Victoria Glenn Christensen, PhD (Former Employee)
Science and Products
Filter Total Items: 52
Rapid-assessment test strips: Effectiveness forcyanotoxin monitoring in a northern temperate lake Rapid-assessment test strips: Effectiveness forcyanotoxin monitoring in a northern temperate lake
Precise and rapid methods of determining toxin levels are needed in lakes used for recreation and drinking water to facilitate a quick risk assessment during cyanobacteria blooms. Therefore, we evaluated rapid-assessment test strips, a newer technology for estimating the toxicity of cyanobacterial blooms, in Kabetogama Lake, a popular recreational area of Voyageurs National Park in...
Authors
Jaime F. LeDuc, Victoria Christensen, Ryan P. Maki
Land use effects on sediment nutrient processes in a heavily modified watershed using structural equation models Land use effects on sediment nutrient processes in a heavily modified watershed using structural equation models
Contemporary land use can affect sediment nutrient processes in rivers draining heavily modified watersheds; however, studies linking land use to sediment nutrient processes in large river networks are limited. In this study, we developed and evaluated structural equation models (SE models) for denitrification and phosphorus retention capacity to determine direct and indirect linkages...
Authors
Rebecca M. Kreiling, Martin C. Thoms, Lynn A. Bartsch, James H. Larson, Victoria Christensen
Freshwater neurotoxins and concerns for human, animal, and ecosystemhealth: A review of anatoxin-a and saxitoxin Freshwater neurotoxins and concerns for human, animal, and ecosystemhealth: A review of anatoxin-a and saxitoxin
Toxic cyanobacteria are a concern worldwide because they can adversely affect humans, animals, and ecosystems. However, neurotoxins produced by freshwater cyanobacteria are understudied relative to microcystin. Thus, the objective of this critical review was to provide a comprehensive examination of the modes of action, production, fate, and occurrence of the freshwater neurotoxins...
Authors
Victoria Christensen, Eakalak Khan
Phytoplankton community and algal toxicity at a recurring bloom in Sullivan Bay, Kabetogama Lake, Minnesota, USA Phytoplankton community and algal toxicity at a recurring bloom in Sullivan Bay, Kabetogama Lake, Minnesota, USA
Kabetogama Lake in Voyageurs National Park, Minnesota, USA suffers from recurring late summer algal blooms that often contain toxin-producing cyanobacteria. Previous research identified the toxin microcystin in blooms, but we wanted to better understand how the algal and cyanobacterial community changed throughout an open water season and how changes in community structure were related...
Authors
Victoria Christensen, Ryan P. Maki, Erin A. Stelzer, Jack E. Norland, Eakalak Khan
Complex response of sediment phosphorus to land use and management within a river network Complex response of sediment phosphorus to land use and management within a river network
Rivers affected by anthropogenic nutrient inputs can retain some of the phosphorus (P) load through sediment retention and burial. Determining the influence of land use and management on sediment P concentrations and P retention in fluvial ecosystems is challenging because of different stressors operating at multiple spatial and temporal scales. In this study, we sought to determine how...
Authors
Rebecca M. Kreiling, Martin C. Thoms, Lynn A. Bartsch, William B. Richardson, Victoria G. Christensen
Denitrification in the river network of a mixed land use watershed: Unpacking the complexities Denitrification in the river network of a mixed land use watershed: Unpacking the complexities
River networks have the potential to permanently remove nitrogen through denitrification. Few studies have measured denitrification rates within an entire river network or assessed how land use affect rates at larger spatial scales. We sampled 108 sites throughout the network of the Fox River watershed, Wisconsin, to determine if land use influence sediment denitrification rates, and to...
Authors
Rebecca Kreiling, William B. Richardson, Lynn A. Bartsch, Martin C. Thoms, Victoria G. Christensen
Science and Products
Filter Total Items: 52
Rapid-assessment test strips: Effectiveness forcyanotoxin monitoring in a northern temperate lake Rapid-assessment test strips: Effectiveness forcyanotoxin monitoring in a northern temperate lake
Precise and rapid methods of determining toxin levels are needed in lakes used for recreation and drinking water to facilitate a quick risk assessment during cyanobacteria blooms. Therefore, we evaluated rapid-assessment test strips, a newer technology for estimating the toxicity of cyanobacterial blooms, in Kabetogama Lake, a popular recreational area of Voyageurs National Park in...
Authors
Jaime F. LeDuc, Victoria Christensen, Ryan P. Maki
Land use effects on sediment nutrient processes in a heavily modified watershed using structural equation models Land use effects on sediment nutrient processes in a heavily modified watershed using structural equation models
Contemporary land use can affect sediment nutrient processes in rivers draining heavily modified watersheds; however, studies linking land use to sediment nutrient processes in large river networks are limited. In this study, we developed and evaluated structural equation models (SE models) for denitrification and phosphorus retention capacity to determine direct and indirect linkages...
Authors
Rebecca M. Kreiling, Martin C. Thoms, Lynn A. Bartsch, James H. Larson, Victoria Christensen
Freshwater neurotoxins and concerns for human, animal, and ecosystemhealth: A review of anatoxin-a and saxitoxin Freshwater neurotoxins and concerns for human, animal, and ecosystemhealth: A review of anatoxin-a and saxitoxin
Toxic cyanobacteria are a concern worldwide because they can adversely affect humans, animals, and ecosystems. However, neurotoxins produced by freshwater cyanobacteria are understudied relative to microcystin. Thus, the objective of this critical review was to provide a comprehensive examination of the modes of action, production, fate, and occurrence of the freshwater neurotoxins...
Authors
Victoria Christensen, Eakalak Khan
Phytoplankton community and algal toxicity at a recurring bloom in Sullivan Bay, Kabetogama Lake, Minnesota, USA Phytoplankton community and algal toxicity at a recurring bloom in Sullivan Bay, Kabetogama Lake, Minnesota, USA
Kabetogama Lake in Voyageurs National Park, Minnesota, USA suffers from recurring late summer algal blooms that often contain toxin-producing cyanobacteria. Previous research identified the toxin microcystin in blooms, but we wanted to better understand how the algal and cyanobacterial community changed throughout an open water season and how changes in community structure were related...
Authors
Victoria Christensen, Ryan P. Maki, Erin A. Stelzer, Jack E. Norland, Eakalak Khan
Complex response of sediment phosphorus to land use and management within a river network Complex response of sediment phosphorus to land use and management within a river network
Rivers affected by anthropogenic nutrient inputs can retain some of the phosphorus (P) load through sediment retention and burial. Determining the influence of land use and management on sediment P concentrations and P retention in fluvial ecosystems is challenging because of different stressors operating at multiple spatial and temporal scales. In this study, we sought to determine how...
Authors
Rebecca M. Kreiling, Martin C. Thoms, Lynn A. Bartsch, William B. Richardson, Victoria G. Christensen
Denitrification in the river network of a mixed land use watershed: Unpacking the complexities Denitrification in the river network of a mixed land use watershed: Unpacking the complexities
River networks have the potential to permanently remove nitrogen through denitrification. Few studies have measured denitrification rates within an entire river network or assessed how land use affect rates at larger spatial scales. We sampled 108 sites throughout the network of the Fox River watershed, Wisconsin, to determine if land use influence sediment denitrification rates, and to...
Authors
Rebecca Kreiling, William B. Richardson, Lynn A. Bartsch, Martin C. Thoms, Victoria G. Christensen