Harmful algal blooms are a major environmental problem in all 50 states.
Overview
Harmful algal blooms affect aquatic ecosystems, endangered species, and drinking water supplies. They are increasingly a public health hazard, and future climate conditions are expected to produce even more favorable conditions for the growth of cyanobacteria, leading to earlier, more frequent, and larger algal blooms.
Over the past decade, various cyanotoxins including microcystins, anatoxin-a, and cylindrospermopsin have been detected in the surface waters of rivers around Oregon, including the Clackamas, North Santiam, and Tualatin River systems, which are important drinking water sources for a substantial number of Oregon’s residents. Harmful blooms have resulted in numerous water contact and recreational closures and health advisories in lakes, reservoirs, and rivers; dog deaths have been associated with exposure to cyanotoxins. Cyanobacterial blooms produce a range of materials (geosmin, organic matter, toxins) that are a threat to the quality of drinking water supplies and impose an increased burden on drinking water providers for monitoring and treatment. These issues are harder to address in a timely and effective manner when the sources and nature of the blooms are not entirely known.
Cyanobacteria and Harmful Blooms (HABs)
Cyanobacteria are a ubiquitous and vital part of Earth's ecosystem, producing atmospheric oxygen through their photosynthesis for billions of years. Today, cyanobacteria continue to share vast amounts of oxygen from their photosynthesis in the ocean and are an important part of many aquatic food webs. They may “fix” atmospheric nitrogen that enhances crop yields and agricultural production. But under certain conditions, when nutrients, light, and proper habitat converge, cyanobacteria often grow into noxious and toxic harmful blooms (HABs) that threaten water quality, drinking water, endangered species and other aquatic life, and human health.
HABs occur in many different types of waterbodies, including drinking water reservoirs, lakes, and other ponded waters. In these environments, cyanobacteria outcompete other algae when the surface warms and the waterbody temperature stratifies. Under these conditions many types of algae sink into the dark depths, whereas the more "buoyant" cyanobacteria (which are rich with gas vesicles) remain higher in the water column, closer to the sun.
Blooms of cyanobacteria may also occur in rivers, both as suspended “seston” in large flowing rivers, as well as extensive growths along riverbeds and channel margins. The basal forms of cyanobacteria form slimy filamentous mats (Microcoelus, Oscillatoria, Phormidium), and globular or “ear” shaped rubbery colonies of Nostoc, which are found on rocks, logs, and freshly exposed faces of basalt. These growths are observed in the rivers draining the Western Cascades that are vital to Oregon’s population for providing municipal drinking water.
While not all cyanobacteria blooms are toxic, they may produce an array of compounds including potent liver toxins (hepatotoxins, such as microcystins and cylindrospermopsins) and neurotoxins (anatoxin-a and saxitoxin, for example) that are especially dangerous to dogs, and even large animals including sheep, mountain goats, and cattle. Cyanobacteria also produce lipopolysaccharides that are skin irritants and may pose other concerns for water contact recreationists. Cyanobacteria also produce compounds that can foul water supplies with unpleasant tastes and odors. HABs are increasingly a public health hazard, with increased efforts to combat HABs at the federal and state levels, including Oregon, California, and Washington.
HABs in Oregon
In Oregon, HABs have potential to impact revenue from recreation, with numerous popular waterbodies having multiple advisories over the past decade due to HABs and the toxins they produce, including Detroit Lake, Timothy Lake, Tenmile Lake, Odell Lake, Upper Klamath Lake, and many others. HABs are not limited to one or two types of waterbodies; blooms of Dolichospermum (formerly Anabaena) are common in the large water storage reservoirs on the Willamette’s tributaries, and in several lakes in Lincoln and Clatsop Counties (Cullaby, Carnahan, Ten Mile, and Devils Lake, for example) where Gloeotrichia, Aphanizomenon, Microcystis, and other cyanobacteria can bloom during summer months. HABs in small agricultural (nursery) irrigation ponds have also led to releases of cyanotoxins downstream, sometimes impacting drinking water intakes. And in central Oregon, various stock ponds and reservoirs used for livestock watering have experienced HABs with resulting deaths of cattle. In one incident in 2017, 32 cattle perished near Lakeview.
Harmful algal blooms (HABs) have occurred in many of the large water storage reservoirs in the Willamette River Basin, resulting in health advisories for water contact recreation, and in 2018 for the first time in Oregon, a drinking water advisory due to cyanotoxins. A HAB in Detroit Lake during spring produced cyanotoxins that were transported downstream in the North Santiam River, affecting the State capital of Salem's drinking water for about a month. Similar types of cyanobacterial blooms occur in Blue River and Cougar Reservoirs, in the McKenzie River Basin, with similar threats to drinking water for the City of Eugene.
To address this issue, and to complement on-going limnological surveys, the USGS partnered with the City of Salem, the Eugene Water and Electric Board, and the U.S. Army Corp of Engineers to monitor algal blooms in Detroit Lake, Blue River Lake, and Cougar Lake - and the downstream rivers - using continuous water-quality monitors that transmit data to water treatment plant operators, dam operations, researchers and the public in near real-time.
Basic parameters, including water temperature, conductance, and turbidity, are collected vertically in the reservoirs approximately every meter for the top 10 meters, then every 5 meters down into the hypolimnion (bottom waters) to a maximum of 75-90 meters (230-295 feet) deep. HAB parameters include surrogates for algal biomass (total chlorophyll [fCHL] and blue-green pigment phycocyanin [PC]), indicators of photosynthetic activity (dissolved oxygen and pH) and fluorescing dissolved organic matter [fDOM] that is often a reliable surrogate for dissolved organic carbon. Each of these parameters is monitored hourly at the surface (~1-meter depth) and through the water column multiple times per day from locations near dams (at the log booms).
View Profile Analysis Tool - Detroit Lake, OR
View Profile Analysis Tool - Blue River Lake, OR
View Profile Analysis Tool - Cougar Lake, OR
Data are available (per parameter) as:
- Profiles with a slider scale to portray conditions with depth over time
- Time-series plots, based on the hourly data collected at 1-meter depth
- Contours, color plots of parameter values by depth over time.
When taken together with the downstream continuous water-quality monitors these data provide an early-warning indicator of an algal bloom in the reservoir, or the possible release and transport of algae downstream to drinking-water intakes. These data also provide insights into the evolution, behavior, and decay of the seasonal blooms which can inform management strategies, modeling, and perhaps prediction of blooms in the future.
USGS Laboratory Capabilities
The USGS Oregon Water Science Center has researched and implemented methods for the evaluation of cyanotoxins in water and in the cyanobacteria colonies on rock substrates and in river and lake/reservoir plankton. These included the use of passive samplers (Solid Phase Adsorption Toxin Trackers, or SPATTs), which concentrate cyanotoxins from the water column over time; these can be extracted and analyzed using Enzyme Linked Immunosorbent Assays (ELISA). Cyanotoxins currently analyzed at the USGS include total microcystins/nodularin (ADDA), cylindrospermopsin, saxitoxin, and anatoxin-a. Chlorophyll-a is also measured in the laboratory as an estimate of the total algal biomass in water, benthic, and plankton net tows.
Additional Resources
Oregon Health Authority
Oregon Department of Environmental Quality
U.S. Environmental Protection Agency
Below are other science projects associated with this project.
Harmful Algal Bloom (HAB) Cooperative Matching Funds Projects
Determination of Algal Toxin Concentrations in Surface Waters at National Parks
Harmful Algal Bloom monitoring in the Finger Lakes region, New York
Harmful Algal Bloom (HAB) Science in Texas
Harmful Algal Blooms (HABs)
Harmful Algae Blooms (HABs)
Using New Tools To Better Understand And Predict Harmful Cyanobacterial Algal blooms (HABs) At Ohio Lake Erie And Inland Beaches
USGS Study Identifies Factors Related to Cyanobacterial Harmful Algal Blooms
OGRL Algal Toxins Methods of Analysis
Algal Biomass Lab
Cyanobacterial (Blue-Green Algal) Blooms: Tastes, Odors, and Toxins
Clackamas River Basin Water-Quality Assessment
Below are ways to access the data associated with this project.
Profile Analysis Tools
These lake profilers display water-quality data collected in Detroit and Cougar Lakes. These data also provide insights into the evolution, behavior, and decay of the seasonal blooms which can inform management strategies, modeling, and perhaps prediction of blooms in the future.
USGS Data Grapher
This is a data graphing utility that allows the user to build graphs of data from selected USGS stations. Select the station, the type of graph, the parameter(s) to plot, and the starting and ending dates for the graph.
National Water Information System (NWIS) - Oregon
National Water Information System: Mapper (Oregon)
Below are publications associated with this project.
Upstream factors affecting Tualatin River algae—Tracking the 2008 Anabaena algae bloom to Wapato Lake, Oregon
Cyanobacterial harmful algal blooms and U.S. Geological Survey science capabilities
Field and laboratory guide to freshwater cyanobacteria harmful algal blooms for Native American and Alaska Native communities
Water quality and algal conditions in the North Umpqua River, Oregon, 1995-2007, and their response to Diamond Lake restoration
The Effects of Urbanization and Other Environmental Gradients on Algal Assemblages in Nine Metropolitan Areas across the United States
Water Quality and Algal Data for the North Umpqua River Basin, Oregon, 2005
Relations of habitat-specific algal assemblages to land use and water chemistry in the Willamette Basin, Oregon
In response to recent harmful algal blooms (HABs) that have occurred in many of the large water storage reservoirs in the Willamette River Basin the USGS is measuring related water-quality parameters in Detroit and Cougar Lakes. The USGS has also developed profiler tools that allow users to see how the water quality parameters vary with depth in those reservoirs.
Below are news stories associated with this project.
Below are partners associated with this project.
- Overview
Harmful algal blooms are a major environmental problem in all 50 states.
Overview
Harmful algal blooms affect aquatic ecosystems, endangered species, and drinking water supplies. They are increasingly a public health hazard, and future climate conditions are expected to produce even more favorable conditions for the growth of cyanobacteria, leading to earlier, more frequent, and larger algal blooms.
Over the past decade, various cyanotoxins including microcystins, anatoxin-a, and cylindrospermopsin have been detected in the surface waters of rivers around Oregon, including the Clackamas, North Santiam, and Tualatin River systems, which are important drinking water sources for a substantial number of Oregon’s residents. Harmful blooms have resulted in numerous water contact and recreational closures and health advisories in lakes, reservoirs, and rivers; dog deaths have been associated with exposure to cyanotoxins. Cyanobacterial blooms produce a range of materials (geosmin, organic matter, toxins) that are a threat to the quality of drinking water supplies and impose an increased burden on drinking water providers for monitoring and treatment. These issues are harder to address in a timely and effective manner when the sources and nature of the blooms are not entirely known.
Algal bloom in the Ross Island Lagoon, Willamette River, Oregon (Photo: Kurt Carpenter, USGS). Cyanobacteria and Harmful Blooms (HABs)
Cyanobacteria are a ubiquitous and vital part of Earth's ecosystem, producing atmospheric oxygen through their photosynthesis for billions of years. Today, cyanobacteria continue to share vast amounts of oxygen from their photosynthesis in the ocean and are an important part of many aquatic food webs. They may “fix” atmospheric nitrogen that enhances crop yields and agricultural production. But under certain conditions, when nutrients, light, and proper habitat converge, cyanobacteria often grow into noxious and toxic harmful blooms (HABs) that threaten water quality, drinking water, endangered species and other aquatic life, and human health.
HABs occur in many different types of waterbodies, including drinking water reservoirs, lakes, and other ponded waters. In these environments, cyanobacteria outcompete other algae when the surface warms and the waterbody temperature stratifies. Under these conditions many types of algae sink into the dark depths, whereas the more "buoyant" cyanobacteria (which are rich with gas vesicles) remain higher in the water column, closer to the sun.
Blooms of cyanobacteria may also occur in rivers, both as suspended “seston” in large flowing rivers, as well as extensive growths along riverbeds and channel margins. The basal forms of cyanobacteria form slimy filamentous mats (Microcoelus, Oscillatoria, Phormidium), and globular or “ear” shaped rubbery colonies of Nostoc, which are found on rocks, logs, and freshly exposed faces of basalt. These growths are observed in the rivers draining the Western Cascades that are vital to Oregon’s population for providing municipal drinking water.
While not all cyanobacteria blooms are toxic, they may produce an array of compounds including potent liver toxins (hepatotoxins, such as microcystins and cylindrospermopsins) and neurotoxins (anatoxin-a and saxitoxin, for example) that are especially dangerous to dogs, and even large animals including sheep, mountain goats, and cattle. Cyanobacteria also produce lipopolysaccharides that are skin irritants and may pose other concerns for water contact recreationists. Cyanobacteria also produce compounds that can foul water supplies with unpleasant tastes and odors. HABs are increasingly a public health hazard, with increased efforts to combat HABs at the federal and state levels, including Oregon, California, and Washington.
Lake profiler deployed on Detroit Lake, Oregon, to study harmful algal blooms in the reservoir (Photo: David Weathers, USGS). HABs in Oregon
In Oregon, HABs have potential to impact revenue from recreation, with numerous popular waterbodies having multiple advisories over the past decade due to HABs and the toxins they produce, including Detroit Lake, Timothy Lake, Tenmile Lake, Odell Lake, Upper Klamath Lake, and many others. HABs are not limited to one or two types of waterbodies; blooms of Dolichospermum (formerly Anabaena) are common in the large water storage reservoirs on the Willamette’s tributaries, and in several lakes in Lincoln and Clatsop Counties (Cullaby, Carnahan, Ten Mile, and Devils Lake, for example) where Gloeotrichia, Aphanizomenon, Microcystis, and other cyanobacteria can bloom during summer months. HABs in small agricultural (nursery) irrigation ponds have also led to releases of cyanotoxins downstream, sometimes impacting drinking water intakes. And in central Oregon, various stock ponds and reservoirs used for livestock watering have experienced HABs with resulting deaths of cattle. In one incident in 2017, 32 cattle perished near Lakeview.
Harmful algal blooms (HABs) have occurred in many of the large water storage reservoirs in the Willamette River Basin, resulting in health advisories for water contact recreation, and in 2018 for the first time in Oregon, a drinking water advisory due to cyanotoxins. A HAB in Detroit Lake during spring produced cyanotoxins that were transported downstream in the North Santiam River, affecting the State capital of Salem's drinking water for about a month. Similar types of cyanobacterial blooms occur in Blue River and Cougar Reservoirs, in the McKenzie River Basin, with similar threats to drinking water for the City of Eugene.
To address this issue, and to complement on-going limnological surveys, the USGS partnered with the City of Salem, the Eugene Water and Electric Board, and the U.S. Army Corp of Engineers to monitor algal blooms in Detroit Lake, Blue River Lake, and Cougar Lake - and the downstream rivers - using continuous water-quality monitors that transmit data to water treatment plant operators, dam operations, researchers and the public in near real-time.
Basic parameters, including water temperature, conductance, and turbidity, are collected vertically in the reservoirs approximately every meter for the top 10 meters, then every 5 meters down into the hypolimnion (bottom waters) to a maximum of 75-90 meters (230-295 feet) deep. HAB parameters include surrogates for algal biomass (total chlorophyll [fCHL] and blue-green pigment phycocyanin [PC]), indicators of photosynthetic activity (dissolved oxygen and pH) and fluorescing dissolved organic matter [fDOM] that is often a reliable surrogate for dissolved organic carbon. Each of these parameters is monitored hourly at the surface (~1-meter depth) and through the water column multiple times per day from locations near dams (at the log booms).
View Profile Analysis Tool - Detroit Lake, OR
View Profile Analysis Tool - Blue River Lake, OR
View Profile Analysis Tool - Cougar Lake, OR
Data are available (per parameter) as:
- Profiles with a slider scale to portray conditions with depth over time
- Time-series plots, based on the hourly data collected at 1-meter depth
- Contours, color plots of parameter values by depth over time.
Cyanobacterium Gloeotrichia echinulata under a microscope (Photo: Barry Rosen, USGS). When taken together with the downstream continuous water-quality monitors these data provide an early-warning indicator of an algal bloom in the reservoir, or the possible release and transport of algae downstream to drinking-water intakes. These data also provide insights into the evolution, behavior, and decay of the seasonal blooms which can inform management strategies, modeling, and perhaps prediction of blooms in the future.
USGS Laboratory Capabilities
The USGS Oregon Water Science Center has researched and implemented methods for the evaluation of cyanotoxins in water and in the cyanobacteria colonies on rock substrates and in river and lake/reservoir plankton. These included the use of passive samplers (Solid Phase Adsorption Toxin Trackers, or SPATTs), which concentrate cyanotoxins from the water column over time; these can be extracted and analyzed using Enzyme Linked Immunosorbent Assays (ELISA). Cyanotoxins currently analyzed at the USGS include total microcystins/nodularin (ADDA), cylindrospermopsin, saxitoxin, and anatoxin-a. Chlorophyll-a is also measured in the laboratory as an estimate of the total algal biomass in water, benthic, and plankton net tows.
Additional Resources
Oregon Health Authority
Oregon Department of Environmental Quality
U.S. Environmental Protection Agency
- Science
Below are other science projects associated with this project.
Harmful Algal Bloom (HAB) Cooperative Matching Funds Projects
New projects from coast to coast will advance the research on harmful algal blooms (HABs) in lakes, reservoirs and rivers. The vivid emerald-colored algal blooms are caused by cyanobacteria, which can produce cyanotoxins that threaten human health and aquatic ecosystems and can cause major economic damage.Determination of Algal Toxin Concentrations in Surface Waters at National Parks
The U.S. Geological Survey, in partnership with the National Park Service began a project in 2012 exploring levels of the algal toxins in surface drinking water and recreational waters in 3 National Park Service Parks: Sleeping Bear Dunes National Lakeshore, Isle Royale National Park, and Pictured Rocks National Lakeshore.Harmful Algal Bloom monitoring in the Finger Lakes region, New York
Background: Harmful algal blooms (HABs) are increasingly a global concern because they pose a threat to human and aquatic ecosystem health and cause economic damages. Cyanobacterial HABs (CyanoHABs) represent a substantial threat to drinking-water supplies, aquatic ecosystem health, and safe recreational uses of freshwater resources in New York. Toxins produced by some species of cyanobacteriaHarmful Algal Bloom (HAB) Science in Texas
Many types of algae can cause HABs in freshwater ecosystems. The most frequent and severe blooms typically are caused by cyanobacteria, the only freshwater “algae” with the potential for production of toxins that can adversely affect human health. USGS Texas Water Science Center (TXWSC) scientists studying HAB issues in water bodies throughout the United States, using a combination of traditional...Harmful Algal Blooms (HABs)
The USGS collaborates with local, state, federal, tribal, university, and industry partners to conduct the science necessary to understand the causes and effects of toxic HABs and inform water management and public health decisions. USGS is characterizing the life cycle of HABs, their asociated toxins, and the genes responsible for cyanotoxin production. This work is enhancing the ability of Great...Harmful Algae Blooms (HABs)
Cyanobacterial harmful algal blooms (HABs) are increasingly a global concern because HABs pose a threat to human and aquatic ecosystem health and cause economic damages. Toxins produced by some species of cyanobacteria (called cyanotoxins) can cause acute and chronic illnesses in humans and pets. Aquatic ecosystem health also is affected by cyanotoxins, as well as low dissolved oxygen...Using New Tools To Better Understand And Predict Harmful Cyanobacterial Algal blooms (HABs) At Ohio Lake Erie And Inland Beaches
In Ohio, local health officials and state agencies have identified the presence toxins associated with harmful algal blooms (HABs) caused by cyanobacteria during the summer and early fall seasons at recreational and water-supply lakes. The USGS, in cooperation with partner organizations, is monitoring recreational beaches and swimming areas in Ohio to better understand the link between...USGS Study Identifies Factors Related to Cyanobacterial Harmful Algal Blooms
U.S. Geological Survey (USGS) scientists identified water-quality and environmental factors related to cyanobacterial harmful algal blooms at beaches in Ohio. This information was collected as part of a long-term plan to develop site-specific predictive models for microcystin concentrations.OGRL Algal Toxins Methods of Analysis
Algal toxins are a group of toxic compounds produced by a range of photosynthetic freshwater and marine plankton. These toxins have the ability to cause sickness in animals and humans and in severe cases lead to death. OGRL has the ability to evaluate and conduct occurrence, fate, transport, effects, and treatability studies methods.Algal Biomass Lab
The Ohio-Kentucky-Indiana Water Science Center Algal Biomass Laboratory processes samples for chlorophyll-a and nutrients. The analytical data for chlorophyll-a and pheophytin provided by USGS [periphyton samples collected by the Indiana Department of Environmental Management (IDEM)] are used by IDEM for water quality assessment and nutrient management planning.Cyanobacterial (Blue-Green Algal) Blooms: Tastes, Odors, and Toxins
Freshwater and marine harmful algal blooms (HABs) can occur anytime water use is impaired due to excessive accumulations of algae. In freshwater, the majority of HABs are caused by cyanobacteria (also called blue-green algae). Cyanobacteria cause a multitude of water-quality concerns, including the potential to produce taste-and-odor causing compounds and toxins that are potent enough to poison...Clackamas River Basin Water-Quality Assessment
Starting in 1997, the USGS began routinely studying water resources in the Clackamas River Basin. Whether it be assessing harmful algal blooms, runoff issues, streamflow, or watershed health, the USGS has worked with its partners to maintain one of Oregon's most beloved rivers. - Data
Below are ways to access the data associated with this project.
Profile Analysis ToolsThese lake profilers display water-quality data collected in Detroit and Cougar Lakes. These data also provide insights into the evolution, behavior, and decay of the seasonal blooms which can inform management strategies, modeling, and perhaps prediction of blooms in the future.
USGS Data GrapherThis is a data graphing utility that allows the user to build graphs of data from selected USGS stations. Select the station, the type of graph, the parameter(s) to plot, and the starting and ending dates for the graph.
National Water Information System (NWIS) - Oregon
National Water Information System: Mapper (Oregon)
- Multimedia
- Publications
Below are publications associated with this project.
Upstream factors affecting Tualatin River algae—Tracking the 2008 Anabaena algae bloom to Wapato Lake, Oregon
Significant Findings A large bloom that included floating mats of the blue-green algae Anabaena flos-aquae occurred in the lower 20 miles of the Tualatin River in northwestern Oregon between July 7 and July 17, 2008. The floating bloom was deemed a hazard to recreational users of the river due to the potential production of algal toxins (anatoxin-a and microcystin), and a public health advisory wCyanobacterial harmful algal blooms and U.S. Geological Survey science capabilities
Cyanobacterial harmful algal blooms (CyanoHABs) are increasingly a global concern because CyanoHABs pose a threat to human and aquatic ecosystem health and cause economic damages. Despite advances in scientific understanding of cyanobacteria and associated compounds, many unanswered questions remain about occurrence, environmental triggers for toxicity, and the ability to predict the timing, duratField and laboratory guide to freshwater cyanobacteria harmful algal blooms for Native American and Alaska Native communities
Cyanobacteria can produce toxins and form harmful algal blooms. The Native American and Alaska Native communities that are dependent on subsistence fishing have an increased risk of exposure to these cyanotoxins. It is important to recognize the presence of an algal bloom in a waterbody and to distinguish a potentially toxic harmful algal bloom from a non-toxic bloom. This guide provides field imaWater quality and algal conditions in the North Umpqua River, Oregon, 1995-2007, and their response to Diamond Lake restoration
The Wild and Scenic North Umpqua River is one of the highest-quality waters in the State of Oregon, supporting runs of wild salmon, steelhead, and trout. For many years, blooms of potentially toxic blue-green algae in Diamond and Lemolo Lakes have threatened water quality, fisheries, and public health. The blooms consist primarily of Anabaena, a nitrogen (N)-fixing planktonic alga that appears toThe Effects of Urbanization and Other Environmental Gradients on Algal Assemblages in Nine Metropolitan Areas across the United States
The U.S. Geological Survey conducted studies from 2000 to 2004 to determine the effects of urbanization on stream ecosystems in nine major metropolitan study areas across the United States. Biological, chemical, and physical components of streams were assessed at 28 to 30 sites in each study area. Benthic algae were sampled to compare the degree to which algal assemblages correlated to urbanizatioWater Quality and Algal Data for the North Umpqua River Basin, Oregon, 2005
The upper North Umpqua River Basin has experienced a variety of water-quality problems since at least the early 1990's. Several reaches of the North Umpqua River are listed as water-quality limited under section 303(d) of the Clean Water Act. Diamond Lake, a eutrophic lake that is an important source of water and nutrients to the upper North Umpqua River, is also listed as a water-quality limitedRelations of habitat-specific algal assemblages to land use and water chemistry in the Willamette Basin, Oregon
Benthic algal assemblages, water chemistry, and habitat were characterized at 25 stream sites in the Willamette Basin, Oregon, during low flow in 1994. Seventy-three algal samples yielded 420 taxa - Mostly diatoms, blue-green algae, and green algae. Algal assemblages from depositional samples were strongly dominated by diatoms (76% mean relative abundance), whereas erosional samples were dominated - Web Tools
In response to recent harmful algal blooms (HABs) that have occurred in many of the large water storage reservoirs in the Willamette River Basin the USGS is measuring related water-quality parameters in Detroit and Cougar Lakes. The USGS has also developed profiler tools that allow users to see how the water quality parameters vary with depth in those reservoirs.
- News
Below are news stories associated with this project.
- Partners
Below are partners associated with this project.