Dr. Christensen is a research hydrologist who studies HABs, algal toxins, and cyanobacteria. She is a member of the Environmental Health Program's Algal Toxin Team and serves as the acting Communications Coordinator for the Water Mission Area.
Victoria Christensen studies cyanotoxins, with a focus on the neurotoxins, anatoxin-a and saxitoxin. Cyanotoxins are produced by cyanobacterial harmful alglal blooms (HABs), which are sometimes called blue-green algae. Her master’s research examined the occurrence and fate of dissolved solids, nutrients, atrazine, and bacteria in an agricultural watershed. Her dissertation research focused on cyanotoxin mixtures with an emphasis neurotoxins—looking at the environmental variables like wind and temperature that may trigger cyanobacteria to produce or release toxins. In addition to the study of harmful algae and their toxins, Victoria's interests and project work include real-time water-quality monitoring, effects of land use on water quality, the fate of nutrients in agricultural and reservoir systems. She also has an interest in writing and communicating science topics to broad audiences and is a trainer and USGS Subject Matter Expert on Scientific Project Management.
Science and Products
Toxin Producing Algae Across U.S. Landscapes—Are They Gaining a Foothold?
There are still many unknowns related to the occurrence and potential range of various types of algae in inland waters. To fill some of these gaps, scientists at the U.S. Geological Survey (USGS) recently published a review and synthesis of toxic algae in inland waters of the conterminous United States.
Review of Cyanobacterial Neurotoxins—Information for Prioritizing Future Science Directions
The current state of knowledge on the modes of action, production, fate, and occurrence of the freshwater cyanobacterial neurotoxins, anatoxin-a and saxitoxin, was reviewed and synthesized to identify gaps and critical research needs to better understand the health effects of algal toxins.
Mixtures of Algal Toxins Present Prior to and After Formation of Visible Algal Blooms—Science to Inform the Timing of Algal Toxin Exposure
Cyanobacteria with toxin-producing potential, genes indicating an ability for toxin synthesis, or cyanotoxins were present before and after formation of a visible algal bloom in Kabetogama Lake, a popular recreation area in Voyageurs National Park that lies along the border of Minnesota and Canada. The temporal patterns observed in this study indicate that sampling only when there is a visible...
Water Quality in Voyageurs National Park
Voyageurs National Park was established in 1975 to preserve the scenery and remote system of interconnected waterways along a portion of the US-Canada border. The complexity of the waterways increased with the installation of dams in the early 1900s. Subsequently, the International Joint Commission set rules governing dam operation (rule curves) for this system of lakes, with the most recent...
Environmental Effects of Agricultural Practices
As agricultural land in the Minnesota River Basin is retired, tile drains are removed or broken and riparian corridors are planted to reduce runoff. Early studies saw decreased sediment and nitrogen and improved biological indicators but no significant changes in phosphorus. This project continues to investigate the linkages between riparian buffer extent, age, and continuity; stream water; and...
National Water-Quality Project Sampling Methods
USGS National Water Quality Assessment (NAWQA) studies require analyses of stream and bed-sediment samples for major ions, nutrients, sediments, and organic contaminants that are consistent across time and space. Procedures have been designed specifically to produce information that is comparable among studies in different parts of the Nation.
Science and Products
- Science
Toxin Producing Algae Across U.S. Landscapes—Are They Gaining a Foothold?
There are still many unknowns related to the occurrence and potential range of various types of algae in inland waters. To fill some of these gaps, scientists at the U.S. Geological Survey (USGS) recently published a review and synthesis of toxic algae in inland waters of the conterminous United States.Review of Cyanobacterial Neurotoxins—Information for Prioritizing Future Science Directions
The current state of knowledge on the modes of action, production, fate, and occurrence of the freshwater cyanobacterial neurotoxins, anatoxin-a and saxitoxin, was reviewed and synthesized to identify gaps and critical research needs to better understand the health effects of algal toxins.Mixtures of Algal Toxins Present Prior to and After Formation of Visible Algal Blooms—Science to Inform the Timing of Algal Toxin Exposure
Cyanobacteria with toxin-producing potential, genes indicating an ability for toxin synthesis, or cyanotoxins were present before and after formation of a visible algal bloom in Kabetogama Lake, a popular recreation area in Voyageurs National Park that lies along the border of Minnesota and Canada. The temporal patterns observed in this study indicate that sampling only when there is a visible...Water Quality in Voyageurs National Park
Voyageurs National Park was established in 1975 to preserve the scenery and remote system of interconnected waterways along a portion of the US-Canada border. The complexity of the waterways increased with the installation of dams in the early 1900s. Subsequently, the International Joint Commission set rules governing dam operation (rule curves) for this system of lakes, with the most recent...Environmental Effects of Agricultural Practices
As agricultural land in the Minnesota River Basin is retired, tile drains are removed or broken and riparian corridors are planted to reduce runoff. Early studies saw decreased sediment and nitrogen and improved biological indicators but no significant changes in phosphorus. This project continues to investigate the linkages between riparian buffer extent, age, and continuity; stream water; and...National Water-Quality Project Sampling Methods
USGS National Water Quality Assessment (NAWQA) studies require analyses of stream and bed-sediment samples for major ions, nutrients, sediments, and organic contaminants that are consistent across time and space. Procedures have been designed specifically to produce information that is comparable among studies in different parts of the Nation. - Data
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