Official Federal and State Harmful Algal Bloom Maps, Advisories and Monitoring Resources
Harmful algal blooms can occur in ponds, lakes, reservoirs, rivers, estuaries and coastal waters throughout the United States. Freshwater blooms are frequently associated with cyanobacteria, commonly called blue-green algae.
Some cyanobacteria can produce toxins that may harm people, pets, livestock, fish and wildlife. However, not every cyanobacteria bloom produces toxins, and the appearance of the water alone cannot determine whether toxins are present.
Unfortunately, there is no single national website that identifies every active harmful algal bloom in the United States. Federal agencies provide satellite monitoring, forecasting, research and nationwide data, but most recreational-water warnings are issued by individual states, local health departments, park managers or waterbody owners.
This directory provides direct links to many of the most useful official federal and state resources currently available.
Last reviewed: July 2026
Important: A waterbody’s absence from an advisory map does not necessarily mean it is free of cyanobacteria or cyanotoxins. Most monitoring programs cover only selected public waters. Private ponds and many smaller lakes are rarely included.
National Harmful Algal Bloom Resources
EPA Harmful Algal Blooms Portal
Agency: U.S. Environmental Protection Agency
Resource type: National information and resource center
Coverage: Freshwater, drinking water and recreational water
The EPA HAB portal provides information about cyanobacteria, cyanotoxins, health risks, monitoring, management, testing methods and state programs.
Direct link:
https://www.epa.gov/habs
EPA State and Tribal HAB Programs
Agency: U.S. Environmental Protection Agency
Resource type: National directory
Coverage: All 50 states, the District of Columbia and participating Tribal programs
This is one of the best starting points for locating official state harmful algal bloom programs.
Direct link:
https://www.epa.gov/habs/state-tribal-hab-programs-and-resources
EPA HAB Advisories and Tracking
Agency: U.S. Environmental Protection Agency
Resource type: National advisory summaries and tracking resources
Coverage: United States
EPA compiles information reported by state and Tribal programs. Reporting practices and update schedules differ considerably among states.
Direct link:
https://www.epa.gov/habs/hab-advisories
EPA Tracking CyanoHABs
Agency: U.S. Environmental Protection Agency
Resource type: Interactive national StoryMap
Coverage: Reported U.S. cyanobacteria and cyanotoxin occurrence
This interactive resource helps visualize where cyanobacterial blooms and cyanotoxins have been reported.
Direct link:
https://storymaps.arcgis.com/stories/d4a87e6cdfd44d6ea7b97477969cb1dd
EPA Cyanobacteria Assessment Network
Agency: EPA, NASA, NOAA and USGS
Resource type: Satellite early-warning system
Coverage: Thousands of larger U.S. lakes and reservoirs
The Cyanobacteria Assessment Network, commonly called CyAN, uses satellite imagery to estimate cyanobacteria abundance in satellite-resolvable waterbodies.
Satellite detection can indicate that cyanobacteria may be present, but it does not confirm toxin production or replace laboratory testing.
Direct link:
https://www.epa.gov/water-research/cyanobacteria-assessment-network-cyan
EPA Cyanobacteria Forecasting Research
Agency: U.S. Environmental Protection Agency
Resource type: Experimental weekly bloom-probability forecasts
Coverage: More than 2,000 lakes in the contiguous United States
The forecasts estimate the probability of cyanobacterial bloom occurrence. They should not be interpreted as official public-health advisories or proof that cyanotoxins are present.
Direct link:
https://www.epa.gov/water-research/cyanobacterial-harmful-algal-blooms-forecasting-research
EPA bloomWatch
Agency: U.S. Environmental Protection Agency
Resource type: Citizen bloom-reporting application
Coverage: United States
BloomWatch allows members of the public to submit photographs and observations of suspected freshwater cyanobacteria blooms.
Direct link:
https://www.epa.gov/habs/what-you-can-do
NOAA Harmful Algal Bloom Forecasts
Agency: National Oceanic and Atmospheric Administration
Resource type: Regional forecasts
Coverage: Selected coastal waters and Lake Erie
NOAA produces operational and experimental HAB forecasts for certain regions. It is not a complete nationwide freshwater advisory system.
Direct link:
https://coastalscience.noaa.gov/science-areas/habs/hab-forecasts/
NOAA Harmful Algal BloomS Observing System
Agency: National Oceanic and Atmospheric Administration
Resource type: Interactive observations and monitoring map
Coverage: Primarily coastal waters, with strong Gulf Coast coverage
HABSOS contains harmful algal bloom observations and environmental monitoring data. It is particularly useful for coastal blooms such as Florida red tide.
Direct link:
https://habsos.noaa.gov/
NOAA Lake Erie HAB Forecast
Agency: National Oceanic and Atmospheric Administration
Resource type: Current bloom forecast
Coverage: Lake Erie
NOAA provides bloom location, movement, intensity and forecast information for western Lake Erie.
Direct link:
https://coastalscience.noaa.gov/science-areas/habs/hab-forecasts/lake-erie/
CDC Harmful Algal Bloom Health Information
Agency: Centers for Disease Control and Prevention
Resource type: Human and animal health guidance
Coverage: Nationwide
CDC provides information about exposure, symptoms, illness prevention and reporting. It is not a live bloom-advisory map.
Direct link:
https://www.cdc.gov/harmful-algal-blooms/
NASA Harmful Algal Bloom Resources
Agency: National Aeronautics and Space Administration
Resource type: Satellite imagery and environmental data
Coverage: Inland and coastal waters
NASA provides satellite datasets and research tools used in the detection and study of algal blooms.
Direct link:
https://www.earthdata.nasa.gov/topics/ocean/harmful-algal-bloom-hab
USGS Cyanobacteria and Cyanotoxins
Agency: U.S. Geological Survey
Resource type: Research, monitoring and scientific data
Coverage: United States
USGS conducts cyanobacteria and cyanotoxin research and participates in national and regional monitoring projects.
Direct link:
https://www.usgs.gov/mission-areas/water-resources/science/cyanobacteria-and-cyanotoxins
State Harmful Algal Bloom Resources
Alabama
Primary agency: Alabama Department of Environmental Management
Resource type: Coastal beach monitoring
Coverage: Coastal Alabama and Mobile Bay beaches
Alabama’s primary centralized public resource focuses on coastal beaches. It is not a comprehensive tracker for inland ponds, lakes and reservoirs.
Direct link:
https://adem.alabama.gov/programs/coastal/beachMonitoring.cnt
Alaska
Primary organization: Alaska Harmful Algal Bloom Network
Resource type: Statewide HAB network, alerts and data portal
Coverage: Primarily coastal and marine waters
The Alaska HAB Network coordinates bloom awareness, research, monitoring and response. Its work has a strong emphasis on shellfish toxins and coastal communities.
Program:
https://ahab.aoos.org/
Data portal:
https://ahab.portal.aoos.org/
Arizona
Primary agency: Arizona Department of Environmental Quality
Resource type: Interactive water-quality map and HAB program
Coverage: Freshwater lakes, reservoirs and rivers
Arizona Water Watch map:
https://adeq.maps.arcgis.com/apps/View/index.html?appid=e7b6b01d60a640f0b320213b340b3228
State HAB information:
https://azdeq.gov/habs
Arkansas
Primary agency: Arkansas Division of Environmental Quality
Resource type: Current advisory table, bloom reporting and monitoring
Coverage: Monitored public-use lakes
The Arkansas page displays active recreational-use health advisories when they are in effect. The state also investigates public reports of suspected blooms.
Direct link:
https://www.adeq.state.ar.us/water/planning/hab/
California
Primary program: California Cyanobacteria and Harmful Algal Bloom Network
Resource type: Statewide portal, reported-bloom map and satellite map
Coverage: Freshwater, estuarine and selected marine reports
California maintains one of the most comprehensive state HAB portals in the country.
Main HAB portal:
https://mywaterquality.ca.gov/habs/
HAB reports map:
https://mywaterquality.ca.gov/habs/resources/reports-map/
Satellite map:
https://mywaterquality.ca.gov/habs/data_viewer/
Colorado
Primary agencies: Colorado Department of Public Health and Environment and Colorado Parks and Wildlife
Resource type: State guidance and individual waterbody condition notices
Coverage: Public lakes, reservoirs and state parks
Colorado does not appear to maintain one comprehensive live statewide freshwater HAB advisory map. Conditions and closures may be posted by state parks, local health departments and individual waterbody managers.
Colorado HAB information:
https://cdphe.colorado.gov/water-quality/harmful-algal-blooms
Colorado Parks and Wildlife:
https://cpw.state.co.us/fishing
Connecticut
Primary agency: Connecticut Department of Energy and Environmental Protection
Resource type: State HAB information and local-response guidance
Coverage: Freshwater lakes and ponds
Current beach closures may be issued by municipalities, local health departments or waterbody managers.
Direct link:
https://portal.ct.gov/DEEP/Water/Water-Quality/Blue-Green-Algae-Blooms
Delaware
Primary agency: Delaware Department of Natural Resources and Environmental Control
Resource type: Recreational-water monitoring and coastal red-tide information
Coverage: Primarily coastal waters and public beaches
Delaware does not appear to operate a comprehensive statewide inland cyanobacteria advisory map.
Recreational-water monitoring:
https://dnrec.delaware.gov/watershed-stewardship/assessment/recreational-water-monitoring/
Red-tide information:
https://dnrec.delaware.gov/watershed-stewardship/assessment/recreational-water-monitoring/red-tide/
District of Columbia
Primary agency: District Department of Energy and Environment
Resource type: Algae information and reporting
Coverage: District waters, including the Potomac and Anacostia rivers
Direct link:
https://doee.dc.gov/service/algaeblooms
Florida
Primary agencies: Florida Department of Environmental Protection and Florida Fish and Wildlife Conservation Commission
Resource type: Current dashboard, sampling results and coastal red-tide reports
Coverage: Freshwater and coastal waters
Florida maintains separate systems for freshwater blue-green algae and marine red tide.
Water Quality Status Dashboard:
https://protectingfloridatogether.gov/water-quality-status-dashboard
Florida DEP blue-green algae information:
https://floridadep.gov/AlgalBloom
Current red-tide status:
https://myfwc.com/research/redtide/statewide/
Georgia
Primary agencies: Georgia Environmental Protection Division and Georgia Department of Public Health
Resource type: HAB information, reports and coastal health guidance
Coverage: Freshwater and coastal waters
Georgia’s previous statewide ArcGIS HAB application has undergone changes and may not always function as expected.
Georgia Environmental Protection Division:
https://epd.georgia.gov/
Coastal Health District HAB information:
https://coastalhealthdistrict.org/harmful-algal-blooms/
Hawaii
Primary agency: Hawaii Department of Health
Resource type: Marine algae and public-health information
Coverage: Primarily marine and coastal waters
Hawaii’s official information emphasizes marine organisms, stinging seaweed disease and seafood-related toxins rather than a statewide freshwater cyanobacteria tracker.
Stinging seaweed disease:
https://health.hawaii.gov/docd/disease_listing/stinging-seaweed-disease/
Clean Water Branch:
https://health.hawaii.gov/cwb/
Idaho
Primary agencies: Idaho Department of Environmental Quality and Idaho Department of Health and Welfare
Resource type: Current advisories, monitoring and reporting
Coverage: Freshwater lakes, reservoirs and rivers
Idaho DEQ HAB program and advisories:
https://www.deq.idaho.gov/water-quality/surface-water/cyanobacteria-harmful-algal-blooms/
Public-health information:
https://healthandwelfare.idaho.gov/health-wellness/environmental-health/harmful-algal-blooms
Illinois
Primary agency: Illinois Environmental Protection Agency
Resource type: Bloom reporting, investigations and monitoring information
Coverage: Freshwater lakes and rivers
Illinois investigates reported blooms, but the program does not represent continuous monitoring of every waterbody.
Direct link:
https://epa.illinois.gov/topics/water-quality/monitoring/algal-bloom.html
Indiana
Primary agencies: Indiana Department of Environmental Management and Indiana Department of Health
Resource type: Interactive HAB map and beach monitoring
Coverage: Selected public swimming beaches and monitored waters
Indiana HAB map:
https://isdh.maps.arcgis.com/apps/instant/basic/index.html?appid=6e042975d61249feb02ff4881aded483
State blue-green algae information:
https://www.in.gov/idem/algae/
Iowa
Primary agencies: Iowa Department of Natural Resources and Iowa Department of Health and Human Services
Resource type: Current beach-monitoring results and public-health information
Coverage: Designated state-park beaches
Iowa’s monitoring program does not cover every public lake or privately owned pond.
Current beach-monitoring results:
https://programs.iowadnr.gov/aquia/programs/beaches
Iowa HHS HAB information:
https://hhs.iowa.gov/environmental-health-services/harmful-algal-blooms
Kansas
Primary agency: Kansas Department of Health and Environment
Resource type: Current statewide watch, warning and hazard list
Coverage: Public lakes, reservoirs and recreational waters
Kansas maintains one of the clearest statewide harmful algal bloom advisory systems.
Direct link:
https://www.kdhe.ks.gov/777/Harmful-Algal-Blooms
Kentucky
Primary agency: Kentucky Division of Water
Resource type: HAB information, sampling and advisories
Coverage: Public lakes, reservoirs and rivers
Direct link:
https://eec.ky.gov/Environmental-Protection/Water/Protection/Pages/Harmful-Algal-Blooms.aspx
Louisiana
Primary agency: Louisiana Department of Environmental Quality
Resource type: HAB information, reporting and agency notices
Coverage: Freshwater and coastal waters
Direct link:
https://www.deq.louisiana.gov/page/harmful-algal-blooms-habs
Maine
Primary agencies: Maine Department of Environmental Protection and Maine Department of Marine Resources
Resource type: Freshwater cyanobacteria map and marine shellfish-toxin closures
Coverage: Freshwater lakes and coastal waters
Freshwater cyanobacteria information:
https://www.maine.gov/dep/water/lakes/cyanobacteria.html
Blue-green algae map:
https://maine.maps.arcgis.com/apps/webappviewer/index.html?id=3da4a1846f674d3fb416a8557c550a79
Marine biotoxin and shellfish closures:
https://www.maine.gov/dmr/fisheries/shellfish/closures
Maryland
Primary agency: Maryland Department of Natural Resources
Resource type: HAB reports and Chesapeake Bay monitoring
Coverage: Freshwater, tidal and coastal waters
Harmful algal blooms in Maryland:
https://dnr.maryland.gov/waters/bay/Pages/algal_blooms/Algae-Bloom-FAQ.aspx
Eyes on the Bay monitoring:
https://eyesonthebay.dnr.maryland.gov/
Massachusetts
Primary agency: Massachusetts Department of Public Health
Resource type: Current statewide cyanobacteria advisory list
Coverage: Reported freshwater advisories
The state list contains advisories reported by state, federal and local partners. It should not be interpreted as complete monitoring of every Massachusetts waterbody.
Current advisories:
https://www.mass.gov/alerts/harmful-cyanobacterial-bloom-advisories-in-massachusetts
HAB information:
https://www.mass.gov/guides/cyanobacterial-harmful-algal-blooms-cyanohabs-water
Michigan
Primary agency: Michigan Department of Environment, Great Lakes, and Energy
Resource type: State HAB program, bloom reporting and monitoring information
Coverage: Inland waters and the Great Lakes
Direct link:
https://www.michigan.gov/egle/about/organization/water-resources/glwarm/harmful-algal-blooms
Minnesota
Primary agencies: Minnesota Pollution Control Agency and Minnesota Department of Health
Resource type: Public information, illness guidance and bloom reporting
Coverage: Freshwater lakes and rivers
Minnesota does not continuously monitor all of its lakes or maintain a complete real-time statewide advisory map.
Minnesota Pollution Control Agency:
https://www.pca.state.mn.us/air-water-land-climate/blue-green-algae-and-harmful-algal-blooms
Minnesota Department of Health:
https://www.health.state.mn.us/diseases/hab/index.html
Mississippi
Primary agency: Mississippi Department of Environmental Quality
Resource type: Current coastal beach-status system
Coverage: Mississippi Gulf Coast beaches
The system primarily monitors coastal recreational-water quality and is not a comprehensive inland cyanobacteria tracker.
Direct link:
https://beaches.mdeq.ms.gov/
Missouri
Primary agencies: Missouri Department of Natural Resources and Missouri Department of Health and Senior Services
Resource type: Reported-bloom information, mapping and public-health guidance
Coverage: Freshwater lakes, reservoirs and rivers
Reported bloom locations are not necessarily toxin-confirmed.
Missouri DNR HAB information:
https://dnr.mo.gov/water/hows-water/pollutants-sources/harmful-algal-blooms-habs
Missouri health information:
https://health.mo.gov/safety/recreationalwater/
Montana
Primary agencies: Montana Department of Environmental Quality and Montana Department of Public Health and Human Services
Resource type: Statewide reports, advisories and bloom reporting
Coverage: Freshwater lakes, reservoirs and rivers
Montana DEQ HAB program:
https://deq.mt.gov/water/Programs/habs
Public-health information:
https://dphhs.mt.gov/publichealth/cdepi/diseases/HarmfulAlgalBlooms
Nebraska
Primary agency: Nebraska Department of Environment and Energy
Resource type: Current beach monitoring and toxic-algae alerts
Coverage: Designated public beaches
Nebraska posts alerts based on microcystin and bacterial sampling at participating beaches.
Direct link:
https://deq-iis.ne.gov/zs/bw/
Nevada
Primary agencies: Nevada Division of Environmental Protection and Nevada State Parks
Resource type: HAB program and current park advisories
Coverage: Selected public lakes, reservoirs and state parks
Nevada HAB program:
https://ndep.nv.gov/water/rivers-streams-lakes/water-quality-monitoring/harmful-algal-bloom-program
Nevada State Parks advisories:
https://parks.nv.gov/about/hab-advisory
New Hampshire
Primary agency: New Hampshire Department of Environmental Services
Resource type: Current statewide cyanobacteria warnings, watches and reports map
Coverage: Participating freshwater beaches and waterbodies
Healthy Swimming Mapper:
https://www.des.nh.gov/water/healthy-swimming/healthy-swimming-mapper
HAB program:
https://www.des.nh.gov/water/healthy-swimming/harmful-algal-blooms
New Jersey
Primary agency: New Jersey Department of Environmental Protection
Resource type: Interactive HAB map, sampling results and advisories
Coverage: Freshwater lakes and reservoirs
New Jersey maintains one of the more developed state freshwater HAB response systems.
Direct link:
https://dep.nj.gov/hab/
New Mexico
Primary agency: New Mexico Environment Department
Resource type: HAB program, reporting and monitoring information
Coverage: Freshwater lakes, reservoirs and rivers
Direct link:
https://www.env.nm.gov/surface-water-quality/habs/
New York
Primary agency: New York State Department of Environmental Conservation
Resource type: Current statewide reported-bloom map and notification program
Coverage: Freshwater lakes, ponds and reservoirs
New York operates one of the country’s most extensive statewide HAB reporting programs.
Direct link:
https://dec.ny.gov/environmental-protection/water/water-quality/harmful-algal-blooms
North Carolina
Primary agency: North Carolina Department of Environmental Quality
Resource type: Algal bloom reports, investigations and monitoring
Coverage: Freshwater, estuarine and coastal waters
Algal bloom program:
https://www.deq.nc.gov/about/divisions/water-resources/water-sciences/ecosystems-branch/algal-blooms
Monitoring information:
https://www.deq.nc.gov/about/divisions/water-resources/water-sciences/ecosystems-branch/algal-blooms/algal-bloom-monitoring
North Dakota
Primary agency: North Dakota Department of Environmental Quality
Resource type: Current or recent advisories and state guidance
Coverage: Recreational lakes and reservoirs
Direct link:
https://deq.nd.gov/WQ/3_Watershed_Mgmt/8_HABS/Habs.aspx
Ohio
Primary agencies: Ohio Environmental Protection Agency and Ohio Department of Health
Resource type: Recreational-water HAB information, beach advisories and Lake Erie forecasts
Coverage: Inland waters, public beaches and Lake Erie
Ohio recreational-water HAB information:
https://epa.ohio.gov/divisions-and-offices/drinking-and-ground-waters/public-water-systems/harmful-algae-blooms
Ohio BeachGuard:
https://publicapps.odh.ohio.gov/beachguardpublic/
NOAA Lake Erie forecast:
https://coastalscience.noaa.gov/science-areas/habs/hab-forecasts/lake-erie/
Oklahoma
Primary agencies: Oklahoma Department of Environmental Quality and Oklahoma Tourism and Recreation Department
Resource type: State HAB information and lake-condition notices
Coverage: Public lakes, reservoirs and state parks
Oklahoma DEQ HAB information:
https://oklahoma.gov/deq/divisions/state-environmental-laboratory-services/environmental-public-health-information/harmful-algal-blooms.html
State park lake conditions:
https://www.travelok.com/state-parks/lake_conditions
Oregon
Primary agency: Oregon Health Authority
Resource type: Current statewide cyanobacteria advisories and map
Coverage: Monitored recreational waters
Pennsylvania
Primary agencies: Pennsylvania Department of Environmental Protection and Pennsylvania Department of Health
Resource type: State HAB program, reporting and regional advisories
Coverage: Freshwater lakes, rivers and Lake Erie
Pennsylvania DEP HAB program:
https://www.dep.pa.gov/Business/Water/HABs/Pages/default.aspx
Pennsylvania health information:
https://www.pa.gov/agencies/health/programs/environmental-health/harmful-algal-blooms.html
Rhode Island
Primary agencies: Rhode Island Department of Environmental Management and Rhode Island Department of Health
Resource type: Current freshwater cyanobacteria advisories and marine HAB information
Coverage: Freshwater lakes, ponds and coastal waters
Freshwater cyanobacteria information and advisories:
https://dem.ri.gov/environmental-protection-bureau/water-resources/research-monitoring/cyanobacteria-blue-green-algae
South Carolina
Primary agency: South Carolina Department of Environmental Services
Resource type: HAB information, reporting and beach monitoring
Coverage: Freshwater and coastal waters
HAB program:
https://des.sc.gov/programs/bureau-water/aquatic-science/harmful-algal-blooms
Beach monitoring map:
https://gis.des.sc.gov/beachaccess/
South Dakota
Primary agency: South Dakota Department of Health
Resource type: Public-health guidance
Coverage: Freshwater lakes and reservoirs
Active notices may be issued through state parks, lake managers or local agencies rather than one centralized statewide advisory map.
Direct link:
https://doh.sd.gov/diseases/algal-toxinscyanobacterium/
Tennessee
Primary agency: Tennessee Department of Environment and Conservation
Resource type: HAB information, monitoring and bloom reporting
Coverage: Freshwater lakes, reservoirs and rivers
Additional notices may be issued by the Tennessee Valley Authority, state parks or local agencies.
Direct link:
https://www.tn.gov/environment/program-areas/wr-water-resources/nutrient-management-in-tennessee/habs.html
Texas
Primary agencies: Texas Parks and Wildlife Department and Texas Department of State Health Services
Resource type: Freshwater and coastal HAB information
Coverage: Lakes, reservoirs, rivers and coastal waters
Texas information may include cyanobacteria, golden algae, red tide and other harmful organisms. These blooms involve different species and risks.
Texas Parks and Wildlife HAB information:
https://tpwd.texas.gov/landwater/water/environconcerns/hab/
Texas health information:
https://www.dshs.texas.gov/environmental-surveillance-toxicology/harmful-algal-blooms
Utah
Primary agency: Utah Department of Environmental Quality
Resource type: Current recreational-water advisories and interactive map
Coverage: Monitored lakes and reservoirs
Main recreational-water page:
https://deq.utah.gov/dwq/recreational-water-quality
HAB program:
https://deq.utah.gov/water-quality/harmful-algal-blooms-home
Vermont
Primary agencies: Vermont Department of Health and Vermont Department of Environmental Conservation
Resource type: Current cyanobacteria tracker
Coverage: Lake Champlain and participating inland lakes
Vermont Cyanobacteria Tracker:
https://www.healthvermont.gov/environment/tracking/cyanobacteria-blue-green-algae-tracker
Virginia
Primary agency: Virginia Department of Health
Resource type: Current statewide HAB surveillance dashboard
Coverage: Freshwater, estuarine and coastal waters
Surveillance map:
https://www.vdh.virginia.gov/waterborne-hazards-control/algal-bloom-surveillance-map/
HAB program:
https://www.vdh.virginia.gov/waterborne-hazards-control/harmful-algal-blooms/
Washington
Primary agencies: Washington State Department of Health and participating local agencies
Resource type: Current freshwater bloom database and toxin results
Coverage: Participating lakes and freshwater waterbodies
Washington State Toxic Algae database:
https://www.nwtoxicalgae.org/
Washington Department of Health:
https://doh.wa.gov/community-and-environment/contaminants/cyanobacteria
West Virginia
Primary agency: West Virginia Department of Health
Resource type: HAB information and recreational-water response guidance
Coverage: Freshwater recreational waters
Current advisories may be issued by state parks, county health departments, utilities or local waterbody managers.
Wisconsin
Primary agencies: Wisconsin Department of Natural Resources and Wisconsin Department of Health Services
Resource type: HAB reporting, public-health information and beach status
Coverage: Freshwater lakes, rivers and participating beaches
Wisconsin DNR blue-green algae information:
https://dnr.wisconsin.gov/topic/lakes/bluegreenalgae
Wisconsin Beach Health:
https://dnr.wisconsin.gov/topic/Beaches
Wisconsin health information:
https://www.dhs.wisconsin.gov/water/bg-algae/index.htm
Wyoming
Primary agency: Wyoming Department of Environmental Quality
Resource type: Current statewide advisories, toxin results and reported blooms
Coverage: Freshwater lakes and reservoirs
Direct link:
https://deq.wyoming.gov/harmful-cyanobacterial-blooms/
Quick Guide to the Different Resource Types
The links in this directory do not all provide the same kind of information.
Current advisory map
Shows waterbodies where an agency has issued an active watch, warning, closure or other health advisory.
Current advisory list
Provides a table or written list of affected waterbodies rather than an interactive map.
Beach-monitoring program
Shows sampling results for participating public swimming beaches. It usually does not include every lake, reservoir or pond in the state.
Reported-bloom map
Shows blooms reported by the public, lake managers or agencies. A reported bloom may not have been tested or confirmed to contain cyanotoxins.
Monitoring results
Provides laboratory results, cell counts, toxin concentrations or field observations from selected sites.
Satellite map
Uses remotely sensed imagery to estimate cyanobacteria abundance or bloom probability. Satellite products do not confirm that toxins are present.
Information and reporting page
Provides safety information and instructions for reporting a bloom but may not list current advisories.
Marine HAB resource
Covers organisms such as red-tide algae and marine phytoplankton that can contaminate shellfish or cause respiratory and wildlife impacts. Marine HAB systems should not be confused with freshwater cyanobacteria monitoring.
Before Entering a Lake, Pond or Reservoir
Before swimming, wading, boating or allowing pets near the water:
- Check the appropriate state advisory or monitoring page.
- Check the local health department, state park or waterbody manager.
- Look for warning signs at beaches, boat ramps and public access points.
- Avoid water that appears paint-like, unusually green, discolored, streaked, foamy or covered with surface scum.
- Keep pets and livestock away from suspected blooms and dried algae along the shoreline.
- Do not drink untreated surface water.
- Report suspected blooms to the appropriate state environmental or health agency.
Blooms can develop rapidly, move with wind and currents, or accumulate in isolated coves and shorelines. Conditions observed at one portion of a lake may be very different elsewhere on the same waterbody.
Important Limitations of HAB Advisory Systems
No state monitors every pond, lake, reservoir, river or shoreline.
Many programs:
- Monitor only designated public beaches.
- Sample only after receiving a bloom report.
- Operate mainly during the summer recreation season.
- Rely partly on citizen observations.
- Post advisories only after laboratory confirmation.
- Do not routinely monitor private ponds.
- May remove an advisory after conditions improve at the sampled location.
- Use different toxin thresholds and advisory terminology.
A waterbody that is not shown on a map may simply not have been inspected, reported or sampled.
Pond Talk Perspective
Federal satellite systems and forecasting tools can help identify where cyanobacteria may be developing, but state and local agencies generally remain the official sources for public-health advisories.
The safest approach is to combine several sources:
- Review the state advisory page.
- Check local beach and park notices.
- Examine current water conditions.
- Avoid suspicious accumulations.
- Test the water when accurate identification or toxin confirmation is important.
Not every cyanobacteria bloom is toxic, but it is impossible to determine toxin production by appearance alone.
When in doubt, stay out—and keep pets away.
Help Us Keep This Directory Current
State websites, dashboards and agency programs frequently change. Some advisories are also issued by counties, municipalities, Tribal governments, state parks, lake associations and individual waterbody managers.
Pond Talk will continue expanding and verifying this directory as additional resources are identified.
Please contact us if you know of an official harmful algal bloom advisory, monitoring dashboard or reporting program that should be included.