Harmful Algal Bloom Program

Report a Bloom

During peak HAB season (spring through summer), NDEP and partner agencies conduct regular, and target monitoring of public surface water bodies throughout the state of Nevada. Following a visual and/or laboratory analytical confirmation of a HAB, the Office of State Epidemiology may issue a recreational advisory for the impacted water body.

Harmful Algal Blooms (HABs) are caused by microscopic organisms called cyanobacteria, often referred to as blue-green algae. Some cyanobacteria can produce toxins that are harmful to humans and animals. Environmental factors that contribute to the formation of cyanobacterial blooms in freshwater systems include:

light availability
water temperature
alteration of water flow
vertical mixing
pH changes
nutrient loading (nitrogen and phosphorus)
trace metals

When environmental conditions are favorable, rapid growth of cyanobacteria can result in HABs and may impact public health and aquatic ecosystems.

Exposure to HABs by touching, swallowing, or inhaling affected water can make humans sick and kill pets, livestock, and wildlife.

A HAB may be present if:

the water smells rotten,
large mats or scums are floating on the surface,
the water looks like green paint,
there are bright colors like blue, green, white, brown, or red.

However, in some cases, HABs may not be visible to the naked eye and the water may still contain hazardous toxins. You can check for Nevada issued swimming advisories on the Nevada HAB Dashboard. You may also view up-to-date HAB data before visiting water bodies.

Recreational Health Advisory Levels

For more information on cyanotoxin sampling and concentrations that determine Recreational Health Advisory levels please visit the HABs Resources webpage. For the most recent HAB data throughout the state of Nevada please refer to the HAB Data webpage.

HABs Exposure Information

Exposure to HABs can cause a variety of health effects, from relatively mild to potentially serious. For information regarding HABs exposures and associated health effects, please review the Guidance for HABs in Nevada Brochure (PDF).

Report a Bloom

Report a possible bloom to the Biological Assessment and Monitoring Branch

HABs Listserv

For weekly updates on HAB data and health advisories, please join the Nevada HABs e-mail list by navigating to the bottom of this webpage and clicking "Get Notices" and selecting "Nevada Harmful Algal Bloom Updates" from the dropdown menu, or by sending an e-mail directly to NEVADAHABS-subscribe-request@LISTSERV.STATE.NV.US