Aphanizomenon flos-aquae (AFA). A pore-water profiler was designed and fabricated to obtain the first high-resolution (centimeter-scale)...
Authors
James S. Kuwabara, Dennis D. Lynch, Brent R. Topping, Fred Murphy, James L. Carter, Nancy S. Simon, Francis Parcheso, Tamara M. Wood, Mary K. Lindenberg, Katryn Wiese, Ronald J. Avanzino
Free zinc ion and dissolved orthophosphate effects on phytoplankton from Coeur d'Alene Lake, Idaho Free zinc ion and dissolved orthophosphate effects on phytoplankton from Coeur d'Alene Lake, Idaho
Coeur d'Alene Lake in northern Idaho is fed by two major rivers: the Coeur d'Alene River from the east and the St. Joe River from the south, with the Spokane River as its outlet to the north. This phosphorus-limited lake has been subjected to decades of mining (primarily for zinc and silver) and other anthropogenic inputs. A 32 full-factorial experimental design was used to examine the
Authors
James S. Kuwabara, Brent R. Topping, Paul F. Woods, James L. Carter
Mercury speciation in piscivorous fish from mining-impacted reservoirs Mercury speciation in piscivorous fish from mining-impacted reservoirs
Guadalupe Reservoir (GUA), California, and Lahontan Reservoir (LAH), Nevada, U.S. are both affected either directly or indirectly by the legacy of gold and silver mining in the Sierra Nevada during the nineteenth century. Analysis of total mercury in fish from these lentic systems consistently indicate elevated concentrations (>1 μg·g-1 wet weight; hereinafter, all concentrations are...
Authors
James S. Kuwabara, Yuji Arai, Brent R. Topping, I.J. Pickering, G.N. George
Interactive effects of dissolved zinc and orthophosphate on phytoplankton from Coeur d'Alene Lake, Idaho Interactive effects of dissolved zinc and orthophosphate on phytoplankton from Coeur d'Alene Lake, Idaho
Within the longitudinal chemical-concentration gradient in Coeur d'Alene Lake, generated by inputs from the St. Joe and Coeur d'Alene Rivers, two dominant algal species, Chlorella minutissima and Asterionella formosa, were isolated and cultured in chemically defined media to examine growth response to a range of dissolved orthophosphate concentrations and zinc-ion activities...
Authors
James S. Kuwabara, Brent R. Topping, Paul F. Woods, James L. Carter, Stephen W. Hager
Mercury accumulation by lower trophic-level organisms in lentic systems within the Guadalupe River watershed, California Mercury accumulation by lower trophic-level organisms in lentic systems within the Guadalupe River watershed, California
The water columns of four reservoirs (Almaden, Calero, Guadalupe and Lexington Reservoirs) and an abandoned quarry pit filled by Alamitos Creek drainage for recreational purposes (Lake Almaden) were sampled on September 14 and 15, 2004 to provide the first measurements of mercury accumulation by phytoplankton and zooplankton in lentic systems (bodies of standing water, as in lakes and...
Authors
James S. Kuwabara, Brent R. Topping, Gerald E. Moon, Peter Husby, Andrew Lincoff, James L. Carter, Marie-Noële Croteau
Sediment remobilization of Mercury in South San Francisco Bay, California Sediment remobilization of Mercury in South San Francisco Bay, California
No abstract available.
Authors
Brent R. Topping, James S. Kuwabara, Mark C. Marvin-DisPasquale, Jennifer L. Agee, Le H. Kieu, John R. Flanders, Francis Parcheso, Stephen W. Hager, Cary B. Lopez, David P. Krabbenhoft
Science and Products
Filter Total Items: 25
Quantifying the benthic source of nutrients to the water column of Upper Klamath Lake, Oregon Quantifying the benthic source of nutrients to the water column of Upper Klamath Lake, Oregon
Executive Summary Five sampling trips were coordinated in April, May and August 2006, and May and July 2007 to sample the water column and benthos of Upper Klamath Lake, OR (Fig. 1; Table 1), before, during and after the annual cyanophyte bloom of Aphanizomenon flos-aquae (AFA). A pore-water profiler was designed and fabricated to obtain the first high-resolution (centimeter-scale)...
Authors
James S. Kuwabara, Dennis D. Lynch, Brent R. Topping, Fred Murphy, James L. Carter, Nancy S. Simon, Francis Parcheso, Tamara M. Wood, Mary K. Lindenberg, Katryn Wiese, Ronald J. Avanzino
Free zinc ion and dissolved orthophosphate effects on phytoplankton from Coeur d'Alene Lake, Idaho Free zinc ion and dissolved orthophosphate effects on phytoplankton from Coeur d'Alene Lake, Idaho
Coeur d'Alene Lake in northern Idaho is fed by two major rivers: the Coeur d'Alene River from the east and the St. Joe River from the south, with the Spokane River as its outlet to the north. This phosphorus-limited lake has been subjected to decades of mining (primarily for zinc and silver) and other anthropogenic inputs. A 32 full-factorial experimental design was used to examine the
Authors
James S. Kuwabara, Brent R. Topping, Paul F. Woods, James L. Carter
Mercury speciation in piscivorous fish from mining-impacted reservoirs Mercury speciation in piscivorous fish from mining-impacted reservoirs
Guadalupe Reservoir (GUA), California, and Lahontan Reservoir (LAH), Nevada, U.S. are both affected either directly or indirectly by the legacy of gold and silver mining in the Sierra Nevada during the nineteenth century. Analysis of total mercury in fish from these lentic systems consistently indicate elevated concentrations (>1 μg·g-1 wet weight; hereinafter, all concentrations are...
Authors
James S. Kuwabara, Yuji Arai, Brent R. Topping, I.J. Pickering, G.N. George
Interactive effects of dissolved zinc and orthophosphate on phytoplankton from Coeur d'Alene Lake, Idaho Interactive effects of dissolved zinc and orthophosphate on phytoplankton from Coeur d'Alene Lake, Idaho
Within the longitudinal chemical-concentration gradient in Coeur d'Alene Lake, generated by inputs from the St. Joe and Coeur d'Alene Rivers, two dominant algal species, Chlorella minutissima and Asterionella formosa, were isolated and cultured in chemically defined media to examine growth response to a range of dissolved orthophosphate concentrations and zinc-ion activities...
Authors
James S. Kuwabara, Brent R. Topping, Paul F. Woods, James L. Carter, Stephen W. Hager
Mercury accumulation by lower trophic-level organisms in lentic systems within the Guadalupe River watershed, California Mercury accumulation by lower trophic-level organisms in lentic systems within the Guadalupe River watershed, California
The water columns of four reservoirs (Almaden, Calero, Guadalupe and Lexington Reservoirs) and an abandoned quarry pit filled by Alamitos Creek drainage for recreational purposes (Lake Almaden) were sampled on September 14 and 15, 2004 to provide the first measurements of mercury accumulation by phytoplankton and zooplankton in lentic systems (bodies of standing water, as in lakes and...
Authors
James S. Kuwabara, Brent R. Topping, Gerald E. Moon, Peter Husby, Andrew Lincoff, James L. Carter, Marie-Noële Croteau
Sediment remobilization of Mercury in South San Francisco Bay, California Sediment remobilization of Mercury in South San Francisco Bay, California
No abstract available.
Authors
Brent R. Topping, James S. Kuwabara, Mark C. Marvin-DisPasquale, Jennifer L. Agee, Le H. Kieu, John R. Flanders, Francis Parcheso, Stephen W. Hager, Cary B. Lopez, David P. Krabbenhoft