Keith A Loftin, Ph.D.
Science and Products
Detecting Sublethal Effects of Harmful Algal Blooms in Mammalian and Avian Cells
USGS Researchers are collaborating to study avian and mammalian cells to detect sublethal toxin effects following exposure to harmful algal blooms.
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.
Satellite Data Used to Estimate and Rank Cyanobacterial Bloom Magnitude in Florida and Ohio Lakes—Developing Tools to Protect Human and Wildlife Health from Cyanotoxin Exposure
Cyanobacterial bloom magnitude during 2003–11 was quantified and ranked in Florida and Ohio lakes with a newly developed modelling tool that allows for the use of multiple satellite data sources and user-defined thresholds. This tool was designed to identify the magnitude of algal blooms, but one metric alone cannot adequately represent the severity of a bloom of interest in terms of toxicity...
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...
The Influence of Aerosols on Harmful Algal Toxin Production and Maintenance
The primary objective of this study is to determine what aerosol events (desert dust storms, volcanic eruptions, fires) or pathways contribute to the propagation of harmful algal toxins. This study provides insight into what type of aerosol events contribute to harmful algal blooms.
Understanding Drivers of Cyanotoxin Production in the Lake Okeechobee Waterway
The U.S. Geological Survey (USGS) and other researchers combined field and laboratory approaches in two studies to understand the factors that drive cyanobacterial bloom development and associated cyanotoxin production in Lake Okeechobee, the St. Lucie River and Estuary, and the Indian River Lagoon in response to the large-scale Lake Okeechobee cyanobacteria bloom in 2016.
Toxins and Harmful Algal Blooms Science Team
The team develops advanced methods to study factors driving algal toxin production, how and where wildlife or humans are exposed to toxins, and ecotoxicology. That information is used to develop decision tools to understand if toxin exposure leads to adverse health effects in order to protect human and wildlife health....
Algal and Other Environmental Toxins — Lawrence, Kansas
About the Laboratory
The Environmental Health Program collaborates with scientists at the Organic Geochemistry Research Laboratory (OGRL) in Lawrence, Kansas, to develop and employ targeted and non-targeted analytical methods for identification and quantitation of known and understudied algal/cyanobacterial toxins. The laboratory contructed in 2019 is a 2,500 square...
Understanding Associations between Mussel Productivity and Cyanotoxins in Lake Erie
Study findings indicate that cyanobacteria and cyanotoxins were not associated with mussel mortality at the concentrations present in Lake Erie during a recent study (2013-15), but mussel growth was lower at sites with greater microcystin concentrations.
New Method Developed to Quantify Spatial Extent of Cyanobacterial Blooms
This study provides a method for quantifying changes in the spatial extent of cyanobacterial blooms at local and regional scales using remotely sensed data to determine if bloom occurrence and size are increasing or decreasing for inland water resources.
Satellite Imagery Used to Measure Algal Bloom Frequency—Steps Toward Understanding Exposure Risk
Study explores the utility and limitations of currently available remotely sensed satellite data for identifying the frequency of algal blooms in the Nation's lakes and reservoirs. This information provides a first step toward the goal of understanding exposure risk to protect the health of humans, pets, livestock, and wildlife.
Cyanobacteria from 2016 Lake Okeechobee Harmful Algal Bloom Photo-Documented
New report provides photographic documentation and identification of the cyanobacteria present in Lake Okeechobee, the Caloosahatchee River, and St. Lucie Canal during an extensive algal bloom in 2016.
Assessing cyanobacterial frequency and abundance at surface waters near drinking water intakes across the United States
This study presents the first large-scale assessment of cyanobacterial frequency and abundance of surface water near drinking water intakes across the United States. Public water systems serve drinking water to nearly 90% of the United States population. Cyanobacteria and their toxins may degrade the quality of finished drinking water and can lead...
Coffer, Megan; Schaeffer, Blake A.; Foreman, Katherine; Porteous, Alex; Loftin, Keith; Stumpf, Richard; Werdell, Jeremy; Urquhart, Erin; Albert, Ryan; Darling, John Satellite remote sensing to assess cyanobacterial bloom frequency across the United States at multiple spatial scales
Cyanobacterial blooms can have negative effects on human health and local ecosystems. Field monitoring of cyanobacterial blooms can be costly, but satellite remote sensing has shown utility for more efficient spatial and temporal monitoring across the United States. Here, satellite imagery was used to assess the annual frequency of...
Coffer, Megan M.; Schaeffer, Blake; Salls, Wilson B.; Urquhart, Erin; Loftin, Keith; Stumpf, Richard P. ; Werdell, P. Jeremy ; Darling, John A. Pilot-scale expanded assessment of inorganic and organic tapwater exposures and predicted effects in Puerto Rico, USA
A pilot-scale expanded target assessment of mixtures of inorganic and organic contaminants in point-of-consumption drinking water (tapwater, TW) was conducted in Puerto Rico (PR) to continue to inform TW exposures and corresponding estimations of cumulative human-health risks across the US. In August 2018, a spatial synoptic pilot assessment of...
Bradley, Paul; Padilla, Ingrid Y.; Romanok, Kristin; Smalling, Kelly; Focazio, Michael J.; Breitmeyer, Sara; Cardon, Mary C.; Conley, Justin M.; Evans, Nicola; Givens, Carrie E; Gray, James L.; Gray, L. Earl; Hartig, Phillip C.; Hladik, Michelle; Higgins, Christopher P.; Iwanowicz, Luke R.; Lane, Rachael; Loftin, Keith; McCleskey, R. Blaine; McDonough, Carrie A.; Medlock-Kakaley, Elizabeth; Meppelink, Shannon M.; Weis, Christopher P.; Wilson, Vickie S. Public and private tapwater: Comparative analysis of contaminant exposure and potential risk, Cape Cod, Massachusetts, USA
BackgroundHumans are primary drivers of environmental contamination worldwide, including in drinking-water resources. In the United States (US), federal and state agencies regulate and monitor public-supply drinking water while private-supply monitoring is rare; the current lack of directly comparable information on contaminant-mixture exposures...
Bradley, Paul; LeBlanc, Denis R.; Romanok, Kristin; Smalling, Kelly; Focazio, Michael J.; Cardon, Mary C.; Clark, Jimmy; Conley, Justin M.; Evans, Nicola; Givens, Carrie E; Gray, James L.; Gray, L. Earl; Hartig, Phillip C.; Higgins, Christopher P.; Hladik, Michelle; Iwanowicz, Luke R.; Loftin, Keith; McCleskey, R. Blaine; McDonough, Carrie A.; Medlock-Kakaley, Elizabeth; Weis, Christopher P.; Wilson, Vickie S. The tide turns: Episodic and localized cross-contamination of a California coastline with cyanotoxins
The contamination of coastal ecosystems from a variety of toxins of marine algal origin is a common and well-documented situation along the coasts of the United States and globally. The occurrence of toxins originating from cyanobacteria along marine coastlines is much less studied, and little information exists on whether toxins from marine and...
Tatters, Avery O.; Smith, Jayme; Kudela, Raphael M.; Hayashi, Kendra; Howard, Meredith D. A.; Donovan, Ariel; Loftin, Keith; Caron, David A. Evaluation of a satellite-based cyanobacteria bloom detection algorithm using field-measured microcystin data
Widespread occurrence of cyanobacterial harmful algal blooms (CyanoHABs) and the associated health effects from potential cyanotoxin exposure has led to a need for systematic and frequent screening and monitoring of lakes that are used as recreational and drinking water sources. Remote sensing-based methods are often used for synoptic and frequent...
Mishra, Sachidananda; Stumpf, Richard P. ; Schaeffer, Blake; Werdell, P. Jeremy ; Loftin, Keith; Meredith, Andrew Neither microcystin, nor nodularin, nor cylindrospermopsin directly interact with human toll-like receptors
Various stressors including temperature, environmental chemicals, and toxins can have profound impacts on immunity to pathogens. Increased eutrophication near rivers and lakes coupled with climate change are predicted to lead to increased algal blooms. Currently, the effects of cyanobacterial toxins on disease resistance in mammals is a largely...
Hansen, John; Loftin, Keith; Laughrey, Zachary; Adamovsky, Ondrei Multiple co-occurring and persistently detected cyanotoxins and associated cyanobacteria in adjacent California lakes
The global proliferation of toxin producing cyanobacterial blooms has been attributed to a wide variety of environmental factors with nutrient pollution, increased temperatures, and drought being three of the most significant. The current study is the first formal assessment of cyanotoxins in two impaired lakes, Canyon Lake and Lake Elsinore, in...
Howard, Meredith D. A.; Kudela, Raphael M.; Hayashi, Kendra; Tatters, Avery O.; Caron, David A.; Theroux, Susanna; Oehrle, Stuart; Roethler, Miranda; Donovan, Ariel; Loftin, Keith; Laughrey, Zachary Exploring the potential value of satellite remote sensing to monitor chlorophyll-a for U.S. lakes and reservoirs
Assessment of chlorophyll-a, an algal pigment, typically measured by field and laboratory in situ analyses, is used to estimate algal abundance and trophic status in lakes and reservoirs. In situ-based monitoring programs can be expensive, may not be spatially, and temporally comprehensive and results may not be available in the timeframe needed...
Papenfus, Michael; Schaeffer, Blake; Pollard, Amina; Loftin, Keith
Ecological forecasting—21st century science for 21st century management
Natural resource managers are coping with rapid changes in both environmental conditions and ecosystems. Enabled by recent advances in data collection and assimilation, short-term ecological forecasting may be a powerful tool to help resource managers anticipate impending near-term changes in ecosystem conditions or dynamics. Managers may use the...
Bradford, John B.; Weltzin, Jake; Mccormick, Molly; Baron, Jill; Bowen, Zack; Bristol, Sky; Carlisle, Daren; Crimmins, Theresa; Cross, Paul; DeVivo, Joe; Dietze, Mike; Freeman, Mary; Goldberg, Jason; Hooten, Mevin; Hsu, Leslie; Jenni, Karen; Keisman, Jennifer L.; Kennen, Jonathan; Lee, Kathy; Lesmes, David; Loftin, Keith; Miller, Brian W.; Murdoch, Peter S.; Newman, Jana; Prentice, Karen L.; Rangwala, Imtiaz; Read, Jordan; Sieracki, Jennifer; Sofaer, Helen; Thur, Steve; Toevs, Gordon; Werner, Francisco; White, C. LeAnn; White, Timothy; Wiltermuth, Mark
Characterization of water-quality and bed-sediment conditions in Currituck Sound, North Carolina, prior to the Mid-Currituck Bridge construction, 2011–18
The North Carolina Turnpike Authority plans to improve transportation in the Currituck Sound area by constructing a two-lane bridge—the Mid-Currituck Bridge—across Currituck Sound from the mainland to the Outer Banks, North Carolina. The results of the final environmental impact statement for the project indicate potential water-quality and...
Harden, Stephen L.; Fitzgerald, Sharon A.; Wagner, Chad R.; Bristow, Emilia L.; Loftin, Keith A.; Rosen, Barry H. Mixed organic and inorganic tapwater exposures and potential effects in greater Chicago area, USA
Safe drinking water at the point of use (tapwater, TW) is a public-health priority. TW exposures and potential human-health concerns of 540 organics and 35 inorganics were assessed in 45 Chicago area United States (US) homes in 2017. No US Environmental Protection Agency (EPA) enforceable Maximum Contaminant Level(s) (MCL) were exceeded in any...
Bradley, Paul; Argos, Maria; Kolpin, Dana W.; Meppelink, Shannon M.; Romanok, Kristin; Smalling, Kelly; Focazio, Michael J.; Allen, Joshua M.; Dietze, Julie E.; Devito, Michael J.; Donovan, Ariel; Evans, Nicola; Givens, Carrie E.; Gray, James L.; Higgins, Christopher P.; Hladik, Michelle; Iwanowicz, Luke; Journey, Celeste A.; Lane, Rachael; Laughrey, Zachary; Loftin, Keith A.; McCleskey, R. Blaine; McDonough, Carrie A.; Medlock Kakaley, Elizabeth K; Meyer, Michael T.; Holthouse-Putz, Andrea; Richardson, Susan D; Stark, Alan ; Weis, Christopher P.; Wilson, Vickie S.; Zehraoui, Abderrahman
Satellite Imagery Can Track Harmful Algal Blooms
A joint collaboration between EPA, NOAA, NASA, and USGS scientists has demonstrated that satellite imagery can be used to track the frequency of harmful algal blooms. The satellites can accomplish this by measuring certain algal pigments in the water.
New Science Challenges Old Assumptions about Harmful Algal Blooms
First-of-its-kind survey shows that algal toxins are found nationwide
Multiple Satellite Eyes to Track Algal Threat to U.S. Freshwater
Four federal agencies including the U.S. Geological Survey have joined forces in an effort to transform satellite data into vital information to protect the American public from freshwater contaminated by harmful algal blooms.